Phytochemical and biological screening of Berberis aristata

Background: Berberis aristata occupies significant position as a medicinal plant. Given its clinical applications and the grave concern of weed based crop damage in Pakistan, the plant was investigated for its antimicrobial and allelopathic activities. Methods: Fresh Berberis aristata plant was obtained from Rawalakot and Hajeera (District Poonch) Azad Kashmir. Methanolic extract preparation and phytochemical analysis was done using standard procedures. Antibacterial and antifungal activities of the root, stem and leaf extracts of the plant were assayed against the bacterial strains E. coli, S. typhi, S. aureus, Shigella, Citrobacter, P. vulgaris, Enterobacter, S. pyrogenes, V. cholera and Klebsiella spp. and fungal strains A. niger, Cladosporium, Rhizoctonia, Alternaria, Trichoderma, Penicillium, Curvularia, Paecilomyces and Rhizopus using disc diffusion method. Also, the phytoxicity of the extracts was evaluated against Lemna minor and the data was recorded after seven days. Results: Phytochemical screening of the three extracts identified the presence of alkaloids, reducing sugars, steroids, flavonoids, terpenoids, glycosides and saponins while tannins were found to be absent. The leaf extract also showed negative tests for alkaloids and steroids. The extracts significantly inhibited the growth of the employed microbial isolates. The leaf extract, however, was not active against A. niger, Curvularia, Paecilomyces and Rhizopus. For most of the tested strains, the effectiveness of the extracts was much higher than that of Amoxicillin and Fluconazole; the positive controls used for bacterial and fungal cultures, respectively. All the extracts demonstrated 100% phytotoxicity against Lemna minor at 1000 μg/mL while low activity (10-20%) was observed at 10 μg/mL and 100 μg/mL, respectively. Conclusion: The results strongly support the profound ethnobotanical applications of this plant and also demonstrate its potential for use in weed control strategies