A study of standardized extracts of Picrorhiza kurroa Royle ex Benth in experimental nonalcoholic fatty liver disease

As a major organ of intermediary metabolism, the liver is exposed to a variety of metabolic insults due to diseases and xenobiotics viz., insulin resistance (IR) drugs, toxins, microbial products, etc. One of the consequences of these metabolic insults including obesity and type 2 diabetes mellitus is the development of non-alcoholic fatty liver disease (NAFLD). The recent alarming increase in the prevalence of NAFLD compels the need to develop an appropriate animal model of the disease so as to evolve effective interventions. In this study, we have developed, in the rat, a new model of NAFLD showing several key features akin to the disease in humans. Male Wistar rats were challenged with 30% high fat diet (HFD) – butter, for 2 weeks to induce NAFLD. A hydroalcoholic extract of Picrorhiza kurroa was administered to study the possible reversal of fatty changes in the liver. The extract was given in two doses viz., 200mg/kg and 400 mg/kg b.i.d., p.o. for a period of 4 weeks. There were three control groups (n = 6/group) – vehicle with a regular diet, vehicle with HFD, and HFD with silymarin – a known hepatoprotective. Histopathology showed that the P. kurroa extract brought about a reversal of the fatty infiltration of the liver (mg/g) and a lowering of the quantity of hepatic lipids (mg/g) compared to that in the HFD control group (38.33 ± 5.35 for 200mg/kg; 29.44 ± 8.49 for 400mg/kg of P. kurroa vs.130.07 ± 6.36mg/g of liver tissue in the HFD control group; P<0.001). Compared to the standard dose of the known hepatoprotective silymarin, P. kurroa reduced the lipid content (mg/g) of the liver more significantly at the dose of 400mg/kg (57.71 ± 12.45mg/kg vs. 29.44 ± 8.49 for the silymarin group vs. 400mg/kg of P. kurroa, P<0.001). In view of the increasing prevalence of metabolic syndrome and NAFLD, P. kurroa should be investigated by the reverse pharmacology path as a potential drug for the treatment of NAFLD, and essential safety studies and preformulation research for concentration of the putative actives should be carried out.