Assessment of In vivo Antiviral Potential of Datura metel Linn. Extracts against Rabies Virus

The soxhlet, cold, and ayurvedic extracts of Datura metel Linn. were evaluated for in vivo antirabies activity.

Soxhlet and cold extraction method were used to extract Datura (fruit and seed) extracts, and ayurvedic extraction of Datura was prepared. In vivo toxicity assay was performed as per the OECD 420. LD₅₀ dose was calculated by Reed and Muench method. The in vivo antirabies activity was screened in Swiss albino mice with the virus challenge dose of 10 LD₅₀ (intracerebrally) in both preexposure (PE) and postexposure treatment with oral administration of Datura extracts in Swiss albino mice and observed for 21 days. The virus load in the mice brain was evaluated by TCID50 titration method.

Datura (ayurvedic preparation) was found to be nontoxic up to 2000 mg/kg in Swiss albino mice, i.e., 60 mg/30 g of mice, when administered (0.5 ml) orally and observed till 21 days. Up to 20% survival rate on the test group (PE of Datura extracts) up to 14 days postinfection as compared to the virus control group (10 LD₅₀) was observed. No survival rate was observed in the postexposure group of Datura extract; however, the survival time was increased by 4 days as compared to the virus control group. Viral load of the infected mice brain sample was estimated in vero cell line, and 3 log reduction in the virus titer was observed in text group as compared to the virus control, suggesting that Datura extract has an in vivo antirabies activity.

To the best of our knowledge, this is the first study of in vivo antiviral activity of an ayurvedic preparation of D. metel Linn. against rabies virus. Datura extracts have a potential in vivo antirabies activity.

In the present study, Datura metel Linn. (ayurvedic preparation) extract exhibited survival (20%) in the preexposure (PE) of the virus and the survival time was increased in the postexposure treatment where the disease was established. The mortality was observed, and the viral load was determined by titration method. Abbreviation Used: TCID50: tissue culture infectious dose 50; LD50: lethal dose 50; RV CVS: Rabies virus challenge virus standard; PE: Pre exposure; IC: intracerebral; PI: post infection; FITC: Fluorescein isothiocyanate.