Preventive effects of the polysaccharide of Larimichthys crocea swim bladder on carbon tetrachloride (CCl4)-induced hepatic damage

Peptides from the croceine croaker (Larimichthys crocea) swim bladder attenuate busulfan-induced oligoasthenospermia in mice

CONTEXT

The swim bladder of the croceine croaker is believed to have a therapeutic effect on various diseases. However, there is no research about its effect on mammalian spermatogenesis.

OBJECTIVE

We investigated the swim bladder peptides (SBPs) effect on busulfan-induced oligoasthenospermia in mice.

MATERIALS AND METHODS

We first extracted SBP from protein hydrolysate of the croceine croaker swim bladder, and then five groups of ICR male mice were randomly assigned: control, control + SBP 60 mg/kg, busulfan, busulfan + SBP 30 mg/kg and busulfan + SBP 60 mg/kg. Mice received bilateral intratesticular injections of busulfan to establish oligoasthenospermia model. After treatment with SBP for 4 weeks, testis and epididymis were collected from all mice for further analysis.

RESULTS

After treatment with SBP 30-60 mg/kg for 4 weeks, epididymal sperm concentration and motility increased by 3.9-9.6- and 1.9-2.4-fold than those of oligoasthenospermia mice induced by busulfan. Meanwhile, histology showed that spermatogenic cells decreased, leading to increased lumen diameters and vacuolization in the busulfan group. These features were reversed by SBP treatment. RNA-sequencing analysis revealed that, compared with the busulfan group, Lin28b and Igf2bp1 expression related to germ cell proliferation, increased with a >1.5-fold change after SBP treatment. Additionally, PGK2 and Cfap69 mRNAs associated with sperm motility, also increased with a >1.5-fold change. Furthermore, these findings were validated by quantitative real-time PCR and Western blotting.

DISCUSSION AND CONCLUSIONS

This is the first reported evidence for the therapeutic effect of SBP on oligoasthenospermia. SBP may be a promising drug for oligoasthenospermia in humans.

Preventive effect of swim bladder hydrolysates on cyclophosphamide-induced ovarian injury in mice

AIMS

This study aimed to prepare swim bladder hydrolysate (SBH) with M_n  < 4000 Da, and investigate its effects on cyclophosphamide (CTX)-mediated ovarian injury in mice.

METHODS

Hydrolysates were prepared by heating extraction, enzymatic hydrolysis and ultrafiltration. M_n and distribution of SBH were analyzed via gel filtration chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Changes in the mouse oestrus cycle were determined by cytological examination. The number of follicles was examined using histopathology. Enzyme-linked immunosorbent assays (ELISAs) were used to determine the serum sex hormone levels.

RESULTS

The M_n of SBH, prepared by heating extraction, enzymatic hydrolysis, ultrafiltration, and from different batches, was below 4000 Da, and the preparation process was stable. Compared with the control group, the low-, middle-, and high-dose SBH treatment groups showed different trends in oestrus duration, serum sex hormone levels, and the number of primordial and secondary follicles. The oestrus cycle duration of the high-dose SBH group was longer than that of the model group. The serum luteinizing hormone, follicle-stimulating hormone, and anti-Müllerian hormone levels in the middle-dose group were the closest to those of control group. The number of primordial and secondary follicles in the medium-dose group was significantly higher than that in the model group and closest to those of control group.

CONCLUSION

After heating extraction, trypsin/Flavourzyme hydrolysis and ultrafiltration, a hydrolysate with M_n below 4000 Da could be prepared. We found that a moderate (400 mg/kg) SBH dose resulted in the greatest effect on ovarian injury remission in mice.

