Lemon (Citrus limonum) Research

Latin Name: Citrus limonum

Family: Rutaceae

A few dozen research articles were found on lemon. It is most researched for its antimicrobial actions, including antibacterial and antifungal possibilities. This gives it an antiseptic action good for cleaning surfaces and skin. Antioxidant and radical scavaging actions of the flavonoids of lemon and its cancer fighting potential have also been studied. Lemon can be used as an insect repellent, digestive aid, expectorant, and mood booster as well. The fruit has been heavily used throughout history and more human studies are warranted.

RESEARCH

The listings of research below represent a compilation of scientific articles found on the species, with a very brief overview description of each article/study.  Research found is catalogued by therapeutic action.  This categorized compilation of research articles does not necessarily imply that there are adequate results to demonstrate safe and/or effective human use.

GENERAL

• Lis-Balchin, M. (2006). Aromatherapy Science: A guide for healthcare professionals. London: Pharmaceutical Press.
• Peace Rhind, J.  (2012). Essential oils.  A handbook for aromatherapy practice.  Singing Drangon.  London.
• Petersen, D. (2015). Aromatherapy materia medica.  Essential oil monographs.  American College of Healthcare Sciences.
• Luteolin is a flavonoid found in carrots, peppers, celery, olive oil, peppermint, thyme, rosemary and oregano. This study reviews its antioxidant, anti-inflammatory, antimicrobial and anticancer activities. From:  López-Lázaro, M. (2009). Distribution and biological activities of the flavonoid luteolin. Mini reviews in medicinal chemistry, 9(1), 31-59.
• Ayurvedic uses of lemon and lime are discussed.  Scientific studies show the following therapeutic actions: antibacterial, antifungal, antidiabetic, anticancer and antiviral.  From: Mohanapriya, M., Ramaswamy, D. L., & Rajendran, D. R. (2013). Health and medicinal properties of lemon (Citrus limonum). International Journal Of Ayurvedic And Herbal Medicine, 3(01).
• Scientific research on the therapeutic actions of Citrus ssp were reviewed.  Lemon showed anxiolytic, cytotoxic, chemoprotective, anti-cancer, antioxidant, neuroprotective, analgesic, antispasmodic, skin absorption enhancing, antibacterial, antifunal, insect repelling, cognitive enhancing and weight loss enhancing activities.  From:  Dosoky, N., & Setzer, W. (2018). Biological activities and safety of Citrus spp. essential oils. International journal of molecular sciences, 19(7), 1966.
• Sohi, S., & Shri, R. (2018). Neuropharmacological potential of the genus Citrus: A review. J. Pharmacogn. Phytochem, 7(2), 1538-1548.
• Osman, A. (2019). Citrus Oils. In Fruit Oils: Chemistry and Functionality (pp. 521-540). Springer, Cham.
• A review of research on the bioactivity of citrus peels was provided and included antioxidant, anti-diabetic, cardioprotective, neuroprotective and anticancer possibilities. From: Ademosun, A. O., Oboh, G., Olasehinde, T. A., & Adeoyo, O. O. (2018). From folk medicine to functional food: a review on the bioactive components and pharmacological properties of citrus peels. Oriental Pharmacy and Experimental Medicine, 18(1), 9-20.
• Furocoumarins have shown in research to have significant antimicrobial, insecticidal, and cancer inhibiting activity. However, there is also a phototoxic effect and there can be interference with drug metabolism. Furocoumarins are found in grapefruit, lemon, lime, orange, carrot, celery, parsnip, dill, parsley, cilantro, cumin, coriander, turnip, and fig. From: Melough, M. M., Cho, E., & Chun, O. K. (2018). Furocoumarins: a review of biochemical activities, dietary sources and intake, and potential health risks. Food and Chemical Toxicology, 113, 99-107.
• This provided an overview on the medicinal uses of lemon. From: Al-Qudah, et al. (2018). Lemon as a source of functional and medicinal ingredient: A review. International Journal of Chemical and Biochemical Sciences. ISSN 2226-9614.

SAFETY

• Furocoumarin is a toxic component that can cause irritation, sensitization, and photoxicity; it is higher in expressed oil than distilled; skin patch test is required (Petersen, 2015).
• Deterpenation techniques may affect chemical make up of the essential oil (Lis-Balchin, 2006).
• Essential oil may be adultered with less expensive oils like synthetics, orange oil, lemongrass oil; may also be adultered with UV absorbers (Lis-Balchin, 2006).
• Citrus essential oils can degrade more quickly than other oils.  If stored correctly, oil can last six months (Lis-Balchin, 2006).
• May cause dermal irritation (Peace-Rhind, 2012).
• Lemon, as well as lime and bitter orange oil contained furocoumarin ( bergapten and oxypeucedanin) causing phototoxicity.  From:  Naganuma, M., Hirose, S., Nakayama, Y., Nakajima, K., & Someya, T. (1985). A study of the phototoxicity of lemon oil. Archives of dermatological research, 278(1), 31-36.
• Look for lemon essential oil labeled “USP” or “BP,” to have chemical constituents such as citral in accordance with the US Pharmacopoeia or the British Pharmacopoeia (Petersen, 2015).
• Furocoumarins have shown in research to have significant antimicrobial, insecticidal, and cancer inhibiting activity. However, there is also a phototoxic effect and there can be interference with drug metabolism. Furocoumarins are found in grapefruit, lemon, lime, orange, carrot, celery, parsnip, dill, parsley, cilantro, cumin, coriander, turnip, and fig. From: Melough, M. M., Cho, E., & Chun, O. K. (2018). Furocoumarins: a review of biochemical activities, dietary sources and intake, and potential health risks. Food and Chemical Toxicology, 113, 99-107.

