title: Phytochemical composition and antinociceptive activity of Bauhinia glauca subsp. hupehana in rats.
abstract: In traditional medicine, Bauhinia glauca subsp. hupehana has long been used as an analgesic agent in China. The aim of this study was to evaluate the antinociceptive activity of the ethanol extract of the aerial parts of B. glauca subsp. hupehana (BHE) in rats and its chemical fingerprint. The antinociceptive activity of BHE was assessed in mice using chemically and heat-induced pain models, such as the acetic acid-induced writhing, hot plate, tail-flick and glutamate tests. Naltrexone hydrochloride, a non-selective opioid receptor antagonist, was utilized to determine the involvement of the opioid system. In addition to this, the involvements of the cGMP and ATP-sensitive K+ channel pathways were also detected using methylene blue and glibenclamide. The oral administration of BHE (at doses of 50, 100 and 200 mg/kg) produced significant and dose-related inhibitions in both the chemically and heat-induced pain models. Interestingly, in the abdominal constriction test, when the dose of BHE was increased to 800 mg/kg (p.o., n = 10), the inhibition rate was 100%. The antinociceptive mechanism may involve the cGMP pathway and ATP sensitive K+ channel pathway. The central antinociceptive effect was not antagonized by naltrexone. One phenolic acid, one lignin and five flavonoids were isolated from BHE. The antinociceptive activity of BHE was most likely due to the presence of the flavonoids. The acute toxicity results showed that BHE was safe at a high dose (2 g/kg, p.o.). The current investigation demonstrates that B. glauca subsp. hupehana is a potential candidate for the development of novel, non-opioid, analgesic phytomedicines.
authors: Department of Natural Product Chemistry, Beijing Institute of Pharmacology and Toxicology, Beijing, China.
authors: Jinlong
authors: J
authors: Xu
authors: Department of Natural Product Chemistry, Beijing Institute of Pharmacology and Toxicology, Beijing, China.
authors: Qizhi
authors: Q
authors: Zhao
authors: Department of Natural Product Chemistry, Beijing Institute of Pharmacology and Toxicology, Beijing, China.
authors: Lei
authors: L
authors: Wei
authors: Department of Natural Product Chemistry, Beijing Institute of Pharmacology and Toxicology, Beijing, China.
authors: Yu
authors: Y
authors: Yang
authors: Department of Natural Product Chemistry, Beijing Institute of Pharmacology and Toxicology, Beijing, China.
authors: Rui
authors: R
authors: Xu
authors: Department of Natural Product Chemistry, Beijing Institute of Pharmacology and Toxicology, Beijing, China.
authors: Nengjiang
authors: N
authors: Yu
authors: Department of Natural Product Chemistry, Beijing Institute of Pharmacology and Toxicology, Beijing, China.
authors: Yimin
authors: Y
authors: Zhao
mesh_terms: D019342:Acetic Acid; D000700:Analgesics / Q000032:analysis / Q000494:pharmacology*; D000818:Animals; D036481:Bauhinia / Q000737:chemistry*; D006152:Cyclic GMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000737:chemistry; D005260:Female; D006358:Hot Temperature / Q000009:adverse effects; D054086:KATP Channels / Q000378:metabolism; D008297:Male; D008813:Mice, Inbred ICR; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D010146:Pain / Q000209:etiology / Q000517:prevention & control*; D064209:Phytochemicals / Q000032:analysis / Q000494:pharmacology*; D008517:Phytotherapy; D035261:Plant Components, Aerial / Q000737:chemistry; D010936:Plant Extracts / Q000032:analysis / Q000494:pharmacology; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000700:Analgesics; D054086:KATP Channels; D009292:Narcotic Antagonists; D064209:Phytochemicals; D010936:Plant Extracts; D009270:Naloxone; D000431:Ethanol; D006152:Cyclic GMP; D019342:Acetic Acid