The diversity of medicinal plants in Vietnam is a rich source to develop novel health products. In this study, the antioxidant and antimicrobial activities of ethanolic extracts of Pluchea indica, Drynaria fortunei, Stephania glabra, lemongrass (Cymbopogon citratus) and lime (Citrus aurantifolia) mixture, and ginger (Zingiber officinale) and kumquat (Citrus japonica) mixture, were evaluated. | VNU Journal of Science Natural Sciences and Technology Vol. 37 No. 3 2021 50-56 Original Article Initial Evaluation of Antioxidant and Antibacterial Activities of Several Medicinal Plant Extracts Collected in Vietnam Le Tuan Anh1 Pham Thi Thanh Hang1 Nguyen Thi Bich Loan1 2 Le Quynh Mai1 1 VNU University of Science 334 Nguyen Trai Thanh Xuan Hanoi Vietnam 2 Laboratory of Therapeutical Chemistry and Pharmacognosy Université de Mons Mons Belgium Received 11 August 2021 Revised 23 August 2021 Accepted 31 August 2021 Abstract The diversity of medicinal plants in Vietnam is a rich source to develop novel health products. In this study the antioxidant and antimicrobial activities of ethanolic extracts of Pluchea indica Drynaria fortunei Stephania glabra lemongrass Cymbopogon citratus and lime Citrus aurantifolia mixture and ginger Zingiber officinale and kumquat Citrus japonica mixture were evaluated. The extract of ginger and kumquat mixture exhibited the highest free radical scavenging activity 85 followed by P. indica and S. glabra 60 and 53 respectively at the concentration of mg ml. Moreover the agar well diffusion assay revealed that the extract of S. glabra and the extract of ginger and kumquat mixture were effective in inhibition against Bacillus cereus Staphylococcus aureus and Vibrio parahaemolyticus. Especially the extract of S. glabra at the concentration of 100 mg ml showed the highest inhibition zone diameter 13 mm against B. cereus which was significantly larger than that of Ceftriaxone 5 g ml and other extracts. Keywords Medicinal plant antioxidant free radical scavenging antibacterial activity. 1. Introduction resistance. For example Staphylococcus aureus is resistant to many common antibiotics Plants contain a wide range of natural including penicillin methicillin and oxacillin bioactive compounds that are good for human 3 . In addition foodborne pathogens Bacillus health due to their antioxidant and antibacterial cereus and Vibrio .