ANTIMICROBIAL / ANTIFUNGAL / ANTIBACTERIAL

• Citrus sinensis (Orange), Citrus limon (lemon) and Citrus bergamia (bergamot)  were studied as a biological control alternative to chemical fungicides against Algerian strains of Phytophthora infestans, responsible for potato late blight.  All three essential oils demonstrated fungicidal effects with bergamot performing the best.  From:  Messgo-Moumene, S., Li, Y., Bachir, K., Houmani, Z., Bouznad, Z., & Chemat, F. (2015). Antifungal power of citrus essential oils against potato late blight causative agent. Journal of Essential Oil Research, 27(2), 169-176.
• Salmonella was less an issue when a blend of carvacrol, thymol, eucalyptol, and lemon when added to drinking water of poultry farm animals.  From:  Alali, W. Q., Hofacre, C. L., Mathis, G. F., & Faltys, G. (2013). Effect of essential oil compound on shedding and colonization of Salmonella enterica serovar Heidelberg in broilers. Poultry science, 92(3), 836-841.
• The following essential oils and their constituents in order of effectiveness were active against pathogens in apple juice:  against E. coli: carvacrol, oregano oil, geraniol, eugenol, cinnamon leaf oil, citral, clove bud oil, lemongrass oil, cinnamon bark oil, and lemon oil, and against S. enterica:  melissa oil, carvacrol, oregano oil, terpeineol, geraniol, lemon oil, citral, lemongrass oil, cinnamon leaf oil, and linalool. From:  Friedman, M., Henika, P. R., Levin, C. E., & Mandrell, R. E. (2004). Antibacterial activities of plant essential oils and their components against Escherichia coli O157: H7 and Salmonella enterica in apple juice. Journal of agricultural and food chemistry, 52(19), 6042-6048
• Lemon essential oil components were effective against oral bacteria.  From:  Miyake, Y., & Hiramitsu, M. (2011). Isolation and extraction of antimicrobial substances against oral bacteria from lemon peel. Journal of food science and technology, 48(5), 635-639.
• The essential oil of Citrus limon exhibited fungitoxicitiy against Epidermophyton floccosum, Microsporum gypseum and Trichophyton mentagrophytes with citral being the most active constituent.  From:  Misra, N., Batra, S., & Mishra, D. (1988). Fungitoxic properties of the essential oil of Citrus limon (L.) Burm. against a few dermatophytes. Mycoses, 31(7), 380-382.
• Cornmint, cumin, laurel, lemon peel, orange, oregano, and ziziphora were active against all of the tested bacteria to various degrees. From:  Kivanç, M., & Akgül, A. (1986). Antibacterial activities of essential oils from Turkish spices and citrus. Flavour and Fragrance Journal, 1(4‐5), 175-179.
• Both Citrus limonum and Citrus aurantium essential oils are effective in controlling microbes in the oral cavity.  From:  Oliveira, S. A. C., Zambrana, J. R. M., Di Iorio, F. B. R., Pereira, C. A., & Jorge, A. O. C. (2014). The antimicrobial effects of Citrus limonum and Citrus aurantium essential oils on multi-species biofilms. Brazilian oral research, 28(1), 22-27.
• From 22 essential oils tested, cornmint, cumin, laurel, lemon peel, orange, oregano, and Ziziphora were active against all assessed bacteria. From:  Kivanç, M., & Akgül, A. (1986). Antibacterial activities of essential oils from Turkish spices and citrus. Flavour and Fragrance Journal, 1(4‐5), 175-179.
• Citrus oils of orange, lemon, and bergamot may be an effective and safe antimicrobial additive in food.  From:  Fisher, K., & Phillips, C. (2008). Potential antimicrobial uses of essential oils in food: is citrus the answer?. Trends in food science & technology, 19(3), 156-164.
• Citrus aurantifolia (lime) and Citrus limon (lemon) showed lethal effects on Pseudomonas aeruginosa bacteria.  From:  Adedeji, G. B., Fagade, O. E., & Oyelade, A. A. (2007). Prevalence of Pseudomonas aeruginosa in clinical samples and its sensitivity to citrus extract. African Journal of Biomedical Research, 10(2).
• Citrus aurantium (bergamot), C. limon (lemon), Lavandula angustifolia (lavender), Matricaria chamomilla (chamomile), Mentha piperita (peppermint), M. spicata (spearmint), Ocimum basilicum (basil), Origanum vulgare(oregano), Thymus vulgaris (thyme), and Salvia officinalis (sage) along with their constituents were tested against human pathogenic bacteria.  The highest and broadest activity was shown by O. vulgare oil and carvacrol had the highest antibacterial activity among the tested constituents.  Other significant constituents included: camphor, 1,8-cineole, linalool, linalyl acetate, limonene, menthol, a-pinene, b-pinene, and thymol.  From:  Soković, M., Glamočlija, J., Marin, P. D., Brkić, D., & van Griensven, L. J. (2010). Antibacterial effects of the essential oils of commonly consumed medicinal herbs using an in vitro model. Molecules, 15(11), 7532-7546.
• The citrus peel oils of Citrus lemon showed strong antimicrobial activity.  From:  Dhanavade, M. J., Jalkute, C. B., Ghosh, J. S., & Sonawane, K. D. (2011). Study antimicrobial activity of lemon (Citrus lemon L.) peel extract. British Journal of Pharmacology and Toxicology, 2(3), 119-122.
• Low concentrations of the lemon, orange, and mandarin essential oils along with a mild heat treatment showed synergistic lethal effects against spoiling and pathogenic food microorganisms.  From: Espina, L., Somolinos, M., Lorán, S., Conchello, P., García, D., & Pagán, R. (2011). Chemical composition of commercial citrus fruit essential oils and evaluation of their antimicrobial activity acting alone or in combined processes. Food control, 22(6), 896-902.
• Out of 21 oils tested, cinnamon, clove, geranium, lemon, lime, orange and rosemary exhibited the strongest activity against the tested bacteria. From:  Prabuseenivasan, S., Jayakumar, M., & Ignacimuthu, S. (2006). In vitro antibacterial activity of some plant essential oils. BMC complementary and alternative medicine, 6(1), 1.
• Lemon, mandarin, grapefruit, and orange oils were antifungal against food spoilage molds.  From:  Viuda-Martos, M., Ruiz-Navajas, Y., Fernández-López, J., & Pérez-Álvarez, J. (2008). Antifungal activity of lemon (Citrus lemon L.), mandarin (Citrus reticulata L.), grapefruit (Citrus paradisi L.) and orange (Citrus sinensis L.) essential oils. Food control, 19(12), 1130-1138.
• Orange, lemon and mandarin showed antioxidant and antimicrobial activity in vitro.  From: Frassinetti, Stefania & Caltavuturo, L & Cini, Marianna & Della Croce, Clara & Maserti, Biancaelena. (2011). Antibacterial and Antioxidant Activity of Essential Oils from Citrus spp. Journal of Essential Oil Research – J ESSENT OIL RES. 23. 27-31. 10.
• An essential oil solution with tea tree, peppermint, and lemon reduced bad breath in patients.  From:  Hur, M. H., Park, J., Maddock‐Jennings, W., Kim, D. O., & Lee, M. S. (2007). Reduction of mouth malodour and volatile sulphur compounds in intensive care patients using an essential oil mouthwash. Phytotherapy Research, 21(7), 641-643.
• Cananga odorata, Boswellia thurifera, Cymbopogon citratus, Marjorana hortensis, Ocimum basilicum, Rosmarinus officinalis, Cinnamomum zeylanicum and Citrus limon exhibited considerable inhibitory effect against all the bacteria and fungi tested, and also demonstrated antioxidant activity comparable with α-tocopherol and butylated hydroxytoluene.  From:  Baratta, M. T., Dorman, H. J., Deans, S. G., Figueiredo, A. C., Barroso, J. G., & Ruberto, G. (1998). Antimicrobial and antioxidant properties of some commercial essential oils. Flavour and fragrance journal, 13(4), 235-244.
• Cinnamon, lemon, basil, thyme, geranium, and clove showed high antifungal activity against Candida ssp. in vitro.  From:  Szweda, P., Gucwa, K., Kurzyk, E., Romanowska, E., Dzierżanowska-Fangrat, K., Jurek, A. Z., … & Milewski, S. (2015). Essential oils, silver nanoparticles and propolis as alternative agents against fluconazole resistant Candida albicans, Candida glabrata and Candida krusei clinical isolates. Indian journal of microbiology, 55(2), 175-183.
• Tested essential oils showed antifungal activity against tested fungi.  From:  Gucwa, K., Milewski, S., Dymerski, T., & Szweda, P. (2018). Investigation of the Antifungal Activity and Mode of Action of Thymus vulgaris, Citrus limonum, Pelargonium graveolens, Cinnamomum cassia, Ocimum basilicum, and Eugenia caryophyllus Essential Oils. Molecules, 23(5), 1116.
• Lemon, ylang ylang, and Vitex trifolia extracts showed antioxidant and antimicrobial actions on tested organisms.  Lemon had the strongest activity of the three tested plant extracts.  From:  Yahaya, M. F., Kubmarawa, D., Yelwa, J. M., & Runde, M. (2018). Antioxidant and antimicrobial activity of essential oils extracted from aromatic plants. World Scientific News, 111, 13-25.
• Thirty essential oils were tested against pathogenic plant bacteria. Ceylon cinnamon (leaf and bark), oregano, clove bud, palmarosa, basil, peppermint, rosemary, blue gum, camphor, lemongrass, aniseed, ylang ylang, silver fir, lemon, dwarf mountain pine, bay laurel, scots pine, black cumin, Indian frankincense, bergamot orange, common juniper, bitter orange, and neem showed varying degrees of reaction.  From: Popović, T., Milićević, Z., Oro, V., Kostić, I., Radović, V., Jelušić, A., & Krnjajić, S. (2018). A preliminary study of antibacterial activity of thirty essential oils against several important plant pathogenic bacteria. Pesticidi i fitomedicina, 33(3-4), 185-195.
• Citrus essential oils showed a variety of effectiveness against foodborne pathogens in vitro. From: Restuccia, C., Conti, G. O., Zuccarello, P., Parafati, L., Cristaldi, A., & Ferrante, M. (2019). Efficacy of different citrus essential oils to inhibit the growth and B1 aflatoxin biosynthesis of Aspergillus flavus. Environmental Science and Pollution Research, 1-10.

