Phytochemical screening and pharmacological evaluation of herbal concoctions sold at Ga Maja Limpopo Province

Abstract

Informal street merchants and traditional health practitioners at Ga Maja (Limpopo Province) primarily offer consumers semi-processed herbal preparations that are indicated to have blood cleansing, detoxifying, antidiarrheal and pain relieving properties. The focus of this study was to evaluate the phytochemical composition of the concoctions and substantiate the pharmacological effects and safety indicated by the traders. Five herbal concoctions and plant material used in their preparation were purchased from five independent traders and a laboratory concoction was prepared according to the traders' instructions. Possible bacterial and fungal contaminants were isolated and identified using Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF-MS). Qualitative phytochemical analysis was determined using standard chemical tests and thin layer chromatography. Total polyphenol content was quantified. Antioxidant activity was quantified using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay and ferric reducing power. Antimicrobial activities were determined using a broth micro-dilution assay and bioautography. Cell viability assay was used to determine the cytotoxicity of the concoctions. Pathogenic bacteria, Enterobacter cloacae, Enterobacter aerogenes, Escherichia coli and Klebsiella pneumoniae were identified as bacterial contaminants. The commercial concoctions and the laboratory standard had similar phyto-constituents and phytochemical fingerprint profiles. The antimicrobial properties of the concoctions were a result of synergistic effects of the compounds because no single compound was observed to have antimicrobial activities on the bioautograms. The phenolic content, antioxidant and antimicrobial activities varied substantially amongst the concoctions. The lack of standardisation methods reduces the pharmacological potential of the products. This study concludes that while plants with biological activities were used by the traders to prepare the concoctions, the efficacious concentrations to produce a therapeutic response were not adequately measured and adhered to. Furthermore, although the concoctions did not exhibit cyctotoxic effects, toxicities may arise from endotoxins produced by the microbial contaminants. Hygienic processing and packaging are essential to ensure that consumers receive quality products that are safe to consume.