Hepatoprotective Effect of Fresh Grape Juice Prepared by a Low-Speed Masticating Juicer in db/db Mice

Abstract

This study investigated the hepatoprotective effect of fresh grape juice prepared using a low-speed masticating (LSM) juicer or a high-speed centrifugal (HSC) juicer in mice. Six-week-old db/db mice were fed on an AIN-93G diet or a diet containing 1% freeze-dried LSM or HSC grape juice for 7 weeks. Treatment with LSM grape juice significantly decreased hepatic triglycerides, serum aspartate transaminase activities, and homeostasis model assessment for insulin resistance values, whereas HSC juice did not significantly influence these parameters. The LSM grape juice showed higher antioxidant and anti-inflammatory activities than HSC juice. The benefits of LSM grape juice are probably due to a much higher proanthocyanidin content than that of HSC juice. These results suggest that LSM grape juice can exert hepatoprotective effects in db/db mice, partly through improving insulin resistance and promoting antioxidant and inflammatory activities.

Keywords: antioxidant activity; grape juice; hepatoprotective effect; insulin resistance; low-speed masticating juicer.

Fig. 1

Hepatic triglycerides and serum activities of aspartate transaminase (AST) and alanine transaminase (ALT) in db/db mice. (A) Hepatic triglycerides, (B) serum AST activity, and (C) serum ALT activity. Control, LSM, and HSC groups were fed AIN-93G diet, diet containing 1% freeze-dried grape juice prepared using a low-speed masticating juicer, and diet containing 1% freeze-dried grape juice prepared using a high-speed centrifugal juicer for 7 weeks, respectively. Values represent means±SE (n=8). Different letters (a–c) are significantly different at P <0.05.