Antioxidant and Antimicrobial Potentials of Endophytic Fungi Residing in Cynanchum Chinense

Abstract

18 strains endophytic fungi were isolated from leaves and branches of Cynanchum chinense. The antioxidant and antibacterial activities of the broth of the 18 strains were studied by vitro methods. The antioxidant activities results showed that all tested strains have different degree of DPPH radical scavenging activities. At the concentration of 0.1mg/mL, 8 of 18 strains played a certain DPPH radical scavenging activities, with the scavenging rate more than 50%, of these, the extract of 1 strain played notable DPPH radical scavenging activity, with the scavenging rate of 84.5%. 15 strains showed a certain hydroxy radical scavenging abilities, but the scavenging activity was weak, with the max scavenging rates of 14.5% at the concentration of 0.8 mg/mL. The antibacterial activities results showed that 9 of 18 strains were active against the six test bacterium (Staphylococcus aureus, Bacillus licheniformis, Streptococcus uberi, Escherichia coli., Pseudomonas aeruginosa, and Klebsiella pneumoniae.), but none played strong inhibitory effect, with (the inhibition zone was greater than 20mm).