East Indian sandalwood (Santalum album L.) oil confers neuroprotection and geroprotection in Caenorhabditis elegans via activating SKN-1/Nrf2 signaling pathway

Santalum album L. alleviates cardiac function injury in heart failure by synergistically inhibiting inflammation, oxidative stress and apoptosis through multiple components

BACKGROUND

Heart failure (HF) is a complex cardiovascular syndrome with high mortality. Santalum album L. (SAL) is a traditional Chinese medicine broadly applied for various diseases treatment including HF. However, the potential active compounds and molecular mechanisms of SAL in HF treatment are not well understood.

METHODS

The active compounds and possible mechanisms of action of SAL were analyzed and validated by a systems pharmacology framework and an ISO-induced mouse HF model.

RESULTS

We initially confirmed that SAL alleviates heart damage in ISO-induced HF model. A total of 17 potentially active components in SAL were identified, with Luteolin (Lut) and Syringaldehyde (SYD) in SAL been identified as the most effective combination through probabilistic ensemble aggregation (PEA) analysis. These compounds, individually and in their combination (COMB), showed significant therapeutic effects on HF by targeting multiple pathways involved in anti-oxidation, anti-inflammation, and anti-apoptosis. The active ingredients in SAL effectively suppressed inflammatory mediators and pro-apoptotic proteins while enhancing the expression of anti-apoptotic factors and antioxidant markers. Furthermore, the synergistic effects of SAL on YAP and PI3K-AKT signaling pathways were further elucidated.

CONCLUSIONS

Mechanistically, the anti-HF effect of SAL is responsible for the synergistic effect of anti-inflammation, antioxidation and anti-apoptosis, delineating a multi-targeted therapeutic strategy for HF.

Diosgenin intervention: targeting lipophagy to counter high glucose diet-induced lipid accumulation and lifespan reduction

Diosgenin (DG), a well-known steroidal sapogenin, is abundantly found in the plants of the Dioscoreaceae family and exhibits diverse pharmacological properties. In our previous study, we demonstrated that DG supplementation protected Caenorhabditis elegans from high glucose-induced lipid deposition, oxidative damage, and lifespan reduction. Nevertheless, the precise biological mechanisms underlying the beneficial effects of DG have not yet been described. In this context, the present study aims to elucidate how DG reduces molecular and cellular declines induced by high glucose, using the powerful genetics of the C. elegans model. Treatment with DG significantly (p < 0.01) prevented fat accumulation and extended lifespan under high-glucose conditions without affecting physiological functions. DG-induced lifespan extension was found to rely on longevity genes daf-2, daf-16, skn-1, glp-1, eat-2, let-363, and pha-4. Specifically, DG regulates lipophagy, the autophagy-mediated degradation of lipid droplets, in C. elegans, thereby inhibiting fat accumulation. Furthermore, DG treatment did not alter the triglyceride levels in the fat-6 and fat-7 single mutants and fat-6;fat-7 double mutants, indicating the significant role of stearoyl-CoA desaturase genes in mediating the reduction of fat deposition by DG. Our results provide new insight into the fat-reducing mechanisms of DG, which might develop into a multitarget drug for preventing obesity and associated health complications; however, preclinical studies are required to investigate the effect of DG on higher models.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-024-04017-3.

Geroprotective Effect of Levilactobacillus brevis and Weizmannia coagulans in Caenorhabditis elegans

The prophylactic use of lactic acid bacteria (LAB) to maintain human health is one of the most important research areas in recent times. LAB supplementation confers a wide range of health benefits to the host, but few studies have focused on their possible role in delaying the aging process. This study explored the health and life-promoting properties of two LAB, Levilactobacillus brevis and Weizmannia coagulans, using the Caenorhabditis elegans model. We found that L. brevis and W. coagulans enhanced the intestinal integrity and intestinal barrier functions without affecting the overall physiological functions of C. elegans. Wild-type worms preconditioned with LAB strains increased their survival under oxidative and thermal stress conditions by reducing intracellular reactive oxygen levels. Live L. brevis and W. coagulans significantly extended the lifespan of C. elegans under standard laboratory conditions independently of dietary restrictions. Genetic and reporter gene expression analysis revealed that L. brevis and W. coagulans extend lifespan via insulin/insulin-like growth factor-1 signaling and the p38 MAPK signaling axis. Furthermore, sirtuin, JNK MAPK, and mitochondrial respiratory complexes were found to be partially involved in W. coagulans-mediated lifespan extension and stress resilience. Preconditioning with LAB ameliorated age-related functional decline in C. elegans and reduced ectopic fat deposition in an NHR-49-dependent manner. Together, our findings indicated that L. brevis and W. coagulans are worth exploring further as "gerobiotic" candidates to delay aging and improve the healthspan of the host.

