Non-alcoholic steatohepatitis (NASH) is a common type of metabolic liver disease which is characterized by fatty changes associated with hepatocyte injury, lobular inflammation, and/or liver fibrosis. Nanoemulsions are kinetically stable colloidal systems characterized by small droplet size. Hemp seed oil is a natural oil derived from Cannabis sativa seeds. The current study was designed to formulate nanoemulsion preparations of hemp seed oil with promising enhanced biological activity against high fat (HF) diet induced NASH in rats. Four nanoemulsion formulas (NEFs) were formulated based on high-pressure homogenization technique and evaluated for droplet size, zeta potential (ZP), polydispersity index (PDI), electrical conductivity, pH, and viscosity, as well as the preparation stability. The best NEF was selected to perform an in vivo rat study; selection was based on the smallest droplet size and highest physical stability. Results showed that NEF#4 showed the best physiochemical characters among the other preparations. Twenty male rats were assigned to four groups as follows: normal, NASH control, NASH + hemp seed oil and NASH + hemp seed oil NEF4. The rats were tested for body weight (BWt) change, insulin resistance (IR) and hepatic pathology. The hemp seed NEF#4 protected against NASH progression in rats and decreased the % of BWt gain compared to the original Hemp seed oil. NEF#4 of Hemp seed oil showed greater protective activity against experimental NASH and IR in rats. Hence, we can consider the nanoemulsion preparations as a useful tool for enhancing the biological action of the hemp seed oil, and further studies are warranted for application of this technique for preparing natural oils aiming at enhancing their activities.
Keywords: O/W nanoemulsion; characterization; free fatty acids; hemp seed oil; oxidation markers; rat NASH.