PRESERVATIVE

• The following essential oils and their constituents in order of effectiveness were active against pathogens in apple juice:  against E. coli: carvacrol, oregano oil, geraniol, eugenol, cinnamon leaf oil, citral, clove bud oil, lemongrass oil, cinnamon bark oil, and lemon oil, and against S. enterica:  melissa oil, carvacrol, oregano oil, terpeineol, geraniol, lemon oil, citral, lemongrass oil, cinnamon leaf oil, and linalool. From:  Friedman, M., Henika, P. R., Levin, C. E., & Mandrell, R. E. (2004). Antibacterial activities of plant essential oils and their components against Escherichia coli O157: H7 and Salmonella enterica in apple juice. Journal of agricultural and food chemistry, 52(19), 6042-6048
• Citrus oils of orange, lemon, and bergamot may be an effective and safe antimicrobial additive in food.  From:  Fisher, K., & Phillips, C. (2008). Potential antimicrobial uses of essential oils in food: is citrus the answer?. Trends in food science & technology, 19(3), 156-164.
• Low concentrations of the lemon, orange, and mandarin essential oils along with a mild heat treatment showed synergistic lethal effects against spoiling and pathogenic food microorganisms.  From: Espina, L., Somolinos, M., Lorán, S., Conchello, P., García, D., & Pagán, R. (2011). Chemical composition of commercial citrus fruit essential oils and evaluation of their antimicrobial activity acting alone or in combined processes. Food control, 22(6), 896-902.
• Lemon, mandarin, grapefruit, and orange oils were antifungal against food spoilage molds.  From:  Viuda-Martos, M., Ruiz-Navajas, Y., Fernández-López, J., & Pérez-Álvarez, J. (2008). Antifungal activity of lemon (Citrus lemon L.), mandarin (Citrus reticulata L.), grapefruit (Citrus paradisi L.) and orange (Citrus sinensis L.) essential oils. Food control, 19(12), 1130-1138.
• Citrus essential oils showed a variety of effectiveness against foodborne pathogens in vitro. From: Restuccia, C., Conti, G. O., Zuccarello, P., Parafati, L., Cristaldi, A., & Ferrante, M. (2019). Efficacy of different citrus essential oils to inhibit the growth and B1 aflatoxin biosynthesis of Aspergillus flavus. Environmental Science and Pollution Research, 1-10.