An aggregation-induced emission-based ratiometric fluorescent chemosensor for Hg(II) and its application in Caenorhabditis elegans imaging

A chromone-based ratiometric fluorescent probe L2 was developed for the selective detection of Hg(II) in a semi-aqueous solution based on aggregation-induced emission (AIE) and chelation-enhanced fluorescence (CHEF) effect. The probe L2 fluoresced significantly at 498 nm in its aggregated state, and when chelated with Hg(II), the soluble state fluoresced 1-fold higher. In addition, Job's plot reveals that the probe forms a 1:1 stoichiometry complex with Hg(II) with an association constant of 9.10 × 103M-1 estimated by the BH plot. The probe L2 detects Hg(II) down to 22.47 nM without interference from other interfering ions. The FTIR, ESI mass, and DFT-based computational studies investigated the binding mechanism of probe L2 with Hg(II). Taking advantage of its AIE characteristics, the probe L2 was successfully applied for bio-capability analysis in Caenorhabditis elegans (a nematode worm) imaging of Hg(II) in a living model.

Fermented cereal-origin gerobiotic cocktails promote healthy longevity in Caenorhabditis elegans

There is growing interest in dietary interventions, particularly gerobiotics, that directly target aging. Several single-strain gerobiotics have proven to be beneficial in alleviating aging and age-related functional declines across species, but multistrain/multispecies gerobiotics have been proven even more advantageous due to the potential synergy and additive effects among individual isolates. However, there is very limited research on how multistrain/multispecies gerobiotic combinations or cocktails extend healthy longevity. This study comprehensively analyzed probiotic bacteria from traditionally fermented Barnyard millet and compared their efficacy in promoting healthy longevity under various combinations using Caenorhabditis elegans. We have shown that dramatic lifespan extension can be achieved by combining gerobiotics, and the effect was found to be strictly strain-specific. Among the 120 combinations tested, we identified two synergistic gerobiotic combinations, cocktail 55 (combination of B. licheniformis PS70, L. delbrueckii subsp. bulgaricus PS77, and L. amylovorus PS60) and cocktail 112 (combination of L. delbrueckii subsp. bulgaricus PS77, L. lactis PS10, and P. pentosaceus PS91), extending the mean lifespan of C. elegans by up to 46.2% and 53.1%, respectively. Our mechanistic study showed that the life-promoting effect of cocktail 55 relied on the p38 MAPK-SKN-1 pathway, while cocktail 112 acted on multiple signaling pathways, including IIS, β-catenin, and TGF-β pathways, to achieve its impact on the host. Moreover, feeding gerobiotic cocktails improved several healthspan markers reported to decline with age. These observations showed that the gerobiotic cocktails target different subsets of the gene regulatory network controlling the aging process in C. elegans, thereby extending healthy longevity.

QM/MM Modeling Aided Enzyme Engineering in Natural Products Biosynthesis

Natural products and their derivatives are widely used across various industries, particularly pharmaceuticals. Modern engineered biosynthesis provides an alternative way of producing and meeting the growing need for diverse natural products. Natural enzymes, on the other hand, often exhibit unsatisfactory catalytic characteristics and necessitate further enzyme engineering modifications. QM/MM, as a powerful and extensively used computational tool in the field of enzyme catalysis, has been increasingly applied in rational enzyme engineering over the past decade. In this review, we summarize recent advances in QM/MM computational investigation on enzyme catalysis and enzyme engineering for natural product biosynthesis. The challenges and perspectives for future QM/MM applications aided enzyme engineering in natural product biosynthesis will also be discussed.

