Gengnianchun, a Traditional Chinese Medicine, Enhances Oxidative Stress Resistance and Lifespan in Caenorhabditis elegans by Modulating daf-16/FOXO

Cremastra appendiculata polysaccharides improve stress resistance and prolong the lifespan of Caenorhabditis elegans via daf-16 in the insulin signaling pathway

Cremastra appendiculata polysaccharide (CAP) exhibits potential anti-aging and stress resistance effects. In this study, we investigated the structure, antioxidant properties, and mechanism of action of CAP in Caenorhabditis elegans. The results showed that CAP primarily comprises mannose and glucose and exerts antioxidant activity in vitro. In vivo, CAP prolonged the lifespan of C. elegans in a concentration-dependent manner, with 2.0 mg/mL CAP prolonging the lifespan by 39.97 %. Compared with the control, the activities of superoxide dismutase (SOD) and catalase (CAT) antioxidant enzymes increased by 46 % and 57 %, respectively. However, the reactive oxygen species (ROS) and malondialdehyde (MDA) contents decreased by 38 % and 19.92 %, respectively, at the same CAP concentration, oxidative and heat stress resistance increased. The target genes of the insulin/insulin-like growth factor (IGF) signaling pathway, daf-16, sod-3, ctl-1, and hsp-16.2, were activated by CAP; their mRNA expression levels were upregulated by 7.23 %, 69.78 %, 43.62 %, and 58.62 %, respectively. A transgenic worm assay indicated that CAP regulates the lifespan of C. elegans through daf-16. These results suggest that CAP improves stress resistance and prolongs the lifespan of C. elegans through daf-16 in the insulin/IGF signaling pathway.

Oxidation and Antioxidation of Natural Products in the Model Organism Caenorhabditiselegans

Natural products are small molecules naturally produced by multiple sources such as plants, animals, fungi, bacteria and archaea. They exert both beneficial and detrimental effects by modulating biological targets and pathways involved in oxidative stress and antioxidant response. Natural products’ oxidative or antioxidative properties are usually investigated in preclinical experimental models, including virtual computing simulations, cell and tissue cultures, rodent and nonhuman primate animal models, and human studies. Due to the renewal of the concept of experimental animals, especially the popularization of alternative 3R methods for reduction, replacement and refinement, many assessment experiments have been carried out in new alternative models. The model organism Caenorhabditis elegans has been used for medical research since Sydney Brenner revealed its genetics in 1974 and has been introduced into pharmacology and toxicology in the past two decades. The data from C. elegans have been satisfactorily correlated with traditional experimental models. In this review, we summarize the advantages of C. elegans in assessing oxidative and antioxidative properties of natural products and introduce methods to construct an oxidative damage model in C. elegans. The biomarkers and signaling pathways involved in the oxidative stress of C. elegans are summarized, as well as the oxidation and antioxidation in target organs of the muscle, nervous, digestive and reproductive systems. This review provides an overview of the oxidative and antioxidative properties of natural products based on the model organism C. elegans.

Lentinan extends lifespan and increases oxidative stress resistance through DAF-16 and SKN-1 pathways in Caenorhabditis elegans

Lentinan, extracted from Lentinus edodes, exhibits bioactive properties in vitro; however, little is known about the antioxidant potential in vivo. In this study, the effects of lentinan at 0.05, 0.25 and 1.25 mg/mL on the lifespan, locomotion, reproductive capacity, and oxidative stress resistance in Caenorhabditis elegans were determined. Compared to the untreated control, lentinan at 0.05, 0.25 and 1.25 mg/mL significantly prolonged the lifespan by 17.6%, 35.3% and 25.3% (p < 0.001), respectively, and improved the brood size, locomotion and stress resistance of the nematodes. Furthermore, lentinan at 0.25 mg/mL significantly reduced accumulation of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) by 38.1% (p = 0.013) and 49.7% (p = 0.028), respectively. In addition, lentinan at all tested concentrations significantly increased the activities of superoxide dismutase (SOD) and catalase (CAT). The expression of skn-1 and daf-16 in the treatments with lentinan at 0.25 and 1.25 mg/mL was significantly (p < 0.005) up-regulated compared with the untreated control, whereas that of the daf-2 gene was significantly down-regulated. Further evidence revealed that ROS production in lentinan-treated daf-16 and skn-1 mutant strains was similar to the untreated control. Consistent with the aforementioned results, lentinan enhanced the nuclear translocation of DAF-16 and SKN-1. Our results demonstrated that lentinan could increase lifespan and protect the nematodes from oxidative stress through DAF-16 and SKN-1.

