Response strategies of stem/leaves endophyte communities to nano-plastics regulate growth performance of submerged macrophytes

Research on the toxicity effects of nano-plastics on submerged macrophytes has been increasing over the past several years. However, how the endophytic bacteria of submerged macrophytes respond to nano-plastics remains unknown, although they have been widely shown to help terrestrial plants cope with various environmental stressors. Here, a microcosm experiment was performed to unravel the effects of high concentration of nano-plastics (20 mg/L) on three submerged macrophyte (Vallisneria natans, Potamogeton maackianus, Myriophyllum spicatum) and their endophytic bacterial communities. Results indicated that nano-plastics induced antioxidative stress in plants, but significantly reduction in relative growth rate (RGR) only occurred in V. natans (from 0.0034 to -0.0029 day-1), accompanied by change in the stem/leaves endophyte community composition. Further analysis suggested nano-plastics caused a reduction in environmental nutrient availability and the proportion of positive interactions between endophyte communities (43%), resulting in the lowest RGR of V. natans. In contrast, endophytes may help P. maackianus and M. spicatum cope with nano-plastic stress by increasing the proportion of positive correlations among communities (70% and 75%), leaving their RGR unaffected. Collectively, our study elucidates the species-specific response strategies of submerged macrophyte-endophyte to nano-plastics, which helps to reveal the different phytoremediation potential of submerged macrophytes against nano-plastic pollution.

Gastroprotective effect of eupatilin, a polymethoxyflavone from Artemisia argyi H.Lév. & Vaniot, in ethanol-induced gastric mucosal injury via NF-κB signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Artemisia argyi H.Lév. & Vaniot (AA) has been extensively utilized as an important medicine and food homology in China, Japan, Korea, and eastern parts of Russia, owing to its pharmacological effects, which include anti-inflammatory, antibacterial, antitussive, and antiallergic properties. Despite the extract of AA can significantly alleviate gastric mucosal injury, its precise material basis for effectiveness is not yet clear. As one of the polymethoxy flavonoids with high content in AA, the gastroprotective activity and molecular mechanism of eupatilin (EUP) require further investigation.

AIM OF THE STUDY

This study aims to investigate the gastroprotective effects and possible mechanisms of EUP by using an ethanol-induced gastric mucosal injury model in rats.

MATERIALS AND METHODS

EUP was isolated from 95% ethanol extract of AA using a systematic phytochemical method. The gastroprotective activity of EUP was evaluated using a male SD rat model with ethanol-induced gastric mucosa injury. Histopathology evaluation of gastric tissues was performed using hematoxylin and eosin (H&E) staining. The levels of cytokines in the plasma and tissues were tested using the ELISA kits, while western blot analysis was employed to assess the expressions of COX-2, iNOS, and NF-κB pathway proteins.

RESULTS

A sufficient amount of EUP was obtained from AA through chromatographic methods and identified by NMR experiment. In vivo, experimental results proved that EUP could significantly alleviate pathological features, increased SOD, GSH, and IL-10 levels, and decreased the contents of MDA, TNF-α, IL-1β, and IL-6. Further in vitro and in vivo Western blot experimental results showed that EUP significantly down-regulates the expressions of the NF-κB signal pathway to relieve inflammatory responses.

CONCLUSION

This study demonstrated that EUP could exert gastroprotective effects by inhibiting inflammation, enhancing gastric mucosal defense, and ameliorating oxidative stress, which is beneficial for providing scientific data for the development of gastric protection.

Copper chaperone antioxidant 1: multiple roles and a potential therapeutic target

Copper (Cu) was recently demonstrated to play a critical role in cellular physiological and biochemical processes, including energy production and maintenance, antioxidation and enzymatic activity, and signal transduction. Antioxidant 1 (ATOX1), a chaperone of Cu previously named human ATX1 homologue (HAH1), has been found to play an indispensable role in maintaining cellular Cu homeostasis, antioxidative stress, and transcriptional regulation. In the past decade, it has also been found to be involved in a variety of diseases, including numerous neurodegenerative diseases, cancers, and metabolic diseases. Recently, increasing evidence has revealed that ATOX1 is involved in the regulation of cell migration, proliferation, autophagy, DNA damage repair (DDR), and death, as well as in organism development and reproduction. This review summarizes recent advances in the research on the diverse physiological and cytological functions of ATOX1 and the underlying mechanisms of its action in human health and diseases. The potential of ATOX1 as a therapeutic target is also discussed. This review aims to pose unanswered questions related to ATOX1 biology and explore the potential use of ATOX1 as a therapeutic target.

