Trigonopleura malayana L. (Euphorbiaceae) resin, locally known as Gambir Sarawak, has been used traditionally to alleviate pain associated with insect bites, muscle ache, toothache and minor injuries. The present study was carried out using various animal models to determine the antinociceptive and antiinflammatory activities of the T. malayana resin aqueous extract. Antinociceptive activity was measured using the abdominal constriction, hot plate and formalin tests, while antiinflammatory activity was measured using the carrageenan-induced paw edema test. The extract, obtained after 24 h of soaking the dried resin in distilled water, was prepared in doses of 0.3, 3 and 10 mg/kg and administered subcutaneously 30 min prior to the assays. The mechanism of action was also determined by prechallenging with naloxone (10 mg/kg), a nonselective opioid antagonist. The extract was found to exhibit significant (P < 0.05) and dose-dependent antinociceptive and antiinflammatory activities; naloxone failed to inhibit the former activity. In conclusion, the aqueous extract of T. malayana resin possesses nonopioid antinociceptive and antiinflammatory activities, thus supporting previous claims regarding its traditional use by the Malays to treat various ailments, particularly those related to pain.
In the present study, the rhizome essential oil from Zingiber zerumbet (Zingiberaceae) was evaluated for antinociceptive activity using chemical and thermal models of nociception, namely, the acetic acid-induced abdominal writhing test, the hot-plate test and the formalin-induced paw licking test. It was demonstrated that intraperitoneal administration of the essential oil of Z. zerumbet (EOZZ) at the doses of 30, 100 and 300 mg/kg produced significant dose-dependent inhibition of acetic acid-induced abdominal writhing, comparable to that of obtained with acetylsalicylic acid (100 mg/kg). At the same doses, the EOZZ produced significant dose-dependent increases in the latency time in the hot-plate test with respect to controls, and in the formalin-induced paw licking test, the EOZZ also significantly reduced the painful stimulus in both neurogenic and inflammatory phase of the test. In addition, the antinociceptive effect of the EOZZ in the formalin-induced paw licking test as well as hot-plate test was reversed by the nonselective opioid receptor antagonist, naloxone suggesting that the opioid system was involved in its analgesic mechanism of action. On the basis of these data, we concluded that the EOZZ possessed both central and peripheral antinociceptive activities which justifying its popular folkloric use to relieve some pain conditions.
This study was performed to determine the antinociceptive and anti-inflammatory activities of aqueous extract of Kaempferia galanga leaves using various animal models. The extract, in the doses of 30, 100, and 300 mg/kg, was prepared by soaking (1:10; w/v) the air-dried powdered leaves (40 g) in distilled water (dH(2)O) for 72 h and administered subcutaneously in mice/rats 30 min prior to the tests. The extract exhibited significant (P < 0.05) antinociceptive activity when assessed using the abdominal constriction, hot-plate and formalin tests, with activity observed in all tests occurring in a dose-dependent manner. Furthermore, the antinociceptive activity of K. galanga extract was significantly (P < 0.05) reversed when prechallenged with 10 mg/kg naloxone. The extract also produced a significantly (P < 0.05) dose-dependent anti-inflammatory activity when assessed using the carrageenan-induced paw-edema test. In conclusion, this study demonstrated that K. galanga leaves possessed antinociceptive and anti-inflammatory activities and thus supports the Malay's traditional uses of the plant for treatments of mouth ulcer, headache, sore throat, etc.