The Structural Characteristics of Collagen in Swim Bladders with 25-Year Sequence Aging: The Impact of Age

Aged swim bladders from the yellow drum (Protonibea diacanthus) are considered collagen-based functional food with extremely high market value. The structural integrity of collagen may be crucial for its biological functions. In the current study, swim bladders with 25-year-old sequences were collected and found to be basically composed of collagen. Then, thermogravimetry (TG), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and attenuated total reflectance–Fourier transform infrared spectroscopy (ATR–FTIR) were conducted to evaluate the integrity of the peptide chain and triple helix in the collagen. The structures of microfibers and fiber bundles were revealed with atomic force microscopy (AFM), scanning electrical microscopy (SEM), and optical spectroscopy. The collagens in the aged swim bladders were found to have similar thermal properties to those of fresh ones, but the relative content of the triple helixes was found to be negatively correlated with aging. The secondary structure of the remaining triple helix showed highly retained characteristics as in fresh swim bladders, and the microfibrils also showed a similar D-period to that of the fresh one. However, the fiber bundles displayed more compact and thick characteristics after years of storage. These results indicate that despite 25 years of aging, the collagen in the swim bladders was still partially retained with structures.

Protective Effect of Blood Cora Polysaccharides on H9c2 Rat Heart Cells Injury Induced by Oxidative Stress by Activating Nrf2/HO-1 Signal Pathway

The protective effect of blood cora polysaccharides (BCP) on H9c2 rat heart cells under oxidative stress was explored with the use of a H9c2 cell oxidative stress model. The ability of BCP to scavenge 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH), and hydroxyl radicals and its reducing power were measured in vitro, indicating a more powerful antioxidant effect of BCP compared to a similar concentration of vitamin C. The cellular metabolic activity was tested through the MTT [3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide] assay. Additionally, the relevant oxidation indicator level within the cell supernatant and cells was tested with reagent kits, and mRNA and protein expression levels in the cells were tested through quantitative polymerase chain reaction (qPCR) and western blot. The chemical composition of BCP was determined through high performance liquid chromatography (HPLC). The results show that compared with the normal group, the model group's cell survival rate (28.75 ± 2.56%) decreased, lactate dehydrogenase (LDH) leakage and the malondialdehyde (MDA) content increased, and superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) levels decreased. The results of qPCR and western blot show that compared with the normal group, the model group's Bcl-2 associated X protein (Bax), caspase-3, nuclear factor erythroid-2 related factor 2 (Nrf2), heme oxygenase-1 (HO-1) expression, NAD(P)H:quinoneoxidoreductase 1 (NQO1), and cytochrome c (Cyt C) decreased, and B-cell lymphoma-2 (Bcl-2) expression was increased, with significant statistical differences. Compared with the model group, the cell survival rate for each BCP-treated group increased, the LDH leakage decreased, the SOD, CAT, and GSH levels in the cells increased, the MDA content decreased, the Bax, caspase-3, Nrf2, HO-1, NQO1, and Cyt C expression was weakened, and the Bcl-2 expression was strengthened. BCP inhibited the reduction of mitochondrial membrane potential caused by H2O2 treatment. According to the component analysis, BCP mainly consist of mannitol, ribose, glucosum anhydricum, galactose, and xylose. It was observed that the Nrf2/HO-1 signaling pathway can be activated, regulated, and controlled by functional BCP to protect H9c2 cells injured by oxidative stress.

Exogenous hydrogen sulfide protects fatty liver against ischemia-reperfusion injury by regulating endoplasmic reticulum stress-induced autophagy in macrophage through mediating the class A scavenger receptor pathway in rats

Fatty liver disease is a disease manifested with excessive alcohol intake and obese. Importantly, hydrogen sulfide (H₂ S) has been revealed to participate in the progression of fatty liver; however, the underlying mechanism has not been clearly elucidated yet. In this study, we aimed to investigate the effects of exogenous H₂ S on fatty liver ischemia-reperfusion injury (IRI) through mediating class A scavenger receptor (SRA) pathway in rats. By determining endoplasmic reticulum stress (ERS)-related factors, autophagy markers and apoptosis-related factors in liver tissue and liver function, levels of oxidative stress, inflammatory factors, and hepatocyte apoptosis, the effects of H₂ S on IRI-induced autophagy, oxidative stress, and inflammation were all examined in rat model of fatty liver IRI. Results from obtained data showed that H₂ S decreased the expression of SRA, Grp78, PERK, CHOP, and Caspase-3, and increased that of LC3-II/LC3-I, in addition to alleviating the pathological changes of liver and reducing the levels of ALT, AST, LDH TBARS, and MDA. Moreover, H₂ S decreased the levels of oxidative stress, the expression of pro-inflammatory factors including tumor necrosis factor α, interleukin 1, and interleukin 6, and the apoptosis of hepatocytes. Our findings suggested exogenous H₂ S could reduce ERS by mediating the SRA pathway and protect liver function by inducing autophagy, and protect against IRI by reducing oxidative stress and inflammation.

