Anti-nociceptive, anti-inflammatory and possible mechanism of anti-nociceptive action of methanol leaf extract of Nymphaea lotus Linn (Nymphaeceae).

The leaf of Nymphaea lotus has been used traditionally for the management of pain and inflammatory diseases. The methanol leaf extract of Nymphaea lotus (NLE) was evaluated for possible anti-nociceptive and anti-inflammatory activities in rats and mice (at the doses of 250, 500 and 1,000 mg/kg) to investigate the existence of scientific basis for the folkloric use of the plant. The standard drugs used were piroxicam (10 mg/kg) and morphine (10 mg/kg). The possible pharmacological mechanism involved in the anti-nociceptive activity was also investigated. The acute toxicity was determined in mice and rats using method of Lorke. The anti-nociceptive activity was evaluated using acetic acid-induced writhing and hot plate tests in mice, while the anti-inflammatory activity was evaluated using carrageenan-induced hind paw edema model in rats. The oral median lethal dose of NLE was found to be greater than 5,000 mg/kg in rats and mice. NLE demonstrated significant and dose-dependent protection against acetic acid induced writhes and increased the reaction time of mice in hot plate test. Pretreatment of the animals with naloxone (2 mg/kg) significantly (p < 0.05) attenuated the anti-nociception elicited by both NLE and morphine. NLE at the doses of 250 and 1,000 mg/kg significantly (p < 0.05) decreased rat paw edema at the 2nd hour in the carrageenan-induced paw edema test. The result of the study revealed that Nymphaea lotus possesses anti-nociceptive activities which may be mediated via the opioidergic system as well as mild anti-inflammatory activities thus providing scientific basis for the use of the plant in the management of pain and inflammatory diseases.

Analgesic, anti-inflammatory and antipyretic activities of the methanol leaf extract of Dalbergia saxatilis Hook.F in rats and mice.

ETHNOPHARMACOLOGICAL RELEVANCE: The decoction of the leaves of Dalbegia saxatilis is used in Traditional Medicine for various ailments such as cough, small pox, skin lesions, bronchial ailments and toothache. The study is aimed at evaluating the analgesic, anti-inflammatory, and antipyretic effects of D. saxatilis to provide scientific basis for its use. MATERIALS AND METHODS: Phytochemical screening and evaluation of oral median lethal dose was carried out on the methanol leaf extract of the plant. Analgesic activity using acetic acid induced writhing and hot plate method in mice, anti-inflammatory activity using carrageenan induced paw oedema in rats, and antipyretic activity using Brewer׳s yeast induced pyrexia in rats were evaluated at 250mg/kg, 500mg/kg, and 1000mg/kg doses of the extract. RESULTS: The oral median lethal dose was found to be above 5000mg/kg. The extract was found to contain alkaloids, flavonoids, tannins, saponins, cardiac glycosides, and triterpenes. The extract and the standard drug (Aspirin) significantly decreased the number of writhes caused by acetic acid at p<0.001. There was statistical significant increase in reaction time in standard group, extract 250mg/kg, and 1000mg/kg from 60 min at p<0.05 and p<0.01, from 30 min in 500mg/kg group at p<0.05 and p<0.01 compared with 0 min. A statistical significant decreases in paw sizes at p<0.05 and p<0.01 compared to the peak increase in both standard and test groups was observed. Statistical significant reduction in rectal temperatures was observed in standard group at 21 and 23 h, and in 500mg/kg and 1000mg/kg doses of the extract at 23 h at p<0.05 compared with the 19h. CONCLUSION: The results obtained indicated potential analgesic, anti-inflammatory and antipyretic effects of the methanol leaf extract of D. saxatilis observed at doses tested which support the claim for the traditional use of the plant in treatment of toothache.

Flavonoid mixture ameliorates increase in erythrocyte osmotic fragility and malondialdehyde concentration induced by Trypanosoma brucei brucei-infection in Wistar rats.

The experiment was performed with the aim of investigating the effect of a flavonoid mixture, Daflon® 500 mg (DF) on the erythrocyte fragility and lipoperoxidative changes, induced by Trypanosoma brucei brucei infection in Wistar rats. Fifty adult male rats randomly divided into five groups of 10 animals each were used. Rats in the control group were administered (1 mL/kg) distilled water only, while the other groups were infected with T. brucei brucei and treated with Daflon® 500 mg and/or Diminazene aceturate. At the end of 5 weeks, EDTA-blood samples and serum samples were collected from the rats, and were used to determine erythrocyte osmotic fragility (EOF) and serum malondialdehyde (MDA) concentration respectively. The results showed that EOF and MDA concentration significantly (P<0.05) increased in the infected untreated group when compared to the treatment groups. Treatment with Daflon® 500 mg and Diminazene aceturate significantly (P<0.05) reduced trypanosome-induced increases in EOF and lipoperoxidative changes, suggesting possible antioxidant properties of Daflon® 500 mg and its therapeutic value in trypanosomosis.