Effect of gamma-ray irradiated reduced graphene oxide (rGO) on environmental health: An in-vitro and in-vivo studies

The unique properties of reduced graphene oxide (rGO) have drawn the attention of scientists worldwide since the last decade and it is explored for a wide range of applications. However, the rapid expansion of rGO use in various products will eventually lead to environenal exposure and rises a safety concern on the environment and humal health risk. Moreover, the utilization of toxic chemicals for the reduction of graphene oxide (GO) into rGO is not environmentally friendly, warranting the exploration of non-toxic approaches. In the present work, rGO was synthesized using a different dose of gamma-ray irradiation and characterized. The in-vitro and in-vivo analysis indicated that the gamma-irradiated rGO induced toxicity depending on its degree of reduction and dosage. In the L929 cells, rGO-30 KGy significantly induced cytotoxicity even at low concentration (1 mg L^-1) by inducing reactive oxygen species (ROS), lactate dehydrogenase (LDH) enzyme production, nuclear fragmentation and apoptosis. The change in morphology of the cells like membrane blebbing and cell rounding was also observed via FESEM. In the in-vivo model Caenorhabditis elegans, rGO-30 KGy significantly affected the functioning of primary and secondary targeted organs and also negatively influenced the nuclear accumulation of transcription factors (DAF-16/FOXO and SKN-1/Nrf2), neuronal health, and antioxidant defense mechanism of the nematodes. The real-time PCR analysis showed significant up-regulation (ced-3, ced-4, cep-1, egl-1, and hus-1) and down-regulation (ced-9) of the gene involved in germ-line and DNA damage-induced apoptosis. The detailed toxicity mechanism of gamma irradiated rGO has been elucidated. This work highlights the toxicity of rGO prepared by gamma-ray radiation and paves way for understating the toxicity mechanism.

Visible light active hybrid silver decorated g-C3N4-CeO2 nanocomposite for ultrafast photocatalytic activity and toxicity evaluation

Development of hybrid graphitic carbon nitride (GCN) nanocomposite is an emerging research area in wastewater treatment. Herein, hybrid visible light active photocatalyst of silver decorated polymeric graphitic carbon nitride and (Ag-GCN) with cerium oxide (CeO₂) nanocomposite was prepared and characterized in detail. The Ag-GCN/CeO₂ photocatalyst has successfully prepared by an electrostatic self-assembly approach. The synthesized Ag-GCN/CeO₂ NCs photocatalysts are characterized by various physio-chemical techniques. Using the Ag-GCN/CeO₂ catalyst, the excellent photodegradation efficiency of Acid yellow-36 (AY-36) and Direct yellow-12 (DY-12) dye solution were achieved 100% within 150 min sun light irradiation. The Ag-GCN/CeO₂ rate constant values of 0.048 and 0.046/min has been determined for AY-36 and DR-12 dyes, respectively. The extraordinary photocatalytic activity is due to incorporation of CeO₂ with Ag-GCN which play a significant role in visible light absorption, superior reactive oxygen generation (ROS) and excellent pollutant catalyst interaction. The toxicity of the photocatalytically degraded AY-36 and DR-12 dyes were measured using the soil nematode Caenorhabditis elegans, a well-established in vivo model in biology, by analyzing survival, physiological functions, intracellular ROS levels, and stress-protective gene expressions.

Green synthesis of zinc oxide nanoparticles using Cananga odorata essential oil and its antibacterial efficacy in vitro and in vivo

Zinc oxide (ZnO) nanostructure exhibits antimicrobial properties, which have prompted more research on their bactericidal effect against foodborne pathogens. The present work focused on the green synthesis of ZnO nanoparticles (ZnO NPs) using Cananga odorata essential oil. The synthesized ZnO NPs were characterized by XRD, UV-Vis spectroscopy, zeta potential, SEM, and FT-IR analysis. The bactericidal activity of biosynthesized ZnO NPs was tested against Pseudomonas aeruginosa and Staphylococcus aureus. The in vitro results indicate that ZnO NPs have excellent antibacterial activity and that the bactericidal and bacteriostatic mechanisms are based on ROS production and depend on its penetration and interaction with bacterial cells. Moreover, ZnO NPs were found to be non-toxic to Caenorhabditis elegans, an in vivo animal model, up to 1 g/L and exert antibacterial activity by reducing the growth and colonization of pathogens. By reducing pathogen virulence, ZnO NPs significantly improved worms' physiological functions such as pharyngeal pumping, body length, reproduction, and movement. The competitive effect of ZnO NPs against pathogenic bacteria increased the gut-barrier integrity of C. elegans. The most interesting observation was noted that ZnO treatment increased the mean survival rate of P. aeruginosa and S. aureus infected C. elegans by 56.6 % and 62.4 %, respectively. As an outcome, our study proved that green synthesized ZnO NPs exhibit remarkable biological properties and can be used as an efficient bactericidal agent against foodborne pathogens.