Preventive effect of flavonoids from Wushan Shencha (Malus doumeri leaves) on CCl4-induced liver injury

Wushan Shencha (Malus doumeri leaf) is a unique tea-like drink. Herein, the effect of flavonoids from Wushan Shencha (FWSSC) on carbon tetrachloride-induced liver injury was studied. The serum and liver tissues of experimental mice were analyzed by kits, a slice technique, and qPCR assay. The liver index is a calculated liver-to-body weight ratio, and the experimental results showed that FWSSC reduced the liver index of the model group with liver injury, which was the highest. Sections stained with H&E showed that FWSSC reduced stem cell necrosis caused by liver injury. FWSSC reduced the serum levels of AST, ALT, TG, and TC, as well as the levels of IL-6, TNF-α, and IFN-γ cytokines in the serum of mice with liver injury. Liver biochemical tests also showed that FWSSC increased the SOD activity and decreased TC, TG, and MPO levels in mice with liver injury. It was found that FWSSC upregulated the expression of Cu/Zn-SOD, Mn-SOD, CAT, and IκB-α, and downregulated the expression of NF-κB, COX-2, TNF-α, and IL-1β in the liver tissue of mice with liver injury by detecting the expression of mRNA in liver tissue. It is concluded that FWSSC is an active substance with hepatoprotective effects. The activity of FWSSC increased with increasing concentration, and the hepatoprotective effect of FWSSC at 100 mg/kg concentration was stronger than that of silymarin.

Preventive Effect of Anji White Tea Flavonoids on Alcohol-Induced Gastric Injury through Their Antioxidant Effects in Kunming Mice

Anji white tea (Camellia sinensis) is a traditional Chinese tea beverage, which is classified as green tea and contains an abundant amount of flavonoids. In this study, the preventive effect of Anji white tea flavonoids (AJWTFs) on ethanol/hydrochloric acid-induced gastric injury in mice was evaluated. The serum and gastric tissues of mice were analyzed using a biochemical kit and by quantitative polymerase chain reaction (qPCR). Observation of the appearance of the stomach indicated that AJWTFs could effectively reduce the area of gastric injury caused by ethanol/hydrochloric acid, and the inhibition rate of AJWTF on gastric injury increased with an increase in AJWTF concentration. The Anji white tea flavonoids could also reduce the volume and pH of gastric juice in mice with gastric injury. Biochemical results showed that AJWTFs could increase the superoxide dismutase (SOD) and glutathione (GSH) activities, as well as decrease the malondialdehyde (MDA) level, in the serum and liver of mice with gastric injury. Pathological observation confirmed that AJWTFs could inhibit the tissue damage caused by ethanol/hydrochloric acid in the stomach of mice. Further qPCR experiments also showed that AJWTFs could inhibit the decreases in neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS), copper/zinc superoxide dismutase (Cu/Zn–SOD), manganese superoxide dismutase (Mn–SOD), catalase (CAT), and the increase in inducible nitric oxide synthase (iNOS) expression in the gastric tissue of mice caused by gastric injury. As observed, AJWTFs exerted a good preventive effect on alcohol-induced gastric injury in mice induced by ethanol/hydrochloric acid, and the effect is close to that of ranitidine. Anji white tea flavonoids present good antioxidant effect, which allows them to effectively prevent alcoholic gastric injury and be used as biologically active substances with a broad range of applications.

Liver Injury Induced by Carbon Tetrachloride in Mice Is Prevented by the Antioxidant Capacity of Anji White Tea Polyphenols

