Extraction, purification, structural characterization and biological activity of polysaccharides from Fritillaria: A review

Ageing is the primary risk factor for most neurodegenerative diseases, including Alzheimer disease (AD) and Parkinson disease (PD). One in ten individuals aged ≥65 years has AD and its prevalence continues to increase with increasing age. Few or no effective treatments are available for ageing-related neurodegenerative diseases, which tend to progress in an irreversible manner and are associated with large socioeconomic and personal costs. This Review discusses the pathogenesis of AD, PD and other neurodegenerative diseases, and describes their associations with the nine biological hallmarks of ageing: genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, mitochondrial dysfunction, cellular senescence, deregulated nutrient sensing, stem cell exhaustion and altered intercellular communication. The central biological mechanisms of ageing and their potential as targets of novel therapies for neurodegenerative diseases are also discussed, with potential therapies including NAD+ precursors, mitophagy inducers and inhibitors of cellular senescence.

Except for an essential step for the pathology of multiple diseases including atherosclerosis and rheumatoid arthritis, inflammation is an imperative therapeutic target for developing novel approaches for pharmacological interventions. Thus, molecular understanding of inflammation not only revealed the mechanisms of drug action and their biological targets but also has spawned innovative maneuvers to influence multifaceted biological systems, providing new prospects for drug designing and suggesting important new implications for existing clinical medicine. Meanwhile, modulation of inflammation with the use of medicinal plants proposed an alternate to conventional therapeutic strategies for numerous ailments, particularly when suppression of inflammation is expected. In modern literature, several species of medicinal plants have been shown substantial antiinflammatory and immunomodulatory actions including inhibitory effects on suppression of cellular and humoral immunity, lymphocyte activation, and propagation of apoptosis. Herein, we reviewed the molecular pharmacology of inflammation, chemical components and biological activities of medicinal plants such as, curcumin from Curcuma longa, and epigallocatechin-3-gallate from Camellia sinensis as well as their mechanism of action during inflammation at molecular level. An extensive review of the literature and electronic databases was conducted, encompassing PubMed, GoogleScholar, ScienceDirect, medlineplus, www.clinicaltrial.gov, www.fda.gov, www.ema.europa.eu, www.drugbank.ca, TrialBulletin.com, www.theplantlist.org, and www.pharmacodia.com for assembling the information. Additionally, data was attained from books, ethnopharmacological literature, and relevant publications for essential elements of molecular mechanisms, signal transduction networks, transcription factors, complement system, reactive species, and clinical trials are selected for substantial understanding of biochemistry, pathophysiology as well as clinical importance of medicinal plants during inflammatory diseases.