The antioxidant capacity evaluation of polysaccharide hydrolyzates from pumpkin using Caenorhabditis elegans model

Anti-aging activities of neutral and acidic polysaccharides from Polygonum multiflorum Thunb in Caenorhabditis elegans

Polygonum multiflorum Thunb (PM) is used to slow the aging process. Although polysaccharides are a major constituent of PM, their anti-aging properties have not been thoroughly investigated. Therefore, this study aimed to examine the anti-aging effects of polysaccharides extracted from PM using the Caenorhabditis elegans (C. elegans) model. Two types of water-soluble heteropolysaccharides, namely a neutral polysaccharide (RPMP-N) and an acidic polysaccharide (RPMP-A), were obtained from PM. Their structures were elucidated by various methods. The effects of these polysaccharides on the lifespan, levels of antioxidants, and activities of antioxidant-related enzymes in C. elegans were also evaluated. The results showed that RPMP-A had higher GalA content compared with RPMP-N. The average molecular weights of RPMP-N and RPMP-A were 245.30 and 28.45 kDa, respectively. RPMP-N is a α-1,4-linked dextran as the main chain, and contains a small amount of branched dextran with O-6 as the branched linkage site；RPMP-A may be a complex of α-1,4-linked dextran, HG and RG-I. Treatment with RPMP-N and RPMP-A increased the mean lifespan of C. elegans, and significantly regulated oxidative stress. RPMP-A exhibited stronger anti-aging effects compared with RPMP-N. These findings suggest that RPMP-A may be a potent antioxidant and anti-aging component that can be used for developing functional food products and effective dietary supplements.

Antioxidant potential evaluation of polysaccharides from Camellia oleifera Abel in vitro and in vivo

The extraction process, structural characterization and free radical scavenging ability of polysaccharides from Camellia oleifera have already been widely studied. However, the antioxidant activities are still lack of systematic experiments. In this study, we used Hep G2 cells and Caenorhabditis elegans to evaluate the antioxidant potential of polysaccharides that from C. oleifera flowers (P-CF), leaves (P-CL), seed cakes (P-CC) and fruit shells (P-CS). The results showed all these polysaccharides could protect cells from oxidative damage induced by t-BHP. The highest cell viabilities were 66.46 ± 1.36 % (P-CF), 55.2 ± 2.93 % (P-CL), 54.49 ± 1.29 % (P-CC) and 61.45 ± 1.67 % (P-CS), respectively. Studies have shown that four polysaccharides may protect cells from apoptosis by reducing ROS levels and maintaining MMP balance. Moreover, P-CF, P-CL, P-CC and P-CS increased the survival rate of C. elegans under thermal stress, which reduced the production of ROS by 56.1 ± 0.67 %, 59.37 ± 1.79 %, 16.63 ± 2.51 % and 27.55 ± 2.62 %, respectively. P-CF and P-CL showed stronger protective effects on C. elegans by increasing the nuclear entry rate of DAF-16 and stimulating the expression of SOD-3. Our study suggested that C. oleifera polysaccharides have the potential to develop into a natural supplement agent.

Pickering emulsion stabilized by casein-caffeic acid covalent nanoparticles to enhance the bioavailability of curcumin in vitro and in vivo

BACKGROUND

In recent years, the design of food-grade Pickering emulsion delivery systems has become an effective strategy for improving the low bioavailability of bioactive substances. Protein-based Pickering emulsions have received extensive attention because of a high biocompatibility and loading capacity. The bioavailability of active substances is mainly evaluated by simulating in vitro gastrointestinal digestion. As a model organism for antioxidation and anti-aging, Caenorhabditis elegans can provide additional biological information for the in vivo utilization of active substances.

RESULTS

After the introduction of caffeic acid, the average particle size and Zeta potential of the casein-caffeic acid covalent complex nanoparticles (CCP) were 171.11 nm and - 37.73 mV, respectively. The three-phase contact angle was also increased to 89.8°. By using CCP to stabilize Pickering emulsion (CCE), the retention quantity of the embedded curcumin increased by 2.19-fold after 28 days. In the simulated gastric digestion, curcumin degradation in CCE was reduced by 61.84%, released slowly in the intestinal environment, and the final bioaccessibility was increased by 1.90-fold. In C. elegans, CCE significantly reduced ROS accumulation, increased SOD activity by 2.01-fold and CAT activity by 2.30-fold, decreased MDA content by 36.76%, prolonging the lifespan of nematodes by 13.33% under H₂ O₂ stimulation and improving bioavailability in vivo.

CONCLUSION

The results indictae that CCP-stabilized Pickering emulsion can efficiently implement the physiological activities of bioactive compounds in vitro digestion and C. elegans, and thus it can be regarded as a reliable delivery system for food and medicine. © 2023 Society of Chemical Industry.

