sinomenine and Pain--Postoperative

Sinomenine, a major bioactive ingredient isolated from traditional Chinese medicine Sinomenium acutum, has been reported to have analgesic effects in various pain animal models. N-demethylsinomenine, the N-demethylated product of sinomenine, has been identified to be the major metabolite of sinomenine and is also a natural component extracted from Sinomenium acutum. This study examined the anti-allodynic effects of N-demethylsinomenine in a mouse model of postoperative pain. A significant and sustained mechanical allodynia that lasted for 4 days was induced by making a surgical incision on the right hind paw in mice. Acute treatment with N-demethylsinomenine (10-40 mg/kg, s.c.) relieved the mechanical allodynia in a dose-dependent manner. Although there was no difference in maximal analgesic effect between N-demethylsinomenine (40 mg/kg, s.c.) and sinomenine (40 mg/kg, s.c.), the onset of action of N-demethylsinomenine was quicker than sinomenine. Repeated treatment with N-demethylsinomenine (10-40 mg/kg/day, s.c.) also dose-dependently exerted sustained antinociception against postoperative allodynia and did not produce analgesic tolerance and carry-over effect. The anti-allodynia induced by N-demethylsinomenine (40 mg/kg, s.c.) was attenuated by bicuculline, a selective γ-aminobutyric acid type A (GABA

Topics: Analgesics; Animals; Bicuculline; Disease Models, Animal; Dose-Response Relationship, Drug; GABA-A Receptor Antagonists; Hyperalgesia; Male; Mice; Mice, Inbred ICR; Morphinans; Pain, Postoperative; Receptors, GABA-A

This study examined the antinociceptive effects of sinomenine in a rat model of postoperative pain.. Male and female rats were subjected to a surgical incision in the right hind paw, and the von Frey filament test was used to measure mechanical hypersensitivity after drug or vehicle treatment (p.o. or i.p.). Rats were treated daily with sinomenine before or after the surgery and the AUCs of the antinociceptive effects measured during a 4 h period were calculated to determine the ED50 values of sinomenine. The anti-hyperalgesic effects of different doses of a combination of sinomenine and acetaminophen (paracetamol) were assessed in another group of rats. Dose combinations were determined by using a fixed ratio dose-addition analysis method.. Sinomenine (5-80 mg·kg(-1) ) produced dose-dependent antinociceptive effects in rats that had been subjected to surgery and this effect lasted for 4 h. The potency of sinomenine, given i.p. or p.o., did not differ between male and female rats. However, sinomenine was fourfold more potent when given i.p. than p.o. The GABAA receptor antagonist bicuculline blocked the antinociceptive effects of sinomenine. The antinociceptive effect of a daily treatment with sinomenine remained stable throughout the course of postoperative pain. Pretreatment with sinomenine did not alter the mechanical hypersensitivity post-surgery. The combination of sinomenine with acetaminophen produced an infra-additive interaction.. Sinomenine demonstrated significant antinociceptive activity against postoperative pain and may be a useful novel pharmacotherapy for the management of postoperative pain.

Topics: Acetaminophen; Analgesics; Animals; Dose-Response Relationship, Drug; Female; Male; Morphinans; Pain, Postoperative; Rats; Rats, Sprague-Dawley

To observe the clinical effect and experimental result of long-acting analgesic in the treatment of anorectal post-operational pain.. Analysing the pathological features of anorectal post-operational pain, and select the Radix Stephana Tetrandra, which could disperse pathogenic Wind and dampness, relieve spasm and pain, as the major component. The authors extracted Sinomenine from the Stephana and by mixing with methylene blue and bupivacaine hydrochloride, an injection was prepared. Three groups were in the clinical observation: Long-acting analgesic group (102 cases), routine treatment group (80 cases) and the control group treated by Tramal (30 cases). The curative effect was observed and animal experiment was conducted.. The total analgesic rate of the long-acting analgesia was 56.86%. The clinical effect was better than using Bupivacaini hydrochloride or Tramal alone (P < 0.05). It was shown in experiment that long-acting analgesic had obvious effects of topical analgesic and muscle relaxant.. Long-acting analgesic has significant effect in relieving the anorectal post-operational pain.

Topics: Adult; Aged; Analgesics, Non-Narcotic; Anti-Inflammatory Agents, Non-Steroidal; Drugs, Chinese Herbal; Female; Fissure in Ano; Hemorrhoids; Humans; Male; Middle Aged; Morphinans; Pain, Postoperative