Therapeutic Effects of Modified Gengnianchun Formula on Stress-Induced Diminished Ovarian Reserve Based on Experimental Approaches and Network Pharmacology

Aim

To verify the effects of modified Gengnianchun formula (MGNC), a traditional Chinese medicine, on a stressed diminished ovarian reserve (DOR) animal model and predict the underlying mechanisms through network pharmacology strategies.

Methods

Sexually mature female C57BL/6 mice were allocated to five groups, abbreviated as the control (C) group, stress manipulated model (M) group, stress with normal saline gavage (N) group, stress with low-dose MGNC gavage (L) group, and stress with high-dose MGNC gavage (H) group. Body weight and the estrous cycle were monitored during the stress and gavage process. Serum stress hormones and reproductive hormones were evaluated by ELISA. Ovarian follicle counts were calculated, and ovarian follicle-stimulating hormone receptor (FSHR) and anti-Müllerian hormone (AMH) expression were assessed by Western blotting and immunohistochemistry. Network pharmacology strategies included active compound screening, drug and disease target analysis, gene ontology analysis, pathway analysis, and visualization of results.

Results

MGNC treatment significantly decreased serum corticosterone (CORT) and follicle-stimulating hormone (FSH) levels and increased testosterone (T) levels in the H group compared with the M and N groups. Primordial and preantral follicle counts and ovarian AMH and FSHR expression were significantly increased in the H group compared to those in the M and N groups. Through pharmacokinetic screening, we found 244 active compounds in MGNC. A total of 186 candidate intersection target genes of disease and MGNC were further screened to construct the interaction network. Gene ontology and KEGG pathway enrichment analysis ultimately unveiled a series of key targets that mainly mediated the effects of MGNC on DOR induced by chronic stress. The PI3K-Akt pathway may serve as the critical pathway underlying this therapeutic mechanism.

Conclusion

MGNC is a promising formula to treat DOR induced by chronic stress, and the PI3K-Akt pathway may play an essential role in this effect.

A Systematic Review of Antiaging Effects of 23 Traditional Chinese Medicines

BACKGROUND

Aging is an inevitable stage of body development. At the same time, aging is a major cause of cancer, cardiovascular disease, and neurodegenerative diseases. Chinese herbal medicine is a natural substance that can effectively delay aging and is expected to be developed as antiaging drugs in the future. Aim of the review. This paper reviews the antiaging effects of 23 traditional Chinese herbal medicines or their active components. Materials and methods. We reviewed the literature published in the last five years on Chinese herbal medicines or their active ingredients and their antiaging role obtained through the following databases: PubMed, EMBASE, Scopus, and Web of Science.

RESULTS

A total of 2485 papers were found, and 212 papers were screened after removing the duplicates and reading the titles. Twenty-three studies met the requirements of this review and were included. Among these studies, 13 articles used Caenorhabditis elegans as the animal model, and 10 articles used other animal models or cell lines.

CONCLUSION

Chinese herbal medicines or their active components play an antiaging role by regulating genes related to aging through a variety of signaling pathways. Chinese herbal medicines are expected to be developed as antiaging drugs or used in the medical cosmetology industry.