Santalol Isomers Inhibit Transthyretin Amyloidogenesis and Associated Pathologies in Caenorhabditis elegans

Transthyretin (TTR) is a homotetrameric protein found in human serum and is implicated in fatal inherited amyloidoses. Destabilization of native TTR confirmation resulting from mutation, environmental changes, and aging causes polymerization and amyloid fibril formation. Although several small molecules have been reported to stabilize the native state and inhibit TTR aggregation, prolonged use can cause serious side effects. Therefore, pharmacologically enhancing the degradation of TTR aggregates and kinetically stabilizing the native tetrameric structure with bioactive molecule(s) could be a viable therapeutic strategy to hinder the advancement of TTR amyloidoses. In this context, here we demonstrated α- and β-santalol, natural sesquiterpenes from sandalwood, as a potent TTR aggregation inhibitor and native state stabilizer using combined in vitro, in silico, and in vivo experiments. We found that α- and β-santalol synergize to reduce wild-type (WT) and Val30Met (V30M) mutant TTR aggregates in novel C. elegans strains expressing TTR fragments fused with a green fluorescent protein in body wall muscle cells. α- and β-Santalol extend the lifespan and healthspan of C. elegans strains carrying TTR_WT::EGFP and TTR_V30M::EGFP transgene by activating the SKN-1/Nrf2, autophagy, and proteasome. Moreover, α- and β-santalol directly interacted with TTR and reduced the flexibility of the thyroxine-binding cavity and homotetramer interface, which in turn increases stability and prevents the dissociation of the TTR tetramer. These data indicate that α- and β-santalol are the strong natural therapeutic intervention against TTR-associated amyloid diseases.

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 (UPR^mt ) 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.

Rationally engineering santalene synthase to readjust the component ratio of sandalwood oil

Plant essential oils (PEOs) are widely used in cosmetic and nutraceutical industries. The component ratios of PEOs determine their qualities. Controlling the component ratios is challenging in construction of PEO biotechnological platforms. Here, we explore the catalytic reaction pathways of both product-promiscuous and product-specific santalene synthases (i.e., SaSSy and SanSyn) by multiscale simulations. F441 of SanSyn is found as a key residue restricting the conformational dynamics of the intermediates, and thereby the direct deprotonation by the general base T298 dominantly produce α-santalene. The subsequent mutagenesis of this plastic residue leads to generation of a mutant enzyme SanSyn^F441V which can produce both α- and β-santalenes. Through metabolic engineering efforts, the santalene/santalol titer reaches 704.2 mg/L and the component ratio well matches the ISO 3518:2002 standard. This study represents a paradigm of constructing biotechnological platforms of PEOs with desirable component ratios by the combination of metabolic and enzymatic engineering.

Controlling the component ratios of plant essential oils is challenging in their heterologous bioproduction. Here, the authors combine metabolic and enzymatic engineering strategies to achieve the production of sandalwood oil with a desirable component ratio in baker’s yeast.

High-throughput screening for amyloid-β binding natural small-molecules based on the combinational use of biolayer interferometry and UHPLC−DAD-Q/TOF-MS/MS

Discovery of drugs rapidly and effectively is an important aspect for Alzheimer's disease (AD). In this study, a novel high-throughput screening (HTS) method aims at screening the small-molecules with amyloid-β (Aβ) binding affinity from natural medicines, based on the combinational use of biolayer interferometry (BLI) and ultra-high-performance liquid chromatography coupled with diode-array detector and quadrupole/time-of-flight tandem mass spectrometry (UHPLC−DAD-Q/TOF-MS/MS) has been firstly developed. Briefly, the components in natural medicines disassociated from biotinylated Aβ were collected to analyze their potential Aβ binding affinity by UHPLC−DAD-Q/TOF-MS/MS. Here, baicalein was confirmed to exhibit the highest binding affinity with Aβ in Scutellaria baicalensis. Moreover, polyporenic acid C (PPAC), dehydrotumulosic acid (DTA), and tumulosic acid (TA) in Kai-Xin-San (KXS) were also identified as potent Aβ inhibitors. Further bioactivity validations indicated that these compounds could inhibit Aβ fibrillation, improve the viability in Aβ-induced PC-12 cells, and decrease the Aβ content and improve the behavioral ability in Caenorhabditis elegans. The molecular docking results confirmed that PPAC, DTA, and TA possessed good binding properties with Aβ. Collectively, the present study has provided a novel and effective HTS method for the identification of natural inhibitors on Aβ fibrillation, which may accelerate the process on anti-AD drugs discovery and development.

