Therapeutic Evaluation of Plants Used Against Respiratory Infections and Related Symptoms in Limpopo Province, South Africa

Abstract

Background and Objective: Respiratory infections (RIs) and related symptoms (RSs) are commonly treated by traditional healers (THs) using herbal remedies in the traditional primary health care sectors. The aim of this study was therefore, to evaluate the therapeutic value of most used plant species namely Clerodendrum ternatum, Cryptocarya transvaalensis, Enicostema axillare and Lasiosiphon caffer by Bapedi THs for these conditions. Material(s) and Method(s): Qualitative phytochemical constitutes of the crude materials from the above-stated species were determined using the standard methods. The antioxidant activities of acetone, dichloromethane, hexane, methanol and water crude extracts were evaluated using qualitative and quantitative 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assays. Antibacterial activities of these extracts was assessed using microdilution (minimum bactericidal concentration (MBC) and minimum inhibitory concentration (MIC) and bioautography assays). Result(s): The phytochemical screening of C. ternatum, C. transvaalensis, E. axillare and L. caffer crude extracts revealed the presence of alkaloids, anthraquinones, cardiac glycosides, flavonoids, phlobatannin, saponins, steroids, tannins and terpenes. All plants including those that did not display any antioxidant activities using qualitative DPPH assay showed a certain level of scavenging activities when quantified, with the mentioned extracts from E. axillare (water and hexane), L. caffer (water and acetone) and C. ternatum (acetone) showing excellent activities almost comparable to a standard antioxidant drug (ascorbic acid). Plant extracts from all used solvents were able to completely exterminate Mycobacterium smegmatis, Klebsiella pneumoniae, Staphylococcus aureus and Pseudomonas aeruginosa, with MBC values between 0.019 and 2.5 mg mLG1 depending on the plant. Some of plant extracts were able to impede the growth of these bacteria with MIC values ranged between 0.63-2.5 mg mLG1. Conclusion(s): Findings of the present study provide support for the use of C. ternatum, C. transvaalensis, E. axillare and L. caffer as medication for RIs and RSs by Bapedi THs. Studies focusing on isolation, identification and characterization of the pure compounds responsible for antibacterial activities of plants are in progress.Copyright © 2020 Sebua Silas Semenya et al.