- Title
- Evaluation and identification of microbial contaminants in polyherbal medicines used for the treatment of tuberculosis in Amathole District Municipality, Eastern Cape Province, South Africa
- Creator
- Famewo, Elizabeth Bosede
- Subject
- Tuberculosis -- Treatment -- South Africa Mycobacterial diseases -- South Africa -- Eastern Cape Medicinal plants -- South Africa -- Eastern Cape
- Date
- 2018
- Type
- Thesis
- Type
- Doctoral
- Type
- PhD
- Identifier
- http://hdl.handle.net/10353/9680
- Identifier
- vital:34818
- Description
- Tuberculosis is caused by Mycobacterium tuberculosis. The emergence of drug-resistant strains of this organism has become a global public health problem. In the continuing search for effective treatment, polyherbal medicines offer a great hope in the development of alternative drugs for the treatment of tuberculosis. The use of herbal formulations for therapeutic purposes has significantly increased in the developed and developing countries because of their curative property, less toxicity and minimal side effects. However, there is little information on their safety and effectiveness in the literature. To address this, polyherbal medicines used for the treatment of tuberculosis in the Eastern Cape Province of South Africa were evaluated. Ethno-medicinal survey was conducted through semi-structured questionnaires coupled with informal conversations with the herbal sellers in five communities in the study area. Bacterial and fungal DNA was extracted from the polyherbal medicines purchased. A fragment of the bacterial 16S rRNA gene and internal transcribed spacer region of the fungal rRNA operon were amplified with universal primers 27F and 518R, and ITS1 and ITS4 respectively. Following standard procedures, the amplicons were finally run on Illumina’s MiSeq platform. Furthermore, the remedies were screened against Mycobacterium tuberculosis H37Rv using Middlebrook 7H9 media and MGIT BACTEC 960 system. Agar dilution method was used to determine the minimum inhibitory concentration (MIC) of the remedies against eight bacteria and three fungi isolates. The herbal preparations were assayed for their toxicity using hatchability success and larval mortality of Artemia salina Leach. Finally, their nutritive properties were analysed using an inductively coupled plasma optical emission spectrometer for mineral analysis while the vitamins were determined using standardized methods A total of nine polyherbal preparations were collected. The herbs used for the preparation of these remedies belong to 20 families. Apiaceae [5(25 percent)] was the most prominent plant family used, followed by Liliaceae [4(20 percent)], Strychnaceae [4(20 percent)], Rutaceae [4(20 percent)] and Hypoxidaceae [3(15 percent)]. The two most frequently used plants were Allium sativum L. (Liliaceae) and Strychnos decussata (Pappe) Gilg. (Strychnaceae). Rhizomes was the most common parts used, followed by the roots and barks. The herbal medicines were prepared mainly by infusion and decoction. The presences of pathogenic and non-pathogenic bacteria were identified in the polyherbal medicines. Generally, the most common bacteria identified from the samples were Bacillus sp., Enterobacter sp., Klebsiella sp., Rahnella sp., Paenibacillus sp., Clostridium sp. and Pantoea sp. The predominant mycoflora obtained belongs to different genera or species of fungi; these include Alternaria, Candida, Ramularia, Cladosporium, Penicillium, Aspergillus and Malassezia. The susceptibility testing revealed that all the remedies contain anti-tubercular activity against M. tuberculosis H37Rv at concentrations below 50 ug/ml. Seven of the polyherbal preparations showed activity at concentrations below 25 ug/ml. The MIC values exhibited inhibitory activity at 1.562 μg/ml. However, isoniazid showed more inhibitory activity against M. tuberculosis at 0.05 μg/ml when compared to the polyherbal remedies. The inhibitory activity of the polyherbal medicines based on the overall MIC revealed that Hogsback first site (HBfs) and Fort Beaufort (FB) remedies were the most active remedies against the bacterial isolates at the concentration of 2.5 mg/mL. Among the nine herbal formulations, only King Williams Town site A (KWTa) remedy showed activity against Aspergillus niger and Aspergillus fumigatus with the MIC valve of 2.5 mg/mL. While King Williams Town site C (KWTc) and Hogsback third site (HBts) had the highest activity at 1.25 mg/mL against Candida albicans, the remaining remedies were active at 2.5 mg/mL. The percentage hatchability of 44.42 percent, 42.96 percent and 39.70 percent were observed in A. salina cysts incubated with herbal preparations from KWTa, HBfs and HBts respectively. The hatching success of the cysts in these remedies was significantly higher than the positive control (nystatin) and the negative control (sea water) at p < 0.05. The mortality of A. salina nauplii incubated in Alice (AL), King Williams Town site B (KWTb) and KWTc remedies were significantly higher than when larvae were incubated in both controls. Based on Meyer’s index, the LD50 of each polyherbal medicine was between 2.9 and 4.0 mg/ml, the LD50 values greater than 1 mg/ml, an indication that they are not toxic. The polyherbal preparations were found to be rich in vitamins and mineral nutrients. Calcium was the highest macronutrient detected while the lowest nutrient was phosphorus. Iron was the highest micronutrient in the majority of the polyherbal preparations while the lowest value was recorded for copper. Vitamin C was absent in the herbal preparations while vitamin A and E were detected. This study provides significant ethno-medicinal information on polyherbal medicines used for the treatment of TB in the study area. The presence of the identified bacteria and fungi in the herbal formulations is a cause for concern. However, the ability of the remedies to possess activity against Mycobacterium tuberculosis and other pathogenic microorganisms associated with tuberculosis infection makes them potential sources of new antimycobacterial agents. Also, they are rich sources of mineral nutrients, and are as well non-toxic, thus, they are safe for consumption. In view of their anti-tubercular properties, this study has provided a better understanding of the reasons why TB-patients make use of these polyherbal formulations. Also, the study supports the folkloric use of polyherbal medicines in the treatment of tuberculosis in the Eastern Cape Province, South Africa.
- Format
- 148 leaves
- Format
- Publisher
- University of Fort Hare
- Publisher
- Faculty of Science and Agriculture
- Language
- English
- Rights
- University of Fort Hare
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