Protective effects of pumpkin polysaccharide hydrolysates on oxidative stress injury and its potential mechanism - Antioxidant mechanism of pumpkin polysaccharide hydrolysates

Pumpkin polysaccharides (PPe) exhibit multiple bioactive properties, including the ability to reduce blood sugar and lipids. Our prior investigation discovered that hydrolysates (PPe-s) derived from PPe demonstrated stronger antioxidant capabilities than PPe. The objective of the current study was to explore the potential mechanism of PPe-s, utilizing Caenorhabditis elegans and MIN6 cells as models. The results of this investigation revealed that PPe-s exhibited strong scavenging ability towards ABTS⁺ and OH·in vitro. Additionally, PPe-s extended the lifespan of C. elegans under hydrogen peroxide stress (p < 0.05) by upregulating the mRNA expression of daf-16, sod-1, sod-3, and skn-1 (all >1.43-fold, p < 0.05). Furthermore, PPe-s enhanced the proliferation activity of MIN6 cells, induced by alloxan, increased insulin secretion and cAMP levels, and excreted intracellular excessive Ca²⁺ in a concentration-dependent manner. Our study demonstrated that PPe-s upregulated the expression levels of antioxidative-related genes and augmented the antioxidant defense system.

Effects of Vegetal Extracts and Metabolites against Oxidative Stress and Associated Diseases: Studies in Caenorhabditis elegans

Oxidative stress is a natural physiological process where the levels of oxidants, such as reactive oxygen species (ROS) and nitrogen (RNS), exceed the strategy of antioxidant defenses, culminating in the interruption of redox signaling and control. Oxidative stress is associated with multiple pathologies, including premature aging, neurodegenerative diseases, obesity, diabetes, atherosclerosis, and arthritis. It is not yet clear whether oxidative stress is the cause or consequence of these diseases; however, it has been shown that using compounds with antioxidant properties, particularly compounds of natural origin, could prevent or slow down the progress of different pathologies. Within this context, the Caenorhabditis elegans (C. elegans) model has served to study the effect of different metabolites and natural compounds, which has helped to decipher molecular targets and the effect of these compounds on premature aging and some diseases such as neurodegenerative diseases and dyslipidemia. This article lists the studies carried out on C. elegans in which metabolites and natural extracts have been tested against oxidative stress and the pathologies associated with providing an overview of the discoveries in the redox area made with this nematode.

A review on biochemical constituents of pumpkin and their role as pharma foods; a key strategy to improve health in post COVID 19 period

Progression of today’s world has been given setback due to the adversity of a novel, viral, deadly outbreak COVID 19, which raised the concerns of the scientists, researchers and health related officials about the inherent and adaptive immune system of the living body and its relation with healthy diet balanced with pharma foods. Now world is coming out of the destructive pandemic era, the choice of right food can help to build and boost adaptive immunity and pumpkin due to excellent profile of functional and nutraceutical constituents could be the part of both infected and non-infected person’s daily diet. Vitamins like A, C and E, minerals like zinc, iron and selenium, essential oils, peptides, carotenoids and polysaccharides present in pumpkin could accommodate the prevailing deficiencies in the body to fought against the viral pathogens. In current post COVID 19 scenario adequate supply of healthy diet, balanced with pharma foods could play a basic role in boosting immune system of the populations. This review covers the pharmacological activities of pumpkin functional constituents in relation with COVID 19 pandemic. Pumpkins are well equipped with nutraceuticals and functional bioactives like tocopherols, polyphenols, terpenoids and lutein therefore, consumption and processing of this remarkable vegetable could be encouraged as pharma food due to its antihyperlipidemic, antiviral, anti-inflammatory, antihyperglycemic, immunomodulatory, antihypertensive, antimicrobial and antioxidant potential. Need of healthy eating in current post COVID 19 period is very crucial for healthy population, and medicinal foods like pumpkin could play a vital role in developing a healthy community around the globe.

In Vitro Role of Pumpkin Parts as Pharma-Foods: Antihyperglycemic and Antihyperlipidemic Activities of Pumpkin Peel, Flesh, and Seed Powders, in Alloxan-Induced Diabetic Rats

Pumpkin is a well-known vegetable, among the members of Cucurbitaceae family, due to its importance as pharma food. Keeping in view the antidiabetic and plasma lipids lowering potential of pumpkin, the present study was conducted to investigate that, which part of pumpkin (peel, flesh, and seeds), possess more bioactive compounds, exhibiting antihyperglycemic and antihyperlipidemic potential. Albino rats with 190-210 g body weight were divided into 11 groups. Five rats were included in each group; group A was negative control, group B was positive control, and groups C to K were diabetic rats fed with pumpkin peel, flesh, and seed powders. Diabetes was induced in rats with the help of alloxan monohydrate. During 28 days of experimental period, blood glucose level of different rat's groups was checked with the help of glucometer, at every 7 days interval and at the end of 28 days study, plasma lipids were checked with the help of commercial kits. A significant decrease in blood glucose level (128.33 ± 1.67 mg/dl), TC (88.43 ± 0.66 mg/dl), TG (69.79 ± 0.49 mg/dl), and LDL-C (21.45 ± 0.08 mg/dl) was recorded in rat groups fed with 15 g pumpkin seed powder, at the end of study. After pumpkin seeds, second significant antihyperglycemic and antihyperlipidemic effect was recorded in rat's groups fed with 15 g pumpkin peel powder. Pumpkin flesh powder effect in lowering blood glucose level and plasma lipids was less significant as compared to seeds and peel powder. As the dose of the pumpkin powders was increased from 5 to 10 and then 15 g, the blood glucose-lowering and plasma lipid-lowering effect became more significant. Similarly, as the experimental duration was expanded from first week to 28 days, this antihyperglycemic and antihyperlipidemic effect became more significant. These results were sufficient to conclude that pumpkin has high potential to be used in human diet to cope with noncommunicable diseases like diabetes and hypercholesterolemia.