Gengnianchun Recipe Protects Ovarian Reserve of Rats Treated by 4-Vinylcyclohexene Diepoxide via the AKT Pathway

Diminished ovarian reserve (DOR) refers to a decrease in the number and quality of oocytes. Western treatment of DOR does not improve the ovarian reserve fundamentally, and the effect is limited. Gengnianchun recipe (GNC) is a traditional Chinese medicine formula originally applied to treat menopausal syndrome but is also found to be effective in treating clinical DOR patients. Here we aim to examine the effect of GNC in a DOR rat model induced by 4-vinylcyclohexene diepoxide (VCD), a chemical that selectively destroys ovarian small preantral follicles, and further investigate the possible mechanisms. Female SD rats were randomly divided into four groups: control group (C), model group (M), high-dose GNC group (H), and low-dose GNC group (L). Rats in M, H, and L were administered with VCD and normal saline, high-dose GNC, and low-dose GNC separately. Rat ovaries were harvested either to conduct HE staining for follicle count, immunohistochemistry, or western blot. We found that high dose of GNC significantly increased the ovarian index and sustained the number of primordial follicles and primary follicles in VCD treated rats. Moreover, high dose of GNC significantly increased the ovarian protein expression of mouse vasa homologue (MVH), anti-Müllerian hormone (AMH), follicle-stimulating hormone receptor (FSHR), and estrogen receptor β (ERβ) compared with that in the model group. Besides, high-dose GNC significantly increased ovarian AKT phosphorylation and the expression of downstream forkhead box O3 (FOXO3a). Proapoptosis proteins of Bax, cleaved caspase-3, and poly ADP-ribose polymerase (PARP) were significantly decreased after high-dose GNC treatment compared with those in the model group. Taken together, these findings suggest that high-dose GNC could protect ovarian reserve against VCD-induced toxicity via the activation of the AKT signaling pathway and reduced cell apoptosis in SD Rats. This effect could either be induced by the increased FSHR signaling or by the nontranscriptional activation of ERβ, which requires further investigation.

Aiweixin, a Traditional Uyghur Medicinal Formula, Extends the Lifespan of Caenorhabditis elegans

Aiweixin (AWX) is a traditional Uyghur medicine prescription, which has been used to treat senile diseases for a long time. We investigate whether the AWX extends the lifespan of Caenorhabditis elegans. The AWX decoction was the conventional product for clinical use. The wild-type Caenorhabditis elegans (N2) and mutational worms, daf-16(mu86), glp-1(e2141), daf-2(e1370), and eat-2(ad465), were applied for the lifespan analysis. We found that the lifespan of the N2 adults' worm received 0.005 and 0.01 volume of AWX/total volume was extended significantly, compared to the control without treatment of AWX. The AWX at 0.01 volume of AWX/total volume significantly prolonged the life of both mutational worms, daf-16 (mu86) and eat-2(ad465), but did not increase the lifespan of the mutational worms, daf-2(e1370) and glp-1(e2141). These results indicated that the AWX significantly extended the lifespan of wild-type nematodes, and the life extension effect of AWX was related to the germline longevity pathway and IIS signaling pathway but independent of DAF-16/FOXO.

Didymin improves UV irradiation resistance in C. elegans

Didymin, a type of flavono-o-glycoside compound naturally present in citrus fruits, has been reported to be an effective anticancer agent. However, its effects on stress resistance are unclear. In this study, we treated Caenorhabditis elegans with didymin at several concentrations. We found that didymin reduced the effects of UV stressor on nematodes by decreasing reactive oxygen species levels and increasing superoxide dismutase (SOD) activity. Furthermore, we found that specific didymin-treated mutant nematodes daf-16(mu86) & daf-2(e1370), daf-16(mu86), akt-1(ok525), akt-2(ok393), and age-1(hx546) were susceptible to UV irradiation, whereas daf-2(e1371) was resistant to UV irradiation. In addition, we found that didymin not only promoted DAF-16 to transfer from cytoplasm to nucleus, but also increased both protein and mRNA expression levels of SOD-3 and HSP-16.2 after UV irradiation. Our results show that didymin affects UV irradiation resistance and it may act on daf-2 to regulate downstream genes through the insulin/IGF-1-like signaling pathway.

