Ameliorative effect of Luffa cylindrica fruits on Caenorhabditis elegans and cellular models of Alzheimer's disease-related pathology via autophagy induction.

BACKGROUND: Alzheimer's disease (AD) is a prevalent neurodegenerative disorder without an effective cure. Natural products, while showing promise as potential therapeutics for AD, remain underexplored. AIMS: This study was conducted with the goal of identifying potential anti-AD candidates from natural sources using Caenorhabditis elegans (C. elegans) AD-like models and exploring their mechanisms of action. MATERIALS & METHODS: Our laboratory's in-house herbal extract library was utilized to screen for potential anti-AD candidates using the C. elegans AD-like model CL4176. The neuroprotective effects of the candidates were evaluated in multiple C. elegans AD-like models, specifically targeting Aß- and Tau-induced pathology. In vitro validation was conducted using PC-12 cells. To investigate the role of autophagy in mediating the anti-AD effects of the candidates, RNAi bacteria and autophagy inhibitors were employed. RESULTS: The ethanol extract of air-dried fruits of Luffa cylindrica (LCE), a medicine-food homology species, was found to inhibit Aß- and Tau-induced pathology (paralysis, ROS production, neurotoxicity, and Aß and pTau deposition) in C. elegans AD-like models. LCE was non-toxic and enhanced C. elegans' health. It was shown that LCE activates autophagy and its anti-AD efficacy is weakened with the RNAi knockdown of autophagy-related genes. Additionally, LCE induced mTOR-mediated autophagy, reduced the expression of AD-associated proteins, and decreased cell death in PC-12 cells, which was reversed by autophagy inhibitors (bafilomycin A1 and 3-methyladenine). DISCUSSION: LCE, identified from our natural product library, emerged as a valuable autophagy enhancer that effectively protects against neurodegeneration in multiple AD-like models. RNAi knockdown of autophagy-related genes and cotreatment with autophagy inhibitors weakened its anti-AD efficacy, implying a critical role of autophagy in mediating the neuroprotective effects of LCE. CONCLUSION: Our findings highlight the potential of LCE as a functional food or drug for targeting AD pathology and promoting human health.

Shenqi formula delayed Alzheimer's disease-like symptoms by skn-1 pathway in Caernorhabditis elegans.

ETHNOPHARMACOLOGICAL RELEVANCE: Shenqi formula is composed of Codonopsis pilosula (Cp) and Lycium barbarum (Lb), and it is traditionally used for promoting qi and nourishing the spleen, liver and kidney. Cp and Lb have been reported to improve cognitive performance in APP/PS1 mice, prevent the accumulation of Aß, and reduce the neurotoxicity of Aß to achieve the anti-Alzheimer's disease (AD) effect. AIM OF THE STUDY: Shenqi formula was explored the therapeutic effect on Caenorhabditis elegans AD pathological model and the underlying mechanism of action. MATERIALS AND METHODS: Paralysis assay and serotonin sensitivity assay was used to detect whether Shenqi formula can alleviate AD paralysis phenotype, and then DPPH, ABTS, NBT and Fenton methods were applied to investigate the scavenging capacity to free radical, ROS, ·O2- and ·OH of Shenqi formula in vitro. H2DCF-DA and MitoSOX™ Red were employed to measure ROS and .O2- accumulation, respectively. RNAi was used to knock down the expression of skn-1 and daf-16 related to oxidative stress resistance signalling pathway. Fluorescence microscopy was used to record the expression of SOD-3::GFP, GST-4::GFP, SOD-1::YFP, and the nuclear translocation of SKN-1 and DAF-16. Western blot assay was carried out to test Aß monomers and oligomers. RESULTS: Shenqi formula delayed the AD-like pathological characteristics in C. elegans, and the complete Shenqi formula was more effective than Cp or Lb alone. The effect of Shenqi formula on delaying worm paralysis was partially eliminated by skn-1 RNAi, but not daf-16 RNAi. Shenqi formula significantly inhibited the abnormal deposition of Aß protein, decreased Aß protein monomers and oligomers. It increased the expressions of gst-4, sod-1, and sod-3 similar to paraquat, companied by rise then fall of ROS and .O2- in AD worms. CONCLUSIONS: Shenqi formula at least partially depended on SKN-1 signalling pathway to exert its anti-AD effect, and it is potential to be used as a kind of health food to prevent the progress of AD.

