Investigation of centrally and peripherally acting analgesic and anti-infl ammatory activity of biological immune response modulator (an Amazonian plant extract) in animal models of pain and infl ammation.

Background: Biological immune response modulator (BIRM) - An aqueous extract of dried roots of the species dulcamara (family Solanaceae) grown in Ecuador, considered as a natural remedy for various disease is promoted as a natural herbal medicine. Our aim of the study was to assess the central and peripheral analgesic and anti-infl ammatory property of BIRM and to study its mechanism of action. Methods: Peripheral analgesic and anti-infl ammatory activity was evaluated using acetic acid induced writhing test and carrageenan paw edema test in male Swiss Albino mice (n=8 per group). Formalin test was taken up to evaluate BIRM’s centrally, as well as peripheral antinociceptive action. Results: We observed through our studies that BIRM when administered repeatedly for 7 days (4 ml/kg, p.o.) was able to exert its anti-nociceptive and anti-infl ammatory activity through central and peripheral mechanism. BIRM was able to signifi cantly inhibit both acetic acid induced writhes and carrageenan-induced paw edema indicating it’s possible peripheral analgesic and anti-infl ammatory action. BIRM was also able to inhibit both neurogenic and infl ammatory pain in the formalin test indicating its action through central and peripheral nervous system. Conclusion: Our study results show that BIRM has the potential anti-infl ammatory property and is able to exert its anti-nociceptive effect through both central and peripheral mechanisms.

Analgesic and Anti-inflammatory Effect of the Aqueous Extract of Dichrostachys glomerata (Forssk.) Hutch Fruits.

Aims: Dichrostachys glomerata is a plant found in the humid areas of Africa and widely used for the treatment of many ailments including rheumatism and snake bite. The present study has been undertaken to assess the analgesic and the anti-inflammatory properties of aqueous extract Dichrostachys glomerata fruit. Place and Duration of Study: Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, Cameroon. Between January 2012 and October 2012. Methodology: Pain was induced in mice by the intraperitoneal administration of 1% acetic acid, hot plate, formalin and tail immersion test. Carrageenan and serotonin (1%) were used to induce inflammation in rat paws. Results: Dichrostachys glomerata significantly inhibited pain induced by acetic acid with a percentage inhibition of 19.4, 69.8, 33.7 and 24.3% respectively at the doses of 25, 50, 100 and 200 mg/kg. An acute pretreatment of mice with extract significantly increased reaction time in the hot plate test with a percentage inhibition more than 68%. Formalin induced pain was also significantly inhibited after treatment of rat with the plant extract at the doses of 25 and 50 mg/kg for the neurogenic phase with percentage of inhibition of 56.14 and 61.46% respectively. The extract significantly reduced oedema induced by carrageenan injection with a PI of 72.57 and 79.85% at the doses of 200 and 25 mg/kg respectively. In contrast, a pi of 65.03% was obtained with the plant extract at the dose of 50 mg/kg on serotonin-induced oedema. Conclusion: The Results obtained showed that D. glomerata aqueous extract have both analgesic and anti-inflammatory properties and could be a potential source of new oral anti-inflammatory and/ or analgesic drug.

Prasarani Sandhan, a Polyherbal Preparationc Shows Anti-nociceptive and Anti-inflammatory Activities.

Aims: Prasarani Sandhan (PRS) is an Ayurvedic formulation approved by the “National formulary of Ayurvedic Medicine 2011”, of Bangladesh. It is traditionally used in arthritic pain, lumbago and sciatia. Sparse scientific evidence is available to support the efficacy of this preparation. Hence, we planned to document scientific evidences of the pharmacological activity of this preparation. Study Design: Our present study aims to elucidate the probable anti-nociceptive and anti-inflammatory mechanisms of PRS. Place and Duration of the study: The experiments were performed at the pharmacology lab of North South University during the period of October 2010 to July 2011. Methodology: Two thermal anti-nociceptive models were used, the hot-plate test and tail immersion test, to find out the possible role of the central nervous system in its action. Three in-vivo analgesic and anti-inflammatory models, carrageenan induced paw edema, acetic-acid writhing, and formalin induced paw lick tests, were carried out to test its potential anti-inflammatory and peripheral analgesic properties. Result: The study of PRS (20mL/kg and 40mL/kg) showed no involvement of the CNS in anti-nociceptive activity of PRS. Carrageenan induced paw edema and acetic acid writhing tests both gave significant results (P=.05), indicating possible peripheral analgesic and anti-inflammatory action. Formalin induced paw-licking test (with and without naloxone co-administration), a differentiator of nurogenic pain (CNS modulated) and inflammatory pain (peripheral nociception), showed that PRS had significant effect in suppressing inflammatory pain (P=.05) but not neurogenic pain. Conclusion: Compiling the results of the experiments, it can be reported that PRS has anti-inflammatory and peripheral analgesic action.