Methyl 3,4-Dihydroxybenzoate Enhances Resistance to Oxidative Stressors and Lifespan in C. elegans Partially via daf-2/daf-16

Genetic studies have elucidated mechanisms that regulate aging; however, there has been little progress in identifying drugs that retard ageing. Caenorhabditis elegans is among the classical model organisms in ageing research. Methyl 3,4-dihydroxybenzoate (MDHB) can prolong the life-span of C. elegans, but the underlying molecular mechanisms are not yet fully understood. Here, we report that MDHB prolongs the life-span of C. elegans and delays age-associated declines of physiological processes. Besides, MDHB can lengthen the life-span of eat-2 (ad1113) mutations, revealing that MDHB does not work via caloric restriction (CR). Surprisingly, the life-span–extending activity of MDHB is completely abolished in daf-2 (e1370) mutations, which suggests that daf-2 is crucial for a MDHB-induced pro-longevity effect in C. elegans. Moreover, MDHB enhances the nuclear localization of daf-16/FoxO, and then modulates the expressions of genes that positively correlate with defenses against stress and longevity in C. elegans. Therefore, our results indicate that MDHB at least partially acts as a modulator of the daf-2/daf-16 pathway to extend the lifespan of C. elegans, and MDHB might be a promising therapeutic agent for age-related diseases.

Gengnianchun Extends the Lifespan of Caenorhabditis elegans via the Insulin/IGF-1 Signalling Pathway

Gengnianchun (GNC), a traditional Chinese medicine (TCM), is believed to have beneficial effects on ageing-related diseases, such as antioxidant properties and effects against Aβ-induced toxicity. We previously found that GNC extended the lifespan of Caenorhabditis elegans. However, the mechanism underlying this effect was unclear. In this study, we further explored the mechanisms of GNC using a C. elegans model. GNC significantly increased the lifespan of C. elegans and enhanced oxidative and thermal stress resistance. Moreover, chemotaxis increased after GNC treatment. RNA-seq analysis showed that GNC regulated genes associated with longevity. We also conducted lifespan assays with a series of worm mutants. The results showed that GNC significantly extended the lifespan of several mutant strains, including eat-2 (ad465), rsks-1 (ok1255), and glp-1 (e2144), suggesting that the prolongevity effect of GNC is independent of the function of these genes. However, GNC failed to extend the lifespan of daf-2 (e1370), age-1 (hx546), and daf-16 (mu86) mutant strains. Our findings suggest that GNC extends the lifespan of C. elegans via the insulin/IGF-1 signalling pathway and may be a potential antiageing agent.

A Chinese Herbal Formula, Gengnianchun, Ameliorates β-Amyloid Peptide Toxicity in a Caenorhabditis elegans Model of Alzheimer's Disease

Alzheimer's disease (AD) is an age-related neurodegenerative disorder, and the few drugs that are currently available only treat the symptoms. Traditional medicine or phytotherapy has been shown to protect against AD. In our previous studies, Gengnianchun (GNC), a traditional Chinese medicine formula with a prolongevity effect, protected against Aβ-induced cytotoxicity in pheochromocytoma cells (PC-12 cells) and hippocampal cells. Here, we investigated the effects and possible mechanisms by which GNC protected against Aβ toxicity using transgenic Caenorhabditis elegans CL4176. Our results showed that GNC effectively delayed the Aβ toxicity-triggered body paralysis of CL4176 worms. GNC decreased Aβ by reducing Aβ mRNA levels. Moreover, GNC significantly reduced reactive oxygen species in the AD model worms compared with the controls. In addition, GNC upregulated the daf-16, sod-3, hsp-16.2 genes, and enhanced DAF-16 translocation from the cytoplasm to the nuclei under oxidative stress conditions. GNC treatment of C. elegans strains lacking DAF-16 did not affect the paralysis phenotype. Taken together, these findings suggest that GNC could protect against Aβ-induced toxicity via the DAF-16 pathway in C. elegans. Further studies are required to analyze its effectiveness in more complex animals.