INSECTICIDAL / LARVICIDAL / PESTICIDAL

• Thirteen oils from 41 plants (camphor, thyme, amyris, lemon, cedarwood, frankincense, dill, myrtle, juniper, black pepper, verbena, helichrysum and sandalwood) induced 100% mortality after 24 hours of mosquito larvae.  From:  Amer, A., & Mehlhorn, H. (2006). Larvicidal effects of various essential oils against Aedes, Anopheles, and Culex larvae (Diptera, Culicidae). Parasitology research, 99(4), 466-472.
• Tea tree and lavender were effective against a wide range of mites, lemon was effective against some mites, but not lice. From:  Williamson, E. M., Priestley, C. M., & Burgess, I. F. (2007). An investigation and comparison of the bioactivity of selected essential oils on human lice and house dust mites. Fitoterapia, 78(7), 521-525.
• Citrus sinensis, Citrus limon and Citrus aurantifolia peels extracts were effective against termites. From: Ito, E., & Ukpohwo, R. (2018). Termiticidal Efficacy of Citrus Peel Extracts against Termites (Macrotermes bellicosus). Journal of Biological Studies, 1(3), 98-105.

​REPELLENT

• Phytochemical extracts from citrus fruit peels (Citrus sinensis, Citrus limonum,Citrus aurantifolia, Citrus reticulata and Citrus vitus) at a dilution of 20-25% applied topically on human volunteers repelled insects for 2-5 hours.  From:  Effiom, O. E., Avoaja, D. A., & Ohaeri, C. C. (2012). Mosquito repellent activity of phytochemical extracts from peels of citrus fruit species. Global J Sci Front Res Interdisc, 12(1).
• These tested citrus essential oils are listed in order of repelling effectiveness against two mosquito species when applied to human skin: C. aurantifolia, C. microcarpa, C. maxima, C. reticulate, C. sinensis, C. hystrix, C. aurantium, and C. medica var sarcodaclylis. From: Soonwera, M. (2015). Efficacy of essential oils from Citrus plants against mosquito vectors Aedes aegypti (Linn.) and Culex quinquefasciatus (Say). Journal of Agricultural Technology, 11(3), 669-681.

ANTI-ALLERGY

• Tea tree and lavender were effective against a wide range of mites, lemon was effective against some mites, but not lice. From:  Williamson, E. M., Priestley, C. M., & Burgess, I. F. (2007). An investigation and comparison of the bioactivity of selected essential oils on human lice and house dust mites. Fitoterapia, 78(7), 521-525.

ANTI-CANCER

• In a review of 17 studies, it was concluded that intake of citrus fruits was associated with a 50% reduction of risk in cavity and pharyngeal cancer. From: Cirmi, S., Navarra, M., Woodside, J. V., & Cantwell, M. M. (2018). Citrus fruits intake and oral cancer risk: A systematic review and meta-analysis. Pharmacological research, 133, 187-194.
• Apoptosis was induced by both limonin and limonin glucoside in lemon for use in treating colon cancer.  From:  Chidambara Murthy, K. N., Jayaprakasha, G. K., Kumar, V., Rathore, K. S., & Patil, B. S. (2011). Citrus limonin and its glucoside inhibit colon adenocarcinoma cell proliferation through apoptosis. Journal of agricultural and food chemistry, 59(6), 2314-2323.
• Citrus oils of sweet orange, grapefruit, and lemon induced apoptosis of human leukemia cancer tumor cells and limonene, decanal, octanal and citral showed strong apoptotic activity.  From:  Hata, T., Sakaguchi, I., Mori, M., Ikeda, N., Kato, Y., Minamino, M., & Watabe, K. (2002). Induction of apoptosis by Citrus paradisi essential oil in human leukemic (HL-60) cells. In vivo (Athens, Greece), 17(6), 553-559
• Naringenin and quercetin from citrus fruits inhibited toxins in cigarette smoke. From:  Bear, W. L., & Teel, R. W. (1999). Effects of citrus phytochemicals on liver and lung cytochrome P450 activity and on the in vitro metabolism of the tobacco-specific nitrosamine NNK. Anticancer research, 20(5A), 3323-3329.

ANXIOLYTIC / ANTIDEPRESSIVE

• Lemon vapor possesses anxiolytic, antidepressant-like effects in mice. From:  Komiya, M., Takeuchi, T., & Harada, E. (2006). Lemon oil vapor causes an anti-stress effect via modulating the 5-HT and DA activities in mice. Behavioural Brain Research, 172(2), 240-249.
• Mice experienced sedative, anxiolytic, and antidepressive effects from Citrus limon leaf essential oil. From:  Lopes Campêlo, L. M., Gonçalves e Sá, C., de Almeida, A. A. C., Pereira da Costa, J., Costa Marques, T. H., Mendes Feitosa, C., … & Mendes de Freitas, R. (2011). Sedative, anxiolytic and antidepressant activities of Citrus limon (Burn) essential oil in mice. Die Pharmazie-An International Journal of Pharmaceutical Sciences, 66(8), 623-627.
• Ingesting lemon essential oil containing components such as limonene and citral reduces both physical and psychological stress.  From:  Fukumoto, S., Morishita, A., Furutachi, K., Terashima, T., Nakayama, T., & Yokogoshi, H. (2008). Effect of flavour components in lemon essential oil on physical or psychological stress. Stress and Health, 24(1), 3-12.
• Aromatherapy with a blend of lemon, lavender, and ylang ylang was effective in lowering systolic blood pressure and the sympathetic nervous system   From:  Cha, J. H., Lee, S. H., & Yoo, Y. S. (2010). Effects of Aromatherapy on Changes in the Autonomic Nervous System, Aortic Pulse Wave Velocity and Aortic Augmentation Index in Patients with Essential Hypertension. Journal of Korean Academy of Nursing, 40(5).
• Aromatherapy massage using lavender, chamomile, rosemary, and lemon reduced anxiety and improved self esteem.  From:  Rho, K. H., Han, S. H., Kim, K. S., & Lee, M. S. (2006). Effects of aromatherapy massage on anxiety and self-esteem in korean elderly women: a pilot study. International Journal of Neuroscience, 116(12), 1447-1455.
• Lemon and valerian inhalation reduced depression in humans.  From:  Komori, T., Matsumoto, T., Motomura, E., & Shiroyama, T. (2009). P. 2. g. 008 Effects of lemon and valerian inhalation on autonomic nerve activity in depressed and healthy subjects. European Neuropsychopharmacology, 19, S475-S476.

