Transformation of berberine to its demethylated metabolites by the CYP51 enzyme in the gut microbiota

Berberine(BBR)is an isoquinoline alkaloid extracted from Coptis chinensis that improves diabetes,hyperlipidemia and inflammation.Due to the low oral bioavailability of BBR,its mechanism of action is closely related to the gut microbiota.This study focused on the CYP51 enzyme of intestinal bacteria to elucidate a new mechanism of BBR transformation by demethylation in the gut microbiota through multiple analytical techniques.First,the docking of BBR and CYP51 was performed;then,the pharmacokinetics of BBR was determined in ICR mice in vivo,and the metabolism of BBR in the liver,kidney,gut microbiota and single bacterial strains was examined in vitro.Moreover,16S rRNA analysis of ICR mouse feces indicated the relationship between BBR and the gut microbiota.Finally,recombinant E.coli containing cyp51 gene was constructed and the CYP51 enzyme lysate was induced to express.The metabolic characteristics of BBR were analyzed in the CYP51 enzyme lysate system.The results showed that CYP51 in the gut microbiota could bind stably with BBR,and the addition of voriconazole(a specific inhibitor of CYP51)slowed down the metabolism of BBR,which prevented the production of the demethylated metabolites thalifendine and berberrubine.This study demonstrated that CYP51 promoted the demethylation of BBR and enhanced its intestinal absorption,providing a new method for studying the metabolic transformation mechanism of isoquinoline alkaloids in vivo.

Raman Imaging Helps Assess and Study the Biocompatibility of Biological Materials

Raman spectroscopy and imaging are known to be valuable tools for the analysis of materials,from organic compounds to inorganic material.Raman Imaging technology provides a fast,non-destructive,in-vivo tool to help study the formation or deformation of the biological tissues or cells.Meanwhile。

Multi-Omics Analysis Provides Insight into the Possible Molecular Mechanism of Hay Fever Based on Gut Microbiota

Due to the worldwide epidemic of allergic disease and a cure nowhere in sight,there is a crucial need to explore its pathophysiological mechanisms.As allergic disease has been associated with gut dysbiosis,we searched for a possible mechanism from the perspective of the molecular interface between host and microbiota with concurrent metabolomics and microbiome composition analysis.Sprague-Dawley rats were injected with Artemisia pollen extract to stimulate a hyper reaction to pollen.This hyper reaction decreased the circulation of valine,isoleucine,aspartate,glutamate,glutamine,indole-propionate(IPA),and myo-inositol,and reduced short-chain fatty acids(SCFAs)in feces.Several beneficial genera belonging to Ruminococcaceae,Lachnospiraceae,and Clostridiales declined in the model group,whereas Helicobacter and Akkermansia were only expressed in the model group.Furthermore,the expression of intestinal claudin-3 and liver fatty acid binding protein was downregulated in the model group and associated with metabolic changes and bacteria.Our results suggest that alterations in amino acids as well as their derivatives(especially valine,and IPA which is the reductive product of tryptophan),SCFAs,and the gut microbiome(specifically Akkermansia and Helicobacter)may disrupt the intestinal barrier function by inhibiting the expression of claudin proteins and affecting the mucus layer,which further results in hay fever.

Berberine treats atherosclerosis via a vitamine-like effect downregulating Choline-TMA-TMAO production pathway in gut microbiota

Trimethylamine-N-oxide(TMAO)derived from the gut microbiota is an atherogenic metabolite.This study investigates whether or not berberine(BBR)could reduce TMAO production in the gut microbiota and treat atherosclerosis.Effects of BBR on TMAO production in the gut microbiota,as well as on plaque development in atherosclerosis were investigated in the culture of animal intestinal bacterial,HFD-fed animals and atherosclerotic patients,respectively.We found that oral BBR in animals lowers TMAO biosynthesis in intestine through interacting with the enzyme/co-enzyme of choline-trimethylamine lyase(CutC)and flavincontaining monooxygenase(FMO)in the gut microbiota.This action was performed by BBR’s metabolite dihydroberberine(a reductive BBR by nitroreductase in the gut microbiota),via a vitamine-like effect down-regulating Choline-TMA-TMAO production pathway.Oral BBR decreased TMAO production in animal intestine,lowered blood TMAO and interrupted plaque formation in blood vessels in the HFD-fed hamsters.Moreover,21 patients with atherosclerosis exhibited the average decrease of plaque score by 3.2%after oral BBR(0.5 g,bid)for 4 months(^(*)P<0.05,n=21);whereas the plaque score in patients treated with rosuvastatin plus aspirin,or clopidogrel sulfate or ticagrelor(4 months,n=12)increased by 1.9%.TMA and TMAO in patients decreased by 38 and 29%in faeces(^(*)P<0.05;^(*)P<0.05),and 37 and 35%in plasma(^(***)P<0.001;^(*)P<0.05),after 4 months on BBR.BBR might treat atherosclerotic plaque at least partially through decreasing TMAO in a mode of action similar to that of vitamins.

Oral berberine improves brain dopa/dopamine levels to ameliorate Parkinson’s disease by regulating gut microbiota

The phenylalanine-tyrosine-dopa-dopamine pathway provides dopamine to the brain.Iin this process,tyrosine hydroxylase(TH)isthe rate-limiting enzyme that hydroxylates tyrosine and generates levodopa(L-dopa)with tetranydrobiopterin(BH_(4))as a coenzyme.Here,we show that oral berberine(BBR)might supply H^(·) through dihydroberberine(reduced BBR produced by bacterial nitroreductase)and promote the production of BHl from dihydrobiopterin;the increased BH,enhances TH activity,which accelerates the production of L-dopa by the gut bacteria.Oral BBR acts in a way similar to vitamins.The L-dopa produced by theintestinal bacteria enters the brain through the circulation and is transformed to dopamine.To verify the gut-brain dialog activatedby BBR's effect,Enterococcus foecalis or Enterococcus faecium was transplanted into Parkinson's disease(PD)mice.The bacteriasignificantly increased brain dopamine and ameliorated PD manifestation in mice;additionally,combination of BBR with bacteriashowed better therapeutic effect than that with bacteria alone.Moreover,2,4,6-trimethy-pyranylium tetrafluoroborate(TMP-TFB)-derivatized matrix-assisted laser desorption mass spectrometry(MALDI-MS)imaging of dopamine identihed elevated striataldopamine levels in mouse brains with oral Enterococcus,and BBR strengthened the imaging intensity of brain dopamine.Theseresults demonstrated that BBR was an agonist of TH in Enterococcus and could lead to the production of L-dopa in the gut.Furthermore,a study of 28 patients with hyperlipidemia conhrmed that oral BBR increased bloodfecal L-dopa by the intestinalbacteria.Hence,BBR might improve the brain function by upregulating the biosynthesis of-dopa in the gut microbiota through avitamin-like effect.