Ferulic Acid Exerts Neuroprotective Effects via Autophagy Induction in C. elegans and Cellular Models of Parkinson's Disease

Parkinson's disease (PD) is a complex neurological disorder characterized by motor and nonmotor features. Although some drugs have been developed for the therapy of PD in a clinical setting, they only alleviate the clinical symptoms and have yet to show a cure. In this study, by employing the C. elegans model of PD, we found that ferulic acid (FA) significantly inhibited α-synuclein accumulation and improved dyskinesia in NL5901 worms. Meanwhile, FA remarkably decreased the degeneration of dopaminergic (DA) neurons, improved the food-sensing behavior, and reduced the level of reactive oxygen species (ROS) in 6-OHDA-induced BZ555 worms. The mechanistic study discovered that FA could activate autophagy in C. elegans, while the knockdown of 3 key autophagy-related genes significantly revoked the neuroprotective effects of FA in α-synuclein- and 6-OHDA-induced C. elegans models of PD, demonstrating that FA exerts an anti-PD effect via autophagy induction in C. elegans. Furthermore, we found that FA could reduce 6-OHDA- or H₂O₂-induced cell death and apoptosis in PC-12 cells. Moreover, FA was able to induce autophagy in stable GFP-RFP-LC3 U87 cells and PC-12 cells, while bafilomycin A1 (Baf, an autophagy inhibitor) partly eliminated the protective effects of FA against 6-OHDA- and H₂O₂-induced cell death and ROS production in PC-12 cells, further confirming that FA exerts an anti-PD effect via autophagy induction in vitro. Collectively, our study provides novel insights for FA as a potent autophagy enhancer to effectively prevent neurodegenerative diseases such as PD in the future.

N-γ-(L-glutamyl)-L-selenomethionine shows neuroprotective effects against Parkinson's disease associated with SKN-1/Nrf2 and TRXR-1 in Caenorhabditis elegans

BACKGROUND

Parkinson's disease (PD) is a common neurodegenerative disease, yet fundamental treatments for the disease remain sparse. Thus, the search for potentially efficacious compounds from medicinal plants that can be used in the treatment of PD has gained significant interest.

PURPOSE

In many medicinal plants, selenium is primarily found in an organic form. We investigated the neuroprotective potential of an organic form of selenium, N-γ-(L-glutamyl)-L-selenomethionine (Glu-SeMet) in a Caenorhabditis elegans PD model and its possible molecular mechanisms.

METHODS

We used a C. elegans pharmacological PD strain (BZ555) that specifically expresses green fluorescent protein (GFP) in dopaminergic neurons and a transgenic PD strain (NL5901) that expresses human α-synuclein (α-syn) in muscle cells to investigate the neuroprotective potential of Glu-SeMet against PD.

RESULTS

We found that Glu-SeMet significantly ameliorated 6-hydroxydopamine (6-OHDA)-induced dopaminergic neuron damage in the transgenic BZ555 strain, with corresponding improvements in slowing behavior and intracellular ROS levels. In addition, compared with clinical PD drugs (L-DOPA and selegiline), Glu-SeMet demonstrated stronger ameliorated effects on 6-OHDA-induced toxicity. Glu-SeMet also triggered the nuclear translocation of SKN-1/Nrf2 and significantly increased SKN-1, GST-4, and GCS-1 mRNA levels in the BZ555 strain. However, Glu-SeMet did not increase mRNA levels or ameliorate the damage to dopaminergic neurons when the BZ555 strain was subjected to skn-1 RNA interference (RNAi). Glu-SeMet also upregulated the mRNA levels of the selenoprotein TRXR-1 in both the BZ555 and BZ555; skn-1 RNAi strains and significantly decreased α-syn accumulation in the NL5901 strain, although this was not observed in the NL5901; trxr-1 strain.

CONCLUSION

We found that Glu-SeMet has a neuroprotective effect against PD in a C. elegans PD model and that the anti-PD effects of Glu-SeMet were associated with SKN-1/Nrf2 and TRXR-1. Glu-SeMet may thus have the potential for use in therapeutic applications or supplements to slow the progression of PD.

