Hepatoprotective Activity of BV-7310, a Proprietary Herbal Formulation of Phyllanthus niruri, Tephrosia purpurea, Boerhavia diffusa, and Andrographis paniculata, in Alcohol-Induced HepG2 Cells and Alcohol plus a Haloalkane, CCl4, Induced Liver Damage in Rats

Excessive alcohol consumption is a worldwide threat with severe morbidity and mortality. Other than abstinence, there is still no FDA-approved drug for alcoholic liver disease (ALD). Liver is the primary site of ethanol metabolism and hence gets the most damage from excessive drinking. It triggers multiple signalling events including inflammation, leading to an array of hepatic lesions like steatosis, hepatitis, fibrosis, and cirrhosis. Similarly, when medications or xenobiotic compounds are ingested orally, the liver gets the highest exposure of those metabolites, which in turn can cause severe liver toxicity. BV-7310 is a standardized mixture of four Ayurvedic plants, namely, Phyllanthus niruri, Tephrosia purpurea, Boerhavia diffusa, and Andrographis paniculata. In different systems of traditional medicine, each of these plants has been known to have use in gastrointestinal disorders. We wanted to assess the combined effect of these plant extracts on alcohol-induced liver damage. First, we investigated the hepatoprotective activity of BV-7310 against alcohol-induced toxicity in human liver HepG2 cells. Ethanol treatment (120 mM for 48 hours) significantly showed toxicity (around 42%) in these cells, and coincubation with BV-7310 prevented ethanol-induced cell death in a dose-dependent manner. Interestingly, the formulation BV-7310 showed synergistic activity than any individual extract tested in this assay. BV-7310 also showed potent antioxidant activity in 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay. Next, we induced hepatitis in Sprague–Dawley (SD) rats using repeated alcohol (40%) dosing, and carbon tetrachloride (CCl4) 24 hours before termination. Both oral doses of BV-7310 (250 and 500 mg/kg body weight) protected the alcohol-induced body weight loss and significantly improved the elevated levels of liver enzymes compared to the vehicle treated group. Thus, BV-7310 prevents alcohol-induced toxicity in both in-vitro and in-vivo models and could be beneficial for the treatment of ALD or other conditions, which may cause liver toxicity

Host–rabies virus protein–protein interactions as druggable antiviral targets

We present an unconventional approach to antiviral drug discovery, which is used to identify potent small molecules against rabies virus. First, we conceptualized viral capsid assembly as occurring via a host-catalyzed biochemical pathway, in contrast to the classical view of capsid formation by self-assembly. This suggested opportunities for antiviral intervention by targeting previously unappreciated catalytic host proteins, which were pursued. Second, we hypothesized these host proteins to be components of heterogeneous, labile, and dynamic multi-subunit assembly machines, not easily isolated by specific target protein-focused methods. This suggested the need to identify active compounds before knowing the precise protein target. A cell-free translation-based small molecule screen was established to recreate the hypothesized interactions involving newly synthesized capsid proteins as host assembly machine substrates. Hits from the screen were validated by efficacy against infectious rabies virus in mammalian cell culture. Used as affinity ligands, advanced analogs were shown to bind a set of proteins that effectively reconstituted drug sensitivity in the cell-free screen and included a small but discrete subfraction of cellular ATP-binding cassette family E1 (ABCE1), a host protein previously found essential for HIV capsid formation. Taken together, these studies advance an alternate view of capsid formation (as a host-catalyzed biochemical pathway), a different paradigm for drug discovery (whole pathway screening without knowledge of the target), and suggest the existence of labile assembly machines that can be rendered accessible as next-generation drug targets by the means described