demethyleneberberine and Inflammation

Demethyleneberberine (DMB) is a natural product from traditional Chinese medicinal herb the rhizome of Coptis chinensis Franch., which has been reported to possess multiple pharmacological activities, especially anti-inflammation and immunoregulation. However, the potential mechanism of DMB in inflammation is still a mystery. In this study, a mouse model of ulcerative colitis (UC) was induced by Dextran sulfate sodium salt (DSS), and in vitro experiments were performed in RAW264.7 macrophages and the primary intestinal macrophages which obtained from Toll-Like receptor 4 (TLR4) and NOD-Like receptor protein 3 (NLRP3) knockout fetal mouse. Mitochondrial was increased by overexpression of peroxlsome proliferator-activated receptor-γ coactlvator-1α (PGC-1α) and exhausted by adding Ethidium Bromide (EtBr) in RAW264.7 to evaluate the function of mitochondria in the maturation of IL-1β. Additionally, the safety of DMB (50 mg/kg/d) in mice was assessed by orally administrating for 98 days. DMB siginificantly improved colon atrophy, colonic tissue mass score, neutrophil infiltration and histological damage, which was mainly attributed to the anti-inflammatory effect of DMB. Further in vitro analysis showed that DMB blocked the excessive mitochondrial biosynthesis and maintained the homeostasis of mitochondria in inflammatory response. Moreover, the maturation of IL-1β was suppressed by DMB in a mitochondria dependent manner. Crucially, DMB was a candidate agent for UC with free of toxicity and side effects. These findings demonstrated that DMB ameliorated inflammatory response by inhibiting TLR4-mitochondria signaling, and revealed the effectiveness and mechanism of DMB for alleviation of UC and provided an additional strategy for UC intervention.

Topics: Animals; Colitis, Ulcerative; Colon; Dextran Sulfate; Disease Models, Animal; Inflammation; Mice; Mice, Inbred C57BL; Mitochondria; NF-kappa B; Toll-Like Receptor 4

Rhizoma coptidis is a rhizome commonly used in traditional Chinese medicine. After oral administration of rhizoma coptidis extract, the plasma concentrations of its effective alkaloid constituents are so low that their systemic therapeutic actions cannot be explained. This study aimed to investigate the influence of lipopolysaccharide (LPS) on the pharmacokinetics of the rhizoma coptidis alkaloids. Pharmacokinetic experiments were performed with rats; both in vitro absorption and efflux experiments were carried out with everted rat gut sacs, whereas in vitro metabolism experiments were conducted with rat liver microsomes and intestinal S9 fractions. Mucosal changes were evaluated with light microscopy and transmission electron microscopy. The results showed that, in rat plasma, LPS pretreatment increased systemic alkaloid exposure. LPS pretreatment increased the in vitro absorption of the alkaloids and decreased their efflux. The efflux of vinblastine and rhodamine 123, P-glycoprotein substrates, also was decreased. The absorption of fluorescein isothiocyanate-labeled dextran (average molecular mass, 4 kDa), a gut paracellular permeability probe, was not influenced. Obvious damage was observed in the mucosa, but the tight junctions between epithelial cells remained intact. Intestinal, rather than hepatic, alkaloid metabolism was decreased. These findings indicated that LPS pretreatment increased systemic exposure to the alkaloids through enhancement of their absorption, which was related to decreased intestinal efflux and metabolism. The results add to the understanding of why rhizoma coptidis is active despite the low plasma concentrations of the rhizoma coptidis alkaloids measured in normal subjects and experimental animals.

Topics: Alkaloids; Animals; Anti-Inflammatory Agents, Non-Steroidal; Berberine; Biological Availability; Coptis chinensis; Drugs, Chinese Herbal; Female; Glucuronides; Ileum; Inflammation; Intestinal Absorption; Intestinal Mucosa; Lipopolysaccharides; Male; Microsomes, Liver; Random Allocation; Rats; Rats, Sprague-Dawley