Saponins from bitter melon (BMS) exert potential bioactivities and pharmacological activities, including anti-oxidation and lifespan extension. However, the exact mechanisms of BMS in response to oxidative stress remain unknown. Results demonstrated that bitter melon saponins could strengthen locomotive activities (body bend and head thrashing) accompanied by delaying the muscle fiber damage with age in Caenorhabditis elegans . In addition, BMS inhibited the ROS accumulation, improved the activities of antioxidant enzymes like SOD (by 57.90% and 94.34% for 100 μg/ml and 200 μg/ml BMS, respectively) and CAT (by 51.45% and 56.91% for 100 μg/ml and 200 μg/ml BMS, respectively), and extend the lifespan of N2 and CL2006 worms under paraquat-induced oxidative stress. Mechanism study suggested that BMS modulated the mRNA expressions of oxidation-related regulators, like the upregulation of cat-1 , hsf-1 , sir-2.1, and hlh-30. Furthermore, gene-deficient mutants verified that IIS (insulin/insulin-like growth factor-1 signaling) pathway linked with sir-2.1 and hlh-30 factors were involved in the BMS's lifespan-extension effects under oxidative stress. In general, this study supplemented the explanation of BMS in promoting oxidation-resistance and lifespan-extension activities, which could be served as a potential candidate for anti-aging. Practical applications Our previous studies have suggested that saponins from bitter melon exhibited fat-lowering activity in C. elegans . However, little was known about the mechanism underlying the anti-oxidation effects of BMS in C. elegans. Current results indicated that the IIS pathway linked with sir-2.1 and hlh-30 transcriptional factors jointly to increase the lifespan in BMS' responses to oxidative stress. Our findings are beneficial to understand the main nutritional ingredients in bitter melon, which are ideal and expected in functional foods for aging.
Lijun Yang,Jiuyi Li,Yihan Zhou,Huaying Xu,Yu Wang,Jiayuan Zhao,Yanan Wang
Background: Aging involves progressive functional decline driven by oxidative stress and mitochondrial dysfunction, and dietary flavonoids are promising aging interventions due to their multi-target regulatory pathways. Methods: This study systematically evaluated the anti-aging activity of myricitrin (MYR) and its underlying mechanisms usingCaenorhabditis elegans, testing MYR at 0.25 mg/mL, employing a rotenone-induced model of mitochondrial oxidative stress, and performing reporter strain analyses, qRT-PCR, and molecular docking analysis with acetylcholinesterases (ACE-1/2). Results: MYR at 0.25 mg/mL significantly extended lifespan and improved locomotor performance without detectable toxicity regarding growth, feeding, or reproduction; reduced reactive oxygen species accumulation and restored antioxidant enzyme activities in the rotenone-induced model; was accompanied by the nuclear translocation of DAF-16 and the upregulation of associated downstream antioxidant genes (sod-3,gst-4); enhanced mitochondrial quality control by upregulatingsir-2.1and modulating genes associated with the mitochondrial unfolded protein response (atfs-1,hsp-6) and mitochondrial dynamics (fzo-1,drp-1); and indicated a favorable interaction between MYR and acetylcholinesterases (ACE-1/2). Conclusions: MYR represents a promising candidate compound for mitigating aging-related phenotypes, with its beneficial effects linked to a DAF-16-associated antioxidant response and SIR-2.1-correlated mitochondrial quality control network.
The drugs extending healthspan in clinic have always been searched. Nitazoxanide is an FDA-approved clinical antiprotozoal drug. Nitazoxanide is rapidly metabolized to tizoxanide after absorption in vivo . Our previous studies find that nitazoxanide and its metabolite tizoxanide induce mild mitochondrial uncoupling and activate cellular AMPK, oral nitazoxanide protects against experimental hyperlipidemia, hepatic steatosis, and atherosclerosis. Here, we demonstrate that both nitazoxanide and tizoxanide extend the lifespan and healthspan of C. elegans through Akt/AMPK/sir 2.1/daf16 pathway. Additionally, both nitazoxanide and tizoxanide improve high glucose-induced shortening of C. elegans lifespan. Nitazoxanide has been a clinical drug with a good safety profile, we suggest that it is a novel anti-aging drug.