Swertiamarin from Enicostemma littorale, counteracts PD associated neurotoxicity via enhancement α-synuclein suppressive genes and SKN-1/NRF-2 activation through MAPK pathway

The elusive targets and the multifactorial etiology of Parkinson's disease (PD) have hampered the discovery of a potent drug for PD. Furthermore, the presently available medications provide only symptomatic relief and have failed to mitigate the pathogenesis associated with PD. Therefore, the current study was aimed to evaluate the prospective of swertiamarin (SW), a secoiridoid glycoside isolated from a traditional medicinal plant, Enicostemma littorale Blume to ameliorate the characteristic features of PD in Caenorhabditis elegans. SW (25 μM) administration decreased the α-synuclein (α-syn) deposition, inhibited apoptosis and increased dopamine level mediated through upregulating the expression of genes linked to ceramide synthesis, mitochondrial morphology and function regulation, fatty acid desaturase genes along with stress responsive MAPK (mitogen-activated protein kinase) pathway genes. The neuroprotective effect of SW was evident from the robust reduction of 6-hydroxydopamine (6-OHDA) induced dopaminergic neurodegeneration independent of dopamine transporter (dat-1). SW mediated translational regulation of MAPK pathway genes was observed through increase expression of SKN-1 and GST-4. Further, in-silico molecular docking analysis of SW with C. elegans MEK-1 showed a promising binding affinity affirming the in-vivo results. Overall, these novel finding supports that SW is a possible lead for drug development against the multi- factorial PD pathologies.

Validation of efficacy and mechanism of Sanwei-Tanxiang powder in improving myocardial ischemia reperfusion injuries

Sanwei-Tanxiang powder (SWTX), a traditional Mongolian and Tibetan medicine containing a cocktail of active molecules, relieves angina pectoris and improves recovery in patients with coronary heart disease (CHD). The pharmacological effect of SWTX on CHD was analyzed at a systemic point of view in our previous studies. The bioinformatics prediction showed that the PI3K/Akt/FoxO3a pathway was one of important pathways of SWTX on treatment of coronary heart disease. Based on it, the aim of this study was to evaluate the benefits of SWTX in acute myocardial ischemic-reperfused (MIR) rat in vivo and H9c2 cardiomyoblast cells under oxidative stress induced by H₂O₂ in vitro, and further investigate the involvement of PI3K/Akt/FoxO3a pathway in these processes. Ex vivo, under physiological conditions, SWTX did not show any modification in the heart rate and contraction amplitude. However, against a MIR injury, SWTX pretreatment provided significant protection, including reduced ST-segment elevation, pathological changes and myocardial infarct size in vivo, meanwhile, some monomers of SWTX showed antioxidant capacity and inhibited cardiomyocytic apoptosis in vitro. The effect was correlated with the activation of the PI3K/Akt/FoxO3a signaling pathway downstream and the regulation of downstream pro-apoptotic Bim of FoxO3a experimental verified by qRT-PCR, Western blot and immunofluorescent assay. In vitro, blocking Akt and p-FoxO3a activation with the PI3K inhibitor LY294002 effectively suppressed the protective effects of several active monomers (including quercetin, macelignan,methyleugenol and Santol) of SWTX against H₂O₂-induced injury. Collectively, these results suggest that SWTX decreases I/R injury, and the PI3K/Akt/FoxO3a pathway takes part in protection during this process, gallogen (G3) and quercetin (G8) of GZ, methyleugenol (R2) and macelignan (R7) of RDK, santol (T1) of TX are responsible at least in part for SWTX’s cardioprotection effect.

α- and β-Santalols Delay Aging in Caenorhabditis elegans via Preventing Oxidative Stress and Protein Aggregation

α- and β-Santalol (santalol isomers) are the most abundant sesquiterpenoids found in sandalwood, contributing to its pleasant fragrance and wide-spectrum bioactivity. This study aimed at identifying the antiaging and antiaggregation mechanism of α- and β-santalol using the genetic tractability of an in vivo model Caenorhabditis elegans. The results showed that santalol isomers retard aging, improved health span, and inhibited the aggregation of toxic amyloid-β (Aβ_1-42) and polyglutamine repeats (Q35, Q40, and HtnQ150) in C. elegans models for Alzheimer's and Huntington's disease, respectively. The genetic study, reporter gene expression, RNA-based reverse genetic approach (RNA interferences/RNAi), and gene expression analysis revealed that santalol isomers selectively regulate SKN-1/Nrf2 and EOR-1/PLZF transcription factors through the RTK/Ras/MAPK-dependent signaling axis that could trigger the expression of several antioxidants and protein aggregation inhibitory genes, viz., gst-4, gcs-1, gst-10, gsr-1, hsp-4, and skr-5, which extend longevity and help minimize age-induced protein oxidation and aggregation. We believe that these findings will further promote α- and β-santalol to become next-generation prolongevity and antiaggregation molecules for longer and healthier life.