The Prevention and Reversal of a Phenytoin-Resistant Model by N-acetylcysteine Therapy Involves the Nrf2/P-Glycoprotein Pathway at the Blood-Brain Barrier

The transporter hypothesis is one of the most popular hypotheses of drug-resistant epilepsy (DRE). P-glycoprotein (P-gp), a channel protein at the blood-brain barrier (BBB), plays an important role in the transport of some anti-seizure drugs from brain tissue into vessels, which reduces drug concentrations and diminishes the effects of drug treatment. We performed this study to test whether P-gp is overexpressed in DRE and identify ways to prevent and reverse DRE. In this study, we established a phenytoin (PHT)-resistant mouse model and revealed that P-gp was overexpressed at the BBB in PHT-resistant mice. The P-gp inhibitor nimodipine decreased the resistance of phenytoin. Antioxidative preventive treatment with N-acetylcysteine (NAC) prevented the mice from entering a PHT-resistant state, and NAC therapy tended to reverse PHT resistance into sensitivity. We were also able to induce PHT resistance by activating the Nrf2/P-gp pathway, which indicates that oxidative stress plays an important role in drug resistance. Taken together, these findings suggest that antioxidative therapy may be a promising strategy for overcoming DRE.

Time-series transcriptomic screening of factors contributing to the cross-tolerance to UV radiation and anhydrobiosis in tardigrades

BACKGROUND

Tardigrades are microscopic animals that are capable of tolerating extreme environments by entering a desiccated state of suspended animation known as anhydrobiosis. While antioxidative stress proteins, antiapoptotic pathways and tardigrade-specific intrinsically disordered proteins have been implicated in the anhydrobiotic machinery, conservation of these mechanisms is not universal within the phylum Tardigrada, suggesting the existence of overlooked components.

RESULTS

Here, we show that a novel Mn-dependent peroxidase is an important factor in tardigrade anhydrobiosis. Through time-series transcriptome analysis of Ramazzottius varieornatus specimens exposed to ultraviolet light and comparison with anhydrobiosis entry, we first identified several novel gene families without similarity to existing sequences that are induced rapidly after stress exposure. Among these, a single gene family with multiple orthologs that is highly conserved within the phylum Tardigrada and enhances oxidative stress tolerance when expressed in human cells was identified. Crystallographic study of this protein suggested Zn or Mn binding at the active site, and we further confirmed that this protein has Mn-dependent peroxidase activity in vitro.

CONCLUSIONS

Our results demonstrated novel mechanisms for coping with oxidative stress that may be a fundamental mechanism of anhydrobiosis in tardigrades. Furthermore, localization of these sets of proteins mainly in the Golgi apparatus suggests an indispensable role of the Golgi stress response in desiccation tolerance.

Schaftoside Suppresses Pentylenetetrazol-Induced Seizures in Zebrafish via Suppressing Apoptosis, Modulating Inflammation, and Oxidative Stress

The lack of disease-modifying therapeutic strategies against epileptic seizures has caused a surge in preclinical research focused on exploring and developing novel therapeutic candidates for epilepsy. Compounds from traditional Chinese medicines (TCMs) have gained much attention for a plethora of neurological diseases, including epilepsy. Herein, for the first time, we evaluated the anticonvulsive effects of schaftoside (SS), a TCM, on pentylenetetrazol (PTZ)-induced epileptic seizures in zebrafish and examined the underlying mechanisms. We observed that SS pretreatments significantly suppressed seizure-like behavior and prolonged the onset of seizures. Zebrafish larvae pretreated with SS demonstrated downregulation of c-fos expression during seizures. PTZ-induced upregulation of apoptotic cells was decreased upon pretreatment with SS. Inflammatory phenomena during seizure progression including the upregulation of interleukin 6 (IL-6), interleukin 1 beta (IL-1β), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) were downregulated upon pretreatment with SS. The PTZ-induced recruitment of immunocytes was in turn reduced upon SS pretreatment. Moreover, SS pretreatment modulated oxidative stress, as demonstrated by decreased levels of catalase (CAT) and increased levels of glutathione peroxidase-1a (GPx1a) and manganese superoxide dismutase (Mn-SOD). However, pretreatment with SS modulated the PTZ-induced downregulation of the relative enzyme activity of CAT, GPx, and SOD. Hence, our findings suggest that SS pretreatment ameliorates PTZ-induced seizures, suppresses apoptosis, and downregulates the inflammatory response and oxidative stress, which potentially protect against further seizures in zebrafish.

