Effect of Diosmin on Lipopolysaccharide-induced Neuroinflammation and Cognitive Impairment in Mice

Context: Neuroinflammation has been linked to some neurobehavioral alterations including cognitive and memory impairment which are prominent features of many neurodegenerative disorders such as Alzheimer’s disease and Parkinson’s disease. Objective: This study explored the cognitive-enhancing properties of a flavonoid, diosmin, against lipopolysaccharide-induced cognitive impairment in mice. Materials and Methods: Thirty-five (35) mice were divided into five groups comprising seven (7) mice each (n=7). These groups were scheduled to receive either vehicle, any of the two doses of diosmin (50 mg/kg and 100 mg/kg) or donepezil for seven (7) consecutive days. Group 1-2 received vehicle, groups 3-4 received diosmin at 50 and 100 mg/kg respectively, and group 5 was the positive control group which received 10 mg/kg donepezil. About sixty (60) minutes post-treatment, groups 2-5 were treated with lipopolysaccharide (LPS; 250 µg/kg, i.p.) daily. Afterwards, all mice were subjected to the Y-maze and the novel object recognition (NOR) tests to assess their spatial and non-spatial working memory, respectively. Subsequently, the mice were sacrificed and whole brain samples were harvested for further biochemical analysis. The data was analysed using one way analysis of variance (ANOVA) and a post hoc test. The level of significance was set at p<0.05. Results: Our data shows that diosmin significantly inhibited the LPS-induced neuroinflammation by inhibiting the expression of selected proinflammatory mediators in the brain and subsequently improving memory (p<0.05). Conclusion: Diosmin possesses significant anti-inflammatory and antioxidant properties that could be beneficial in management of inflammation-related cognitive disorders.