STIMULANT

• A blend of Santalum album, Citrus aurantium, Citrus limonum, Styrax benzoin, Citrus paradisi, Mentha piperata, Acori tatarinowii rhizoma, Rhodiolae crenulatae radix et rhizoma, and Camellia sinensis aromatherapy at night reduced fatigue in rodents.  It enhanced physical endurance, improved cognition, reduced negative emotion and decrease anxiety. From:  Han, C., Li, F., Tian, S., Liu, Y., Xiao, H., Wu, X., … & Mao, M. (2018). Beneficial effect of compound essential oil inhalation on central fatigue. BMC complementary and alternative medicine, 18(1), 309.

SEDATIVE

• Mice experienced sedative, anxiolytic, and antidepressive effects from Citrus limon leaf essential oil. From:  Lopes Campêlo, L. M., Gonçalves e Sá, C., de Almeida, A. A. C., Pereira da Costa, J., Costa Marques, T. H., Mendes Feitosa, C., … & Mendes de Freitas, R. (2011). Sedative, anxiolytic and antidepressant activities of Citrus limon (Burn) essential oil in mice. Die Pharmazie-An International Journal of Pharmaceutical Sciences, 66(8), 623-627.
• Aromatherapy with a blend of lemon, lavender, and ylang ylang was effective in lowering systolic blood pressure and the sympathetic nervous system   From:  Cha, J. H., Lee, S. H., & Yoo, Y. S. (2010). Effects of Aromatherapy on Changes in the Autonomic Nervous System, Aortic Pulse Wave Velocity and Aortic Augmentation Index in Patients with Essential Hypertension. Journal of Korean Academy of Nursing, 40(5).

REDUCED PAIN

• Pain was reduced with prolonged lemon aroma in rats.  From: Ceccarelli, I., Lariviere, W. R., Fiorenzani, P., Sacerdote, P., & Aloisi, A. M. (2004). Effects of long-term exposure of lemon essential oil odor on behavioral, hormonal and neuronal parameters in male and female rats. Brain research, 1001(1), 78-86.
• Research on analgesic activities of essential oils is reviewed. Included is: wild caraway (Bunium persicum ), lemon (Citrus limon), lemongrass (Cymbopogon citrates), eucalyptus (Eucalyptus citriodora), clove (Eugenia caryophyllata), hogweed (Heracleum persicum), Hofmeisteria schaffneri, bushmint (Hyptis fruticosa), star anise (Illicum lanceolatum), verbenea (Lippia gracilis), chamomile (Matricaria recutita), Cuban mint (Mentha x villosa), catmint (Nepeta crispa Willd), basil (Ocimum basilicum), Peperomia serpens, Pimenta pseudocaryophyllus, long pepper (Piper alyreanum), Summer savory (Satureja hortensis), Senecio rufinervis, Tetradenia riparia, Teucrium stocksianum, Ugni myricoides, valerian (Valeriana wallichii), Xylopia laevigata, and candeeiro (Vanillosmopsis arborea). From: Sarmento-Neto, J., do Nascimento, L., Felipe, C., & de Sousa, D. (2015). Analgesic potential of essential oils. Molecules, 21(1), 20.

HYPOGLYCEMIC/HYPOLIPIDEMIC

• Oral intake of d-limonene may reduce dyslipidemia and hyperglycemia and is a potential dietary supplement.  From:  Jing, L., Zhang, Y., Fan, S., Gu, M., Guan, Y., Lu, X., … & Zhou, Z. (2013). Preventive and ameliorating effects of citrus D-limonene on dyslipidemia and hyperglycemia in mice with high-fat diet-induced obesity. European journal of pharmacology, 715(1), 46-55.
• Phenolic components from citrus fruits showed antioxidant, hypoglycemic, hypotensive activities in vitro.   From: Alu’Datt, M. H., Rababah, T., Alhamad, M. N., Al-Mahasneh, M. A., Ereifej, K., Al-Karaki, G., … & Ghozlan, K. A. (2017). Profiles of free and bound phenolics extracted from Citrus fruits and their roles in biological systems: content, and antioxidant, anti-diabetic and anti-hypertensive properties. Food & function, 8(9), 3187-3197.

SKIN HEALTH

• Related to treating human skin against oxidative damage, lemon essential oil was more active than tocopherol against oxygen and peroxide free radical inhibition.  From:  Bertuzzi, G., Tirillini, B., Angelini, P., & Venanzoni, R. (2013). Antioxidative action of Citrus limonum essential oil on skin. European Journal of Medicinal Plants, 3(1), 1.
• Antimicrobial action of litsea, rosemary, and lemon were demonstrated against tested skin microbes.  From: Ogbechie, A., Abioye, A. O., Shen, J., & Laird, K. (2017). Antimicrobial activity of Litsea cubeba, Rosmarinus officinalis and Citrus lemon essential oils against five skin-infection related pathogens. Phytochemical Society of Europe.
• Lemon essential oil was effective in vitro against a variety of human dermal fungi.  From: Jain, N., & Sharma, M. (2017). Evaluation of Citrus lemon Essential Oil for its Chemical and Biological Properties Against Fungi Causing Dermatophytic Infection in Human Beings. Analytical Chemistry Letters, 7(3), 402-409.