Hyaluronic acid-coated polymeric micelles with hydrogen peroxide scavenging to encapsulate statins for alleviating atherosclerosis

Inflammation and oxidative stress are two major factors that are involved in the pathogenesis of atherosclerosis. A smart drug delivery system that responds to the oxidative microenvironment of atherosclerotic plaques was constructed in the present study. Simvastatin (SIM)-loaded biodegradable polymeric micelles were constructed from hyaluronic acid (HA)-coated poly(ethylene glycol)-poly(tyrosine-ethyl oxalyl) (PEG-Ptyr-EO) for the purpose of simultaneously inhibiting macrophages and decreasing the level of reactive oxygen species (ROS) to treat atherosclerosis. HA coating endows the micelle system the ability of targeting CD44-positive inflammatory macrophages. Owing to the ROS-responsive nature of PEG-Ptyr-EO, the micelles can not only be degraded by enzymes, but also consumes ROS by itself at the pathologic sites, upon which the accumulation of pro-inflammatory macrophages is effectively suppressed and oxidative stress is alleviated. Consequently, the cellular uptake experiment demonstrated that SIM-loaded HA-coated micelles can be effectively internalized by LPS-induced RAW264.7 cells and showed high cytotoxicity against the cells, but low cytotoxicity against LO2 cells. In mouse models of atherosclerosis, intravenously SIM-loaded HA-coated micelles can effectively reduce plaque content of cholesterol, resulting in remarkable therapeutic effects. In conclusion, the SIM-loaded micelle system provides a promising and innovative option against atherosclerosis.

Retinol-binding protein 4 (RBP4) and high sensitivity C-reactive protein (hs-CRP) levels in patients with diminished ovarian reserve (DOR): a cross-sectional study

BACKGROUND

Antioxidant/oxidant imbalance has been reported to be related to diminished ovarian reserve (DOR). Vitamin A (retinol), a kind of antioxidant, plays a role in restoring ovarian oxidative damage, while C-reactive protein (CRP) is the classical marker of oxidative stress and has recently been identified as an independent variable that is associated with low anti-Mullerian hormone (AMH) levels in young women with DOR. Additionally, retinol binding protein 4 (RBP4) can be considered a substitute for retinol in healthy, nonobese women. The study aim was to determine the relationship between serum RBP4, high sensitivity C-reactive protein (hs-CRP) concentrations and ovarian reserve in nonobese DOR patients.

METHODS

This study included 24 DOR women and 48 normal ovarian reserve (NOR) women from the reproductive medical center of Renmin Hospital of Wuhan University. The serum RBP4 and high-sensitivity CRP (hs-CRP) levels were measured with ELISA kits.

RESULTS

RBP4 levels (20,648.36 ± 5475.16 ng/ml vs 23,986.48 ± 5995.64 ng/ml, p = 0.025) were decreased, and hs-CRP levels (695.08 ± 1090.19 ng/ml vs 364.32 ± 786.29 ng/ml, p = 0.012) were increased in the DOR group. Serum RBP4 was positively related to AMH (Pearson r = 0.518, p = 0.000), while hs-CRP was negatively correlated with AMH (Spearman r = - 0.345, p = 0.005). after adjustments were made for the covariables, multiple line regression analysis showed that positive association between RBP4 and AMH still existed (β = 0.450, p < 0.001).

CONCLUSION

Decreased serum RBP4 levels and increased serum hs-CRP were observed in DOR patients in our study, and the strong correlation between RBP4 and AMH supports the notion that oxidative stress plays a role in DOR, and that appropriate levels of antioxidant vitamin A may be protective against ovarian reserve dysfunction.

