Herbal remedies are popular in Indonesia as an alternative to using chemical-based treatments. In the field of dental medicine, essential oil from lemon peels was developed as an alternative medicine to treat thrush caused by trauma. Lemon is one type of citrus that is very common in the Citrus species group. This lemon is not only used by the fruit, but the peel can also be used to produce a useful ingredient, namely essential oil.
Research conducted at Department of Oral Medicine, Faculty of Dental Medicine, Universitas Airlangga, used local lemons from East Java as an alternative ingredient to accelerate the healing of thrush. The essential oil from lemon peel is processed into a gel preparation so that it can be easily applied or applied to thrush. Using essential oil from lemon peel, once per day for 5 and 7 days in cob, shows an increase in the number of lymphocytes and IL-10 expression. These two indicators are an indicator of the wound healing process, both wounds on the skin and in canker sores.
The essential oil from lemon peel contains 51 active substances. The most dominant essence is fumaric acid, which has anti-inflammatory and anti-oxidant effects. Fumaric acid can increase endogenous GSH, which can increase cell protection against oxidative stress. Apart from fumaric acid, there is also a D-limonene compound which is a unique compound that can only be found in lemons. This compound functions as an anti-oxidant, anti-inflammatory, and anti-bacterial.
The content of fumaric acid and D-limonene can reduce the number of free radicals, namely, reactive oxygen species. These radicals are compounds that can destroy all types of proteins, fats, carbohydrates, and nucleic acids. These radicals can cause prolonged healing time such as in wounds and canker sores because they can induce the release of inflammatory mediators such as pro-inflammatory cytokines. Besides, the essential oil from lemon peel also has anti-microbial effects that can inhibit secondary infection in thrush.
The increase in lymphocyte count is due to the anti-inflammatory properties of D-limonene. This compound works by reducing the number of pro-inflammatory cytokines, such as tumour necrosis factor α (TNF α) and IL-6, because it can inhibit lymphocyte activation and proliferation. The increase in IL-10 expression is thought to occur through several mechanisms involving limonene and immune cells.
One molecular mechanism is the nuclear factor kappa beta (NF-κB) because limonene suppresses the inflammatory response by inhibiting the expression or activation of NF-κB. NF-κB is an essential modulator of chemokine transcription, such as chemokine ligands, which play a vital role in the migration of T-helper 1 and T-helper 17 cells. Therefore, inhibition of NF-κB activation induces decreased Th17 cell infiltration in the ulcer or canker sores.
The research results obtained at this time are the initial stage to develop and prove other benefits of lemon peel. Therefore, further research is needed to be able to create, apply and use lemon as an alternative to canker sores.
Author: Fatma Yasmin Mahdani, drg., M.Kes
Link: F.Y.Mahdani, D.S.Ernawati, P.Hadi, B.Soebadi, S.D.Mardiyana, D.Susanti, M.D.C.Surboyo. Citrus limon L.Gel Stimulate Lymphocytes and Interleukin-10 Expression in Traumatic Diabetic Oral Ulcers. Phcog Res 2020; 12: 299-302. http://www.phcogres.com/temp/PhcogRes123299-6870517_015430.pdf