Lactobacillus brevis MTCC 1750 enhances oxidative stress resistance and lifespan extension with improved physiological and functional capacity in Caenorhabditis elegans via the DAF-16 pathway

Redox imbalance plays a crucial role in the development of age-related diseases, and resistance to oxidative stress is crucial for optimum longevity and healthy aging. Using the wild-type, mutant and transgenic strains, this study explored the antioxidative potential and lifespan extension benefits of different Lactobacillus strains in Caenorhabditis elegans (C. elegans). We observed that Lactobacillus brevis MTCC 1750 could enhance the resistance of C. elegans against juglone induced oxidative stress by reducing its intracellular reactive oxygen species (ROS) accumulation. Also, live L. brevis MTCC 1750 could prolong the worm's lifespan. These effects are dependent on transcription factor DAF-16 evident with significant upregulation of its target gene sod-3. This also explained the significant improvements in different age-associated changes in physiological and mechanical parameters of the worm by L. brevis MTCC 1750. Further investigations revealed that DAF-16 activation and, its enhanced translocation in the nucleus is independent of DAF-2 or JNK pathway. These findings highlighted L. brevis MTCC 1750 as a potent anti-oxidant source for complementing current antioxidant therapeutic strategies. Nonetheless, the findings showed how different signaling events are regulated based on an organism's diet component, and their consequences on the aging process in multiple species.

The changes of antioxidant system and intestinal bacteria in earthworms (Metaphire guillelmi) on the enhanced degradation of tetracycline

Tetracycline (TC) in soil severely imperils food security and ecosystem function. Metaphire guillelmi is a common species in farmland. It could impact the degradation of antibiotics. However, how it affects is rarely unknown. Hence, the present study aimed to investigate the effects of M. guillelmi on the TC degradation in soil and the changes of the antioxidant system and intestinal bacteria in M. guillelmi. The treatments that M. guillelmi was inoculated on soil contaminated with different TC concentrations were contrasted with those without M. guillelmi. After 21 days, the degradation rate of TC significantly increased by 13.70%, 18.14% and 29.01% at 10, 50 and 100 mg kg ^-1 TC dose, respectively, due to the inoculation of M. guillelmi. The half-life of TC was also shortened nearly by 1/3 to 2/3. Superoxide dismutase (SOD) increased in a dose-dependent manner with the increase of TC concentration on the 7th and 14th day. Catalase (CAT) and glutathione S-transferase (GST) presented an inverted U-shaped dose response on the 7th day, and the peak of enzyme activities occurred at TC concentration of 0.1, 1 mg kg ^-1 (CAT) and 0.1 mg kg ^-1 (GST). Malondialdehyde (MDA) contents did not change significantly. At the phylum level, only Verrucomicrobia significantly decreased under 1 mg kg ^-1 and 100 mg kg ^-1 TC dose. Genus Paracoccus, Singulisphaera, Acinetobacter and Bacillus significantly increased and became the dominant bacterium during the TC degradation. Overall, the antioxidant system and intestinal bacteria of M. guillelmi were affected by the different concentrations of TC pollution, which provided new ideas for the research of mechanism of TC degradation by earthworms in the future.

The Antioxidant Capacity In Vitro and In Vivo of Polysaccharides From Bergenia emeiensis

Polysaccharides from Bergenia emeiensis (PBE) showed a robust antioxidant ability on scavenging free radicals in vitro. However, the further antioxidant potential in cell level and in vivo was still unknown. Therefore, in this present study, the protective effect of PBE on human cervical carcinoma cell (Hela) cells and Caenorhabditis elegans against oxidative stress was evaluated. The results showed PBE could reduce the reactive oxygen species (ROS) level in Hela cells and promote the mitochondrial membrane potential. Then, the cell apoptosis was reduced. Moreover, PBE could enhance the survival of C. elegans under thermal stress to 13.44%, and significantly reduce the ROS level, which was connected with the overexpression of sod-3 and the increased nuclear localization of daf-16 transcription factor. Therefore, PBE exhibited a strong antioxidant capacity in the cellular level and for a whole organism. Thus, polysaccharides from B. emeiensis have natural potential to be a safe antioxidant.