Neurological Applications of Exosome-Delivered Bioactives from Ancient Chinese Herbal Components

Abstract

A bioactive substance derived from Chinese herbal medicines with established biological activity and pharmacological
effects is known as a traditional Chinese medicine (TCM) monomer. It has drawn a lot of interest for the treatment of
neurological disorders. However, the low solubility and poor blood-brain barrier (BBB) crossing of TCM monomers restrict
their use. Small extracellular vesicles (EVs) with a diameter of 30 to 150 nm, exosomes may be employed as drug delivery
vehicles that target cells or tissues directly. They have special benefits, such as low immunogenicity, low toxicity, high blood
stability, and the capacity to pass the blood-brain barrier. The biogenesis, components, stability, surface modification,
separation method, benefits, and drawbacks of exosomes as drug carriers are covered in this review, which also contrasts
exosomes with other comparable drug delivery systems. Additionally, exosome-encapsulated TCM monomers exhibit
neuroprotective properties, such as anti-oxidation, anti-apoptosis, anti-inflammation, and anti-mitophagy, in a variety of
neuronal diseases, such as cerebral ischemia and reperfusion (CI/R) injury, Alzheimer's disease (AD), Parkinson's disease
(PD), multiple sclerosis (MS), and anti-drug resistance, anti-tumorigenesis, and anti-angiogenesis, as well as the promotion
of apoptosis in brain tumors. These findings further motivate the development of an exosome-based delivery tool in targeted
therapy for neuronal diseases.