Effects of ZnO nanoparticles on aerobic denitrifying bacteria Enterobacter cloacae strain HNR

The aerobic denitrification process is a promising and cost-effective alternative to the conventional nitrogen removal process. Widely used ZnO nanoparticles (NPs) will inevitably reach wastewater treatment plants, and cause adverse impacts on aerobic denitrification and nitrogen removal. Therefore, a full understanding of the responses and adaption of aerobic denitrifiers to ZnO NPs is essential to develop effective strategies to reduce adverse effects on wastewater treatment. In this study, the responses and adaption to ZnO NPs were investigated of a wild type strain (WT) and a resistant type strain (Re) of aerobic denitrifying bacteria Enterobacter cloacae strain HNR. When exposed to 0.75 mM ZnO NPs, the nitrate removal efficiency of Re was 11.2% higher than that of WT. To prevent ZnO NPs entering cells by adsorption, the production of extracellular polymeric substances (EPS) of WT and Re strains increased 13.2% and 43.9%, respectively. The upregulations of amino sugar and carbohydrate-related metabolism contributed to the increase of EPS production, and the increased nitrogen metabolism contributed to higher activities of nitrate and nitrite reductases. Interestingly, cationic antimicrobial peptide resistance contributed to resist Zn (II) released by ZnO NPs, and many antioxidative stress-related metabolism pathways were upregulated to resist the oxidative stress resulting from ZnO NPs. These findings will guide efforts to improve the aerobic denitrification process in an environment polluted by NPs, and promote the application of aerobic denitrification technologies.

Corydalis edulis total alkaloids (CETA) ameliorates cognitive dysfunction in rat model of Alzheimer disease through regulation of the antioxidant stress and MAP2/NF-κB

BACKGROUND

In recent years, the morbidity of Alzheimer's disease in the world has become more and more serious. Therefore, it is an important means to find new drugs for treating AD from traditional medicines. It was found that Corydalis edulis Maxim. has a significant effect in the treatment of Alzheimer's disease (AD) in traditional application. In this work, we evaluated the efficacy of Corydalis edulis Maxim. total alkaloids (CETA) in AD model rats.

METHODS

In this work, CETA was prepared by alkali extraction and acid precipitation, 11 alkaloids were identified by UPLC-MS/MS from CETA. AD model rats induced with D-galactose (D-gal) for 7 weeks. In modeling, the different doses of CETA (5, 20 mg/kg/Day) were continuously administered. Firstly, the change of the cognitive function, behavior, brain tissue pathology, and the activity of ROS, MDA, SOD, IL-1β, TNF-α and CAT in rat hippocampal homogenate was measurement. Finally, the protein expression of Aβ, microtubule-associated protein 2 (MAP2) and nuclear factor (κBp65) in rat brain was measurement.

RESULT

CETA was found to have the activity in regulating AD. Compared with the normal control group, the levels of SOD and CAT in the hippocampus of the AD model group were decreased, and the level of ROS, MDA, IL-1β and TNF-α was increased. The protein expression of Aβ, and NF-κB were increased, and MAP2 were decreased. After treatment by CETA, the levels of SOD and CAT in hippocampus of AD model rats was significantly increased, ROS, MDA, IL-1β and TNF-α were significantly decreased. The protein expression of Aβ, and NF-κB were decreased, and MAP2 were increased.

CONCLUSION

CETA can improve the learning and memory ability in AD model. The mechanism may be achieved by regulating the oxidative stress and inflammatory of AD rats, inhibiting the protein expression levels of Aβ, and NF-κB, and promote the protein expression the levels of MAP2. Among them, 5 mg/kg is more effective than 20 mg/kg of CETA. Therefore, the therapeutic potential of CETA has been confirmed by our research, which may be a valuable drug for the treatment of AD.

Antioxidative stress-induced damage in cochlear explants

The imbalance of reactive oxygen species and antioxidants is considered to be an important factor in the cellular injury of the inner ear. At present, great attention has been placed on oxidative stress. However, little is known about fighting oxidative stress. In the current study, we evaluated antioxidant-induced cochlear damage by applying several different additional antioxidants. To determine whether excessive antioxidants can cause damage to cochlear cells, we treated cochlear explants with 50 μM M40403, a superoxide dismutase mimetic, 50 μM coenzyme Q-10, a vitamin-like antioxidant, or 50 μM d-methionine, an essential amino acid and the important antioxidant glutathione for 48 h. Control cochlear explants without the antioxidant treatment maintained their normal structures after incubation in the standard serum-free medium for 48 h, indicating the maintenance of the inherent oxidative and antioxidant balance in these cochlear explants. In contrast, M40403 and coenzyme Q-10-treated cochlear explants displayed significant hair cell damage together with slight damage to the auditory nerve fibers. Moreover, d-methiodine-treated explants exhibited severe damage to the surface structure of hair cells and the complete loss of the spiral ganglion neurons and their peripheral fibers. These results indicate that excessive antioxidants are detrimental to cochlear cells, suggesting that inappropriate dosages of antioxidant treatments can interrupt the balance of the inherent oxidative and antioxidant capacity in the cell.