Anti-Oxidative and Anti-Aging Effects of Probiotic Fermented Ginseng by Modulating Gut Microbiota and Metabolites in Caenorhabditis elegans.

Antioxidative and antiaging abilities of probiotic fermented ginseng (PG) were evaluated in Caenorhabditis elegans (C. elegans). Lifespan and effect on heat stress and acute oxidative stress in C. elegans were significantly enhanced by PG. Antioxidative enzymes such as T-SOD, GSH-PX, CAT were significantly up-regulated, and MDA, ROS and apoptosis levels were significantly down-regulated. At the same time, PG exerted antioxidant and anti-aging activities by reducing the expression of DAF-2 mRNA and increasing the expression of SKN-1 and SOD-3 mRNA in C. elegans. In addition, the mechanism of antioxidative and antiaging activities of PG was explored through gut microbiota sequencing and untargeted metabolomics. The results of gut microbiota indicated that PG could significantly improve the composition and structure of microbes in the gut of C. elegans, and the relative abundance of beneficial bacteria was up-regulated. Untargeted metabolomic results elucidated that PG modulated antioxidant and antiaging activities through neuroactive ligand-receptor interaction, Citrate cycle (TCA cycle), pyruvate metabolism, ascorbate and aldarate metabolism and D-Arginine and D-ornithine metabolism of C. elegans. These results indicated that PG had excellent antioxidant and anti-aging activities, providing research value for the development of functional foods and improvement of aging-related diseases.

Black mulberry (Morus nigra) fruit extract alleviated AD-Like symptoms induced by toxic Aß protein in transgenic Caenorhabditis elegans via insulin DAF-16 signaling pathway.

Alzheimer's disease (AD) is one of the most severe neurodegenerative disorders. Recently, there is no effective treatment drug for AD. Morus nigra (M. nigra) is a black mulberry and widely distributed fruit in the Moraceae family with various undiscovered biological activities. The study aimed to investigate the potential anti-AD effect of M. nigra. Mulberry fruit extract (MF) was obtained from M. nigra and treated up to 1.00 mg/mL on transgenic AD Caenorhabditis elegans (C. elegans) models. MF inhibited Amyloid-ß (Aß)-induced paralysis symptoms by about 55.65 %, reduced Aß accumulation more than 50 % via immunoblotting, and suppressed over-sensitivity to exogenous serotonin in C. elegans. Furthermore, MF decreased the Aß oligomeric depositions in worm CL2006. MF activated the DAF-16 nuclear translocation and its downstream SOD-3 and GST-4. AD is a major age-related disorder. Therefore, MF treated for an aging test and proved to be expanded the lifespan of the worms up to 34.7 %. Besides, we have evaluated the MF in vivo antioxidative properties, where MF reduced reactive oxygen species (ROS) generations in C. elegans and remitted the activation of HSP-16.2 induced by the oxidative action of Juglone. Gene knockout and extended the lifespan of AD worms. However, RNA interference (RNAi) successfully silenced the daf-16 on the Aß phenotypic paralysis proved by MF effect. Our results indicate that MF alleviates AD-Like symptoms by activating the DAF-16 insulin signal pathway in C. elegans. Therefore, this MF study may provide new insights for mulberry application in safe AD treatment and clinical study.

Potential anti-Parkinsonian's effect of S-(+)-linalool from Cinnamomum osmophloeum ct. linalool leaves are associated with mitochondrial regulation via gas-1, nuo-1, and mev-1 in Caenorhabditis elegans.

Parkinson's disease (PD) is one of the prevalent neurodegenerative diseases, and developing new treatments from natural products is of particular interest. Essential oils from Cinnamomum osmophloeum ct. linalool leaves contain high levels (~95%) of S-(+)-linalool. The neuroprotective effects of linalool have been previously described, yet the underlying molecular mechanisms remain largely unknown. This study aimed to investigate the potential anti-Parkinsonian's effect of S-(+)-linalool on mitochondrial regulation and decipher the underlying molecular mechanisms in Caenorhabditis elegans PD model. Essential oils at 20 mg/L and 20 mg/L S-(+)-linalool each significantly attenuated the damaging effects of 6-hydroxydopamine (6-OHDA) on dopaminergic (DA) neurons and decreased the mitochondrial unfolded protein response (UPRmt ) to antimycin. RNAi knockdown of mitochondrial complex I (gas-1, nuo-1), and complex II (mev-1) genes prevented the improvement of mitochondrial activity by S-(+)-linalool. The protective effects of S-(+)-linalool on 6-OHDA-induced behavior changes were absent in a DA-specific strain of C. elegans produced by gas-1, nuo-1, and mev-1 RNAi knockdown. These results suggest the potential anti-Parkinsonian's effect of S-(+)-linalool is associated with mitochondrial activity and regulated by gas-1, nuo-1, and mev-1 in C. elegans. Our findings suggest that S-(+)-linalool might be a promising candidate for therapeutic application to inhibit the progression of PD.

