Anti-nociceptive and anti-inflammatory activities of methanol root extract of Andropogon gayanus Kunth (Poaceae) in rodents

Background: Andropogon gayanus is widely used in traditional medicine for various ailments such as postpartum pain, bronchitis and oedema. Objective: This study evaluated the anti-nociceptive and anti-inflammatory activities of methanol root extract of A. gayanus in experimental rodents. Methods: Phytochemical screening tests and acute toxicity studies were carried out. Analgesic activity using acetic acid-induced writhing response and hot plate test in mice, formalin-induced pain and carrageenan-induced paw oedema in rats were evaluated at doses of 250, 500 and 1000 mg/kg of the extract. Results: Oral median lethal dose was >5000 mg/kg in both mice and rats. The extract significantly (p<0.01) decreased the number of writhing movements at all tested doses. It also significantly (p<0.05) increased the mean reaction times. A significant (p<0.05) decrease in mean pain scores was also observed in both phases of the formalin test at 1000 mg/kg. The extract at 1000 mg/kg significantly (p<0.05) reduced the oedema at the 1st hour, while at the 5th hour, all doses tested significantly reduced the oedema. Conclusion: The methanol root extract of Andropogon gayanus possesses antinociceptive and anti-inflammatory activities. Keywords: Andropogon gayanus, Analgesic, Anti-inflammatory, Pai

Acute Toxicological, Analgesic and Anti-Inflammatory Effects of Methanol Extract of Laggera aurita Linn F (Compositae) in Mice and Rats

Background: The plant Laggera aurita is an annual or biannual plant belonging to the family Compositae that has been used for management of pain related conditions locally.  It reportedly has anti-oxidant as well as antimicrobial properties. Objectives: To conduct LD50 and phytochemical studies, evaluate the analgesic and anti-inflammatory properties of the methanol extract of L. aurita and determine possible mechanism of action. Methodology: Analgesic and anti-inflammatory properties of the extract were investigated using acetic acid induced writhing, thermally-induced pain, and formalin induced inflammation in rats and mice. Phytochemical and acute toxicological screenings were also conducted. Results: The LD50 was found to be above 5000 mg/kg with slight changes in histological architecture observed in the kidney, liver, lungs and stomach. The extract at dose 200, 400 and 800 mg/kg significantly (p<0.05) inhibited acetic acid induced writhes in mice and increased mean reaction time in the thermal pain model, both dose dependently. The effect on thermally induced pain was blocked by naloxone, a non-specific opioid antagonist, suggesting opioid receptor involvement in analgesia. The extract also significantly (p<0.05) decreased formalin induced paw edema dose dependently. Conclusion: These findings suggest that the methanol extract of L. aurita possesses analgesic and anti-inflammatory properties that justify its ethnomedicinal use in management of pain and inflammation. Keywords: Laggera aurita, anti-inflammatory, analgesic, acute toxicity

Immune-mediated Anti-inflammatory Activity of Root Bark Extracts of Calotropis procera (Ait) R.Br. in Rodents

Background: The root bark of Calotropis procera has been reported to be a part of herbal remedies for the management of allergic diseases like asthma. However, there is paucity of data on its anti-inflammatory activity in allergic disorders. Objectives: This study is aimed to investigate the immune mediated anti-inflammatory activity of root bark extracts of Calotropis procera in rats. Materials and Methods: Aqueous and methanol root bark extracts of Calotropis Procera were subjected to preliminary phytochemical screening and their oral median lethal doses were estimated in rats. The aqueous and methanol root bark extracts were investigated for anti-allergic activity using carageenan-induced leucocytosis (100 and 200 mg/kg doses) and egg albumin induced passive paw anaphylaxis (250 and 350 mg/kg doses) test in rats. Results: The oral median lethal doses of both extracts were found to be greater than 5000 mg/kg in wistar rats. Both extracts were found to contain alkaloids, flavonoids, tannins, saponins, cardiac glycosides, and triterpenes. Both extracts significantly (p˂0.001) decreased leucocyte count in carrageenan induced leucocytosis test at the dose of 100 and 200 mg/kg, with both aqueous and methanol extracts exhibiting the same level of decrease in leucocyte count. Equally, there was a statistically significant decrease (p<0.05) in paw size at 250 mg/kg and 350 mg/kg in egg albumin-induced passive paw anaphylaxis compared to the peak increase for both standard and test groups, but with the aqueous extract exhibiting a greater level of decrease in paw size than methanol extract. Conclusion: The aqueous and methanol root bark extracts of Calotropis procera possesses Anti-inflammatory activity in in vivo anti-allergic tests on animal models, thus support the folkloric use of the plant in inflammatory and allergic conditions including asthma. Key words: Calotropis procera; Anti-inflammatory; Allergy; Carrageenan; Egg albumin

Analgesic and Anti-Inflammatory activities of Rothmannia Longiflora Salisb In Mice And Rats

Abstract: In this study, the analgesic and anti-inflammatory activities of the methanolic leaf extract of Rothmannialongiflora were investigated. The methanolic leaf extract of the plant at the doses of 250, 500, and 1000mg/kg orally was evaluated for analgesic activity using acetic acid-induced writhing test, hot plate test and formalin test. The anti-inflammatory potential of the extract was evaluated using carrageenan-induced paw oedema test in rats. The methanolic leaf extract exhibited significant dose dependent analgesic and antiinflammatory effects comparable to piroxicam (20mg/kg body weight orally), which is a standard analgesic and anti-inflammatory drug. The preliminary phytochemical screening of the methanolic leaf extract of Rothmannialongiflora revealed the presence of flavonoids, tannins, saponins, glycosides, steroids/terpanoids, and carbohydrates. The oral median lethal dose (LD 50 ) of the extract in mice and rats were found to be greater than 5000mg/kg, suggesting that the methanolic leaf extract of Rothmannialongiflora is non-toxic. The present findings suggest that the methanolic leaf extract of the plant possesses analgesic and anti-inflammatory activities, and supports the ethno medical claims of the use of the plant in the management of pain and inflammatory conditions

Comparative analgesic effects of paracetamol with paracetamol-caffeine formulation

This study was designed to evaluate the contribution of caffeine to analgesia in paracetamol-caffeine preparation. Analgesic properties were evaluated in mice using acetic acid-induced writhing and hot plate methods. In the acetic acid method, the test drugs were administered orally to the mice. After 30 min. all the mice received 0.7% aqueous solution of acetic acid (10ml/kg i.p) and writhing was counted for 30 min. after acid injection. The percentage inhibition was then determined. In the case of hot plate method, the mice were placed singly on a hot plate maintained at 45±0.50C before and at 15, 30, 45, 60 and 90 min. after administration of the tested drugs orally. The latency of nociceptive responses (time taken before the mouse jumped out of the hot plate) was measured each time the mouse was placed on the hot plate. The mean percentage maximum possible effect (% MPE) was determined. The results revealed dose dependent analgesic activities in both paracetamol alone and paracetamol-caffeine combination. The activities were significantly higher compared to the control which received normal saline (