Engineering the surface of graphene oxide with bovine serum albumin for improved biocompatibility in Caenorhabditis elegans

Graphene oxide (GO) has been extensively studied for its potential biomedical applications. However, its potential risk associated with the interactions of GO in a biological system hampers its biomedical applications. Therefore, there is an urgent need to enhance the biocompatibility of GO. In the present study, we decorated the surface of GO with bovine serum albumin (GO-BSA) to mitigate the in vivo toxic properties of GO. An in vivo model Caenorhabditis elegans has been used to study the potential protective effect of BSA decoration in mitigating GO induced toxicity. The BSA decoration on the surface of GO prevents the acute and prolonged toxicity induced by GO in primary and secondary organs by maintaining normal intestinal permeability, defecation behavior, development, and reproduction. Notably, GO-BSA treatment at 0.5-100 mg L^-1 does not affect the intracellular redox status and lifespan of C. elegans. Reporter gene expression analysis revealed that exposure to GO-BSA (100 mg L^-1) did not significantly influence the nuclear accumulation and expression patterns of DAF-16/FOXO and SKN-1/Nrf2 transcription factors and their downstream target genes sod-3, hsp-16.2, ctl-1,2,3, gcs-1, and gst-4 when compared to exposure to pristine GO. Also, quantitative real-time PCR results showed that GO-BSA did not alter the expression of genes involved in regulating DNA damage checkpoints (cep-1, hus-1 and egl-1) and core signaling pathways of apoptosis (ced-4, ced-3 and ced-9), in contrast to GO treatment. All these findings will have an impact on the future development of safer nanomaterial formulations of graphene and graphene-based materials for environmental and biomedical applications.

Reconstruction of the Biosynthetic Pathway of Santalols under Control of the GAL Regulatory System in Yeast

Sandalwood oil has been widely used in perfumery industries and aromatherapy. Santalols are its major components. Herein, we attempted to construct santalol-producing yeasts. To alter flux from predominant triterpenoid/steroid biosynthesis to sesquiterpenoid production, expression of ERG9 (encoding yeast squalene synthase) was depressed by replacing its innate promotor with P_HXT1 and fermenting the resulting strains in galactose-rich media. And the genes related to santalol biosynthesis were overexpressed under control of GAL promotors, which linked santalol biosynthesis to GAL regulatory system. GAL4 (a transcriptional activator of GAL promotors) and PGM2 (a yeast phosphoglucomutase) were overexpressed to overall promote this artificial santalol biosynthetic pathway and enhance galactose uptake. 1.3 g/L santalols and 1.2 g/L Z-α-santalol were achieved in the strain WL17 expressing SaSS (α-santalene synthase from Santalum album) and WL19 expressing SanSyn (α-santalene synthase from Clausena lansium) by fed-batch fermentation, respectively. This study constructed the microbial santalol-producing platform for the first time.

Ameliorative effect of urolithin A ond-gal-induced liver and kidney damage in aging miceviaits antioxidative, anti-inflammatory and antiapoptotic properties

Urolithin A, a metabolite produced by human colon microflora from ellagic acid and related compounds, has been reported to have antioxidant, anti-inflammatory and antiapoptotic properties. The present study investigates the protective effects of urolithin A (Uro A) on d-galactose (d-gal)-induced liver and kidney injury and the possible mechanisms in mice. In this study, we first investigated the antioxidant ability of Uro A in vitro. Then mice were treated with d-gal subcutaneously (150 mg kg⁻¹ d⁻¹), followed by Uro A at different dosages (50, 100, 150 mg kg⁻¹ d⁻¹, administered orally) for 8 weeks. The levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN) and creatinine (Cr) in the serum were tested. Histopathological features were assessed by hematoxylin and eosin (HE) staining followed by an assessment of the antioxidant and anti-inflammatory activities. Furthermore, we also evaluated the expression levels of the genes Bax, Bcl-2 and cleaved caspase-3 in the liver and kidney. The results showed that Uro A treatment obviously attenuated d-gal-induced liver and kidney damage. The beneficial effects of Uro A were accompanied by a decline in malondialdehyde (MDA) levels and a rise in the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and total antioxidant capacity (T-AOC) activity in the liver and kidney and downregulation of the levels of inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6), in serum. Moreover, Uro A could modulate the expression of Bax, Bcl-2 and cleaved caspase-3 in the livers and kidneys of aging mice. These findings suggested that Uro A ameliorated d-gal-induced liver and kidney injury through attenuating oxidative stress, inflammatory responses and apoptosis.

