Protective effects of berberine against diabetes-associated cognitive decline in mice.

Aims: Diabetes associated cognitive decline (DACD) is a common CNS-related consequence of diabetes. The primary clinical manifestation of DACD includes learning and memory impairment. Unfortunately, there is no cure to delay the cognitive symptoms of diabetes. Although berberine (BBR) has shown promising effect in the treating diabetes and cognitive dysfunction, more research is needed to understand the mechanism of its therapeutic effect. For better understanding, we investigated the functions of BBR involved in anti-inflammation, anti-oxidant and neuroprotection in the hippocampus of diabetic mice.

Methods: Diabetes was induced in mice using STZ. BBR was administered for 4 weeks before (pre-treatment), and after (post-treatment) STZ administration. The effect of BBR on cognitive functions in diabetic mice was determined using neurobehavioural test. Moreover, how BBR affected neuroinflammation, oxidative stress, and acetylcholine levels in the hippocampus and BBB permeability were analyzed using standard biochemical assays. Lastly, we evaluated the mRNA expression of neuroprotective genes in the hippocampus to uncover the mechanism of BBR.

Results: Treatment with BBR improved cognition in diabetic mice. It significantly reduced the levels of IL-6, iNOS, TNF-α, IL-1β, ROS and MDA and increased the levels of TAC, GSH, SOD and Catalase. Moreover, levels of acetylcholine and BBB permeability were reduced in the diabetic mice which was reversed by BBR treatment and increased the expression of IGF and BDNF in the hippocampus of diabetic mice.

Conclusion: Our results suggest that BBR might be a potential therapeutic candidate for the treatment of DACD. Our study might serve as a basis for developing novel drugs for treating DACD.