Cymbopogon citratus, commonly known as West Indian lemon grass or simply lemon grass,[3] is a tropical plant native to Maritime Southeast Asia and introduced to many tropical regions.[4]
Cymbopogon citratus is often sold in stem form. While it can be grown in warmer temperate regions, such as the UK, it is not hardy to frost.
Morphology
Cymbopogon citratus is part of the grass family, Poaceae. They contain simple, bluish-green leaves with entire margins and are linear in shape. The blades tend to be 18–36 inches long. Like other grasses, the leaves also have parallel venation.[5]
In its native range, Cymbopogon citratus is known as sereh, serai, or serai dapur in Indonesia and Malaysia; and tanglad (from Proto-Austronesian *Caŋelaj originally referring to Themeda gigantea, a type of elephant grass[7]), salai, or balioko in the Philippines.[6]
Culinary uses
Knots of C. citratus leaves sold at a supermarket in the PhilippinesReady-to-use bundles of lemon grass, galangal, kaffir lime leaves, and, for chicken tom yam, also turmeric, are sold at Thai markets.
Cymbopogon citratus is abundant in the Philippines and Indonesia where it is known as tanglad or sereh, respectively. Its fragrant leaves are traditionally used in cooking, particularly for lechon and roasted chicken.[8]
The dried leaves can also be brewed into a tea, either alone or as a flavoring in other teas, imparting a flavor reminiscent of lemon juice but with a mild sweetness without significant sourness or tartness.
In Sri Lanka, lemongrass is known as sera (සේර). It is used as a herb in cooking, in addition to its use for the essential oils.[9]
Lemongrass in Thailand is called takhrai (ตะไคร้). It is the essential ingredient of tom yam and tom kha kai. Fresh thin slices of lemongrass stem also used in miangpla, as a snack food.
The leaves of Cymbopogon citratus have been used in traditional medicine and are often found in herbal supplements and teas. Evidence of effective Cymbopogon citratus essential oil anti-protozoa activity against Leishmania amazonensis.[10]
Chemical composition
Lemon grass oil contains 65–85% citral in addition to myrcene, citronellal, citronellol, linalool and geraniol.[11][12] Hydrosteam distillation, condensation, and cooling can be used to separate the oil from the water. The hydrosol, as a by-product of the distillation process, is used for the production of skin care products such as lotions, creams, and facial cleansers. The main ingredients in these products are lemon grass oil and "negros oil" (mixture of lemon grass oil with virgin coconut oil) used in aromatherapy.[13]
Citronellol is an essential oil constituent from Cymbopogon citratus, Cymbopogon winterianus, and Lippia alba. Citronellol has been shown to lower blood pressure in rats by a direct effect on the vascular smooth muscle leading to vasodilation.[14] In a small, randomized, controlled trial, an infusion made from C. citratus was used as an inexpensive remedy for the treatment of oral thrush in HIV/AIDS patients.[15]
Laboratory studies have shown cytoprotective, antioxidant, and anti-inflammatory properties in vitro.[16][17][18]
Traditional medicinal use
In the folk medicine of the Krahô people of Brazil, it is believed to have anxiolytic, hypnotic, and anticonvulsant properties.[19][20]
Video tracking of a stable fly, demonstrating repellency of lemongrass oil [21]
Beekeepers sometimes use lemon grass oil in swarm traps to attract swarms. Lemon grass oil has also been tested for its ability to repel the pestilent stable fly,[21] which bite domestic animals.
^USDA, NRCS (n.d.). "Cymbopogon citratus". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved January 12, 2019.
^Shaikh, Mosma; Suryawanshi, Yogesh; Digambar, Mokat (2019). "Volatile Profiling and Essential Oil Yield of Cymbopogon citratus (DC.) Stapf Treated with Rhizosphere Fungi and Some Important Fertilizers". Journal of Essential Oil Bearing Plants. 22 (2): 477–483. doi:10.1080/0972060X.2019.1613933. S2CID191177588.
^Baby P. Skaria; P.P. Joy; Samuel Mathew; Gracy Mathew; Ancy Joseph; Ragina Joseph (2007). Aromatic Plants. Vol. 1. New Delhi, India: New India Publishing Agency. p. 103. ISBN9788189422455.
^Wright SC. Maree JE. Sibanyoni M. (2009). "Treatment of oral thrush in HIV/AIDS patients with lemon juice and lemon grass (Cymbopogon citratus) and gentian violet". Phytomedicine. 16 (2–3): 118–124. doi:10.1016/j.phymed.2008.07.015. PMID19109001.
^Figueirinha A. Cruz MT. Francisco V. Lopes MC. Batista MT. (2010). "Anti-inflammatory activity of Cymbopogon citratus leaf infusion in lipopolysaccharide-stimulated dendritic cells: contribution of the polyphenols". Journal of Medicinal Food. 13 (3): 681–690. doi:10.1089/jmf.2009.0115. PMID20438326.
^Lee HJ. Jeong HS. Kim DJ. Noh YH. Yuk DY. Hong JT. (2008). "Inhibitory effect of citral on NO production by suppression of iNOS expression and NF-kappa B activation in RAW264.7 cells". Archives of Pharmacal Research. 31 (3): 342–349. doi:10.1007/s12272-001-1162-0. PMID18409048. S2CID20909743.
^Tiwari M, Dwivedi UN, Kakkar P (2010). "Suppression of oxidative stress and pro-inflammatory mediators by Cymbopogon citratus D. Stapf extract in lipopolysaccharide stimulated murine alveolar macrophages". Food Chem. Toxicol. 48 (10): 2913–2919. doi:10.1016/j.fct.2010.07.027. PMID20655974. S2CID9395057.
^Blanco MM, Costa CA, Freire AO, Santos JG, Costa M (March 2009). "Neurobehavioral effect of essential oil of Cymbopogon citratus in mice". Phytomedicine. 16 (2–3): 265–70. doi:10.1016/j.phymed.2007.04.007. PMID17561386.
^Rodrigues, Eliana & Carlini, E.A. (2006): Plants with possible psychoactive effects used by the Krahô Indians, Brazil. Revista Brasileira de Psiquiatria28(4): 277-282. PDF fulltextArchived 2020-08-01 at the Wayback Machine
