Medicinal Plants with Neuroprotective Potential in Neurodegenerative Diseases: A Critical Review of Phytochemistry, Mechanisms and Evidence, with Relevance to Bangladesh

Many plants used traditionally to aid memory have been put forward as neuroprotective candidates against dementia. This mini review weighs the preclinical and clinical evidence for six of them (Centella asiatica, Ginkgo biloba, Salvia species, Withania somnifera, Bacopa monnieri and Semecarpus anacardium), briefly describes five more, and considers their relevance to Bangladesh. Sources were PubMed, Google Scholar and Semantic Scholar, with a targeted update in 2026. In cells and rodents, the same mechanisms recur cholinergic modulation, antioxidant and anti-inflammatory activity, and protection against amyloid-beta toxicity. Human evidence is thin. Two large ginkgo trials did not prevent dementia, while small trials of sage, ashwagandha and Bacopa point to modest cognitive gains. Centella and Semecarpus have no controlled human data. Before any clinical recommendation, the field needs standardised extracts, safety assessment, and adequately powered trials in people at the earliest stages of Alzheimer's disease.