Andrographolide Inhibits Rabies Virus Replication

Pretreatment of RABV with Andro in test tubes for 1 h did not affect the virus replication in host cells, implying that Andro did not directly reduce RABV viability. Of interest, Andro treatment impeded RABV binding to cells despite no effect on RABV invasion of cells. Also, Andro treatment downregulated the expression of RABV genomic RNA and structural genes in the cells.

To investigate the therapeutic efficacy of Andro in vivo, mice were administered Andro via intraperitoneal injection or intragastric gavage. Neither the administration route nor the dosage significantly affected body weight. Notably, Andro protected mice against a lethal challenge with RABV strain CVS-11.

Specifically, intraperitoneal injection of 100 mg/kg and 1 mg/kg Andro increased survival rates from 20% to 60% and 80%, respectively, while intragastric gavage of 250 mg/kg Andro elevated the survival rate from 30% to 60%. The results suggest that Andro has a great potential as a novel anti-RABV agent for the treatment of rabies.