Evaluation of Median Lethal Dose and Analgesic Activity of Foeniculum vulgare Miller Essential Oil

Toxic effects of sub-chronic exposure of male albino rats to emamectin benzoate and possible ameliorative role of Foeniculum vulgare essential oil

Emamectin benzoate (EB) is an avermectin insecticide used extensively in pest control on vegetable and field crops. Few studies have been done for evaluating adverse effects of EB. In the current study, we evaluated the toxic effects of EB on male rats and the possible ameliorative role of fennel essential oil (FEO). Thirty two male rats were randomly divided into 4 equal groups. All groups were treated orally with distilled water (control group), 0.5mlFEOkg(-1) BW (FEO group), 2.5mgEBkg(-1) BW (EB group), and 0.5mlFEOkg(-1) BW+2.5mgEBkg(-1) BW (FEO+EB group) for 28 days. The obtained results showed that EB treatment resulted in a significant decrease in body weight, body weight gain, RBC count, Hb concentration, % PCV, MCV and MCHC. Moreover, EB significantly decreased total leukocyte, lymphocyte, monocyte and platelet count but significantly increased granulocyte count. EB markedly decreased total protein, albumin, globulin, IgG and IgM concentrations with a significant increase in TNF-α secretion. EB had a negative impact on the liver as it significantly increased ALT, ALP, and MDA, while decreasing SOD activity. Regarding to the histopathological examination, EB treatment induced coagulative necrosis and blood vessels congestion of the liver in treated rats. Furthermore, it resulted in depletion and necrosis of the white pulp of the spleen in treated rats. The co-administration of FEO with EB, however, improved the majority of parameters studied, suggesting that FEO is an important substance in decreasing toxic effects of EB.

Chemical composition and analgesic activity of Senecio rufinervis essential oil

CONTEXT

Senecio rufinervis D.C (Asteraceae) is a tall aromatic herb, commonly found in Uttarakhand, India. No investigations on the biological activity of this plant have been published so far. Hence, this plant species became a subject of our scientific interest.

OBJECTIVE

The aim of the study was to investigate the chemical composition and analgesic activity of Senecio rufinervis essential oil in mice using both thermal and chemical models of pain.

MATERIALS AND METHODS

Essential oil from dried leaves of Senecio rufinervis was extracted by steam distillation and then subjected to GC-MS analysis. Varying doses of essential oil were given to mice, 30 min prior to the induction of abdominal constrictions and determination of mean reaction time in hot-plate maintained at 55° ± 0.5°C.

RESULTS

The main component detected in the essential oil of Senecio rufinervis was germacrene D (40.19%) followed by β-pinene (12.23%), β-caryophyllene (6.21%) and β-longipinene (4.15%). Essential oil exhibited significant and dose-dependent analgesic activity against acetic acid-induced writhing in mice. The percentage inhibition in number of writhes produced by 25, 50 and 75 mg/kg doses was, respectively, 69, 80 and 85%. The oil, at doses 50 and 75 mg/kg, significantly increased the mean latency in the hot-plate after 15 and 30 min of drug administration as compared to the control group.

DISCUSSION AND CONCLUSION

The results depicted both central and peripheral analgesic activity of S. rufinervis essential oil which was attributed to the presence of terpenes.