The role of Caenorhabditis elegans in the discovery of natural products for healthy aging

Covering: 2012 to 2023The human population is aging. Thus, the greatest risk factor for numerous diseases, such as diabetes, cancer and neurodegenerative disorders, is increasing worldwide. Age-related diseases do not typically occur in isolation, but as a result of multi-factorial causes, which in turn require holistic approaches to identify and decipher the mode of action of potential remedies. With the advent of C. elegans as the primary model organism for aging, researchers now have a powerful in vivo tool for identifying and studying agents that effect lifespan and health span. Natural products have been focal research subjects in this respect. This review article covers key developments of the last decade (2012-2023) that have led to the discovery of natural products with healthy aging properties in C. elegans. We (i) discuss the state of knowledge on the effects of natural products on worm aging including methods, assays and involved pathways; (ii) analyze the literature on natural compounds in terms of their molecular properties and the translatability of effects on mammals; (iii) examine the literature on multi-component mixtures with special attention to the studied organisms, extraction methods and efforts regarding the characterization of their chemical composition and their bioactive components. (iv) We further propose to combine small in vivo model organisms such as C. elegans and sophisticated analytical approaches ("wormomics") to guide the way to dissect complex natural products with anti-aging properties.

Purification of polyphenols from Phyllanthus emblica L. pomace using macroporous resins: Antioxidant activity and potential anti-Alzheimer's effects

Phyllanthus emblica L. pomace is a waste residue obtained following juicing that contains many polyphenols. In this study, NKA-II resin was selected as the optimal macroporous resin for separation and employed to separate the crude polyphenol extract of P. emblica pomace. The separation conditions were optimized, and the polyphenol content, polyphenol components, antioxidant activity, and potential anti-Alzheimer's effects of the extract were measured before and after purification. Results showed that the polyphenol content of the purified extract was 656.85 mg/g, which was 2.1 times higher than that of the nonpurified form. Further, the polyphenol components of the pomace, which was like that of the fruit, did not vary after purification. The antioxidant activity of the purified extract was also significantly improved. Moreover, purified extract significantly reduced the paralysis rate of the transgenic Caenorhabditis elegans model of Alzheimer's disease, and the mechanism was related to maintenance of redox homeostasis. PRACTICAL APPLICATION: The polyphenol content and antioxidant activity of purified polyphenol from Phyllanthus emblica L. pomace extracts were significantly improved using optimal separation methods with NKA-II macroporous resin and 70% aqueous ethanol as the eluent in this study. Moreover, purified polyphenols showed potential effects in alleviating Alzheimer's disease. These results suggest that polyphenols separated from P. emblica pomace are valuable for further research and development, and the utilization rate of P. emblica fruit is improved due to the further development of P. emblica pomace.

Flavonoids: Potential Candidates for the Treatment of Neurodegenerative Disorders

Neurodegenerative disorders, such as Parkinson's disease (PD), Alzheimer's disease (AD), Amyotrophic lateral sclerosis (ALS), and Huntington's disease (HD), are the most concerning disorders due to the lack of effective therapy and dramatic rise in affected cases. Although these disorders have diverse clinical manifestations, they all share a common cellular stress response. These cellular stress responses including neuroinflammation, oxidative stress, proteotoxicity, and endoplasmic reticulum (ER)-stress, which combats with stress conditions. Environmental stress/toxicity weakened the cellular stress response which results in cell damage. Small molecules, such as flavonoids, could reduce cellular stress and have gained much attention in recent years. Evidence has shown the potential use of flavonoids in several ways, such as antioxidants, anti-inflammatory, and anti-apoptotic, yet their mechanism is still elusive. This review provides an insight into the potential role of flavonoids against cellular stress response that prevent the pathogenesis of neurodegenerative disorders.