In vitro Evaluation of Antimicrobial and Antioxidant Profile of Grewia L. Root Extracts

Aims: To analyze and compare the in vitro antimicrobial activity and antioxidant profile of Grewia asiatica L.; Grewia tiliifolia Vahl.; Grewia tenax (Forsk.) Fiori.

Study Design: This study was designed to evaluate and compare the antimicrobial activity and antioxidant profile of different extracts of Grewia which are commonly used in Ayurvedic drug preparations.

Place and Duration of Study: The work was done in National research institute of Basic Ayurvedic Sciences during the month of August to December 2015.

Methodology: All the three Grewia species were subjected to screen the antioxidant potential by various methods, such as FRAP, DPPH, ABTS and NO radical scavenging assay. Further, to assess the in vitro antimicrobial activity of Grewia species by using Broth microdilution technique by CLSI guidelines against different microrganisms.

Results: Total phenolics and flavonoids were highest in G. tenax as compared to other species. Highest antioxidant activity was seen in G. tenax while lowest in G. tiliifolia. All extracts showed significant antimicrobial activity, hydroalcoholic extract of G. asiatica had most effective antibacterial activity against K. pneumoniae (MIC – 3.90 µg/ml) as well as same extract showed effective antifungal potential against C. albicans and A. fumigatus (MIC – 31.2 µg/ml). G. tenax possesses remarkable antibacterial activity against B. subtilis and G. tiliifolia showed the same activity against E. coli.

Conclusion: The species which exhibited well marked antioxidant and antimicrobial activity was rich in secondary metabolite contents (flavonoids and phenols). Antioxidant results of present investigation provided supportive scientific evidence for G. tenax. Findings of this study supported the traditional use of G. asiatica and G. tenax in the treatment of some microbial infections.