Study On Lipid-lowering Effect Of Anthocyanin Extracts From Color Potato

Obesity is a global public health problem,the prevalence rate increases year by year,but also causes a variety of diseases,so the intervention of obesity has become a serious problem facing the world.Pancreatic lipase is one of the important target enzymes in the treatment of obesity.Although slimming drugs such as orlistat are effective,they may produce certain side effects,which limits its use in special populations.Therefore,it has become an important research trend and approach to intervene in obesity to find safe and effective active ingredients from natural products.Color potato anthocyanin is a kind of natural pigment,which has antioxidant,blood pressure lowering,antiviral,anti-cancer,improve vision,prevent cardiovascular disease and other effects.In recent years,people’s health consciousness is gradually enhanced,and the new products developed with colored potato as raw materials are increasingly concerned by people.Therefore,in this paper,four new color potato varieties provided by the College of Agriculture of Southwest University were selected as the research objects.The anthocyanin components were identified by UPLC-QTOF-MS,and the anthocyanin content,antioxidant activity,stability and their effects on pancreatic lipase activity were studied.The lipid-lowering effect and possible mechanism of action of anthocyanin extracts from color potato were discussed,which provided theoretical basis and experimental basis for developing health food with color potato anthocyanin as functional ingredient.The main research results are as follows:（1）Among the four new color potato varieties,Jinyun Potato 5 had the highest anthocyanin content and the strongest antioxidant activity.A total of 11 anthocyanins were identified by UPLC-QTOF-MS in four new varieties of potato.The were Petunidin-3-O-caffeoylrutinoside-5-O-glucoside,Delphinidin-3-O-p-coumaroylrutinoside-5-O-glucoside,Cyanidin-3-O-p-coumaroyl-rutinoside-5-O-glucoside,Petunidin-3-O-rutinoside-5-O-glucoside,Petunidin-3-O-cis-coumaroylrutinoside,Petunidin-3-O-p-coumaroylrutinoside-5-O-glucoside,Petunidin-3-O-feruloylrutinoside-5-O-glucoside,Pelargonium-3-O-p-coumaroylrutinoside-5-O-glucoside,Paeoniflorin-3-p-coumaroylrutinoside-5-O-glucoside,Malvain-3-O-p-coumaroylrutinoside-5-O-glucoside,Malvain-3-O-feruloylrutinoside-5-O-glucoside.The most important anthocyanins of Jinyun Potato 5 and 11AO30-1 were Petunidin,while the most important anthocyanins of Jinyun Potato 7 and 15AO47-2 were Pelargonium,followed by Paeoniflorin.（2）The anthocyanin of color potato can inhibit the activity of pancreatic lipase.With the increase of anthocyanin concentration,the UV absorption of pancreatic lipase gradually increased,and the maximum absorption wavelength also showed obvious red shift.Meanwhile,the color potato anthocyanins also changed the internal fluorescence microenvironment of pancreatic lipase,resulting in static quenching.It was inferred that the molecular interaction between Jinyun Potato 5,11AO30-1,15AO47-2 and pancreatic lipase was mainly hydrophobic,and the molecular interaction between Jinyun potato 7and pancreatic lipase was mainly hydrogen bond and van der Waals force.The stability of anthocyanins decreased with the increase of light time and temperature.Anthocyanins are more stable in acidic medium,but less stable in alkaline condition.The effects of Na⁺,Mg²⁺,K⁺and Ca²⁺on the stability of anthocyanins were not obvious,Al³⁺could change the color of anthocyanin solution,while Fe³⁺had a greater destructive effect on the stability of anthocyanins.The anthocyanins were relatively stable in simulated stomach environment and rapidly degraded in simulated intestine environment.Jinyun Potato 5was less affected by the above environmental factors and more stable than anthocyanins.（3）Color potato anthocyanin extract can significantly reduce the Reactive Oxygen Species（ROS）level and Triglyceride（TG）content in a dose-dependent manner,and the effect of high concentration group is better.The lifespan of C.elegans decreased under heat stress and oxidative stress,and the anthocyanins of C.elegans could enhance the stress resistance of C.elegans.The results of oil red O staining showed that anthocyanin extract of color potato could effectively improve lipid accumulation in high fat C.elegans.Anthocyanin extracts of color potato can enhance antioxidant activity by increasing Superoxide Dismutase（SOD）and Catalase（CAT）content in high fat C.elegans,so as to maintain the balance of lipid metabolism.Based on the expression of lipid metabolism-related genes,it is speculated that the lipid-lowering effect of anthocyanin extracts from colored potato on C.elegans is mainly through 5-hydroxytryptamine signaling pathway,IIS signaling pathway and mdt-15/sbp-1 signaling pathway.