DANDRUFF

• Lemon essential oil was effective in vitro against a variety of human dermal fungi.  From: Jain, N., & Sharma, M. (2017). Evaluation of Citrus lemon Essential Oil for its Chemical and Biological Properties Against Fungi Causing Dermatophytic Infection in Human Beings. Analytical Chemistry Letters, 7(3), 402-409.

ASTRINGENT

• Lemon juice is commonly used as a skin astringent.  From:  Goswami, S., Sharma, P., & Shivhare, Y. (2011). Phytopharmaceuticals as Cosmetic Agents: A Review. Research Journal of Topical and Cosmetic Sciences, 2(1), 11.

DIGESTIVE AID

• An essential oil blend including rosemary, lemon, and peppermint rubbed on the abdomine reduced constipation in the elderly.  From:  Kim, M. A., Sakong, J. K., Kim, E. J., & Kim, E. H. (2005). Effect of aromatherapy massage for the relief of constipation in the elderly. Taehan Kanho Hakhoe Chi, 35(1), 56-64.
• In a randomized controlled trial of 90 pregnant women, both the aromas of lemon and ginger helped reduce nausea. From: Kustriyanti, D., & Putri, A. A. (2019). The Effect of Ginger and Lemon Aromatherapy on Nausea and Vomiting among Pregnant Women. Jurnal Keperawatan Soedirman, 14(1), 15-22.
• In a review of research on plants for nausea, Citrus lemon (lemon), Berberis vulgaris (barberry), Malus domestica (apple juice), Mentha piperita (peppermint), Valeriana officinalis (valerian) and Zingiber officinale (ginger) were most effective.  From:  Azadbakht, M., Darvishpor, S., Hosseini, A., Davoodi, A., Salehifar, E., & Akbari, J. (2018). A Review on Medicinal Plants Used for Nausea and Vomiting in Persian Medicine. Global Journal of Medical Research.
• Lemon and its constituents of limonene showed gastroprotective activity, causing mucus formation in vivo.  From:  Rozza, A. L., de Mello Moraes, T., Kushima, H., Tanimoto, A., Marques, M. O. M., Bauab, T. M., … & Pellizzon, C. H. (2011). Gastroprotective mechanisms of Citrus lemon (Rutaceae) essential oil and its majority compounds limonene and β-pinene: Involvement of heat-shock protein-70, vasoactive intestinal peptide, glutathione, sulfhydryl compounds, nitric oxide and prostaglandin E2. Chemico-biological interactions, 189(1-2), 82-89.
• In a review of research, eating citrus fruits help reduce inflammatory bowel disease. From: Musumeci, L., Maugeri, A., Cirmi, S., Lombardo, G. E., Russo, C., Gangemi, S., … & Navarra, M. (2019). Citrus fruits and their flavonoids in inflammatory bowel disease: an overview. Natural product research, 1-15.
• In a review of research, flavones from citrus fruits can help improve digestive health. From: Stevens, Y., Rymenant, E. V., Grootaert, C., Camp, J. V., Possemiers, S., Masclee, A., & Jonkers, D. (2019). The Intestinal Fate of Citrus Flavanones and Their Effects on Gastrointestinal Health. Nutrients, 11(7), 1464.

DIURETIC

• A compilation of research showed the following herbs to have a diuretic effect:  yarrow, lemon verbena, pineapple, dill, gorden asparagus, mugwort, oats, barberry, Indian tree, turnip, marigold, chicory, lemon, cucumber, pumpkin seed, quince, carrot, flix weed, horsetail, asafetida, fig, barely, St. John’s wort, bay, alfalfa, European pennyroyal, mulberry, water cress, catnip, black cumin, parsley, green bean, pistachio, cherry, pomegranate, purstane, savory, tomato, brinjal, tea, haritali, coltsfoot, nettle, bell bean, and corn.  From:  Rouhi-Boroujeni, H., Rouhi-Boroujeni, H., Khoddami, M., Khazraei, H. R., Dehkordil, E. B., & Rafieian-Kopaei, M. (2017). Hypolipidemic herbals with diuretic effects: A systematic review. In Biol. Sci (Vol. 8, pp. 21-28).

ANTI-ULCER

• Lemon and its constituents of limonene showed gastroprotective activity, causing mucus formation in vivo.  From:  Rozza, A. L., de Mello Moraes, T., Kushima, H., Tanimoto, A., Marques, M. O. M., Bauab, T. M., … & Pellizzon, C. H. (2011). Gastroprotective mechanisms of Citrus lemon (Rutaceae) essential oil and its majority compounds limonene and β-pinene: Involvement of heat-shock protein-70, vasoactive intestinal peptide, glutathione, sulfhydryl compounds, nitric oxide and prostaglandin E2. Chemico-biological interactions, 189(1-2), 82-89.

ANTI-NAUSEA

• In a review of research on plants for nausea, Citrus lemon (lemon), Berberis vulgaris (barberry), Malus domestica (apple juice), Mentha piperita (peppermint), Valeriana officinalis (valerian) and Zingiber officinale (ginger) were most effective.  From:  Azadbakht, M., Darvishpor, S., Hosseini, A., Davoodi, A., Salehifar, E., & Akbari, J. (2018). A Review on Medicinal Plants Used for Nausea and Vomiting in Persian Medicine. Global Journal of Medical Research.
• In a review of studies, the author found Matricaria chamomilla, elettaria cardamomum, pomegranate and spearmint syrup, lemon, and ginger to help pregnant women with nausea. From: Khorasani, F., Aryan, H., Sobhi, A., Aryan, R., Abavi-Sani, A., Ghazanfarpour, M., … & Rajab Dizavandi, F. (2019). A systematic review of the efficacy of alternative medicine in the treatment of nausea and vomiting of pregnancy. Journal of Obstetrics and Gynaecology, 1-10.

