Justification of The Use of<em>Grewia occidentalis</em>L. for The Traditional Treatment of Wounds in The Eastern Cape Province, South Africa

Author

Grierson, DS and Afolayan AJ.

Proceeding

Traditional & Complementary Medicine Exhibition 2007 (TCME 2007),Putra World Trade Centre (PWTC), Kuala Lumpur, Malaysia

Date

17/7/2007

Keyword

wounds, ethnomedical, Grewia occidentalis

Abstract

The shrub,Grewia occidentalisL. is one of the plants frequently used traditionally for the treatment of wounds in the Eastern Cape Province of South Africa. Investigations were conducted to justify this use. Antimicrobial screening of extracts from the plant was performed against 10 bacterial and five fungal species. Some bioactive compounds were isolated and identified using various techniques. SEM studies were carried out to investigate the possible sites of production of these compounds. Antibacterial activity: The methanol extracts inhibited the growth of both Gram-positive and negative bacteria, while onlyS. aureusandE. cloacaewere inhibited by the water extract. No inhibition was observed from the acetone extracts. Antifungal activity: A number of the extracts showed some antimycotic activity against the microbes at concentrations of 10 mg/ml or lower. The acetone and water extracts did not inhibit the growth ofMucor hiemalisorSchizophyllum commune. Isolation of compounds: A total of 12 compounds were identified from the n-hexane extract, with hexadecanoic acid, methyl ester asthe most abundant, followed by nonanedioic acid, di-m.e. and octadecanoic acid. UV, IR and NMR spectroscopic data of an amorphous precipitate were found to be identical to that of daucosterol. Ultrastucture of leaf surfaces: Stalked club-shapedglandular and stellate trichomes were observed on the leaf surfaces ofG. occidentalis. The glandular trichomes were more abundant. The general antibiotic properties ofG. occidentalisappear to have justified its usage for the treatment of woundsby the indigenous people of the Eastern Cape. Aromatic carboxylic acids were the most prominent group of compounds isolated, followed by alkanes. These compounds probably contribute in a major way to the antibiotic activity of this plant. Glandular and non-glandular trichomes, observed on the leaves, are possibly the sites of production of these bioactive compounds. Generally, the findings from this research have justified the traditional use ofG. occidentalisfor the treatment of wounds and reinforce the concept of screening plants as potential sources of bioactive substances.