Alternations in oxidative stress, apoptosis, and innate-immune gene expression at mRNA levels in subadult tiger puffer (Takifugu rubripes) under two different rearing systems

Tiger puffer (Takifugu rubripes) is one of the major aquaculture fish species in China due to its high economic value. In this study, the transcriptions of hepatic antioxidant enzyme, stress, apoptosis, and immune-related genes of sub-adult tiger puffers (Takifugu rubripes) were evaluated under two different rearing systems [offshore sea cage aquaculture system (OSCS) and recirculating aquaculture system (RAS)]. Results showed that the mRNA expression levels of the antioxidant enzyme (mn-sod, cu/zn-sod, gpx, and gr) and stress-related (hsp70 and hsp90) genes of male tiger puffers reared in the OSCS were significantly higher than female fish reared in the OSCS and fish reared in the RAS. The anti-apoptotic gene bcl2 exhibited the similar results. By contrast, the mRNAs of the pro-apoptotic genes (p53, caspase8, caspase9, and caspase3) of male tiger puffers reared in the OSCS were significantly lower than female fish reared in the OSCS and fish reared in the RAS. Male tiger puffers reared in the OSCS displayed significantly higher complement components (c3) and inflammatory cytokine (il-6) mRNAs, whereas B-cell activating factor (baf) and tumor necrosis factor α (tnf-α) mRNAs remained unchanged. Meanwhile, the mRNA levels of pro-apoptotic (bax, caspase8) and immunity-related (c3, il-6 and il-7) genes of female tiger puffers reared in the OSCS were significantly lower and higher than female fish reared in the RAS, respectively. In conclusion, the hepatic antioxidant, anti-apoptosis, and innate immunity of tiger puffers reared in the OSCS were better than fish in the RAS, male tiger puffer obtained the best values. These results expand the knowledge on the combined RAS and OSCS alternative aquaculture model for tiger puffers and aid in their management in captive.

Costunolide inhibits pulmonary fibrosis via regulating NF-kB and TGF-β1/Smad2/Nrf2-NOX4 signaling pathways

Specific study about the inhibitory effect of costunolide (CN) and relevant mechanism is of great significance for the treatment of pulmonary fibrosis. Here, the pharmacological activity of costunolide on the treatment of pulmonary fibrosis was investigated in vivo and in vitro. The in vivo mice study, mice were received intratracheal injection of bleomycin (BLM, 5 mg/kg) on 0 day to obtain BLM-induced pulmonary fibrosis firstly. From 2 day to 21 day, mice were orally administered with different dose of CN (low dose(CNL): 10 mg/kg, high dose(CNH): 20 mg/kg) and pirfenidone (PFD)(positive control, 50 mg/kg). The in vitro cells model, cells were incubated with recombinant human TGF-β1 for 24 h to get TGF-β₁-induced pulmonary fibrosis. Cells were treated differently for 24 h and divided into five groups. Then, the activity of CN was evaluated by the expression level of related protein and the factors of oxidative stress in vivo and in vitro, and the mechanism was tested from the involved channel protein aspect. As a result, from the comparison of multiple factors (α-SMA, collagen type I/III, HYP, MDA, SOD) between pirfenidone group and CN group, it revealed the beneficial effects of CN against BLM-induced and TGF-β₁-induced pulmonary fibrosis. In addition, our study also proved that CN exerted its effects through suppressing the NF-kB dependent inflammation and regulated TGF-β₁/Smad₂/ NOX₄-Nrf₂ signaling pathways. In conclusion, CN could be a potential theraputic candidate for the treatment pulmonary fibrosis in the future.

