Analgesic activity of allopurinol and febuxostat in experimental animals

Background: Currently, two classes of analgesics, nonsteroidal anti-inflammatory drugs (NSAIDs) and opioid analgesics are used to manage pain in different clinical situations. Chronic uses of these drugs have various adverse effects like gastric ulceration/bleeding, analgesic nephropathy and respiratory depression, physical dependence, addiction, respectively. Xanthine oxidase inhibitors, used for chronic gout, might have a role in alleviation of pain, as per literature survey. Hence, the present study was carried out to evaluate the potential analgesic activity of allopurinol and febuxostat in different experimental models.Methods: The analgesic activity of allopurinol and febuxostat was assessed by employing two different experimental pain models-tail flick latency model in rats for central analgesia and acetic acid induced writhing model in mice for peripheral analgesia and was compared with tramadol and aspirin.Results: Allopurinol and febuxostat produced significant central and peripheral analgesic effects as is evident from increase in reaction time in tail flick test and inhibition in number of writhes in acetic acid induced writhing test.Conclusions: The results of the present study demonstrate marked analgesic effect of allopurinol and febuxostat.

Examination of CNS Activity of Rhizomes of Alpinia Oxyphylla.

The study is based on the examination of the CNS activity observed from the methanolic extract of the rhizomes of Alpinia oxyphylla. Tail immersion method in mice has been used for the evaluation of the central pharmacological actions. Similarly acetic-acid induced writhing-test was used for the evaluation of the peripheral pharmacological properties. A significant rise in pain threshold is seen in a dose dependent manner with the methanolic extract of A. oxyphylla at doses of 100, 200 and 400 mg/kg body weight with the tail immersion methods. The methanolic extract at 400 mg/kg dose possessed 73.12% writhing inhibition, (p <0.001) in acetic-acid induced writhing-test that could be compared to the standard, Diclofenac-Na (25 mg/kg) with 75.78% inhibition. Open-field and hole-cross tests have been conducted in mice for further investigation of the extract in support of its neuro-pharmacological actions, where dosedependent suppression of exploratory and motor activities were observed in the tested models. Hence, the above results evidence the presence of CNS depressant and analgesic properties of the plant, A. oxyphylla.

Investigation of Neuropharmacological Activity of Seeds of Alpinia Zerumbet.

The study is based on the investigation of the neuropharmacological and analgesic properties observed from the methanolic extract of the seeds of Alpinia zerumbet. Tail immersion method in mice has been used for the evaluation of the central pharmacological actions. Similarly acetic-acid induced writhing-test was used for the evaluation of the peripheral pharmacological properties. A significant rise in pain threshold is seen in a dose dependent manner with the methanolic extract of A. zerumbet at doses of 100, 200 and 400 mg/kg body weight with the tail immersion methods. The methanolic extract at 400 mg/kg dose possessed 73.12% writhing inhibition, (p <0.001) in acetic-acid induced writhing-test that could be compared to the standard, Diclofenac-Na (25 mg/kg) with 75.78% inhibition. Open-field and hole-cross tests have been conducted in mice for further investigation of the extract in support of its neuropharmacological actions, where dose-dependent suppression of exploratory and motor activities were observed in the tested models. Hence, the above results evidence the presence of CNS depressant and analgesic properties of the plant, A. zerumbet.

Experimental evaluation of analgesic activity of PPAR γ agonists: pioglitazone and rosiglitazone.

Background: To evaluate analgesic activity of pioglitazone and rosiglitazone by tail flick method in rats and acetic acid induced writhing method in mice. Methods: Albino wistar rats of either sex weighing 180-200 g and Swiss mice weighing 25-30 g were used. Study was conducted after approval from the Institutional Animal Ethics Committee. The tail flick method in rats described by D’Amour and Smith (1941) and acetic acid induced writhing in mice were used. The dose of pioglitazone and rosiglitazone were 20 mg/kg and 10 mg/kg respectively. Results: In tail flick method of analgesia, both, pioglitazone and rosiglitazone have analgesic activity which was statistically comparable to aspirin. In acetic acid induced writhing model of analgesia, the action of pioglitazone and rosiglitazone was significantly greater than the control group but it was less when compared to aspirin. Conclusions: Analgesic activity of pioglitazone and rosiglitazone was comparable to aspirin in tail flick model of analgesia in rats while it was significantly less when compared to tramadol. Analgesic activity of pioglitazone and rosiglitazone was significantly less than aspirin in acetic acid induced writhing method.

