Anti-Obesity Effects of Marine Macroalgae Extract Caulerpa lentillifera in a Caenorhabditis elegans Model.

Obesity is a multifactorial disease characterized by an excessive accumulation of fat, which in turn poses a significant risk to health. Bioactive compounds obtained from macroalgae have demonstrated their efficacy in combating obesity in various animal models. The green macroalgae Caulerpa lentillifera (CL) contains numerous active constituents. Hence, in the present study, we aimed to elucidate the beneficial anti-obesity effects of extracts derived from C. lentillifera using a Caenorhabditis elegans obesity model. The ethanol (CLET) and ethyl acetate (CLEA) extracts caused a significant decrease in fat consumption, reaching up to approximately 50-60%. Triglyceride levels in 50 mM glucose-fed worms were significantly reduced by approximately 200%. The GFP-labeled dhs-3, a marker for lipid droplets, exhibited a significant reduction in its level to approximately 30%. Furthermore, the level of intracellular ROS displayed a significant decrease of 18.26 to 23.91% in high-glucose-fed worms treated with CL extracts, while their lifespan remained unchanged. Additionally, the mRNA expression of genes associated with lipogenesis, such as sbp-1, showed a significant down-regulation following treatment with CL extracts. This finding was supported by a significant decrease (at 16.22-18.29%) in GFP-labeled sbp-1 gene expression. These results suggest that C. lentillifera extracts may facilitate a reduction in total fat accumulation induced by glucose through sbp-1 pathways. In summary, this study highlights the anti-obesity potential of compounds derived from C. lentillifera extracts in a C. elegans model of obesity, mediated by the suppression of lipogenesis pathways.

Holothuria scabra extracts confer neuroprotective effect in C. elegans model of Alzheimer's disease by attenuating amyloid-ß aggregation and toxicity.

Background and aim: Alzheimer's disease (AD) is the most common aged-related neurodegenerative disorder that is associated with the toxic amyloid-ß (Aß) aggregation in the brain. While the efficacies of available drugs against AD are still limited, natural products have been shown to possess neuroprotective potential for prevention and therapy of AD. This study aimed to investigate the neuroprotective effects of H. scabra extracts against Aß aggregation and proteotoxicity in C. elegans model of Alzheimer's diseases. Experimental procedure: Whole bodies (WB) and body wall (BW) of H. scabra were extracted and fractionated into ethyl acetate (WBEA, BWEA), butanol (WBBU, BWBU), and ethanol (BWET). Then C. elegans AD models were treated with these fractions and investigated for Aß aggregation and polymerization, biochemical and behavioral changes, and level of oxidative stress, as well as lifespan extension. Results and conclusion: C. elegans AD model treated with H. scabra extracts, especially triterpene glycoside-rich ethyl acetate and butanol fractions, exhibited significant reduction of Aß deposition. These H. scabra extracts also attenuated the paralysis behavior and improved the neurological defects in chemotaxis caused by Aß aggregation. Immunoblot analysis revealed decreased level of Aß oligomeric forms and the increased level of Aß monomers after treatments with H. scabra extracts. In addition, H. scabra extracts reduced reactive oxygen species and increased the mean lifespan of the treated AD worms. In conclusion, this study demonstrated strong evidence of anti-Alzheimer effects by H. scabra extracts, implying that these extracts can potentially be applied as natural preventive and therapeutic agents for AD. Taxonomy classification by EVISE: Alzheimer's disease, Neurodegenerative disorder, Traditional medicine, Experimental model systems, Molecular biology.

Neuroprotective effects of a medium chain fatty acid, decanoic acid, isolated from H. leucospilota against Parkinsonism in C. elegans PD model.

