Phytosome for Targeted Delivery of Natural Compounds: Improving Efficacy, Bioavailability, and Delivery across BBB for the Treatment of Alzheimer's Disease

Alzheimer’s disease (AD) is a progressive neurological disorder. Recent studies show that AD is the most common cause of dementia. There are several symptomatic treatments available to counterbalance the neurotransmitter disturbance. Currently, cholinesterase inhibitors are available for the treatment of mild to moderate AD. In addition to that, memantine (an N-methyl-D-aspartate receptor non-competitive antagonist) is also available for moderate to severe AD. Poor blood-brain barrier permeability is a limitation of existing drugs. These drugs may slow the disease progression, but there are chances of reoccurrence of the disease. Several medicinal plants such as Jasminum sambac, Rosmarinus officinalis, Eucalyptus globulus, Nigella sativa, and Acorus gramineus are reported to have neuroprotective effects. Salvia officinalis has cholinergic binding properties. Ginger root extract may prevent behavioral dysfunction in AD. Extensive research on these plants should be carried out. Drug delivery systems such as lipid nanoparticles, polymer nanoparticles, nanomicelles, nano-gels, liposomes, phytosomes, etc., could significantly improve the pharmacokinetics, stability, efficacy and reduce the side effects. Phytosomes have the advantage over other drug delivery systems to selectively target the drugs into the brain. In contrast to traditional approaches, polar phytoconstituents loaded phytosomes are more bioavailable on the site of brain tissue, as they can easily go for systemic circulation crossing the Blood-Brain Barrier (BBB). Phytosomes have a low hazard profile as toxicological outcomes are negligible and assure duration of action at a lowrisk profile due to upgraded absorption of the active constituents. In addition to this, the improved pharmacodynamic properties of phytosomes make them suitable for the treatment of neurological disorders.