Investigation of the anti-inflammatory and analgesic activities of promising pyrazole derivative.

The development of new COX-2 inhibitors with analgesic and anti-inflammatory efficacy as well as minimal gastrointestinal, renal and cardiovascular toxicity, is of vital importance to patients suffering from chronic course pain and inflammatory conditions. This study aims at evaluating the therapeutic activity and adverse drug reactions associated with the use of the newly synthesized pyrazole derivative, compound AD732, E-4-[3-(4-methylphenyl)-5-hydroxyliminomethyl-1H-pyrazol-1-yl]benzenesulfonamide, as compared to indomethacin and celecoxib as standard agents. Anti-inflammatory activity was assessed using carrageenan-induced rat paw edema and cotton pellet granuloma tests; formalin-induced hyperalgesia and hot plate tests were done to study analgesic activity. In vitro tests to determine COX-1/COX-2 selectivity and assessment of renal and gastric toxicity upon acute exposure to AD732 were also conducted. Compound AD732 exhibited promising results; higher anti-inflammatory and analgesic effects compared to standard agents, coupled with the absence of ulcerogenic effects and minimal detrimental effects on renal function. Additionally, compound AD732 was a less potent inhibitor of COX-2 in vitro than celecoxib, which may indicate lower potential cardiovascular toxicity. It may be concluded that compound AD732 appears to be a safer and more effective molecule with promising potential for the management of pain and inflammation.

Probiotic Bifidobacterium bifidum G9-1 attenuates 5-fluorouracil-induced intestinal mucositis in mice via suppression of dysbiosis-related secondary inflammatory responses.

Bifidobacterium, a major component of the intestinal microbiota, has been clinically used for the treatment of diarrhoea and constipation. 5-Fluorouracil (5-FU), widely used for cancer chemotherapy, is known to frequently induce intestinal mucositis accompanied by severe diarrhoea. The present study examined the effect of Bifidobacterium bifidum G9-1 (BBG9-1) on 5-FU-induced intestinal mucositis in mice. Intestinal mucositis was induced by repeated administration of 5-FU for 6 days. BBG9-1 was administered orally once daily for 9 days, beginning 3 days before the onset of 5-FU treatment. Repeated administration of 5-FU caused severe intestinal mucositis, characterised by shortening of villi and destruction of crypts, accompanied by increases in intestinal myeloperoxidase activity and inflammatory cytokine expression, body weight loss, and diarrhoea on day 6. Daily administration of BBG9-1 significantly reduced the severity of intestinal mucositis and inflammatory responses and tended to attenuate clinical symptoms. In contrast, BBG9-1 failed to prevent apoptosis induction on day 1 after the first 5-FU administration. The structure of the intestinal microbiota, as analysed by weighted UniFrac distance, was largely altered by 5-FU treatment, but this change was mitigated by daily administration of BBG9-1. Moreover, 5-FU treatment decreased the abundance of Firmicutes and increased the abundance of Bacteroidetes, but these responses were also significantly inhibited by daily administration of BBG9-1. These results suggest that BBG9-1 has an ameliorative effect against 5-FU-induced intestinal mucositis through the attenuation of inflammatory responses via improve dysbiosis. BBG9-1 could be useful for the prevention of intestinal mucositis during cancer chemotherapy.

G protein-coupled receptor 35 contributes to mucosal repair in mice via migration of colonic epithelial cells.

G protein-coupled receptor 35 (GPR35), a receptor for lysophosphatidic acid, is highly expressed in the gastrointestinal tract. Recently, GPR35 has been implicated in the onset of inflammatory bowel disease (IBD), but its role in physiological and pathological processes in the colon remains undefined. In this study, we investigated the contribution of GPR35-mediated signalling to mucosal repair of colonic epithelium in IBD. GPR35 function was examined in a wound healing model, using young adult mouse colon epithelium (YAMC) cells, and in a dextran sulphate sodium (DSS)-induced mouse model of colitis. Cell proliferation, mRNA expression, extracellular signal-regulated kinase (ERK) activation, and protein localization were determined by MTT assay, quantitative RT-PCR, western blotting, and immunohistochemistry, respectively. GPR35 agonists (YE120, zaprinast, and pamoic acid) promoted wound repair in a concentration-dependent manner independently of cell proliferation, whereas a specific GPR35 antagonist CID2745687, forskolin, and pertussis toxin reversed the YE120-induced effect. YE120 increased the mRNA expression of fibronectin and its receptor integrin α5, and ERK1/2 phosphorylation, but these responses were attenuated by CID2745687 and forskolin. Furthermore, the severity of DSS-induced colitis was significantly reduced by daily injections of pamoic acid via upregulation of fibronectin and integrin α5 in the colonic epithelium. GPR35 signalling promotes mucosal repair by inducing fibronectin and integrin α5 expression, coupling to Gi protein, and activating ERK1/2 in colonic epithelial cells. These findings define GPR35 as a candidate therapeutic target in IBD.

Apoptosis, Dysbiosis and Expression of Inflammatory Cytokines are Sequential Events in the Development of 5-Fluorouracil-Induced Intestinal Mucositis in Mice.

The chemotherapeutic agent 5-fluorouracil (5-FU) causes intestinal mucositis with severe diarrhoea, but the pathogenesis is not fully understood. In this study, we investigated the pathogenic effects of 5-FU in mice, focusing on apoptosis, enterobacteria and inflammatory cytokines. Repeated administration of 5-FU caused severe intestinal mucositis on day 6, accompanied by diarrhoea and body-weight loss. TNF-α expression increased 1 day after exposure to the drug, and spiked a second time on day 4, at which point myeloperoxidase activity and IL-1ß expression also increased. Apoptotic cells were observed in intestinal crypts only on day 1. 5-FU also induced dysbiosis, notably decreasing the abundance of intestinal Firmicutes while increasing the abundance of Bacteroidetes and Verrucomicrobia. Twice-daily co-administration of oral antibiotics significantly reduced the severity of intestinal mucositis and dysbiosis, and blocked the increase in myeloperoxidase activity and cytokine expression on day 6, without affecting apoptosis and TNF-α up-regulation on day 1. In cultured colonic epithelial cells, exposure to 5-FU also up-regulated TNF-α expression. Collectively, the data suggest that crypt apoptosis, dysbiosis and expression of inflammatory cytokines are sequential events in the development of intestinal mucositis after exposure to 5-FU. In particular, 5-FU appears to directly induce apoptosis via TNF-α and to suppress intestinal cell proliferation, thereby resulting in degradation of the epithelial barrier, as well as in secondary inflammation mediated by inflammatory cytokines.