Molecular Mechanisms for Anti-aging of Low-Vacuum Cold Plasma Pretreatment in Caenorhabditis elegans.

Cold plasma pretreatment has the potential of anti-aging. However, its molecular mechanism is still not clear. Here, cold plasma pretreatment was firstly used to investigate the anti-aging effects of Caenorhabditis elegans using transcriptomic technique. It showed that the optimal parameters of discharge power, processing time, and working pressure for cold plasma pretreatment were separately 100 W, 15 s, and 135 Pa. The released 0.32 mJ/cm2 of the moderate apparent energy density was possibly beneficial to the strong positive interaction between plasma and C. elegans. The longest lifespan (13.67 ± 0.50 for 30 days) was obviously longer than the control (10.37 ± 0.46 for 23 days). Furthermore, compared with the control, frequencies of head thrashes with an increase of 26.01% and 37.31% and those of body bends with an increase of 33.37% and 34.51% on the fourth and eighth day, respectively, indicated movement behavior was improved. In addition, the variation of the enzyme activity of superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) hinted that the cold plasma pretreatment contributed to the enhanced anti-aging effects in nematodes. Transcriptomics analysis revealed that cold plasma pretreatment resulted in specific gene expression. Anatomical structure morphogenesis, response to stress, regulation of biological quality, phosphate-containing compound metabolic process, and phosphorus metabolic process were the most enriched biological process for GO analysis. Cellular response to heat stress and HSF1-dependent transactivation were the two most enriched KEGG pathways. This work would provide the methodological basis using cold plasma pretreatment and the potential gene modification targets for anti-aging study.

Phytochemical Composition and Anti-Aging Activity of Butanol Extract of Hedyotis diffusa in Caenorhabditis elegans.

Hedyotis diffusa Willd. (H. diffusa), a kind of traditional Chinese medicine, has been evaluated to potential display antioxidant and anti-aging effects in vitro experiments. In this work, we investigated the effects on lifespan and stress resistance of the butanol extract from H. diffusa (NHD) in vivo using a Caenorhabditis elegans (C. elegans) model. The phytochemicals of NHD were identified by UPLC-ESI-qTOF-MS/MS method. NHD-treated wild-type N2 worms showed an increase in survival time under both normal and stress conditions. Meanwhile, NHD promoted the healthspan of nematodes by stimulating growth and development, reducing the deposition of age pigment, increasing the activities of superoxide dismutase (SOD) and glutathione peroxidase dismutase (GSH-Px), and decreasing the level of ROS without impairing fertility. Moreover, the upregulating of the expression of daf-16, gst-4, sod-3, hsp12.6 genes and the downregulating of the expression of daf-2 were involved in the NHD-mediated lifespan extension. Finally, the increasing of the expression of GST-4::GFP in CL2166 transgenic nematodes and the life-span-extending activity of NHD was completely abolished in daf-2 and daf-16 mutants further revealed that the potential roles for these genes in NHD-induced longevity in C. elegans. Collectively, our findings suggest that NHD may have an active effect in healthy aging and age-related diseases.

Eugenol Elicits Prolongevity by Increasing Resistance to Oxidative Stress in C. elegans.

