EVALUATION OF WALNUT GREEN HUSK, CAPPARIS SPINOSA, CISTANCHES HERBA, ECLIPTA PROSTRATA, SCUTELLARIA BARBATA, SARGENTODOXA CUNEATA, AND SOPHORA FLAVESCENS EXTRACTS AGAINST STAPHYLOCOCCUS AUREUS, ESCHERICHIA COLI, AND SALMONELLA ENTERITIDIS

Herbs are widely used in the treatment of a wide range of illnesses in humans and animals. They contain an array of natural antibacterial compounds and possess potent antibacterial properties, making them a promising source of low-toxicity, high-efficiency alternative antimicrobial agents that are less likely to develop drug resistance. In this experiment, total phenols and flavonoids, free radical scavenging ability of extracts derived from seven traditional Chinese herbs, including walnut (Juglans regia) green husk, Cistanche herba, Capparis spinosa, Eclipta prostrata, Sophora flavescens, Scutellaria barbata, and Sargentodoxa cuneata, were investigated. Furthermore, the antibacterial properties of the extracts against Staphylococcus aureus, Escherichia coli, and Salmonella enteritidis were assessed. The results showed that the concentrations of total phenols and flavonoids of the seven extracts ranged from 5.45 to 226.89 mg gallic acid equivalent (GAE)/mL and 7.34 to 428.04 mg rutin equivalent (RE)/mL, respectively. S. cuneata extract exhibited the highest contents of total phenols and flavonoids, which were significantly higher than those of the other herbs extract (P < 0.05). The 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging rates of the extracts were ranged from 28.25% to 85.33%. The extracts from S. cuneata and E. prostrata showed the highest antioxidant activity as compared to other extracts (P < 0.05). Extract from the walnut green husk possessed the best antibacterial properties against S. aureus and S. enteritidis with inhibition zone diameters of 13.05 and 8.59 mm, respectively, which were significantly greater than those of the other herbal extracts (P < 0.05). For E. coli, S. barbata extract displayed the highest antibacterial activity of with a diameter of inhibition zone of 9.83 mm. Based on the findings of the current study, it is concluded that the extracts from S. cuneata and E. prostrata exhibited favorable antioxidant capacity and the extracts derived from the walnut green husk and S. barbata have the potential to serve as alternatives for antibiotics. Keywords: Herbs, phenols, flavonoids, antioxidant activity, antibacterial properties