Urolithin A, a metabolite produced by human colon microflora from ellagic acid and related compounds, has been reported to have antioxidant, anti-inflammatory and antiapoptotic properties.

α-Santalol functionalized chitosan nanoparticles as efficient inhibitors of polo-like kinase in triple negative breast cancer

Polo-like kinase 1 (PLK-1) is a protein kinase that plays a significant role in the initiation, maintenance, and completion of mitotic processes in the cell cycle.

Absolute removal of ciprofloxacin and its degraded byproducts in aqueous solution using an efficient electrochemical oxidation process coupled with adsorption treatment technique

Pharmaceutical-based contaminants are the major reasons for morbidity and mortality in aquatic animals and lead to several side effects and diseases in human community. Availability of proper, efficient, and cost-effective treatment technologies is still scarce. In this study, an efficient combined treatment technique (electrochemical oxidation and adsorption processes) was developed for the complete detoxification of most commonly used antibiotic, ciprofloxacin in aqueous solution. Electrochemical degradation of ciprofloxacin was performed using titanium-based tri-metal oxide mesh type anode, and the effective oxidative potential, electrolysis time, and pH for the degradation of ciprofloxacin were thoroughly evaluated. Sulfate, fluoride ions and toxic byproducts generated during electrochemical oxidation of ciprofloxacin were subsequently removed through a simple adsorption treatment using activated charcoal for 90 min. Further, the toxicity of the treated water was assessed with the nematode Caenorhabditis elegans species at different time intervals by observing the expressions of important stress-responsive genes viz., sod-3, hsp-16.2, ctl-1,2,3 and gst-4. The results exhibited that the combined process of electrochemical oxidation and adsorption treatment is simple, low-cost as well as effective to eliminate ciprofloxacin and its toxic byproducts in aqueous solution.

A new route to tricyclane sesquiterpenoids: total synthesis of α-ekasantalic acid

Chemical manipulation of the cycloadduct of citraconic anhydride and cyclopentadiene enables a new synthetic route to tricyclane sesquiterpenoids. This methodology is applied to the first total synthesis of α-ekasantalic acid.

Organoruthenium(II) complexes attenuate stress in Caenorhabditis elegans through regulating antioxidant machinery

The 1:1 stoichiometric reactions of 3-methoxy salicylaldehyde-4(N)-substituted thiosemicarbazones (H₂L^1-4) with [RuCpCl(PPh₃)₂] was carried out in methanol. The obtained complexes (1-4) were characterized by analytical, IR, absorption and ¹H NMR spectroscopic studies. The structures of ligand [H₂-3MSal-etsc] (H₂L³) and complex [RuCp(Msal-etsc) (PPh₃)] (3), were characterized by single crystal X-ray diffraction studies. The interaction of the ruthenium(II) complexes (1-4) with calfthymus DNA (CT-DNA) has been explored by absorption and emission titration methods. Based on the observations, an intercalative binding mode of DNA has been proposed. The protein binding abilities of the new complexes were monitored by quenching the tryptophan and tyrosine residues of BSA, as model protein. From the studies, it was found that the new ruthenium metallacycles exhibited better affinity than their precursors. The free radical scavenging assay suggests that all complexes effectively scavenged the DPPH radicals as compared to that of standard control ascorbic acid and scavenging activities of complexes are in the order of 4 > 2 > 3 > 1. In addition, ruthenium(II) complexes (2-4) also exhibited an excellent in vivo antioxidant activity as it was able to increase the survival of worms exposed to lethal oxidative and thermal stresses possibly through reducing the intracellular ROS levels. It was interesting to note that complexes 2-4 failed to increase the lifespan of mev-1 mutant worms having shortened lifespan due to the over production of free radicals. This data confirmed that complexes 2-4 conferred stress resistance in C. elegans, but they also require an endogenous detoxification mechanism for doing so. The genetic and reporter gene expression analysis revealed that complexes 2-4 maintained the intracellular redox status and offered stress protection through transactivation of antioxidant defence machinery genes gst-4 and sod-3 which are directly regulated by SKN-1 and DAF-16 transcription factors, respectively. Altogether, our results suggested that complexes 2-4 might play a crucial role in stress modulation and they perhaps exert almost similar effects in higher models, which is an important issue to be validated in future.