Depicting the physiological and ultrastructural responses of soybean plants to Al stress conditions

Aluminium (Al) is a toxic element for plants living in soils with acidic pH values, and it causes reductions in the roots and shoots development. High Al concentrations can cause physiological and structural changes, leading to symptoms of toxicity in plant tissue. The aim of this study was to describe the Al toxicity in soybean plants through physiological, nutritional, and ultrastructure analyses. Plants were grown in nutrient solution containing increasing Al concentrations (0; 0.05; 0.1; 1.0, 2.0 and 4.0 mmol L-1). The Al toxicity in the soybean plants was characterized by nutritional, anatomical, physiological, and biochemical analyses. The carbon dioxide assimilation rates and stomatal conductance were not affected by the Al. However, the capacity for internal carbon use decreased, and the transpiration rate increased, resulting in increased root biomass at the lowest Al concentration in the nutrient solution. The soybean plants exposed to the highest Al concentration exhibited lower root and shoot biomass. The nitrate reductase and urease activities decreased with the increasing Al concentration, indicating that nitrogen metabolism was halted. The superoxide dismutase and peroxidase activities increased with the increasing Al availability in the nutrient solution, and they were higher in the roots, showing their role in Al detoxification. Despite presenting external lesions characterized by a damaged root cap, the root xylem and phloem diameters were not affected by the Al. However, the leaf xylem diameter showed ultrastructural alterations under higher Al concentrations in nutrient solution. These results have contributed to our understanding of several physiological, biochemical and histological mechanisms of Al toxicity in soybean plants.

Physiological highlights of manganese toxicity symptoms in soybean plants: Mn toxicity responses

Manganese (Mn) is an essential element for plants; however, high concentrations in certain soil conditions can cause toxicity symptoms in the plant tissue. Here, we describe Mn toxicity symptoms and Mn toxicity responses in soybean plants. Soybean plants exposed to excess Mn showed reductions in the CO2 assimilation rate and stomatal conductance, which in turn resulted in decreased shoot biomass. Furthermore, peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activity were higher in plants grown with the highest Mn concentration. The Mn doses increased the activity of antioxidant enzymes such as CAT, POD, and SOD. The toxicity symptoms presented by the leaves included hypertrophying of the adaxial epidermis and the formation of necrotic areas with purple-colored veins. Dramatic movement of calcium from the healthy region to the purple-colored necrotic region was observed, as was the exit of potassium from the necrotic area to the healthy region of the tissue. The high activities of POD and SOD in the presence of high Mn compartmented in the roots was the main physiological responses at high Mn uptake by soybean plants.

Selenoprotein W was Correlated with the Protective Effect of Selenium on Chicken Myocardial Cells from Oxidative Damage

Selenium (Se) mainly performs its function through Se-containing proteins. Selenoprotein W (SelW), one member of the selenoprotein family, plays important roles in the normal function of the heart. To investigate the possible relationship between Se and SelW for the regulation of oxidative damage in chicken embryo myocardial cells, we treated myocardial cells with Se and H2O2. Then, the levels of lactate dehydrogenase (LDH) and 3,4-methylenedioxyamphetamine in the culture media, levels of SelW, inflammatory genes NF-κB, tumor necrosis factor (TNF)-α, p53, and the cell cycle were analyzed. Furthermore, the correlation between SelW and the levels of these factors was determined. The results indicated that Se treatment increased the expression of SelW (P < 0.05) and caused a downregulation of p53, NF-κB, and TNF-α (P < 0.05). In contrast, H2O2 increased the expression of p53, NF-κB, TNF-α, and LDH (P < 0.05) and induced early cell apoptosis, which was alleviated by treatment with Se. In addition, SelW had a positive correlation with the levels of inflammatory genes investigated. Taken together, our findings suggested that SelW is sensitive to Se levels and oxidative stress, and may play a role in the protective function of Se against oxidative damage and inflammation in chicken myocardial cells.

Dietary Aloe vera improves plasma lipid profile, antioxidant, and hepatoprotective enzyme activities in GIFT-tilapia (Oreochromis niloticus) after Streptococcus iniae challenge

