Studies On Digestion,Absorption,Metabolism And Anti-aging Activities Of Freeze-dried Mulberry Leaf Powder And Ethanol Extract In Vitro And In Vivo

Purpose:Senescence is an unavoidable biological process.It is a degenerative change of tissue and organ function that occurs with the aging of organisms.At present,the problem of population aging is becoming more and more serious,which has caused great burden to society and individuals.At present,the theory of free radicals has been widely accepted and recognized in the research on the mechanism of aging,and many natural plants are considered as the source of free radical scavenging materials.As a plant resource with thousands of years of planting history,mulberry leaves have the functions of anti-oxidation,anti-aging,immune regulation and lowering blood sugar.Phenolic compounds in mulberry leaves are one of the main substances that play these biological activities.However,the traditional extraction process will cause a large amount of loss of phenolic compounds and other nutrients,so the use of whole mulberry leaves as raw materials for production and processing may be more valuable than their extracts.The purpose of this study was to explore the in vitro digestion,fermentation and metabolism of phenolic compounds of freeze-dried mulberry leaf powder and ethanol extract of mulberry leaf,and to explore the differences in their anti-aging activities,so as to provide experimental data for the development of whole mulberry leaf anti-aging functional food.Method:This study will explore the changes of phenolic compounds in freeze-dried mulberry leaf powder and its ethanol extract in vitro during simulated gastrointestinal digestion and intestinal microbial fermentation.UPLC-Q-Exactive Focus technique was used to identify the active components of phenolic compounds in freeze-dried mulberry leaf powder and its ethanol extract,and the anti-aging network pharmacology was studied based on the active components in blood.A mouse model of accelerated aging was established using D-galactose,and the anti-aging function of freeze-dried mulberry leaf powder and its ethanol extract was studied.Results:1.Through in vitro digestion simulation and intestinal microbial fermentation model,it was found that the content of phenolic compounds in freeze-dried mulberry leaf powder and its ethanol extract decreased gradually during gastrointestinal digestion;Compared with ethanol extract of mulberry leaves,freeze-dried mulberry leaf powder can produce more phenols after gastrointestinal digestion,and phenols can produce abundant fermentation products under the action of intestinal microorganisms.2.The metabolites of phenols in freeze-dried mulberry leaf powder and its ethanol extract were preliminarily identified by UPLC-Q-Exactive-MS /MS technology.A total of 18 metabolites were identified,which were mainly the Ⅰ andⅡ reaction products of phenols.Including reduction,decarboxylation,hydrolysis,hydroxylation,deoxygenation and deglycosylation,etc.Ⅰ reaction,Ⅱ reaction such as methylation,gluconaldehyde and sulfation;The release of metabolites from freeze-dried mulberry leaf powder lasted longer than ethanol extract.3.Animal experimental studies showed that freeze-dried mulberry leaf powder and its ethanol extract had certain anti-aging effects on aging mice,which could improve the weight loss of aging mice to varying degrees,alleviate liver pathological injury,improve blood antioxidant capacity,improve learning memory and exercise ability.The comprehensive anti-aging effect of freeze-dried mulberry leaf powder was better than that of ethanol extract of mulberry leaf.4.Animal experiments showed that freeze-dried mulberry leaf powder and its ethanol extract had certain improvement effect on intestinal flora of aging mice,which could increase the overall diversity and richness of intestinal flora of aging mice,and improve the relative abundance of intestinal dominant flora such as Bacteroides.The improvement effect of freeze-dried mulberry leaf powder on intestinal flora was better than that of mulberry leaf ethanol extract.5.The visual network system of "functional component-target-pathway" was constructed by network pharmacology method,and the expression of Kegg-enriched related pathway proteins was verified by experiments.The results showed that lyze-dried mulberry leaf powder and its ethanol extract may regulate the phosphorylation level of some proteins by regulating MAPK signal,so as to achieve the effect of anti-aging.Conclusion:In this paper,the differences and similarities of phenolic compounds in freeze-dried mulberry leaf powder and its ethanol extract in vitro digestion,intestinal microbial fermentation and in vivo metabolism of mice were compared.It was found that freeze-dried mulberry leaf powder could produce more phenolic compounds into colon fermentation process after digestion in vitro,and the release of metabolites in vivo lasted longer.The freeze-dried mulberry leaf powder and its ethanol extract have certain anti-aging effects.The anti-aging effect of freeze-dried mulberry leaf powder is better than that of mulberry leaf ethanol extract in improving blood antioxidant capacity and regulating intestinal flora.