Pharmacological and toxicological properties of leaf extracts of Kingelia africana (Bignoniaceae)

Abstract

Leaf extracts of Kingelia africana were evaluated for wound healing, antibacterial, toxicological and chemical properties. Antibacterial activity was done using hole-in-plate bioassay, wound healing by circular incision, toxicological and chemical properties were evaluated using standard methods. The results show a more rapid wound healing at all the hydromethanolic concentrations employed than 90 mg mL-1 of procaine penicillin on the 4, 7, 10, 13, 16 and 19th day. Exudation was more prominent in control and antibiotic treated groups compared to other groups on day 2 of wounding. Clinical features revealed redness, exudation, scab formation and other changes. The aqueous and organic solvent leaf extracts exhibited significant (p<0.05) antibacterial activity against Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli at concentrations ranging from 30 to 120 mg mL-1. Most of the hepatorenal indices were significantly (p<0.05) increased at doses of 2000 to 4000 mg kg-1 indicating compromised functions of these organs. The lethal dose (LD50) of the leaf extract was greater than 3000 mg kg-1. Alkaloids (9.80±0.20), tannins (22.80±0.05), saponins (8.85±0.50), flavonoids (7.80±1.00% w/v), glycosides, saponin glycosides, steroids and anthraquinones were detected. Low values of sodium (6.5±0.01) potassium (3.1±0.01), magnesium (0.126±0.03), phosphorus (2.04±0.04) and calcium (0.108±0.01 mg%) were observed. The results show that leaves extracts of K africana could be cautiously used and also provide support for the traditional use of the plant in treating bacterial diseases and wound healing due to its chemical constituents. © 2011 Academic Journals Inc.