The current study investigated the effects of dietary Aloe vera on plasma lipid profile status, antioxidant, and hepatoprotective enzyme activities of GIFT-tilapia juveniles under Streptococcus iniae challenge. Five dietary groups were designed including a control and 100 % Aloe powder incorporated into a tilapia feed at 0.5, 1, 2, and 4 %/kg feed, which were administered for 8 weeks. Fish fed dietary Aloe at 4 %/kg feed significantly reduced in total cholesterol, while triacylglycerol reduced (P < 0.05) in those fed 0.5, 2, and 4 % Aloe/kg feed compared to unsupplemented ones. High-density lipoprotein was significantly elevated in fish fed 0.5 and 1 % Aloe/kg feed compared to unsupplemented ones, and no significant changes (P > 0.05) were noted in low-density lipoprotein among test groups. Furthermore, high activities of superoxide dismutase, catalase, and glutathione peroxide in liver tissues were observed in Aloe-supplemented fish compared to unsupplemented ones, before and after S. iniae challenge (7.7 × 10(6) CFU cells/mL). Variations were also noted in malondialdehyde activity throughout the trial, but no significant difference (P > 0.05) was observed between groups. Meanwhile, Aloe-supplemented fish reduced serum aspartate and alanine aminotransferase (AST and ALT) activities before and after challenge. Based on the second-order polynomial regression analysis, dietary Aloe inclusion levels less than or equal to 1.88, 1.86, and 2.79 %/kg feed were determined to be suitable in improving plasma lipid profile status, antioxidant, and hepatoprotective enzyme activities in GIFT-tilapia in this study, respectively. Thus, A. vera extracts may be recommended as a tilapia feed supplement to enhance fish antioxidant and hepatoprotective capacities, especially during disease outbreaks.

Comparative studies of polydatin and resveratrol on mutual transformation and antioxidative effect in vivo

BACKGROUND

Polydatin and resveratrol are extractives of radix or rhizoma of Polygonum cuspidatum, and as the glycoside forms, it is a natural precursor of resveratrol.

PURPOSE

In this study, we aimed to explore the mutual transformation between polydatin and resveratrol in rats, and to compare the antioxidative effect of them in vivo.

STUDY DESIGN

In this study, we analyzed the serum molar concentration of polydatin and resveratrol after oral administration in rats and evaluated the anti-oxidative stress effects of them using a mouse model.

METHODS

Rats were orally administered polydatin or resveratrol and the concentration of them in serum were analyzed by high performance liquid chromatography (HPLC). Their antioxidative effect was compared in mice with oxidative stress cardiomyopathy induced by doxorubicin (DOX).

RESULTS

The results showed that polydatin and resveratrol could mutually transform in vivo, the molar concentration of polydatin in serum was always averagely 3.35 and 4.28 times as much as resveratrol after oral administration of polydatin and resveratrol at 200 mg/kg, respectively. Both polydatin and resveratrol could significantly decrease the content of malonydialdehyde (MDA), promote the activities of total superoxide dismutase (T-SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in plasma, and increase the content of glutathione (GSH) in myocardial tissue. The effect of polydatin surpassed resveratrol, particularly embodied in increasing the activities of T-SOD and CAT, and the content of GSH.

CONCLUSION

It illustrates that polydatin is the main substance in serum after intragastric administration with polydatin or resveratrol, and the mutual transformation between polydatin and resveratrol keeps balance; they both have the ability of antioxidative stress in vivo, and polydatin has a better effect than resveratrol, which hints that polydatin may be a substitute for resveratrol in antioxidant for clinical use.

The good and bad of antioxidant foods: An immunological perspective

Maintenance of redox homeostasis plays a central role in health and disease prevention, and antioxidant foods are thought to exert protective effects by counteracting oxidative stress. The term "dietary antioxidant" implies a classical reducing or radical-scavenging capacity, but more data on the in vivo bioactivity of such compounds are needed. Indeed, several dietary antioxidants activate signaling cascades that lead to effects that extend beyond radical scavenging, such as the induction of endogenous cytoprotective mechanisms and detoxification. Currently, the overall uptake of antioxidants with diet exceeds actual needs, as food additives that include vitamins, colorants, flavoring agents, and preservatives are often also relatively strong antioxidants. Chronic antioxidative stress favors adverse effects, such as the suppression of T helper (Th) type 1 immune responses and consequent activation of Th2 reactions that support the development of asthma, allergies, and obesity. In this context, we discuss the immunoregulatory pathway of tryptophan breakdown by enzyme indoleamine 2,3-dioxygenase (IDO), which represents a central regulatory hub for immune, metabolic, and neuroendocrine processes. Activation of IDO-mediated tryptophan metabolism is strongly redox-sensitive and is therefore susceptible to modulation by dietary components, phytochemicals, preservatives, and drugs.