Gastroprotective and safety effects of WIN-34B, a novel treatment for osteoarthritis, compared to NSAIDs.

Abstract Ethnopharmacological relevance The dried flowers of Lonicera japonica , also known as Japanese honeysuckle, and the dried root of Anemarrhena asphodeloides , the component herbs of WIN-34B, are traditionally used in Eastern medicine to treat various inflammatory conditions including arthritis. Objective To study the acute and chronic toxicities of WIN-34B and to compare its effects on gastric mucosa with those of diclofenac, a widely used NSAID, and celecoxib, a selective COX-2 inhibitor. Materials and methods To investigate acute toxicity, we orally administered a single dose of 5000 mg/kg WIN-34B to rats. To investigate chronic toxicity, we orally administered 500, 1000 or 2000 mg/kg WIN-34B to rats daily for 13 weeks. To assess its effects on gastric mucosa, rats received either a single dose or repeated doses of WIN-34B (400, 1000, or 2000 mg/kg), diclofenac (10, 40, or 80 mg/kg), celecoxib (100 or 1000 mg/kg), or vehicle, after which samples of gastric mucosa were assessed grossly and histologically. We also measured tissue activity of myeloperoxidase and synthesis of eicosanoids, including prostaglandin E 2 (PGE 2 ) and leukotriene B 4 (LTB 4 ). To further assess its effects, we administered WIN-34B to rats either intraperitoneally or orally, measured gastric injury scores using a rat model of diclofenac-induced gastric injury, and measured eicosanoid synthesis. Results WIN-34B showed no signs of acute or chronic toxicity in terms of general behavior, gross appearance of the internal organs, blood chemistry, or mortality. WIN-34B did not cause significant gastric mucosal damage after single or repeated doses. In contrast, diclofenac and celecoxib both caused gastric damage. In terms of eicosanoid synthesis, WIN-34B significantly suppressed LTB 4 synthesis while both diclofenac and celecoxib increased LTB 4 synthesis. WIN-34B slightly reduced PGE 2 production, while both diclofenac and celecoxib significantly reduced PGE 2 production. In a rat model of diclofenac-induced gastric injury, WIN-34B significantly suppressed LTB 4 synthesis and restored PGE 2 release. Conclusions These results demonstrate that WIN-34B did not cause acute or chronic toxicity in male or female rats. In addition, WIN-34B did not cause significant gastric mucosal damage, instead appearing to protect the mucosa from diclofenac-induced gastric damage through the regulation of PGE 2 and LTB 4 .