Antinociceptive Effect of Extract of Mangrove (Avicennia Marina) in Male Rats

The application of pharmaceutical herbs instead of synthetic drugs is increasing in recent years because of their lower side effects and high varieties of efficient components. The study of antinociceptive effects of hydroalcoholic extract of Avicennia marina leaf seems to be necessary due to the existence of antinociceptive compounds types such as steroids, phytoalexins, flavonoids, carboxylic acids, triterpenes and tannins and its use in traditional medicine for pain cure. According to growing trend of using of pharmaceutical herbs, biologically active compounds in harra, the existence of rich ecosystem of mangrove and unique growing of this plant in Bushehr province, Antinociceptive effects of harra using formalin test in rats in present study have investigated. This study contained 24 Wistar male rats with the weight of 180-200 g. Rats were divided into four groups (n=6 for each group) including Sham, Control, receiving morphine at dose of 2 mg/kg body weight, and Tests groups receiving hydroalcoholic extract at doses of 200 and 400 mg/kg body weight. The injection of extracts was done 15 minutes before formalin tests intraperitoneally. 0-5 and 20-60 minutes considered as acute and chronic phase respectively. Avicennia marina has no effect on early response of pain but its effect on late phase of formalin test in chronic response of pain is significant (P0.05). This effect was the same as morphine. According to our finding Avicennia marina extract significantly reduced pain sensation in inflammatory phase of formalin test. This may be due to its essential oil which has been reported to have antinociceptive effects. The hydroalcoholic extract of A. marina has antinociceptive effect in both phases which is caused by formalin, and this effect may be because of the flavonoid and tannin components in plants, which have antinociceptive properties.