Background
Grewia flava infusions are consumed to assist with kidney problems and stomach ailments, however, there are no scientific data on the phytochemical profile or biological properties of the extract to validate its folklore use. Thus, the study aim was to assess the phytochemical profile, antioxidant, and antimicrobial activities of Grewia flava twigs extracts.
Results
The antioxidant activities of the extracts were assayed using 1,1-Diphenyl-2-picrylhydrazyl radical radical scavenging, reducing power, metal chelation, and total phenolic and flavonoid content assays. The agar well diffusion and microdilution methods were used for crude extracts and fractions (from 80% methanol extract) antimicrobial screening against P. aeruginosa, S. aureus, E. coli, B. subtilis, A. niger, and R. oryzae. The 80% methanol twig extract (250 ± 2 GAE/g) exhibited a high concentration of phenolic content followed by distilled water extract (192 ± 2 mg GAE/g) and the hexane extract (43.1 ± 0.2 mg GAE/g). Fraction 14 of the methanol twig extract exhibited MIC values of 0.21–0.31 mg/mL against all test microorganisms. The roots and twigs extracts exhibited significant antioxidant and antimicrobial activities, which were attributed to the extracts bioactive phytochemical compounds such as alkaloids, flavonoids, saponins, steroids, glycosides, anthraquinones, and tannins that were detected in the extracts. Also the roots and twigs non-polar extracts were subjected to gas chromatography–mass spectrometry analysis, which identified several bioactive compounds like betulin, β-amyrin, palmitic acid, lupenone, and phytol, highlighting the potential of the plant species as a botanical drug.
Conclusions
The study supports the traditional use of plant roots and twigs for treating various ailments, indicating its medicinal value. For sustainable harvesting of Grewia flava, twigs maybe used in place of roots; which to avoid killing the whole plant. However, a comparison of active compounds quantities in twigs relative to those in roots is crucial.