Toxicological evaluation of polyherbal medicines used for the treatment of tuberculosis in Eastern Cape, South Africa

Abstract

Background: Polyherbal remedies are widely used for the treatment and management of various diseases in developing countries. These remedies often contain active pharmacological compounds, thus, the evaluation of herbal remedies used for the treatment of tuberculosis in the Eastern Cape province for their toxicity is of great importance. Materials and Methods: Nine polyherbal medicines used for the treatment of tuberculosis were assayed for their toxicity using hatchability success and larval mortality of brine shrimp [Artemia salina Leach). These remedies were liquid preparations and coded according to their respective place of collection, viz., King Williams Town site A, King Williams Town site B, King Williams Town site C, Hogsback first site, Hogsback second site, Hogsback third site, East London, Alice and Fort Beaufort. Results: The percentage hatchability success of 44.42, 42.96 and 39.70% were observed in cysts incubated with herbal preparations from King Williams Town site A, Hogsback first site and Hogsbackthird site, respectively. The hatching success in these remedies was significantly higher than the positive control (nystatin) and the negative control (sea water) at p<0.05. The herbal preparations from King Williams Town site A and East London exhibited significantly more inhibitory hatchability effects with minimum inhibitory concentration values of 2.4 and 2.8 mg mL-1, respectively. The mortality of A salina nauplii incubated in Alice, King Williams Town site B and King Williams Town site C remedies was significantly higher than when larvae was incubated in both controls. Based on Meyer’s index, the LD50of each polyherbal medicine was between 2.9-4.0 mg mL-1, the LD50values greater than 1 mg mL-1. Conclusion: The polyherbal remedies evaluated in this study are considered non-toxic and are therefore safe for the patients. However, further in vivo toxicity tests are required to validate the safe use of these polyherbal remedies.