Ethnopharmacological uses, biological activities, chemistry and toxicological aspects of Ocimum americanum var. americanum (Lamiaceae)

Abstract

The rationale for the use of Ocimum americanum var. americanum in herbal medicine is largely based on the longstanding experience of traditional medicine practitioners. The genus Ocimum is extensively used in Eastern Africa in folkloric practice against a wide range of illnesses. The present paper intends to bring a comprehensive overview of O. americanum var. americanum in regard to its biological activities, ethnopharmacological uses, phytochemical and toxicological effects. The literature search was conducted using Google, Google Scholar, Chemical abstracts, Sciverse; JSTOR, Medline, PubMed, Science Direct, Scopus and Springer Link. O. americanum var. americanum extracts have been shown to have antimicrobial, antioxidant, antiproliferative, insecticidal, and repellent activities. Literature on the activity of O. americanum var. americanum extracts against metabolic syndromes such as diabetes, hyperlipidaemias and hypertension is scanty. Toxicological data is also limited; however, the accessible information indicates non-toxicity of O. americanum var. americanum extracts. Substantial variations in phytochemical constituents of this particular species are observed, which may be attributed to edaphic differences as well as ecoclimatic regions.