A study on anti-microbial activity of the Extracts from Oenothera rosea

Objective The anti-bacterial and anti-fungal activity of the four fractions extracted from the aboveground of Oenothera rosea were studied for its exploitation. Methods The inhibition zone method and hypha growth-inhibiting method were used to investigate the inhibition effects of the petroleum ether fraction,chloroform fraction,ethyl acetate fraction and water fraction in the alcoholic extracts from the aboveground of Oenothera rosea on the five types of bacteria Escherichia coli,Bacillus subtilis,Proteus vulgaris,Staphylococcus aureus and Pseudomonas aeruginosa and the five types of popular plant pathogenic fungi Botryosphaeria rhodina,Fusarium oxysporum,Fusarium solani,Corynespora cassiicola and Colletotrichum acutatum. Results The results showed that there was no obvious inhibition of the petroleum ether extract and chloroform extract to the 5 species bacteria. There was inhibition of the ethyl acetate extract and water extract to the 5 species bacteria. The minimal inhibitory for the ethyl acetate extract water extract to the 5 species bacteria were 8,4,2,0. 5,2mg /mL and 10,4,2,1,4mg /mL respectively. For the five types of plant pathogenic fungi,different extracts had different degrees of anti-fungal activity. The ethyl acetate extract had the best inhibition effect to Botryosphaeria rhodina and Corynespora cassiicola with the EC50 values of 2. 20 and 3. 73 mg /mL respectively. The chloroform extract had the best inhibition to Fusarium oxysporum,Fusarium solani and Colletotrichum acutatum with the EC50 values of 5. 33,0. 9 and 9. 19 mg /mL respectively. Conclusion The ethyl acetate extract and water extract from the aboveground of Oenothera rosea exhibited significant anti-bacterial activity and the four fractions extracted exhibited significant anti-fungal activity.