Neuroprotective effect of Bryophyllum pinnatum flavonoids against aluminum chloride-induced neurotoxicity in rats

Abstract

Toxic metals such as aluminum accumulation in the brain have been associated with the pathophysiology of several neurodegenerative disorders. Bryophyllum pinnatum leaves contain a vast array of polyphenols, particularly flavonoids, that may play a role in the prevention of toxic and degenerative effects in the brain. This study assessed the neuro-restorative potential of leaves of B. pinnatum enriched flavonoid fraction (BPFRF) in aluminum-induced neurotoxicity in rats. Neurotoxicity was induced in male Wistar rats by oral administration of 150 mg/kg body weight of aluminum chloride (AlCl₃) for 21 days. Rats were grouped into five (n = 6); Control (untreated), Rivastigmine group, AlCl₃ group and BPFRF group (50 and 100 mg/kg b.wt.) for 21 days. Neuronal changes in the hippocampus and cortex were biochemically and histologically evaluated. Expression patterns of acetylcholinesterase (AChE) mRNA were assessed using semi-quantitative reverse-transcription-polymerase chain reaction protocols. Molecular interactions of BPFRF compounds were investigated in silico. The results revealed that oral administration of BPFRF ameliorated oxidative imbalance by augmenting antioxidant systems and decreasing lipid peroxidation caused by AlCl₃. BPFRF administration also contributed to the down-regulation of AChE mRNA transcripts and improved histological features in the hippocampus and cortex. Molecular docking studies revealed strong molecular interactions between BPFRF compounds, catalase, superoxide dismutase and glutathione peroxidase Overall, these findings suggest the neuroprotective effect of Bryophyllum pinnatum against aluminum-induced neurotoxicity.

Keywords:

• Acetylcholinesterase
• aluminum
• Bryophyllum pinnatum
• flavonoid
• oxidative stress
• neurotoxicity

Ethical approval

The protocols for animal handling as well as other procedures were performed according to the National Institute of Health (NIH, 1985) Guide for Care and Use of Laboratory Animals with the guidelines strictly observed. Ethical approval was obtained from the Ethics and Biosafety Committee, Faculty of Biological Sciences, UNN with protocol number UNN/FBS/EC/1009.

Acknowledgement

The authors would like to appreciate and acknowledge the kind assistance of Malcolm Taylor of the Spectroscopy Unit, Central Analytical Facility (CAF), Stellenbosch University, South Africa for the LC/MS analysis and data interpretation. The authors would like to thank Dr Kingsley Omeje, Dr Daniel Emmanuel Ekpo and Miss Okpalefe Okeimute for their technical support. The authors are also thank Dr. Iyora Ogar of the Univeristy of Calabar, Nigeria for proofreading the manuscript.

Disclosure statement

The authors declare that there is no conflict of interest to disclose.

Data availability statements

All data generated during and/or analyzed during the current study are available from the corresponding author on request.