Ecdysteroids from the Stem Bark of Vitex doniana Sweet (Lamiaceae; ex. Verbenaceae): A Geographically Variable African Medicinal Species

Abstract

Vitex doniana Sweet is an African medicinal species that is prescribed as an aqueous bark extract to be applied topically or orally to achieve anti-infective outcomes. In select regions it is also taken orally as an antimalarial agent. The aim of the current study was to explore the biological properties of V. doniana and isolated compounds in the context of pathogenic bacteria and the protozoan parasite Plasmodium falciparum. Three compounds were isolated and assigned by nuclear magnetic resonance spectroscopy as ecdysteroids: (1) 20-hydroxyecdysone, (2) turkesterone, and (3) ajugasterone C. Interestingly, two of these compounds had not previously been identified in V. doniana, providing evidence of chemical variability between regions. The bark extract and three ecdysteroids were screened for activity against a panel of pathogenic bacteria associated with skin, stomach and urinary tract infections, and the protozoan parasite P. falciparum. The crude extract of the bark inhibited all bacterial strains with MIC values of 125–250 μg.mL−1. The three isolated compounds demonstrated less activity with MIC values of 500–1000 μg.mL−1. Furthermore, no activity was observed against P. falciparum at the screening concentration of 4.8 μg.mL−1. Nevertheless, we present a hypothesis for the possible mechanism for symptomatic relief of malarial fever, which may involve reduction of prostaglandin E(1) & E(2) activity in the hypothalamus via modulation of the monoaminergic system. While further studies are required to identify all antimicrobial agents within this plant species and to determine the cytotoxicity of each of these compounds, these data suggest that the traditional application of this species as an antiseptic is valid.

Vitex doniana L. Growing in Southwestern Nigeria: Leaf Essential Oil Composition and Antimicrobial Activity

“…[9][10][11] Antimicrobial potency of V. doniana has been reported against several bacteria, including methicillin resistant Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Shigella dysenteriae, Pseudomonas aeruginosa, and Salmonella typhi among others. [12][13][14][15][16][17] Hydroxycinnamic acid, saponins, allicins, flavonoids, and terpenoids have been identified in leaf extracts of V. doniana. 18 This present report is aimed at the characterization of the components of the essential oil of V. doniana and its antimicrobial activity for future exploitation in pharmaceutical applications.…”

Chemical Composition, Antioxidant, and Antimicrobial Activities of the Leaf and Fruit Essential Oils of the West African Plum, Vitex doniana

“…Te Vitex genus has about 270 species of trees and shrubs in the tropical regions while a few species are also found in temperate zones [24]. V. doniana has a lot of useful applications-it serves as a source of food and medicine and provides timber for furniture [25]. Also, jam and syrup can be made from the fruit pulp.…”