Extraction Of Non-volatile Bioactive Compounds From Cinnamomum Cassia Leaf And Their Biological Activities

Cinnamomum cassia,also known as Chinese cinnamon,is an evergreen tree native to southern China.The bark of C.cassia has been widely developed as spice or traditional Chinese medicine;whereas the leaves of C.cassia are mainly used to produce essential oil by steam distillation with the oil yields between 0.8%and 1.2%.After extraction of oil,a large amount of C.cassia leaf residues(CcLRs)are usually discarded or utilized as fuel,resulting in the waste of natural resources or environmental pollution.Actually,CcLRs may be a great source of bioactive compounds with potential utilization value.However,few studies have been done on the active components and bioactivities of CcLRs after extraction of oil.Therefore,in this study,the bioactive compounds from CcLRs were extracted and their bioactivities including the antioxidant,anti-aging activities and the effect on gut microbiota in aging mice were also studied.The main research contents and results of this study are as follows:(1)Extraction of bioactive compounds from CcLRs and bioactivities evaluationFirst,the bioactivities of ethanol extract,ethyl acetate extract and water extract of CcLRs were investigated and the results showed that all extracts exhibited great antioxidant activity but poor antimicrobial and hypoglycemic activities,of which,the ethanol extract possessed the highest antioxidant activity.Their great antioxidant properties may be attributed to the presence of polyphenols in extracts.Then,the extraction conditions of ethanol extract of CcLRs were optimized and the results showed that the optimum extraction conditions were ethanol concentration of 80%,extraction temperature of 60? and liquid-solid ratio of 16:1 mL/g,under which,the extraction yield of extract was 11.60%of the original CcLRs sample,TPC in the extract was 233.67±2.13 mg GAE/g extract,TFC in the extract was 529.95±9.12 mg RE/g extract,and DPPH scavenging rate of extract was 80.65%at the concentration of 120 ?g/mL.Afterwards,UHPLC-ESI-Orbitrap-MS was used to analyze the main chemical components of ethanol extract and 14 chemical components(such as quercitrin,carnosol,iristectorigenin B,eupatilin etc.)were identified.Finally,the LPS-stimulated macrophage RAW 264.7 cell study demonstrated that ethanol extract also presented great anti-inflammatory activity,and at the concentration of 200 ?g/mL,its inhibitory rate on NO production was 76.67%.(2)Study on anti-aging activity of CcLRs extractD-galactose-induced aging mouse model was carried out to study the anti-aging activity of ethonal extract of CcLRs(abbreviated as extact).The results indicated that extract presented great anti-aging property as follows:(a)the brain index,liver index and lung index of aging model mice were restored to normal level with high dose of extract;(b)the antioxidant defense ability of mice was enhanced by increasing the levels of T-SOD,GSH-Px and T-AOC in serum of aging mice,decreasing the MDA content in serum,as well as the decrease in inflammatory markers TNF-? and IL-6 in serum,and the increase in IL-10 in serum;(c)extract treatments could increase ChAT,T-SOD,GSH-Px and T-AOC levels,decrease AchE,MDA,iNOS and NO levels in brain tissues of aging mice,upregulate the protein expression of SOD and GSH,and downregulate the protein expression of iNOS and TNF-? in brain tissues;(d)extract treatments could also relileve liver damage,by increasing T-SOD,GSH-Px and T-AOC levels in liver tissues of aging mice,decreasing MDA,iNOS and NO levels in liver tissues,upregulating the protein expression of SOD and GSH,and downregulating the protein expression of iNOS and TNF-? in liver tissues.(3)Effect of extract on gut microbiota in aging miceHigh-throughput sequencing was used to study the gut microbiota of mice.The results showed that oral administration of extract can modulate gut microbiota of aging mice.It can increase the richness of communities of the gut microbiota of aging mice,shift the gut microbiota composition of the treatment group to be substantially like that of the control group,improve the ratio of Firmicutes to Bacteroidetes in the gut of aging mice,and promote the abundance of beneficial bacteria.In addition,the morphology of colon tissues of mice was determined by H&E staining,indicating that the extract could protect against colon damage.This study provides the comprehensive utilization value of CcLRs and form a basis for the potential application of CcLRs in the field of functional foods.