ABSTRACT
Background: Pain is the most common symptom in various pathological conditions requiring appropriate treatment with analgesics. Use of analgesics is limited by various adverse drug effects. The present study was aimed to evaluate the analgesic activity of hydroalcoholic extract of Costus pictus leaves in Wistar albino rats. Aim and Objective: The objective of this study is to evaluate the analgesic activity of hydroalcoholic extract of C. pictus leaves in Wistar albino rats. Materials and Methods: The study was conducted on 30 Wistar albino rats and was divided into five groups each of six rats. Group-I (Sterile water-equivalent volume/po), Group-II Morphine (5 mg/kg/ip), Group-III CPHAE (200 mg/kg/po), Group-IV CPHAE (400 mg/kg/po), and Group-V Diclofenac (12.5 mg/kg/po). All the rats were administered respective drugs before starting of 30 min of experiment. Central analgesic (Tail clip and hot plate) and peripheral analgesic (Writhing test) methods were used to evaluate the analgesic activity. The data were recorded and analyzed with SPSS software. Results: Group-II, III, IV and V showed significant analgesic activity compared to Group-I in both central and peripheral animal models. Group-II showed significant effect compared to Group-III and IV in the central analgesic activity. Group-V showed significant effect compared to Group-III and IV in peripheral analgesic activity. Group-IV showed significant effect compared to Group-III. Conclusion: High dose of (400 mg/kg) C. pictus plant extract showed significant analgesic activity in the central and peripheral animal models compared to low dose.
ABSTRACT
Background: Herbal remedies and alternative therapies have been employed in the treatment of pain from time immemorial. Ginger is a widely used spice with a lot of medicinal properties, and it is especially soothing to the gastro-intestinal system. Most of the analgesics used in modern medicine have side effects to either gastro-intestinal tract or nervous system. Ginger has neither. Scientific evaluation of the analgesic properties of Zingiber officinale is needed. Aim and Objective: The aim of the study was to evaluate the analgesic effect of three doses of orally administered petroleum ether extract of Z. officinale and to compare with morphine. When tested for analgesic activity, to find out the difference in reaction time at various time intervals for each dose of the extract, and their significance. Materials and Methods: Petroleum ether extract of Z. officinale rhizomes was used. Wistar strain albino rats (150-200 g) and Swiss albino mice (20-25 g) housed under standard laboratory conditions were used. The central analgesic activities of the extract were evaluated by the tail clip method and hot plate method. Statistical analysis was done by one-way analysis of variance to compare the means in the experimental groups. Results: In tail clip method, pain was mechanically induced pain and the pain threshold was measured in terms of mice’ reaction time in seconds. All doses of the extract of Z. officinale were capable of increasing the reaction time in mice during the various time periods. Maximum analgesic activity was shown by 800 mg/kg of the extract at 90 minutes. In hot plate test, maximum analgesic activity was shown by 800 mg/kg of the extract at 180 min. At 30 and 60 min, 800 mg/kg of the extract was as effective as the standard drug, morphine. Conclusions: The study revealed that Z. officinale has significant analgesic properties especially in higher doses.
ABSTRACT
Background: The objective of the study was to evaluate anti-nociceptive effect of methanolic extract of Murraya koenigii leaves on thermal and mechanical pain in swiss albino mice.Methods: Thirty adult male swiss albino mice weighing 25-30 grams were selected and allocated in to five groups. Each group consists of six animals. The control group received vehicle (10 ml/kg), standard group received morphine (10 mg/kg) and test groups received dried methanolic extract of Murraya koenigii leaves (100 mg/kg, 200 mg/kg, 400 mg/kg per oral respectively) 1 hour before placing the animal over the hot plate at temperature of 55?C . A cut off period of 10 sec was observed to avoid damage of the paw. The response in the form of withdrawal of paws or licking of the paws. The delay in the reaction time denotes analgesic activity. The latency was recorded before and after 15, 30, 60, 120 minutes administration of drug. After washout period of 1 month the same group of animals were utilized to evaluate the analgesic effect by tail clip method for better comparison.Results: All the doses of Murraya koenigii leaves significantly delayed reaction time in hot plate method and tail clip method. The results were comparable to that produced by standard drug morphine.Conclusions: Murraya koenigii leaves has analgesic activity which was comparable to morphine.
ABSTRACT
Human studies of brain stimulation have demonstrated modulatory effects on the perception of pain. However, whether the primary somatosensory cortical activity is associated with antinociceptive responses remains unknown. Therefore, we examined the antinociceptive effects of neuronal activity evoked by optogenetic stimulation of primary somatosensory cortex. Optogenetic transgenic mice were subjected to continuous or pulse-train optogenetic stimulation of the primary somatosensory cortex at frequencies of 15, 30, and 40 Hz, during a tail clip test. Reaction time was measured using a digital high-speed video camera. Pulse-train optogenetic stimulation of primary somatosensory cortex showed a delayed pain response with respect to a tail clip, whereas no significant change in reaction time was observed with continuous stimulation. In response to the pulse-train stimulation, video monitoring and local field potential recording revealed associated paw movement and sensorimotor rhythms, respectively. Our results show that optogenetic stimulation of primary somatosensory cortex at beta and gamma frequencies blocks transmission of pain signals in tail clip test.