Sea cucumbers are marine organism that have long been used for food and traditional medicine in Asian countries. Recently, we have shown that ethyl acetate fraction (HLEA) of the crude extract of the black sea cucumber, Holothuria leucospilota, could alleviate Parkinsonism in Caenorhabditis elegans PD models. In this study, we found that the effective neuroprotective activity is attributed to HLEA-P1 compound chemically isolated and identified in H. leucospilota ethyl acetate. We reported here that HLEA-P1 could attenuate DAergic neurodegeneration, improve DAergic-dependent behaviors, reduce oxidative stress in 6-OHDA-induced C. elegans. In addition, HLEA-P1 reduced α-synuclein aggregation, improved behavior deficit and recovered lipid deposition in transgenic C. elegans overexpressing α-synuclein. We also found that HLEA-P1 activates nuclear localization of DAF-16 transcription factor of insulin/IGF-1 signaling (IIS) pathway. Treatment with 25 µg/ml of HLEA-P1 upregulated transcriptional activity of DAF-16 target genes including anti-oxidant genes (such as sod-3) and small heat shock proteins (such as hsp16.1, hsp16.2, and hsp12.6) in 6-OHDA-induced worms. In α-synuclein-overexpressed C. elegans strain, treatment with 5 µg/ml of HLEA-P1 significantly activated mRNA expression of sod-3 and hsp16.2. Chemical analysis demonstrated that HLEA-P1 compound is decanoic acid/capric acid. Taken together, our findings revealed that decanoic acid isolated from H. leucospilota exerts anti-Parkinson effect in C. elegans PD models by partly modulating IIS/DAF-16 pathway.

Diterpene glycosides from Holothuria scabra exert the α-synuclein degradation and neuroprotection against α-synuclein-Mediated neurodegeneration in C. elegans model.

ETHNOPHARMACOLOGICAL RELEVANCE: Holothuria (Metriatyla) scabra Jaeger (H. scabra), sea cucumber, is the marine organism that has been used as traditional food and medicine to gain the health benefits since ancient time. Although our recent studies have shown that crude extracts from H. scabra exhibited neuroprotective effects against Parkinson's disease (PD), the underlying mechanisms and bioactive compounds are still unknown. AIM OF THE STUDY: In the present study, we examined the efficacy of purified compounds from H. scabra and their underlying mechanism on α-synuclein degradation and neuroprotection against α-synuclein-mediated neurodegeneration in a transgenic Caenorhabditis elegans PD model. MATERIAL AND METHODS: The H. scabra compounds (HSEA-P1 and P2) were purified and examined for their toxicity and optimal dose-range by food-clearance and lifespan assays. The α-synuclein degradation and neuroprotection against α-synuclein-mediated neurodegeneration were determined using transgenic C. elegans model, Punc-54::α-syn and Pdat-1:: α-syn; Pdat-1::GFP, respectively, and then further investigated by determining the behavioral assays including locomotion rate, basal slowing rate, ethanol avoidance, and area-restricted searching. The underlying mechanisms related to autophagy were clarified by quantitative PCR and RNAi experiments. RESULTS: Our results showed that HSEA-P1 and HSEA-P2 significantly diminished α-synuclein accumulation, improved motility deficits, and recovered the shortened lifespan. Moreover, HSEA-P1 and HSEA-P2 significantly protected dopaminergic neurons from α-synuclein toxicity and alleviated dopamine-associated behavioral deficits, i.e., basal slowing, ethanol avoidance, and area-restricted searching. HSEA-P1 and HSEA-P2 also up-regulated autophagy-related genes, including beclin-1/bec-1, lc-3/lgg-1, and atg-7/atg-7. RNA interference (RNAi) of these genes in transgenic α-synuclein worms confirmed that lc-3/lgg-1 and atg-7/atg-7 were required for α-synuclein degradation and DAergic neuroprotection activities of HSEA-P1 and HSEA-P2. NMR and mass spectrometry analysis revealed that the HSEA-P1 and HSEA-P2 contained diterpene glycosides. CONCLUSION: These findings indicate that diterpene glycosides extracted from H. scabra decreases α-synuclein accumulation and protects α-synuclein-mediated DAergic neuronal loss and its toxicities via lgg-1 and atg-7.

Saponin-rich extracts from Holothuria leucospilota mediate lifespan extension and stress resistance in Caenorhabditis elegans via daf-16.