Anji white tea is a unique variety of green tea that is rich in polyphenols. In this study, the effect of Anji white tea polyphenols (AJWTP) on the prevention of carbon tetrachloride (CCl₄)-induced liver injury through its antioxidant properties was studied. Biochemical and molecular biology methods were used to analyze the serum and liver tissue of mice. The antioxidant capacity and liver injury preventive effect of AJWTP were determined, and the mechanism was elaborated. The results showed that AJWTP decreased the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglyceride (TG), and total cholesterol (TC) in mice with liver injury, it increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the serum and liver tissue of mice with liver injury, and it also decreased the amount of malondialdehyde (MDA). Further quantitative polymerase chain reaction (qPCR) results showed that AJWTP upregulated the mRNA expression of Cu/Zn-SOD, Mn-SOD, catalase (CAT), and nuclear factor of kappa light polypeptide gene enhancer in B-cell inhibitor alpha (IκB-α) and downregulated the expression of nuclear factor κ-light-chain-enhancer of activated B-cells (NF-κB), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), interleukin-1 beta (IL-1β), and tumor necrosis factor alpha (TNF-α) in the liver tissue of mice with liver injury. Therefore, AJWTP produces sufficient antioxidant action to prevent liver injury, and the effect increases with the increase in AJWTP concentration. The effect of 200 mg/kg AJWTP was similar to that of the same concentration of the drug (silymarin) used for the treatment of liver injury. This indicates excellent potential for the development and utilization of AJWTP because it is an active substance with excellent antioxidant effects and can prevent liver injury.

Polyphenols in Liubao Tea Can Prevent CCl₄-Induced Hepatic Damage in Mice through Its Antioxidant Capacities

The present study investigated the preventive effect of polyphenols in Liubao tea (PLT) on carbon tetrachloride (CCl₄)-induced liver injury in mice. The mice were initially treated with PLT, followed by induction of liver injury using 10 mL/kg CCl₄. Then liver and serum indices, as well as the expression levels of related messenger RNAs (mRNAs) and proteins in liver tissues were measured. The results showed that PLT reduces the liver quality and indices of mice with liver injury. PLT also downregulates aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglycerides (TGs), and malondialdehyde (MDA), and upregulates superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the sera of mice with liver injury. PLT also reduces serum levels of interleukin-6 (IL-6), interleukin-12 (IL-12), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) cytokines in mice with liver injury. Pathological morphological observation also shows that PLT reduces CCl₄-induced central venous differentiation of liver tissues and liver cell damage. Furthermore, qPCR and Western blot also confirm that PLT upregulates the mRNA and protein expressions of Gu/Zn-SOD, Mn-SOD, catalase (CAT), GSH-Px, and nuclear factor of κ-light polypeptide gene enhancer in B-cells inhibitor-α (IκB-α) in liver tissues, and downregulates the expression of cyclooxygenase 2 (COX-2) and nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB). Meanwhile, PLT also raised the phosphorylated (p)-NF-κB p65 and cytochrome P450 reductase protein expression in liver injury mice. The components of PLT include gallic acid, catechin, caffeine, epicatechin (EC), epigallocatechin gallate (EGCG), gallocatechin gallate (GCG), and epicatechin gallate (ECG), which possibly have a wide range of biological activities. Thus, PLT imparts preventive effects against CCl₄-induced liver injury, which is similar to silymarin.

Hepatoprotective and antioxidant activities of Spondias mombin leaf and stem extracts against carbon tetrachloride-induced hepatotoxicity

Objective

Spondias mombin L. is a tree used in folk medicine in Nigeria for the treatment of hepatitis. This study was carried out to comparatively evaluate the hepatoprotective and antioxidant effects of S. mombin leaf and stem (SML and SMS) methanolic extracts in a rat model of carbon tetrachloride (CCl₄)-induced hepatotoxicity.

Methods

Forty-two rats were distributed into seven groups. Groups A and B received water; groups C and D received 500 and 1000 mg/kg SML extract, respectively; groups E and F received 500 and 1000 mg/kg SMS extract, respectively; and group G received 100 mg/kg silymarin. Water, the two extracts, and silymarin were administered daily by oral gavage for 7 days. Hepatotoxicity was induced in groups B to G by the administration of CCl₄ once on the seventh day. After 48 h, rats were sacrificed, and tissues and serum samples were examined for histological and biochemical indices of hepatotoxicity.

Results

Administration of CCl₄ resulted in liver injury with significant elevation in the hepatocellular injury markers alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin (TBIL), and conjugated bilirubin (CBIL), associated with a significant reduction in total circulatory protein. Pretreatment with SML and SMS extracts at both doses significantly ameliorated liver injury; lowered ALT, AST, ALP, TBIL, and CBIL levels; elevated cellular glutathione levels as well as catalase and superoxide dismutase activities; and decreased the levels of thiobarbituric acid reactive substances.

