(-)-Limonene

(+)-Limonene is a monoterpene that has been found in citrus oils and Cannabis and has diverse biological activities, including anticancer, antimicrobial, antioxidant, anti-inflammatory, and chemoprotective properties.^1,2,3,4 It inhibits the growth of bacteria including S. aureus, B. cereus, E. faecalis, E. coli, P. aeruginosa, K. pneumoniae, M. catarrhalis, and C. neoformans with MIC values ranging from 3 to 27 mg/ml.¹ In a human BGC-823 gastric cancer nude mouse orthotopic transplantation model, (+)-limonene inhibits tumor growth by 47.6% compared to controls and reduces the number of metastases in the liver, peritoneum, and other organs when administered by gastric perfusion at a dose of 15 ml/kg of a 1% emulsion.⁵ Dietary administration of (+)-limonene (5 and 10% in chow) reverses doxorubicin-induced decreases in glutathione (GSH) levels in rat kidney.³ Formulations containing (+)-limonene have been used as flavoring and fragrance agents and in the treatment of gallstones, heartburn, and gastroesophageal reflux disorder.

1.van Vuuren, S.F., and Viljoen, A.M.Antimicrobial activity of limonene enantiomers and 1,8-cineole alone and in combinationFlavor and Frag. J.22(6)540-544(2007) 2.Sun, J.D-Limonene: Safety and clinical applicationsAltern. Med. Rev.12(3)259-264(2007) 3.Rehman, M.U., Tahir, M., Khan, A.Q., et al.D-limonene suppresses doxorubicin-induced oxidative stress and inflammation via repression of COX-2, iNOS, and NFκB in kidneys of Wistar ratsExp. Biol. Med. (Maywood)239(4)465-476(2014) 4.Handbook of Cannabis therapeutics from bench to bedside(2010) 5.Lu, X.-G., Zhan, L.-B., Feng, B.-A., et al.Inhibition of growth and metastasis of human gastric cancer implanted in nude mice by d-limoneneWorld J. Gastroenterol.10(14)2140-2144(2004)