piperine and Nerve-Degeneration

Spinocerebellar ataxia 17 (SCA17) belongs to the family of neurodegenerative diseases caused by polyglutamine (polyQ) expansion. In SCA17, polyQ expansion occurs in the TATA box binding protein (TBP) and leads to the misfolding of TBP and the preferential degeneration in the cerebellar Purkinje neurons. Currently there is no effective treatment for SCA17. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is a recently identified neurotrophic factor, and increasing MANF expression ameliorated SCA17 neuropathology in TBP-105Q knock-in (KI) mouse model, indicating that MANF could be a therapeutic target for treating SCA17.. In this study, we screened a collection of 2000 FDA-approved chemicals using a stable cell line expressing luciferase reporter, which is driven by MANF promoter. We identified several potential candidates that can induce the expression of MANF. Of these inducers, piperine is an agent that potently induces the luciferase expression or MANF expression.. Addition of piperine in both cellular and mouse models of SCA17 alleviated toxicity caused by mutant TBP. Although mutant TBP is primarily localized in the nuclei, the polyQ expansion in TBP is able to induce ER stress, suggesting that nuclear misfolded proteins can also elicit ER stress as cytoplasmic misfolded proteins do. Moreover, piperine plays its protective role by reducing toxicity caused by the ER stress.. Our study established piperine as a MANF-based therapeutic agent for ER stress-related neuropathology in SCA17.

Topics: Alkaloids; Animals; Benzodioxoles; Brain; Endoplasmic Reticulum Stress; Mice; Mice, Transgenic; Nerve Degeneration; Nerve Growth Factors; Neuroprotective Agents; Piperidines; Polyunsaturated Alkamides; TATA-Box Binding Protein

Recently, numerous medicinal plants possessing profound central nervous system effects and antioxidant activity have received much attention as food supplement to improve cognitive function against cognitive deficit condition including in Alzheimer's disease condition. Based on this information, the effect of piperine, a main active alkaloid in fruit of Piper nigrum, on memory performance and neurodegeneration in animal model of Alzheimer's disease have been investigated. Adult male Wistar rats (180-220 g) were orally given piperine at various doses ranging from 5, 10 and 20mg/kg BW at a period of 2 weeks before and 1 week after the intracerebroventricular administration of ethylcholine aziridinium ion (AF64A) bilaterally. The results showed that piperine at all dosage range used in this study significantly improved memory impairment and neurodegeneration in hippocampus. The possible underlying mechanisms might be partly associated with the decrease lipid peroxidation and acetylcholinesterase enzyme. Moreover, piperine also demonstrated the neurotrophic effect in hippocampus. However, further researches about the precise underlying mechanism are still required.

Topics: Acetylcholinesterase; Alkaloids; Alzheimer Disease; Animals; Aziridines; Benzodioxoles; Choline; Cognition Disorders; Donepezil; Hippocampus; Indans; Injections, Intraventricular; Lipid Peroxidation; Male; Malondialdehyde; Maze Learning; Nerve Degeneration; Neuromuscular Blocking Agents; Neuroprotective Agents; Nootropic Agents; Piper nigrum; Piperidines; Polyunsaturated Alkamides; Rats; Space Perception; Thailand