Citrus fruits have been a commercially important crop for thousands of years all over the world. Lemon is the third most important citrus species after orange and mandarin. The lemon essential oil obtained from the fresh leaves and flowers of lemon (Citrus limon) is in the citrus family (Rutaceae). The main method of extraction is hydrodistillation. It had a light yellow color with an oil yield was 3% (volume/fresh weight).
Components of Lemon essential oil
Citrus essential oils are characterized by volatile and non-volatile fractions that are composed of more than 200 compounds. Lemon essential oils are valuable in the perfume, food, and beverage industries, and have also enjoyed use as aromatherapy. The main ingredients are hydrocarbon monoterpene, oxygenated monoterpene, and nitrogen compounds (1).
Nine major detected components were found to be: β-Pinene, Limonene, Linalool, α-Terpineol, linalyl acetate, Acétate geranyl, Nerolidol, Acetate neryl, and Farnesol. The minor components (< 1%) were identified as α-Pinene, Sabinene, Myrcene, 1,8-cineol, cis-linalool oxide, and Geranial.
Health benefits of Lemon essential oil
Various pharmacological effects of Lemon essential oil are antiseptic, antioxidant, anticancer, antimicrobial, antifungal, neuroprotective, anxiolytic, anticonvulsant, antinociceptive, anti-inflammatory, wound healing, and insecticidal/insect repellent properties
1. Presence of antioxidants
Presence of various powerful antioxidants such as limonene, β-Pinene, Linalool, Terpineol, linalyl acetate, Acetate geranyl, Nerolidol, Acetate neryl, Farnesol, α-Pinene, Sabinene, Myrcene, cineol, linalool oxide, and Geranial, it is able to fight free radicals, thus helps in strengthening of the blood capillaries. Thus, lemon essential oils may be helpful as a substitute for synthetic antioxidants (2).
2. Prevent food contamination
Lemon oil contains the ability to quench peroxide radicals and to terminate the peroxidation chain reaction thus inhibit lipid peroxidation. It also inhibits the growth of various microorganisms such as Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, S. enteritidis Aspergillus niger, and A. flavus which are responsible for food spoilage (3). Thus lemon oil acts as a natural antioxidant and antimicrobial agent which combat the growth of common cause’s food spoilage and food-borne pathogens (4).
3. Treat Nausea and vomiting during pregnancy
Nausea and vomiting during pregnancy affect both physical and mental conditions. One or two drops of lemon oil inhalation aromatherapy (oil burner or a diffuser) relieve nausea, vomiting, and morning sickness. It is also a safe drug in pregnancy (5,6).
4. Anti-stress or anti-depression properties of Lemon oil
Limonene, γ‐terpinene, and citral found in lemon oil modulate serum corticosterone and brain neurotransmitter related to the stress response to improve creativity, mood, and health by modulating GABAnergic, serotonergic, and dopaminergic systems in the brain (7). Thus lemon oil aroma possesses anxiolytic, an antidepressant-like effect that alleviates both physical and psychological stress and helps with relaxation (8).
5. Anticancer properties
Lemon essential oil (60 g/ml) exhibited strong antioxidant activities as well as antiproliferative activity against the HeLa cell line (39%). Limonenes present in lemon oil induce apoptosis on tumor cells and inhibit the growth of human cervical adenocarcinoma cell lines (9). Moreover, limonene also inhibits pulmonary adenoma formation and the occurrences of forestomach tumors thus inhibit carcinogen-induced neoplasia (10).
6. Insect repellents
Application of lemon oil is highly toxic against Aedes (Stegomyia) aegypti which cause dengue fever, chikungunya, Zika fever, Mayaro, yellow fever viruses, and Anopheles stephensi (malaria vector) without adverse effects on the skin or other parts of the body of the human thus protect against mosquito vectors of disease (11, 12). Lemon oil also shows insecticidal activities against larvae and adults of Culex pipiens and Musca domestica (13).
Furthermore, lemon oil is safe, inexpensive, available, and easy to apply of 10 and 20 % diluted in water caused mortality to 100 % of mites after 24 h thus play powerful acaricidal activity due to its lethal effect on sacoptic mite which causes irritation, inflammation, pruritus, and consequently skin destruction and hyperkeratosis (14).