In vivo analgesic, antipyretic, and anti-inflammatory potential in Swiss albino mice and in vitro thrombolytic activity of hydroalcoholic extract from Litsea glutinosaleaves

BACKGROUND: The study was conducted to evaluate the in vitro thrombolytic activity, and in vivo analgesic, anti-inflammatory and antipyretic potentials of different hydrocarbon soluble extracts of Litsea glutinosaleaves for the first time widely used in the folkloric treatments in Bangladesh. This work aimed to create new insights on the fundamental mechanisms of the plant extracts involved in these activities. RESULTS: In thrombolytic activity assay, a significant clot disruption was observed at dose of 1 mg/mL for each of the extracts (volume 100 µL) when compared to the standard drug streptokinase. The n-hexane, ethyl acetate, chloroform, and crude methanolic extracts showed 32.23 ± 0.26, 37.67 ± 1.31, 43.13 ± 0.85, and 46.78 ± 0.9% clot lysis, respectively, whereas the positive control streptokinase showed 93.35 ± 0.35% disruption at the dose of 30,000 I.U. In hot plate method, the highest pain inhibitory activity was found at a dose of 500 mg/kg of crude extract (15.54 ± 0.37 sec) which differed significantly (P <0.01 and P <0.001) with that of the standard drug ketorolac (16.38 ± 0.27 sec). In acetic acid induced writhing test, the crude methanolic extract showed significant (P <0.01 and P <0.001) analgesic potential at doses 250 and 500 mg/kg body weight (45.98 and 56.32% inhibition, respectively), where ketorolac showed 64.36% inhibition. In anti-inflammatory activity test, the crude methanolic extract showed significant (P <0.001) potential at doses 250 and 500 mg/kg body weight (1.51 ± 0.04 and 1.47 ± 0.03 mm paw edema, respectively), where ketorolac showed 1.64 ± 0.05 mm edema after 3 h of carrageenan injection. In antipyretic activity assay, the crude extract showed notable reduction in body temperature (32.78 ± 0.46°C) at dose of 500 mg/kg-body weight, when the standard (at dose 150 mg/kg-body weight) exerted 33.32 ± 0.67°C temperature after 3 h of administration. CONCLUSIONS: Our results yield that the crude hydroalcoholic extract has better effects than the other in all trials. In the context, it can be said that the leaves of L. glutinosa possess remarkable pharmacological effects, and justify its traditional use as analgesic, antipyretic, anti-inflammatory, and thrombolytic agent.

Antinociceptive and anti-inflammatory effects of the essential oil of Eugenia candolleana DC., Myrtaceae, on mice / Efeito antinociceptivo e antiinflamatório do óleo essencial de Eugenia candolleana DC. (Myrtaceae) em roedores

Eugenia candolleana DC. (Myrtaceae), commonly known as "murta" or "murtinha", is a plant species without any chemical or pharmacological study described in the literature. It has been popularly used for the treatment of pain and fever. This report aimed to investigate the possible antinociceptive and anti-inflammatory effects of the essential oil extracted from fresh leaves of Eugenia candolleana DC. (EOEc) in rodents. Following intraperitoneal injection, EOEc (25, 50 and 100 mg/kg) reduced the number of writhes significantly in a writhing test and the number of paw licks during phase two of formalin test (p < 0.001). However, administration of EOEc did not alter the time of reaction in hot plate test. Furthermore, EOEc inhibited (p < 0.01) the carrageenan-induced leukocyte migration to the peritoneal cavity. These results indicate antinociceptive and anti-inflammatory properties of EOEc probably mediated via inhibition of prostaglandin synthesis or other peripherally pathway.

Eugenia candolleana DC. (Myrtaceae), conhecida popularmente como "murta" ou "murtinha", é uma espécie vegetal sem estudos químicos e farmacológicos descritos na literatura, distribuída no Nordeste brasileiro, principalmente, na Zona da Mata. Na medicina popular do Estado de Sergipe é utilizada no tratamento de distúrbios febris e da dor. O presente estudo buscou avaliar as possíveis atividades antinociceptiva e antiinflamatória do óleo essencial extraído das folhas de E. candolleana DC (OEEc) em roedores. A administração intraperitoneal (i.p.) do OEEc (25, 50 e 100 mg/kg) reduziu significativamente o número de contorções no teste das contorções abdominais e a duração da lambida da pata na segunda fase do teste da formalina (p < 0,001). Entretanto, a administração do OEEc não alterou o tempo de reação no teste da placa quente. No experimento de peritonite induzido por carragenina, o OEEc reduziu de forma significativa (p < 0,01) a migração de leucócitos para a cavidade peritoneal. Os resultados obtidos sugerem que o OEEc possui ação antinociceptiva, provavelmente mediado por mecanismos periféricos, e ação antiinflamatória.