Studies on antivenom activity of Andrographis paniculata and Aristolochia indica plant extracts against Echis carinatus venom
S Meenatchisundaram, Prajish, G Parameswari, T Subbraj, A Michael
S Meenatchisundaram, Prajish, G Parameswari, T Subbraj, A Michael. Studies on antivenom activity of Andrographis paniculata and Aristolochia indica plant extracts against Echis carinatus venom. The Internet Journal of Toxicology. 2008 Volume 6 Number 1.
Snake envenoming is a major public health issue in the rural tropics with large numbers of envenoming and deaths. In India there are about 216 different species are found, of which 53 species are reported to be poisonous. The common poisonous snakes found in India are Cobra (
Materials and Methods
Venom and Experimental animals
The free-dried snake venom powder of
Preparation of Extracts
The whole plant material was dried in shade and the air-dried plant was ground and extracted first by refluxing with petroleum ether (50–60 °C, for 72 h) and then with methanol (60–80 °C for 72 h). The methanol extract was concentrated in vaccuo and kept in a desiccator at room temperature for further use. Before use, it was dissolved in saline and centrifuged at 2000 rpm for 10 min at room temperature. The supernatant was used for further investigation and kept at 4 °C. The plant extracts were expressed in terms of dry weight.
Tests for anti-snake venom activities
The median lethal dose (LD50) of
Edema- forming Activity
The Minimum edema-forming dose (MED) of
The minimum haemorrhagic dose (MHD) of
Phospholipase A2 activity was measured using an indirect hemolytic assay on agarose–erythrocyte–egg yolk gel plate by the methods described by Gutierrez et al., 1988. Increasing doses of
The procoagulant activity was done according to the method described by Theakston and Reid, 1983 modified by Laing
Statistical evaluation was performed using XL stat 2007 and SPSS 10 Softwares. P< 0.005 was considered statistically significant.
The antivenom potential of
In edema forming activity, the mice immunized with Echis carinatus venoms showed increase in footpad thickness. About 7μg of Saw-scaled viper venom induced edema formation within 3h which is considered as 100% activity. The edema was reduced up to 30% when 3.5mg of plant extracts /mg venom was given. There was no further reduction in the percentage of edema even when there was an increase in antivenom dose (Fig 2).
In the case of hemorrhagic activity, Saw-scaled viper venom produced visible hemorrhagic spot. About 8μg of venom produced a hemorrhagic spot of 10mm diameter (MHD). Both Plant extracts were able to neutralize the hemorrhage induced by the venom. In phospholipase activity (PLA2),
The minimum coagulant dose (MCD) was determined as the venom dose inducing clotting of plasma in 60s. About 120μg of Saw-scaled viper venom clotted human citrated plasma within 60s. In the neutralization assay, the absence of clot formation shows the neutralizing ability of both Plant extracts. We found that that 2.1mg of
Snakebite is a common medical emergency encountered in the tropics and estimated 35,000 to 50,000 people die of snakebite every year in India (Sharma