COMMON COLD

• In a large double blind study, vitamin C reduced the duration and symptoms of the common cold.  From:  Anderson, T. W., Reid, D. B. W., & Beaton, G. H. (1972). Vitamin C and the common cold: a double-blind trial. Canadian Medical Association Journal, 107(6), 503.

ORAL HEALTH

• Lemon essential oil components were effective against oral bacteria.  From:  Miyake, Y., & Hiramitsu, M. (2011). Isolation and extraction of antimicrobial substances against oral bacteria from lemon peel. Journal of food science and technology, 48(5), 635-639.
• Both Citrus limonum and Citrus aurantium essential oils are effective in controlling microbes in the oral cavity.  From:  Oliveira, S. A. C., Zambrana, J. R. M., Di Iorio, F. B. R., Pereira, C. A., & Jorge, A. O. C. (2014). The antimicrobial effects of Citrus limonum and Citrus aurantium essential oils on multi-species biofilms. Brazilian oral research, 28(1), 22-27.
• An essential oil solution with tea tree, peppermint, and lemon reduced bad breath in patients.  From:  Hur, M. H., Park, J., Maddock‐Jennings, W., Kim, D. O., & Lee, M. S. (2007). Reduction of mouth malodour and volatile sulphur compounds in intensive care patients using an essential oil mouthwash. Phytotherapy Research, 21(7), 641-643.

EXPECTORANT

• Lemon oil had an expectorant action in rabbits, limonene and pinene were active components.  From:  Sheppard, E. P., & Boyd, E. M. (1970). Lemon oil as an expectorant inhalant. Pharmacological Research Communications, 2(1), 1-16.

IMPROVED COGNITION  / REDUCED DEMENTIA

• In a controlled study with 58 fourth grade students, the group that inhaled lemon aroma twice a week for 4 weeks had better standardized English test scores than the group who inhaled no aroma. From: Akpinar, B. (2005). The effects of olfactory stimuli on scholastic performance. The Irish Journal of Education/Iris Eireannach an Oideachais, 86-90.
• Aromatherapy of rosemary and lemon essential oils in the morning, and lavender and orange in the evening improved cognition of Alzheimer’s patients.  From:  Jimbo, D., Kimura, Y., Taniguchi, M., Inoue, M., & Urakami, K. (2009). Effect of aromatherapy on patients with Alzheimer’s disease. Psychogeriatrics, 9(4), 173-179.
• Rats exposed to lemon aroma had improved learning.  From:  Ogeturk, M., Kose, E., Sarsilmaz, M., Akpinar, B., Kus, I., & Meydan, S. (2010). Effects of lemon essential oil aroma on the learning behaviors of rats. Neurosciences, 15(4), 292-293.
• Two lemon essential oil components, limonene and perillyl, reduced the symptoms of dementia.  From:  Zhou, W., Fukumoto, S., & Yokogoshi, H. (2013). Components of lemon essential oil attenuate dementia induced by scopolamine. Nutritional neuroscience.

ANTI-INFLAMMATORY

• Essential oils from C. limon, C. aurantifolia and C. limonia had a significant anti-inflammatory effect in vivo, likely related to the limonene constituent. However, C. aurantifolia, caused myelotoxicity in mice, likely related to the citral constituent. From: Amorim, J. L., Simas, D. L. R., Pinheiro, M. M. G., Moreno, D. S. A., Alviano, C. S., da Silva, A. J. R., & Fernandes, P. D. (2016). Anti-inflammatory properties and chemical characterization of the essential oils of four citrus species. PloS one, 11(4), e0153643.
• In a summary of research, hesperidin is a bioflavonoid found in high concentrations in citrus fruit with a significant anti-inflammatory and antioxidant effect. From: Tejada, S., Pinya, S., Martorell, M., Capó, X., Tur, J. A., Pons, A., & Sureda, A. (2018). Potential anti-inflammatory effects of hesperidin from the genus Citrus. Current medicinal chemistry, 25(37), 4929-4945.

NEUROPROTECTIVE

• Lemon oil showed neuroprotective activity related to astrocyte cells in vitro.  From:  Koo, H. N., Hong, S. H., Kim, C. Y., Ahn, J. W., Lee, Y. G., Kim, J. J., … & Kim, H. M. (2002). Inhibitory effect of apoptosis in human astrocytes CCF-STTG1 cells by lemon oil. Pharmacological research, 45(6), 469-473.

ANTIOXIDANT

• Orange, lemon and mandarin showed antioxidant and antimicrobial activity in vitro.  From: Frassinetti, Stefania & Caltavuturo, L & Cini, Marianna & Della Croce, Clara & Maserti, Biancaelena. (2011). Antibacterial and Antioxidant Activity of Essential Oils from Citrus spp. Journal of Essential Oil Research – J ESSENT OIL RES. 23. 27-31. 10.
• Related to treating human skin against oxidative damage, lemon essential oil was more active than tocopherol against oxygen and peroxide free radical inhibition.  From:  Bertuzzi, G., Tirillini, B., Angelini, P., & Venanzoni, R. (2013). Antioxidative action of Citrus limonum essential oil on skin. European Journal of Medicinal Plants, 3(1), 1.
• Lemon, ylang ylang, and Vitex trifolia extracts showed antioxidant and antimicrobial actions on tested organisms.  Lemon had the strongest activity of the three tested plant extracts.  From:  Yahaya, M. F., Kubmarawa, D., Yelwa, J. M., & Runde, M. (2018). Antioxidant and antimicrobial activity of essential oils extracted from aromatic plants. World Scientific News, 111, 13-25.
• In a summary of research, it was concluded that flavonoids from citrus fruits have antioxidant activity that may help reduce disease like cancer and inflammation. From: Asjad, H. M. M., Akhtar, M. S., Bashir, S., Din, B., Gulzar, F., Khalid, R., & Asad, M. (2013). Phenol, flavonoid contents and antioxidant activity of six common citrus plants in Pakistan. Journal of Pharmaceutical and Cosmetic Sciences, 1(1), 1-5.
• Flavonoids and other constituents isolated from citrus demonstrated antioxidant activities in vitro. From: Yu, J., Wang, L., Walzem, R. L., Miller, E. G., Pike, L. M., & Patil, B. S. (2005). Antioxidant activity of citrus limonoids, flavonoids, and coumarins. Journal of agricultural and food chemistry, 53(6), 2009-2014.
• In a summary of research, hesperidin is a bioflavonoid found in high concentrations in citrus fruit with a significant anti-inflammatory and antioxidant effect. From: Tejada, S., Pinya, S., Martorell, M., Capó, X., Tur, J. A., Pons, A., & Sureda, A. (2018). Potential anti-inflammatory effects of hesperidin from the genus Citrus. Current medicinal chemistry, 25(37), 4929-4945.
• Phenolic components from citrus fruits showed antioxidant, hypoglycemic, hypotensive activities in vitro.   From: Alu’Datt, M. H., Rababah, T., Alhamad, M. N., Al-Mahasneh, M. A., Ereifej, K., Al-Karaki, G., … & Ghozlan, K. A. (2017). Profiles of free and bound phenolics extracted from Citrus fruits and their roles in biological systems: content, and antioxidant, anti-diabetic and anti-hypertensive properties. Food & function, 8(9), 3187-3197.

