Initial Study Of Anti-inflammatory Effects Of Hemp Seed Phenylpropionamides And Their Characteristics Of Absorption And Metabolism

Recent studies have reported that hemp seed(the dry mature seeds of Cannabis sativa L.)is rich in fatty acids and their esters,proteins,fibres,cannabinoids,phenylpropionamides,steroids and terpenoids,flavonoids and their glycosides,alkaloids,and so on.Modern pharmacological studies have showed that hemp seed extracts have strong anti-inflammatoty,anti-oxidant and antihypertensive effects,especially potential effects on aging and Alzheimer's disease(AD).In previous work,we found that total phenylpropionamides extracts from hemp seed improved learning and memory damage induced by lipopolysaccharide(LPS)in neuroinflammation mice model.We established neuroinflammatory model using LPS-induced BV2 cells and screened anti-inflammatory activity of phenylpropionamides,further mechanism studies were carried out with active compounds.On the other hand,only few studies on metabolism of phenylpropionamides were reported,even though it could contribute to the pharmacological effect of hemp seed.Hence,we explored the metabolic characteristics of two representative phenylpropionamides rich in hemp seed preliminarily.Anti-inflammatory screening test using LPS-induced BV2 cells found that most hemp seed phenylpropionamides,especially coumaroylaminobutanol glucopyranoside(CLG)were active.Further mechanism studies have found that CLG could reduce the expression and mRNA levels of inflammatory factors,decrease ROS production,inhibit inflammatory reaction and oxidative stress response in LPS-induced BV2 cells by AMPK-mediated TLR4/MyD88/NF-?B and Nrf-2/HO-1 signaling pathways.These results suggested the potential effects of CLG on neuroinflammation-related diseases.The metabolic characteristics of hemp seed phenylpropionamides,represented by Cannabisin A(CA)and N-trans-caffeoyltyramine(NC),were initially studied using various in vitro drug metabolism model.(1)In vitro simulated gastrointestinal digestion studies have found that the bioavailabilities of CA and NC were low;(2)Transportation studies were successful established in caco-2 cell monolayer model(the integrity of monolayer were verified by the morphological changes,transepithelial electrical resisitance,the leakage of fluorescein sodium and the activity of alkaline phosphatase),our results showed CA and NC had poor absorbility and exocytosis participated in the transport process;(3)The pharmacokinetic parameters were detected by in vitro liver microsomal incubation:t1/2(CA)=1.52 min,CL=0.76 mL·min-1·mg-1;t1/2(NC)=2.35 min,CL=1.175 mL·min-1·mg-1,indicating that both of CA and NC were not stable in microsomes incubation medium,the metabolic rate of CA is faster than NC;(4)In vitro intestinal microflora incubation found that CA and NC were not stable in rat intestinal flora incubation medium,NC were almost undetectable after 24 h while CA decreased 87%.In summary,represented by CA and NC,phenylpropionamides have low oral bioavailability and are mainly metabolized in intestinal tract.Based on the important role of intestinal microflora,further studies need to be carried out to clarify the in vivo material basis of pharmacological effects of hemp seed.