Magnolol extends lifespan and improves age-related neurodegeneration in Caenorhabditis elegans via increase of stress resistance.

Magnolol is a naturally occurring polyphenolic compound in many edible plants, which has various biological effects including anti-aging and alleviating neurodegenerative diseases. However, the underlying mechanism on longevity is uncertain. In this study, we investigated the effect of magnolol on the lifespan of Caenorhabditis elegans and explored the mechanism. The results showed that magnolol treatment significantly extended the  lifespan of nematode and alleviated senescence-related decline in the nematode model. Meanwhile, magnolol enhanced stress resistance to heat shock, hydrogen peroxide (H2O2), mercuric potassium chloride (MeHgCl) and paraquat (PQ) in nematode. In addition, magnolol reduced reactive oxygen species and malondialdehyde (MDA) levels, and increased superoxide dismutase and catalase (CAT) activities in nematodes. Magnolol also up-regulated gene expression of sod-3, hsp16.2, ctl-3, daf-16, skn-1, hsf-1, sir2.1, etc., down-regulated gene expression of daf-2, and promoted intranuclear translocation of daf-16 in nematodes. The lifespan-extending effect of magnolol were reversed in insulin/IGF signaling (IIS) pathway-related mutant lines, including daf-2, age-1, daf-16, skn-1, hsf-1 and sir-2.1, suggesting that IIS signaling is involved in the modulation of longevity by magnolol. Furthermore, magnolol improved the age-related neurodegeneration in PD and AD C. elegans models. These results indicate that magnolol may enhance lifespan and health span through IIS and sir-2.1 pathways. Thus, the current findings implicate magnolol as a potential candidate to ameliorate the symptoms of aging.

Mulberrin extends lifespan in Caenorhabditis elegans through detoxification function.

Mulberrin, a naturally occurring flavone found in mulberry and Romulus Mori, exhibits diverse biological functions. Here, we showed that mulberrin extended both the lifespan and healthspan in C. elegans. Moreover, mulberrin increased the worms' resistance to toxicants and activated the expression of detoxification genes. The longevity-promoting effect of mulberrin was attenuated in nuclear hormone receptor (NHR) homologous nhr-8 and daf-12 mutants, indicating that the lifespan extending effects of mulberrin in C. elegans may depend on nuclear hormone receptors NHR-8/DAF-12. Further analyses revealed the potential associations between the longevity effects of mulberrin and the insulin/insulin-like growth factor signaling (IIS) and adenosine 5'-monophosphate-activated protein kinase (AMPK) pathways. Together, our findings suggest that mulberrin may prolong lifespan and healthspan by activating detoxification functions mediated by nuclear receptors.

Targeting stress granules in neurodegenerative diseases: A focus on biological function and dynamics disorders.

Stress granules (SGs) are membraneless organelles formed by eukaryotic cells in response to stress to promote cell survival through their pleiotropic cytoprotective effects. SGs recruit a variety of components to enhance their physiological function, and play a critical role in the propagation of pathological proteins, a key factor in neurodegeneration. Recent advances indicate that SG dynamic disorders exacerbate neuronal susceptibility to stress in neurodegenerative diseases (NDs) including Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), Huntington's disease (HD) and Parkinson's disease (PD). Here, we outline the biological functions of SGs, highlight SG dynamic disorders in NDs, and emphasize therapeutic approaches for enhancing SG dynamics to provide new insights into ND intervention.

Nomilin and its analogue obacunone alleviate NASH and hepatic fibrosis in mice via enhancing antioxidant and anti-inflammation capacity.

Nonalcoholic steatohepatitis (NASH) and hepatic fibrosis are leading causes of cirrhosis with rising morbidity and mortality worldwide. Currently, there is no appropriate treatment for NASH and hepatic fibrosis. Many studies have shown that oxidative stress is a main factor inducing NASH. Nomilin (NML) and obacunone (OBA) are limonoid compounds naturally occurring in citrus fruits with various biological properties. However, whether OBA and NML have beneficial effects on NASH remains unclear. Here, we demonstrated that OBA and NML inhibited hepatic tissue necrosis, inflammatory infiltration and liver fibrosis progression in methionine and choline-deficient (MCD) diet, carbon tetrachloride (CCl4 )-treated and bile duct ligation (BDL) NASH and hepatic fibrosis mouse models. Mechanistic studies showed that NML and OBA enhanced anti-oxidative effects, including reduction of malondialdehyde (MDA) level, increase of catalase (CAT) activity and the gene expression of glutathione S-transferases (GSTs) and Nrf2-keap1 signaling. Additional, NML and OBA inhibited the expression of inflammatory gene interleukin 6 (Il-6), and regulated the bile acid metabolism genes Cyp3a11, Cyp7a1, multidrug resistance-associated protein 3 (Mrp3). Overall, these findings indicate that NML and OBA may alleviate NASH and liver fibrosis in mice via enhancing antioxidant and anti-inflammation capacity. Our study proposed that NML and OBA may be potential strategies for NASH treatment.

Pregnane X receptor agonist nomilin extends lifespan and healthspan in preclinical models through detoxification functions.

Citrus fruit has long been considered a healthy food, but its role and detailed mechanism in lifespan extension are not clear. Here, by using the nematode C. elegans, we identified that nomilin, a bitter-taste limoloid that is enriched in citrus, significantly extended the animals' lifespan, healthspan, and toxin resistance. Further analyses indicate that this ageing inhibiting activity depended on the insulin-like pathway DAF-2/DAF-16 and nuclear hormone receptors NHR-8/DAF-12. Moreover, the human pregnane X receptor (hPXR) was identified as the mammalian counterpart of NHR-8/DAF-12 and X-ray crystallography showed that nomilin directly binds with hPXR. The hPXR mutations that prevented nomilin binding blocked the activity of nomilin both in mammalian cells and in C. elegans. Finally, dietary nomilin supplementation improved healthspan and lifespan in D-galactose- and doxorubicin-induced senescent mice as well as in male senescence accelerated mice prone 8 (SAMP8) mice, and induced a longevity gene signature similar to that of most longevity interventions in the liver of bile-duct-ligation male mice. Taken together, we identified that nomilin may extend lifespan and healthspan in animals via the activation of PXR mediated detoxification functions.