Black Tea Improves Resistance Of Caenorhabditis Ele G Ans Under Radiation Stress Of Ultraviolet

As one of the most consumed drinks in the world,Tea possesses many benifical effects on human health.The protective effects of black tea extract and green tea extract on the Caenorhabditis elegans under UV stress were studied in this paper.The results were showed as follows:To control the variables in our study,fresh tea leaves from a single specialty cultivar grown under the same conditions were harvested with the same plucking standard,and processed by the same hand as a green and black tea.Also,the tea aqueous extracts were prepared according to the same way.The black tea and green tea water extracts at the range of 100-1000 mg/L,did not prolong or shorten the lifespan of C.elegans under normal condition.C.elegans has been cultivated with black tea and green tea extract in 48h,then stress with ultraviolet radiation of 2000 J/M~2,.The tea extract significantly increased the average life span of the C.elegans.Compared with the control group,C.elegans'average life have increased by 9.7%,7.2%,2.5%,4.4%with black tea the under the concentration of 50 mg/L,100 mg/L and 200 mg/L and 500mg/L.C.elegans'average life have increased by 9.9%,7%,5.4%,5.4%with green tea under the concentration of50 mg/L,100 mg/L and 200 mg/L and 500mg/L..The results showed that the tea extract could increase the average life span of the C.elegans under UV stress,and the effect was better in the low concentration.Under the condition of ultraviolet radiation stress,compared with the control group,C.elegans of 50 mg/L black tea extract treatment group body length increased by 18.7%,Time of body strokes assay increase 29.7%.C.elegans of 50 mg/L green tea water extract treatment group body length increased 10.6%,Time of body strokes assay increase 24.4%.It shows that black tea extract and green tea extract can improve the physical condition of C.elegans.Sequencing results showed that black tea water extract can improve the expression of DAF-9,MSP,which related with reproduction,regulate the expression of DPY gene family related synthetic cuticle collagen.Black tea water extract can also up-regulate the expression of genes related to stress pathways,such as sek-1,sodh-2.