Pseudodictamnus africanus (L.) Salmaki & Siadati (Lamiaceae): Ethnomedicinal uses, phytochemistry and pharmacological properties

Abstract

Pseudodictamnus africanus (L.) Salmaki & Siadati is a perennial herb which naturally occurs in Namibia and South Africa. Southern Africa is characterized by several indigenous medicinal plants and natural products that are widely used in traditional materia medica. However, there is dearth of information on botanical description, medicinal uses, plant parts used, preparation and dosage, active ingredients and pharmacological effects of medicinal plants like P. africanus in the public domain. Therefore, this study reviewed the medicinal uses, active bioactives and biological activities of P. africanus. A systematic review of electronic databases and pre-electronic sources with information on the botany, medicinal uses, herbal preparations, active bioactives and pharmacological effects of P. africanus was conducted. No time limit was set for the research and all literature sources aligned with the scope of the research were included. This study showed that P. africanus is used as traditional medicine for liver problems, sores, wounds, heart problems, hysteria, skin ailments, headache, insomnia, fever, typhoid fever and respiratory problems. Pharmacological research identified hispanolone, dehydrohispanolone, saponins, tannins, phenolics, flavonoids, reducing sugars, resveratrol, triterpene steroids and essential oils. The crude extracts of P. africanus and essential oils isolated from the species exhibited antibacterial, antifungal, anti-inflammatory, anti-nociceptive, immunological and sedative-hypnotic activities. More research is needed to assert the medicinal and ethnopharmacological properties of the crude extracts of P. africanus and phytochemical compounds isolated from the species, and also determine the toxicological effects of the species and its phytochemical compounds.