Alzheimer’s Disease: A Study on Natural and Herbal Treatment

Alzheimer’s disease (AD) is an illness that give rise to the degeneration of the neurons. It is termed after Dr. Alois Alzheimer and is expressed by memory impairment and cognitive dysfunction. Major challenges of the conventional therapies were barriers like blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier (BCSFB). Cerebrospinal fluid (CSF) is generated by specialised ependymal cells in the choroid plexus (CP) that create the blood-CSF barrier (BCSFB). There are tight junctions in BBB that limits paracellular diffusion of solutes. Moreover, drugs of Acetylcholine (AChE) inhibitors like Tacrine, Donepezil, Galantine, Rivastigmine and N-Methyl-D-Aspartate (NMDA) antagonist like Memantine have gastrointestinal effects such as nausea, vomiting, diarrhoea and other common adverse effects. NMDA receptor-mediated excitatory glutamatergic neurotransmission is essential for neuronal survival and synaptic development. On the other hand, increased NMDAR activity increases cell death and excitotoxicity, which may be a contributing factor to the neurodegeneration associated with Alzheimer's disease (AD). The ever-increasing statistics of AD stating a rise up of 1 crore cases annually all over the world with its risk factors have caused a need for preventive measures and safe methods to treat the disease. The involvement of free radicals and inflammation in the aetiology of Alzheimer's disease suggests that antioxidant and anti-inflammatory medicines might have a therapeutic role. Herbal medications, which are based on a richness of traditional knowledge, may be useful because they can address AD pathogenesis at numerous places, including the cellular and molecular levels. It has been postulated that they exert their protective benefits against cognitive impairment through generic antioxidant and anti-inflammatory activities, as well as particular actions on AChE, β-amyloid fibril production and tau aggregation. This review discusses the various natural and herbal alternatives such as Melissa officinalis, Evolvus alsinoides, Bacopa monnieri, Celastrus paniculatus, Centella asiatica, etc. prepared using nanotechnologies (liposomes, niosome, phytosomes, solid lipid nanoparticle) that have been found to show rapid and efficient absorption. This makes it a promising plan for the future aspects and for the upcoming improvements posing least toxicity and harm to the human health.