AIMS: To analyze the efficacy of eugenol on longevity by assessing its antioxidant effect using Caenorhabditis elegans as an animal model. BACKGROUND: Eugenol is a major polyphenolic component of Ocimum sanctum (Tulsi) which attributes wide pharmacological activities and can serve as a biomarker. However, the possible effect of eugenol on longevity in Caenorhabditis elegans has not been reported. OBJECTIVE: The objective of this investigation was to provide the first scientific based results about the effect of eugenol on longevity, slowing down of paralysis in Alzheimer's model and the mechanism behind it in Caenorhabditis elegans animal model system. METHODS: The phenolic components of methanolic extract of Ocimum sanctum were analyzed by RP-HPLC. Worms were exposed to different concentrations of extract and one of its components - eugenol. Lifespan, health span, survival in CL4176 Alzheimer's model and molecular mechanism were analyzed. RESULTS: Extract of Ocimum sanctum and eugenol increased lifespan and provided indemnity against pro-oxidants. It also significantly improved healthy ageing and slowed the progression of neurodegeneration in CL4176 Alzheimer's model of the worm by increasing survival against prooxidants and slowing down the paralysis. Longevity effect was independent of the DAF-16 as observed by using DAF-16::GFP and daf-16 null mutant strains. These results implicate eugenol as a potent therapeutic compound that may curtail ageing and age related disorders like- Alzheimer's disease. CONCLUSION: The present work demonstrated eugenol as a potential anti-ageing compound that may curtail ageing, improve heath span by enhancing resistance to oxidative stress and exerts its effect independent of DAF-16 pathway. So, it can be assumed that eugenol can be beneficial to humans as well, albeit further research is necessary before declaring it for human consumption.

Transgenic expression of n-3 fatty acid desaturase (fat-1) in C57/BL6 mice: Effects on glucose homeostasis and body weight.

The fat-1 gene, derived from Caenorhabditis elegans, encodes for a fatty acid n-3 desaturase. In order to study the potential metabolic benefits of n-3 fatty acids, independent of dietary fatty acids, we developed seven lines of fat-1 transgenic mice (C57/BL6) controlled by the regulatory sequences of the adipocyte protein-2 (aP2) gene for adipocyte-specific expression (AP-lines). We were unable to obtain homozygous fat-1 transgenic offspring from the two highest expressing lines, suggesting that excessive expression of this enzyme may be lethal during gestation. Serum fatty acid analysis of fat-1 transgenic mice (AP-3) fed a high n-6 unsaturated fat (HUSF) diet had an n-6/n-3 fatty acid ratio reduced by 23% (P < 0.025) and the n-3 fatty acid eicosapentaenoic acid (EPA) concentration increased by 61% (P < 0.020). Docosahexaenoic acid (DHA) was increased by 19% (P < 0.015) in white adipose tissue. Male AP-3-fat-1 line of mice had improved glucose tolerance and reduced body weight with no change in insulin sensitivity when challenged with a high-carbohydrate (HC) diet. In contrast, the female AP-3 mice had reduced glucose tolerance and no change in insulin sensitivity or body weight. These findings indicate that male transgenic fat-1 mice have improved glucose tolerance likely due to increased insulin secretion while female fat-1 mice have reduced glucose tolerance compared to wild-type mice. Finally the inability of fat-1 transgenic mice to generate homozygous offspring suggests that prolonged exposure to increased concentrations of n-3 fatty acids may be detrimental to reproduction.

Protection with estradiol in developmental models of apoptotic neurodegeneration.

Medical measures that bear no known danger for the adult brain may trigger active neuronal death in the developing brain. Pharmacological blockade of N-methyl-D-aspartate or activation of GABA(A) receptors, blockade of voltage-dependent sodium channels, and oxygen induce widespread apoptotic neurodegeneration during the period of rapid brain growth in rodents. Because such measures are often necessary in critically ill infants and toddlers, search for adjunctive neuroprotective strategies is warranted. We report that 17beta-estradiol ameliorates neurotoxicity of drugs that block N-methyl-D-aspartate receptors, activate GABA(A) receptors, or block voltage-gated sodium channels and reduces neurotoxicity of oxygen in the infant rat brain. This neuroprotective effect is reversed by tamoxifen and cannot be reproduced by 17alpha-estradiol. 17Beta-estradiol did not affect GABA(A) or N-methyl-D-aspartate currents in hippocampal neuronal cultures, indicating that direct modulation of neurotransmitter receptor/channel properties by this compound cannot explain neuroprotective effect. 17beta-Estradiol did, however, increase levels of phosphorylated extracellular signal-regulated kinase 1/2 and AKT, suggesting that activation of these prosurvival proteins may represent one mechanism for its neuroprotective action. 17Beta-estradiol and related compounds may be neuroprotective agents suitable for use in critically ill infants and toddlers. Its supplementation may particularly help to improve neurocognitive outcome in preterm infants who are prematurely deprived of maternal estrogen.