Conclusion

This study provides preliminary evidence supporting the potential therapeutic benefit of S. mombin in xenobiotic-induced hepatotoxicity.

Prophylactic effects of alkaloids from Ba lotus seeds on L-NNA-induced hypertension in mice

Alkaloids from Ba lotus seeds (ABLS) are a kind of important functional compounds in lotus seeds. The present study was designed to determine its hypertension prophylactic effects in the L-NNA-induced mouse hypertension model. The mice were treated with ABLS, the serum and tissues levels of NO, MDA, ET-1, VEGF, and CGRP were determined using the experimental kits, the mRNA levels of various genes in the heart muscle and blood vessel tissues were further determined by RT-PCR assay. ABLS could reduce the systolic blood pressure (SBP), mean blood pressure (MBP), and diastolic blood pressure (DBP), compared to that of the model control group. After ABLS treatment, the NO (nitric oxide) contents in serum, heart, liver, kidney and stomach of the mice were higher than that of the control mice, but the MDA (malonaldehyde) contents were lower than that of the control mice. The serum levels of ET-1 (endothelin-1), VEGF (vascular endothelial growth factor) were decreased after ABLS treatment, but CGRP (calcium gene related peptide) level was increased. The ABLS treated mice had higher mRNA expressions of HO-1, nNOS, and eNOS and lower expressions of ADM, RAMP2, IL-1β, TNF-α, and iNOS than the control mice. Higher concentration of ABLS had greater prophylactic effects, which were close to that of the hypertension drug captopril. These results indicated the hypertension prophylactic effects of ABLS could be further explored as novel medicine or functional food in the future.

Anti-Fatigue Effect by Peptide Fraction from Protein Hydrolysate of Croceine Croaker (Pseudosciaena crocea) Swim Bladder through Inhibiting the Oxidative Reactions including DNA Damage

The swim bladder of the croceine croaker (Pseudosciaena crocea) was believed to have good curative effects in various diseases, including amnesia, insomnia, dizziness, anepithymia, and weakness after giving birth, in traditional Chinese medicine. However, there is no research focusing on the antioxidant and anti-fatigue peptides from croceine croaker swim bladders at present. Therefore, the purpose of this study was to investigate the bioactivities of peptide fractions from the protein hydrolysate of croceine croaker related to antioxidant and anti-fatigue effects. In the study, swim bladder peptide fraction (SBP-III-3) was isolated from the protein hydrolysate of the croceine croaker, and its antioxidant and anti-fatigue activities were measured using in vitro and in vivo methods. The results indicated that SBP-III-3 exhibited good scavenging activities on hydroxyl radicals (HO•) (EC50 (the concentration where a sample caused a 50% decrease of the initial concentration of HO•) = 0.867 mg/mL), 2,2-diphenyl-1-picrylhydrazyl radicals (DPPH•) (EC50 = 0.895 mg/mL), superoxide anion radical ( O 2 - •) (EC50 = 0.871 mg/mL), and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical (ABTS⁺•) (EC50 = 0.346 mg/mL). SBP-III-3 also showed protective effects on DNA damage in a concentration-effect manner and prolonged the swimming time to exhaustion of Institute of Cancer Research (ICR) mice by 57.9%-107.5% greater than that of the control. SBP-III-3 could increase the levels of muscle glucose (9.4%-115.2% increase) and liver glycogen (35.7%-157.3%), and decrease the levels of blood urea nitrogen (BUN), lactic acid (LA), and malondialdehyde (MDA) by 16.4%-22.4%, 13.9%-20.1%, and 28.0%-53.6%, respectively. SBP-III-3 also enhanced the activity of lactic dehydrogenase to scavenge excessive LA for slowing the development of fatigue. In addition, SBP-III-3 increased the activities superoxide dismutase, catalase, and glutathione peroxidase to reduce the reactive oxygen species (ROS) damage in mice. In conclusion, SBP-III-3 possessed good anti-fatigue capacities on mice by inhibiting the oxidative reactions and provided an important basis for developing the swim bladder peptide functional food.