Investigation on Central and Peripheral Analgesic and Anti-Inflammatory Activity of Punarnavasava, an Ayurvedic Preparation.

Aims: Punarnavasava (PNR) is an Ayurvedic formulation approved by the “National formulary of Ayurvedic Medicine 2011”, of Bangladesh. It is traditionally used in arthritic pain, lumbago and sciatia. Sparse scientific evidence is available to support the efficacy of this preparation. Hence, we planned to document scientific evidences of the pharmacological activity of this preparation. Study Design: Our present study aims to elucidate the probable anti-nociceptive and anti-inflammatory mechanisms of PNR. Place and Duration of the Study: The experiments were performed at the pharmacology lab of North South University during the period of October 2010 to July 2011. Methodology: Two thermal anti-nociceptive models were used, the hot-plate test and tail immersion test, to find out the possible role of the central nervous system in its action. Three in-vivo analgesic and anti-inflammatory models, carrageenan induced paw edema, acetic-acid writhing, and formalin induced paw lick tests, were carried out to test its potential anti-inflammatory and peripheral analgesic properties. Results: The dose dependent study of PNR (10mL/kg, 20mL/kg, and 40mL/kg) showed potential involvement of the CNS in anti-nociceptive activity of PNR. Carrageenan induced paw edema and acetic acid writhing tests both gave significant results (P=.05), indicating possible peripheral analgesic and anti-inflammatory action. Formalin induced paw-licking test (with and without naloxone co-administration), a differentiator of nurogenic pain (CNS modulated) and inflammatory pain (peripheral nociception), showed that PNR had significant effect in suppressing inflammatory pain (P=.05) but not neurogenic pain. Conclusion: Compiling the results of the experiments, it can be reported that Punarnavasava has both central and peripheral analgesic and anti-inflammatory action.

A Study on the Effect of Topical 5% Lidocaine Patches on Postherpetic Neuralgia

BACKGROUND: Postherpetic neuralgia (PHN) is the most common and serious complication of herpes zoster and its incidence is increasing in the aging population. Despite the many approaches thath have been proposed to treat postherpetic neuralgia, none of the therapies are satisfactory in their efficacy and safety. OBJECTIVE: Assessment of the effectiveness and safety of the 5% lidocaine patch, a targeted peripheral analgesic, for the treatment of postherpetic neuralgia. METHOD: Fifteen patients with established PHN completed a three-session, random-order, double-blind, vehicle-controlled study. A maximum of three patches were applied to the most painful area for 12 hours, twice in two consecutive days (i.e., 12 hours on followed by 12 hours off). Two sessions were done with the 5% lidocaine patches and one session with a placebo patch. The sessions were conducted at least 7 days apart. RESULTS: The 5% lidocaine patch significantly reduced the mean VAS scores (pain intensity) at the time points from hours 12 to 72 compared with baseline (individual time points p<0.001 to p=0.033) and from hours 12 to 72 compared with the vehicle patch (individual time points p<0.001 to p=0.015). The lidocaine patch also provided significantly greater pain relief on the 6-item scale compared with the vehicle patch (individual time points p<0.001 to p=0.04). The patches were well tolerated by all patients. Neither systemic side effects nor significant skin irritation were noted. CONCLUSION: This study demonstrates that use of the 5% lidocaine patch resulted in statistically significant pain relief. Patients suffering from PHN will find the patches easy to use and there is minimal risk of systemic toxicity

Effect of Intraarticular Ketamine after Knee Arthroscopy / 대한통증학회지

BACKGROUND: This study was designed to demonstrate the peripheral effect of ketamine on the synovia of the knee joint and evaluate the analgesic effect of an intraarticular ketamine injection following knee arthroscopy. METHODS: In a double blind randomized study, 80 ASA class 1 or 2 patients were selected for elective arthroscopic knee surgery. The patients received either 20 ml of normal saline (Group C, n = 19), 20 ml of 0.5% ropivacaine (Group R, n = 21), 1 mg/kg of ketamine mixed with 20 ml of normal saline (Group K, n = 20) or 1 mg/kg of ketamine mixed with 20 ml of 0.5% ropivacaine (Group RK, n = 20), intraarticularly, just prior to wound closure. Postoperative pain was evaluated using a visual analogue scale (VAS 0 to 100) score at 1, 2, 6, 12, 24 and 48 hours after the intraarticular injection, with the side effects found in the four groups also evaluated. The patients' requests for rescue analgesic were recorded, total doses of tarasyn calculated and the overall patient satisfaction also evaluated. RESULTS: The difference in the VAS scores for all time periods was not significant. The number of patients receiving rescue analgesics and the total doses received in Group C were greater than those for the other groups, but this was not significant. No side effects were observed in any of the patients. CONCLUSIONS: Ketamine and local anesthetics have been reported to have peripheral analgesic effects, with variable duration in the measurements of pain and hyperalgesia. However, we failed to demonstrate a peripheral analgesic effect on postoperative arthroscopic pain.