Saponins are secondary metabolite compounds that can be found in sea cucumbers (Holothuroidea spp.). However, little is known about how saponin-rich extracts from Holothuria leucospilota can delay and prolong the lifespan of the whole organism. In this study, anti-aging effects of H. leucospilota extracts were studied on Caenorhabditis elegans. NMR analysis revealed that body wall n-butanol-extract of H. leucospilota (BW-BU) is saponin-rich. BW-BU extracts exhibited antioxidant activities by 2,2'-diphenyl-2-picrylhydrazyl assay (EC50  = 10.23 ± 0.12 mg/ml) and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid assay (EC50  = 3.91 ± 0.04 mg/ml). BW-BU extracts increased lifespan of L4 and L1 C. elegans (5.92% and 15.76%, respectively), which also increased worm growth, stress resistance, and reduced biomarkers for aging. BW-BU extracts activated DAF-16 nuclear localization and upregulated daf-16 and DAF-16 target genes expression. Taken together, this study revealed the evidences on anti-aging activities of saponin-rich extracts from H. leucospilota, which can extend lifespan of C. elegans via daf-16. PRACTICAL APPLICATIONS: In recent years, age-associated chronic diseases have had a significant impact on quality of life. Many natural compounds exhibit anti-aging activities, especially in sea cucumber, H. leucospilota. Our results indicated that H. leucospilota is good for health. Extracts from H. leucospilota contain a bioactive compound that can be potentially used to promote longevity and disease prevention in aging.

Leaf extract of Caesalpinia mimosoides enhances oxidative stress resistance and prolongs lifespan in Caenorhabditis elegans.

BACKGROUND: Caesalpinia mimosoides, a vegetable consumed in Thailand, has been reported to exhibit in vitro antioxidant properties. The in vivo antioxidant and anti-aging activities have not been investigated. The aim of this research was to study the antioxidant activity of C. mimosoides extracts in Caenorhabditis elegans, a widely used model organism in this context. METHODS: C. elegans were treated with C. mimosoides extracts in a various concentrations. To investigate the protective effects of the extract against oxidative stress, wild-type N2 were used to determine survival rate under oxidative stress and intracellular ROS. To study underlying mechanisms, the mutant strains with GFP reporter gene including TJ356, CF1553, EU1 and LD4 were used to study DAF-16, SOD-3, SKN-1 and GST-4 gene, respectively. Lifespan and aging pigment of the worms were also investigated. RESULTS: A leaf extract of C. mimosoides improved resistance to oxidative stress and reduced intracellular ROS accumulation in nematodes. The antioxidant effects were mediated through the DAF-16/FOXO pathway and SOD-3 expression, whereas the expression of SKN-1 and GST-4 were not altered. The extract also prolonged lifespan and decreased aging pigments, while the body length and brood size of the worms were not affected by the extract, indicating low toxicity and excluding dietary restriction. CONCLUSIONS: The results of this study establish the antioxidant activity of C. mimosoides extract in vivo and suggest its potential as a dietary supplement and alternative medicine to defend against oxidative stress and aging, which should be investigated in intervention studies.

Ethanolic extract of Streblus asper leaves protects against glutamate-induced toxicity in HT22 hippocampal neuronal cells and extends lifespan of Caenorhabditis elegans.

