Acute and subchronic toxicity profile of methanol extract of leaves of Fimbristylis miliacea (L.) Vahl.

Ethnopharmacological relevance: Fimbristylis miliacea (L.) Vahl (Cyperaceae) is a grass like herb habitually breeds as weed in paddy fields and mostly disseminated in tropical or sub-tropical countries of south and south-east Asia, northern Australia, and west Africa. The plant has been traditionally used to treat fever as a form of poultice. However, no scientific study regarding its toxicity profile has been testified. Aim of the study: The study has been carried out to determine the potential toxicity of the methanol extract from leaves of the Fimbristylis miliacea, employing the technique of acute and subchronic oral administration in mice. Materials and methods: In the acute toxicity study according to OECD guideline 425, oral administration of FM methanol extract at single doses of 2000 and 5000 mg/kg in both sexes of Swiss albino mice was performed. Toxic symptoms, abnormal behavior, changes in body weight, and mortality were observed for 14 consecutive days. In subchronic toxicity study according to OECD guideline 407, plant extract was administered orally at doses of 100, 500, 1000, and 2000 mg/kg daily for 28 days. The general toxic symptoms, abnormal behavior, changes in body weight were observed daily. Biochemical analysis of serum, and histopathological examination of liver were performed at the end of the study. Results: No mortality, abnormal behavior and urination, changes in sleep, food intake, adverse effect, and non-linearity in body weight have been recorded during acute toxicity study at the doses of 2000 and 5000 mg/kg. Also, in subchronic toxicity study, FM extract produced no mortality or any kind of adverse effects in regards of general behavior, body weight, urination, sleeping routine, and food intake. In case of analysis of thirteen different biochemical parameters, concentrations of aspartate transaminase (AST) and glucose were altered significantly in male and female mice in both acute and subchronic study. Total cholesterol and triglycerides at 5000 mg/kg.bw were changed in male mice in acute toxicity study. On the other hand, female mice had altered triglycerides in subchronic test. All other critical parameters were found unaffected. In subchronic test, histopathological examination of liver demonstrated cellular necrosis at 2000 mg/kg.bw in both male and female mice while minor necrosis was observed at 1000 mg/kg.bw. Thus, the no observed adverse effect level (NOAEL) can be assumed around 1000 mg/kg.bw. Conclusion: The present study suggests that treatment with FM extract does not reveal significant toxicity.

Antipyretic and anti-nociceptive effects of methanol extract of leaves of Fimbristylis miliacea in mice model.

ETHNOPHARMACOLOGICAL RELEVANCE: Fimbristylis miliacea (L.) Vahl (Cyperaceae) is a grass like herb usually grows as a weed in rice fields and is mainly distributed in tropical or sub-tropical countries of south and south-east Asia, central America, northern Australia and west Africa. The plant has been traditionally used to treat fever as a form of poultice. AIM OF THE STUDY: The present study aimed to investigate antipyretic and anti-nociceptive effects of methanol extract of leaves of Fimbristylis miliacea in mice model. MATERIALS AND METHODS: Antipyretic effect of Fimbristylis miliacea was examined using Baker's yeast induced hyperthermia test. Anti-nociceptive effect was investigated using acetic acid induced writhing test, formalin induced hind paw licking test and hot plate test. RESULTS: The extract at concentration of 400 mg/kg produced significant reduction in body temperature after 0.5 h of administration (4.12 °F, p ≤ 0.001) and continued to decrease (after 4 h, 5.92 °F, p ≤ 0.001). Extracts at 100 mg/kg and 200 mg/kg decreased the temperature by about 2.77 °F (from 99.47 °F to 96.7 °F) and 5.58 °F (98.2 °F-92.62 °F) respectively after 4 h whereas paracetamol dropped by about 7.2 °F (p ≤ 0.001). The extract showed significant decrease in number of writhes at all concentrations. Highest effect was found at 200 mg/kg having 35.7 writhes (p ≤ 0.001), much lower than control (89.2); standard drug diclofenac showed 23.2 writhes. Percent inhibition of writhing were 54.26 and 73.99 for 200 mg/kg and diclofenac respectively. The result of hind paw licking test also corroborated writhing test. Significant reduction in percent inhibition of licking was observed mainly in late phase. Percent inhibition of licking were 93.77 and 51.55 for 400 mg/kg extract and diclofenac respectively. In hot plate test, extract at 400 mg/kg showed significant increase in latency from 10.77 s to 13.59 s (p ≤ 0.05). Extract at this dose after 2 h demonstrated greater percent maximal effect (43.26%) compared to ketorolac (40.19%). CONCLUSION: The experiment confirmed the traditional use of F. miliacea in the treatment of fever with possible anti-nociceptive effects.