Elucidating beneficial effects of Wolfberry (Lycium barbarum) in experimnetal depression

Abstract

The polysaccharides of Wolfberry (LBP), has been shown to exhibit protective effect on retinal neurons from a chronic ocular hypertension insult or cortical neurons from A-beta toxicity. Apart from these two experimental models, increasing line of evidence have proved a sharp decline of new neurons generation in dendate gyrus in depression. Therefore, we investigated whether LBP could also play a neuroprotective role on the neurogenesis in the dentate gyrus. To test this hypothesis, we studied the effects of 21-day LBP (1mg/kg) oral treatment on the neurogenesis in a rat depression model involving daily injection corticosterone (40 mg/Kg) for 14 days. Our results showed that 21-day LBP treatment reversed the inhibitory effect of corticosterone on the neurogenesis in the dentate gyrus, while 21-day LBP treatment alone did not affect neurogenesis in rats without the injection of corticosterone. Furthermore, our data showed that LBP treatment decreased depression-like behavior since the period of immobility in forced swimming test in corticosterone-treated rats was significantly decreased. In conclusion, our data demonstrate that LBP is able to block the reduction of neurogenesis induced by the corticosterone injection and ameliorates the behavioral performance in depressed rats. The underlying mechanisms of this neuroprotective effects of LBP need to be further explored.