Caffeine, vanillin and their combination modulate purinergic enzyme activities, mRNA expressions of some synapticsentry proteins and histomorphological status of hippocampal tissue in aluminum chloride-induced neurotoxicity in rats

Background

The neurotoxic properties of aluminum (Al) is associated with Alzheimer's disease (AD) development. Consequently, there has been an increasing interest in exploring how bioactive compounds from functional foods mitigate the detrimental impact of this redox metal in AD. Hence, this study evaluated neuromodulatory effects of caffeine, vanillin and their combination on some hippocampal biochemical parameters in AlCl₃-induced neurotoxicity in rats.

Methods

Thirty-six (36) adult male Wistar rats (150–200 g) were randomly divided into 6 treatment groups of 6 rats each. Animals were exposed to AlCl₃ (100 mg/kg body weight, bw) orally at a single dose to induce neurotoxicity. Experimental AlCl₃-induced animals were administered with 50 mg/kg bw caffeine, vanillin and their combination for 21 days with donepezil (10 mg/kg bw) as control.

Results

However, following the 21 days treatment with 50 mg/kg caffeine, vanillin and their combination, a noticeable significant (p < 0.05) decrease was observed in the hippocampal ENTPDase activity with a concomitant increase significantly (p < 0.05) in eNTDase activity, respectively. Also, a significant (p < 0.05) reduction was evident in the hippocampal relative mRNA gene levels of eNOS, AChE and β-amyloid protein with no significant difference in the expression of GABA receptor protein in some treatment groups compared to untreated AlCl₃-induced control group. Similarly, hippocampal architecture revealed a restoration of dentate gyrus with an increased granular cell counts after the 21 days of treatment.

Conclusion

Therefore, based on the findings of this report, caffeine, vanillin and their combination could be further studied as potential candidates for therapeutic management of AD.