ASTHMA

• In a large review of over 4000 children showed eating citrus and kiwi reduced asthma and wheezing symptons.  From:  Forastiere, F., Pistelli, R., Sestini, P., Fortes, C., Renzoni, E., Rusconi, F., … & SIDRIA Collaborative Group. (2000). Consumption of fresh fruit rich in vitamin C and wheezing symptoms in children. Thorax, 55(4), 283-288.

FEMALE HEALTH

• In a review of studies, the author found Matricaria chamomilla, elettaria cardamomum, pomegranate and spearmint syrup, lemon, and ginger to help pregnant women with nausea. From: Khorasani, F., Aryan, H., Sobhi, A., Aryan, R., Abavi-Sani, A., Ghazanfarpour, M., … & Rajab Dizavandi, F. (2019). A systematic review of the efficacy of alternative medicine in the treatment of nausea and vomiting of pregnancy. Journal of Obstetrics and Gynaecology, 1-10.

WEIGHT

• Olfactory stimulation of the aromas of grapefruit and lemon increased lipolysis and caused a suppression in body weight gain in rats. From: Niijima, A., & Nagai, K. (2003). Effect of olfactory stimulation with flavor of grapefruit oil and lemon oil on the activity of sympathetic branch in the white adipose tissue of the epididymis. Experimental Biology and Medicine, 228(10), 1190-1192.

ANTI-DIABETIC

• In a review of research, flavone glycosides (naringin, hesperidin, and diosmin) found in citrus fruit have an anti-diabetic effect. From: Srinivasan, S., Vinothkumar, V., & Murali, R. (2019). Antidiabetic Efficacy of Citrus Fruits With Special Allusion to Flavone Glycosides. In Bioactive Food as Dietary Interventions for Diabetes (pp. 335-346). Academic Press.
• Phenolic components from citrus fruits showed antioxidant, hypoglycemic, hypotensive activities in vitro.   From: Alu’Datt, M. H., Rababah, T., Alhamad, M. N., Al-Mahasneh, M. A., Ereifej, K., Al-Karaki, G., … & Ghozlan, K. A. (2017). Profiles of free and bound phenolics extracted from Citrus fruits and their roles in biological systems: content, and antioxidant, anti-diabetic and anti-hypertensive properties. Food & function, 8(9), 3187-3197.

GREEN GARDENING

• Thirty essential oils were tested against pathogenic plant bacteria. Ceylon cinnamon (leaf and bark), oregano, clove bud, palmarosa, basil, peppermint, rosemary, blue gum, camphor, lemongrass, aniseed, ylang ylang, silver fir, lemon, dwarf mountain pine, bay laurel, scots pine, black cumin, Indian frankincense, bergamot orange, common juniper, bitter orange, and neem showed varying degrees of reaction.  From: Popović, T., Milićević, Z., Oro, V., Kostić, I., Radović, V., Jelušić, A., & Krnjajić, S. (2018). A preliminary study of antibacterial activity of thirty essential oils against several important plant pathogenic bacteria. Pesticidi i fitomedicina, 33(3-4), 185-195.

GREEN CLEANING

• Essential oil from lemon peel is a useful cleaner in the following ways: as air freshener, for pest repellent activity and to clean glass, ceramics, tiles, and more. From: Sarder, M. R., & Alamgir, M. (2019). Characterization of Essential Oil Extracted from a Kitchen Waste: Lemon Peel. In Waste Valorisation and Recycling (pp. 505-513). Springer, Singapore.

SPASMOLYTIC

• Carvone and limonene showed involuntary muscle spasmolytic activity in vitro. From: de Sousa, D. P., Mesquita, R. F., de Araújo Ribeiro, L. A., & de Lima, J. T. (2015). Spasmolytic activity of carvone and limonene enantiomers. Natural product communications, 10(11), 1934578X1501001120.

ANTI-INFLAMMATORY

• Essential oils from C. limon, C. latifolia, C. aurantifolia or C. limonia showed in vivo anti-inflammatory activities. In high concentration, C. aurantifolia induced myelotoxicity in mice. From: Amorim, J. L., Simas, D. L. R., Pinheiro, M. M. G., Moreno, D. S. A., Alviano, C. S., da Silva, A. J. R., & Fernandes, P. D. (2016). Anti-inflammatory properties and chemical characterization of the essential oils of four citrus species. PloS one, 11(4), e0153643.
• In a summary of research, hesperidin is a bioflavonoid found in high concentrations in citrus fruit with a significant anti-inflammatory and antioxidant effect. From: Tejada, S., Pinya, S., Martorell, M., Capó, X., Tur, J. A., Pons, A., & Sureda, A. (2018). Potential anti-inflammatory effects of hesperidin from the genus Citrus. Current medicinal chemistry, 25(37), 4929-4945.

By: Kathy Sadowski

Updated: 8/18/2020