BACKGROUND: Although such local herb as Streblus asper (family Moraceae) has long been recognized for traditional folk medicines and important ingredient of traditional longevity formula, its anti-neurodegeneration or anti-aging activity is little known. This study aimed to investigate the neuroprotective effect of S. asper leaf extracts (SA-EE) against toxicity of glutamate-mediated oxidative stress, a crucial factor contributing to the neuronal loss in age-associated neurodegenerative diseases and the underlying mechanism as well as to evaluate its longevity effect. METHODS: Using mouse hippocampal HT22 as a model for glutamate oxidative toxicity, we carried out MTT and LDH assays including Annexin V-FITC/propidium iodide staining to determine the SA-EE effect against glutamate-induced cell death. Antioxidant activities of SA-EE were evaluated using the radical scavenging and DCFH-DA assays. To elucidate the underlying mechanisms, SA-EE treated cells were analyzed for the expressions of mRNA and proteins interested by immunofluorescent staining, western blot analysis and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) techniques. The longevity effect of SA-EE was examined on C. elegans by lifespan assay. RESULTS: We demonstrate that a concentration-dependent reduction of glutamate-induced cytotoxicity was significant after SA-EE treatment as measured by MTT and LDH assays. Annexin V-FITC/propidium iodide and immunofluorescent staining showed that co-treatment of glutamate with SA-EE significantly reduced apoptotic-inducing factor (AIF)-dependent apoptotic cell death. DCFH-DA assay revealed that this extract was capable of dose dependently attenuating the ROS caused by glutamate. Western blot analysis and qRT-PCR showed that nuclear factor erythroid 2-related factor 2 (Nrf2) protein levels in the nucleus, as well as mRNA levels of antioxidant-related genes under Nrf2 regulation were significantly increased by SA-EE. Furthermore, this extract was capable of extending the lifespan of C. elegans. CONCLUSIONS: SA-EE possesses both longevity effects and neuroprotective activity against glutamate-induced cell death, supporting its therapeutic potential for the treatment of age-associated neurodegenerative diseases.

Nematicidal effect of plumbagin on Caenorhabditis elegans: a model for testing a nematicidal drug.

Plumbagin, (5-hydroxy-2-methyl-1,4-naphthoquinone), a natural substance found in the roots of plant species in the genus Plumbago, has been used as a traditional medicine against many diseases. In this study, Caenorhabditis elegans was used as a model for testing the anthelmintic effect of plumbagin. The compound exhibited a nematicidal effect against all stages of C. elegans: L4 was least susceptible, while L1 was most susceptible to plumbagin with an LC(50) of 220 and 156 µM, respectively. Plumbagin inhibited C. elegans development from L1 to adult stages with an IC(50) of 235 µM, and body length was also reduced at concentrations of 25 and 50 µg/ml. Brood sizes decreased from 203±6 to 43±6 and 18±3 eggs per hatch in plumbagin-treated worms at 10, 25, 50 µg/ml, respectively. Furthermore, plumbagin was lethal to strains resistant to the nematicides levamisole, albendazole, and ivermectin, indicating that it possesses a strong and unique nematicidal action. Plumbagin decreased the number of mitochondria in hypodermal and intestinal cells and body wall muscles and damaged the ultrastructure of these tissues. Taken together, plumbagin may be a new drug against parasitic nematodes.

Molecular cloning and characterization of leucine aminopeptidase from Fasciola gigantica.

M17 leucine aminopeptidase (LAP) is one of a family of metalloexopeptidases, of which short peptide fragments are cleaved from the N-terminals. In this study, the full length of cDNA encoding Fasciola gigantica LAP (FgLAP) was cloned from adult parasites. The amino acid sequences of FgLAP showed a high degree of identity (98%) with that from Fasciola hepatica and a low degree of identities (11% and 9%) with those from cattle and human. Phylogenetic analysis revealed that the FgLAP was closely related and grouped with F. hepatica LAP (FhLAP). Northern analysis showed that FgLAP transcriptional products have 1800 base pairs. Analysis by RNA in situ hybridization indicated that LAP gene was expressed in the cecal epithelial cells of adult parasites. A polyclonal antibody to a recombinant FgLAP (rFgLAP) detected the native LAP protein in various developmental stages of the parasite. In a functional test, this rFgLAP displayed aminolytic activity using a fluorogenic Leu-MCA substrate, and was significantly inhibited by bestatin. Its maximum activity was at pH 8.0 and enhanced by Mn(2+) ions. Localization of LAP proteins by immunohistochemistry and immunofluorescence techniques indicated that the enzyme was distributed in the apical cytoplasm of cecal epithelial cells. Because of its important metabolic role and fairly exposed position, FgLAP is a potential drug target and a possible vaccine candidate against fasciolosis.