Punica granatum L. leaf extract enhances stress tolerance and promotes healthy longevity through HLH-30/TFEB, DAF16/FOXO, and SKN1/NRF2 crosstalk in Caenorhabditis elegans

Abstract

Background: Punica granatum L., commonly known as pomegranate, is renowned for its health benefits, primarily associated with the consumption of its fruit and seeds. However, its non-edible parts, including leaves, have been used in traditional medicine as a remedy with anti-inflammatory and anti-diabetic properties. Considering the abundance of bioactive compounds, predominantly flavonols, flavones, and tannins P. granatum leaf (PGL) extract holds potential as health-promoting agent. Yet, its effect on longevity and healthspan remains largely unexplored.

Purpose: Our study aims to explore the potential of PGL extract to enhance healthspan and ameliorate age-related frailty in Caenorhabditis elegans. Additionally, we seek to elucidate its effect on the molecular signaling networks associated with stress resistance and longevity.

Methods: After characterizing the extract metabolite profile by NMR spectroscopy, phenotypic and stress analyses were performed. In order to establish the molecular mechanism of action, the involvement of signaling pathways key to longevity were investigated by means of real-time quantitative PCR (RT-qPCR) and the use of transgenic strains (MIR13, MAH240, LD1, and OH16024). In addition, the effect of PGL on metabolism and lipid accumulation, as well as mitochondrial homeostasis, was examined.

Results: The PGL extract supplementation significantly enhanced stress resistance and extended the lifespan of C. elegans. Additionally, it improved locomotion, as well as metabolic and mitochondrial functions, indicating an overall improvement in health. The molecular mechanisms highlight the coordinated regulation of stress response, metabolic homeostasis, and longevity signaling pathways. Specifically, our results demonstrate the essential roles of HLH-30/TFEB, in conjunction with DAF-16/FOXO and SKN-1/NRF2, as mediators of the PGL extract effect on healthspan.

Conclusion: Our findings emphasize the potential of PGL extract to ameliorate age-related decline, induce longevity and further enhance healthspan. Given the diverse effects on the molecular network associated with stress-adaptations, longevity and metabolic control, PGL extract might become a promising natural product with a particular importance to the field of gerontology.

Keywords: Aging; Caenorhabditis elegans; Healthspan; Longevity; Pomegranate; Punica granatum.