7. Flavor enhancer
The lemon essential oil can be useful as a substitute for lemon juice or as a flavor enhancer in combination with lemon juice in food, beverages, and confections recipes. Furthermore, due to its antioxidant activity and procholinesterase properties lemon oil may be used as an extra-nutrient for use in food industries as a valuable new flavor with functional properties for food or nutraceutical products with particular relevance to supplements for the elderly (15).
8. Anti-inflammatory properties of Lemon essential oil
Presence of geranial, limonene, β-pinene, γ-terpinene, and other bioactive compounds in lemon oil exhibited anti-inflammatory effects by reducing cell migration, and inflammatory mediator production (16).
9. Antifungal properties Lemon essential oil
The presence of high content of monoterpenoids, D-limonene, and linalool in lemon oil exert their antifungal actions against different pathogenic fungi such as Candida albicans, C. tropicalis, C. glabrata and Fusarium graminearum (17). Therefore, this oil acts as a natural therapeutic agent for the treatment of human mucous membranes and skin infection and an effective remedy against candidiasis and phytopathogens (18).
10. Lemon essential oil keeps skin healthy
The lemon essential oil contains antiseptic, astringent, and detoxifying properties which may be beneficial for the treatment of various skin diseases such as abscesses, acne, antiseptic, athlete’s foot, blisters, boils, cellulite, corns, cuts, grazes, greasy and oily conditions, insect bites, mouth ulcers, rosacea, sores, ulcers, viral infections (cold sores, herpes, verrucae, and warts), and wounds (19).
11. Limonene s-perillyl of Lemon essential oil treat dementia
Lemon oil may inhibit the activity of acetylcholinesterase and regulate the behavioral and neural reactions which improved impaired memory and in the treatment of cognitive disorders thus treat dementia (20). Thus (100 mg/kg) lemon oil aroma may have some effects on learning may be effective in learning to escape from aversive conditions (21).
12. Anti-aging properties of Lemon essential oil
It helps in enhancing the penetration of α-tocopherol (E) and retinyl acetate (A), pyridoxine (B(6)), and ascorbic acid (C) vitamins in the skin (22). Moreover, compounds isolated from lemon oil, known as Lem1, show strong antioxidant activity and that it is capable of inhibiting free radical-mediated reactions controlling free radical-induced lipid peroxidation and tissue damage in the skin (23).
13. Antispasmodic activity
Limonene, beta-pinene, gamma-terpinene and citral found in lemon oil possess important spasmolytic properties which prevent or lowers the incidence of muscle spasms (24).
14. Antiprotozoal properties of Lemon essential oil
Limonene has a toxic effect on different organisms and possesses an antiprotozoal effect on two intestinal flagellates of poultry thus may be useful as chemotherapeutic agents against several poultry parasites (25).
15. Manage weight
As we know that lemon oil fragrance is refreshing and exciting which increases sympathetic nerve activity to white adipose tissue which increases lipolysis and suppression in body weight gain (26).
16. Healthy brain
The lemon essential oil may play a modulatory role in the treatment of neurodegenerative diseases because this oil contains a phenolic compound that interrupts cellular oxidative processes in the central nervous system (CNS) (27).
17. Prevent mold growth
The lemon essential oil may be very useful to inhibit mold growth and aflatoxin production. Thus this oil suppression of mold growth (Aspergillus parasiticus) and toxin formation (28).
18. Lower cholesterol level
Lemon oil contains gamma-terpinene, which therefore slows down the oxidation of low-density lipoprotein oxidation and lipid peroxidation and prevents erythrocyte deformation and aortic intimal proliferation (29). Thus lemon essential oil lower cholesterol level which further lowers the risk for atherosclerosis (30).
19. Reduce pain
Lemon essential oil inhalation has a wonderful effect on reducing pain (31).
Lemon peel oil (LPO) is considered to be a viable alternative fuel for diesel engine applications due to its wider availability, renewable nature, easy extraction process, almost equivalent calorific value as neat diesel, and low viscosity (32).
The side effect of Lemon essential oil
Risk of phototoxicity
Lemon oil contains furocoumarin derivatives and is known to cause phototoxicity. Thus oxypeucedanin present in lemon oil results in skin irritations in some people like visible erythema (33).
Edited By: Dr. Asha Jyoti Bharati