Using Caenorhabditis Elegans To Study The Mechanism Of Longan Extract In Stress Response

With the rapid change of the living environment and the acceleration of the pace of life,human beings are subjected to more and more internal and external stimuli,and the types of external stimuli are more and more diversified.These stimuli can lead to the imbalance of the oxidative and antioxidant systems in the body,resulting in a stress response that affects the mental and physical health of the individual.Therefore,the prevention and treatment of stress have attracted more and more attention of researchers.Natural products are derived from the nature with abundant species,and have been regarded by researchers as the best drugs for treating various diseases due to their advantages of a wide range of sources,stable action and small drug resistance.Therefore,ultraviolet radiation was selected as the stress source in this paper to screen the natural products.dried Longan,a natural product with better anti-radiation effect,was further studied to explore the mechanism of its action in the ultraviolet stress response of nematodes.First of all,relevant data were consulted,nine kinds of traditional Chinese medicines with in vitro antioxidant effect were selected and their effects on the resistance of nematode to ultraviolet radiation were detected.The nine traditional Chinese medicines are cohosh,madder,lobelia,Xu Changqing,Coastal Glehnia Root,Morinda officinalis,Gordon euryale seed,longan,red peony root..After comparison,It was found that 40 mg/m L dried longan water extract could prolong the life of nematodes by 41.13% under ultraviolet radiation.Secondly,it was found that dried longan water extract could not only prolong the lifespan of nematodes under UV radiation,but also improve the ability of nematodes to resist Pseudomonas aeruginosa infection,hydrogen peroxide oxidation and heat stress.In addition,the oviposition,life span and movement of the nematodes were used as health indicators to test whether the water extract of dried longan had adverse effects on the health of nematodes.The results showed that the water extract of dried longan had no toxic effects on the health of nematodes.This study further explored the reason why dried longan water extract could improve the UV radiation resistance of nematodes,and found that dried longan water extract could reduce the ROS content in nematodes.Compared with the control group,the content of ROS in nematodes in the experimental group of 40 mg/m L dried longan water extract decreased by 25.4%.At the same time,the activity and expression of SOD in C.elegans were also increased,indicating that the water extract of dried longan could reduce the imbalance of superoxide and antioxidant in C.elegans after UV stress.UV radiation resistance experiments were carried out on insulin signaling pathpath-related mutant nematode strains CF1588 and CF1308,and it was found that the life of mutant nematode strains in the medication administration group was not prolonged after UV irradiation,which indicated that the effect of dried longan water extract may be related to the insulin signaling pathway.We observed the translocation of DAF-16,a transcription factor in insulin signaling pathway,and found that dried longan water extract could promote the translocation of DAF-16 in insulin signaling pathway.Meanwhile,we observed the expression level of sod-3,the downstream target gene of daf-16,and found that the expression level of sod-3 was increased.The downstream genes of insulin signaling pathway daf-16、hsp-16.1、hsp-16.2、sod-3、hsf-12.6、and hsp-16.49 were selected for real-time quantitative PCR,and it was found that dried longan water extract could promote the expression of its downstream genes daf-16、hsp-16.1,hsp-16.2,sod-3 and hsf-12.6.At the end of the paper,the effect of fresh longan was studied.It was found that both fresh longan water extract and fresh longan juice could improve the ability of nematode to UV irradiation,but less effective than dry longan water extract.We extracted longan polysaccharides and found that it was not longan polysaccharides that played an anti-UV irradiation role.Comparing the differences of polyphenols content in the three extracts,it was found that the content of polyphenols in the water extract of dried longan was higher than that of the other two extracts,which indicated that polyphenols play a role in the anti-stress effect of longan.In summary,nine natural products were screened for UV radiation resistance by using nematode model,and the anti-stress effect and the mechanism of UV radiation resistance of dried longan water extracts were studied.The new function of longan water extract was found,which provides theoretical basis for the research and development of related drugs,and has certain market prospect and social significance.