Molecular cloning, expression, and functional analysis of a putative lectin from the pearl oyster (Pinctada fucata, Gould 1850).

Marine lectins are a group of proteins that possess specific carbohydrate recognition and binding domains. They exhibit various activities, including antimicrobial, antitumor, antiviral, and immunomodulatory effects. In this study, a novel galectin-binding lectin gene named PFL-96 (GenBank: OQ561753.1) was cloned from Pinctada fucata. The PFL-96 gene has an open reading frame of 324 base pairs (bp) and encodes a protein comprising 107 amino acids. The protein has a molecular weight of 11.95 kDa and an isoelectric point of 9.27. It contains an N-terminal signal peptide and a galactose-binding lectin domain. The sequence identity to lectin proteins from fish, echinoderms, coelenterates, and shellfish ranges from 31.90 to 40.00 %. In the phylogenetic analysis, it was found that the PFL-96 protein is closely related to the lectin from Pteria penguin. The PFL-96 recombinant protein exhibited coagulation activity on 2 % rabbit red blood cells at a concentration of ≥8 µg/mL. Additionally, it showed significant hemolytic activity at a concentration of ≥32 µg/mL. The PFL-96 recombinant protein exhibited significant antibacterial activity against Bacillus subtilis, Staphylococcus aureus, Candida albicans, and Vibrio alginolyticus, with minimum inhibitory concentrations (MIC) of 4, 8, 16, and 16 µg/mL, respectively. The minimum bactericidal concentrations (MBC) were determined to be 8, 16, 32, and 32 µg/mL, respectively. Furthermore, the PFL-96 recombinant protein exhibited inhibitory effects on the proliferation of Hela tumor cells, HepG2 tumor cells, and C666-1 tumor cells, with IC50 values of 7.962, 8.007, and 9.502 µg/mL, respectively. These findings suggest that the recombinant protein PFL-96 exhibits significant bioactivity in vitro, contributing to a better understanding of the active compounds found in P. fucata. The present study establishes a fundamental basis for further investigation into the mechanism of action and structural optimization of the recombinant protein PFL-96. The aim is to develop potential candidates for antibacterial and anti-tumor agents.

A comparative study on oxidative stress response in the hepatopancreas and midgut of the white shrimp Litopenaeus vannamei under gradual changes to low or high pH environment.

White shrimp Litopenaeus vannamei were reared under conditions of gradual changes to a low pH (gradual-low pH, 6.65-8.20) or a high pH (gradual-high pH, 8.20-9.81) versus a normal pH environment (8.14-8.31) during a 28-day period. Survival of shrimp, and ROS production, antioxidant responses and oxidative damage in the hepatopancreas and midgut were investigated. Consequently, shrimp enhanced MnSOD, GPx, and Hsp70 transcripts as early defense mechanism in the hepatopancreas and midgut to scavenge excessive ROS during short-term (≤ 7 days) gradual-low and high pH stress. Meanwhile, the hepatopancreas was more sensitive to ROS than midgut because of earlier ROS production increase, antioxidant response and oxidative damage. Then, suppressed antioxidant response in the hepatopancreas and midgut of shrimp suggested a loss of antioxidant regulatory capacity caused by aggravated oxidative damage after long-term (≥ 14 days) gradual-high pH stress, leading to continuous death. However, enhanced GPx, GST, and Hsp70 transcripts in the hepatopancreas and midgut might be long-term(≥ 14 days) antioxidant adaptation mechanism of shrimp to gradual-low pH stress, which could prevent further ROS perturbation and weaken oxidative damage to achieve a new immune homeostasis, contributing to stable survival rate. Therefore, we have a few insights that it is necessary to protect hepatopancreas for controlling shrimp death under gradual-high pH stress.

Adaptation of the white shrimp Litopenaeus vannamei to gradual changes to a low-pH environment.

pH variation could cause a stress response in euryhaline penaeids, we evaluated the mortality, growth performance, osmoregulation gene expression, digestive enzyme activity, histology, and resistance against Vibrio parahemolyticus of white shrimp Litopenaeus vannamei reared under conditions of gradual changes to a low-pH environment (gradual-low pH, 6.65-8.20) or a high-pH environment (gradual-high pH, 8.20-9.81) versus a normal pH environment (8.14-8.31) during a 28-d experiment. Consequently, under gradual-high pH, the cumulative mortality rate (CMR) rose with time until 39.9% on days 28; the weight gain percentage (WGP) and length gain percentage (LGP) decreased continuously. However, under gradual-low pH, the CMR of shrimp stabilized at 6.67% during 7-28 d; the WGP and LGP decreased first and then returned to normal. These results indicated that L. vannamei displayed a moderate tolerance to gradual-low pH, compared with gradual-high pH. Under gradual-low pH, the Na+/K+-ATPase, cytoplasmic carbonic anydrase (CAc), and glycosyl-phosphatidylinositol-linked carbonic anhydrase (CAg) transcripts of shrimp increased continuously or then back to normal; the amylase, lipase, and trypsin activities decreased first and then returned to normal or increased; the hepatopancreases and midguts showed histopathological lesions first and then got remission. Thus, the major adaptation mechanism of shrimp to gradual-low pH might be its high osmoregulation ability, which made shrimp achieve a new, balanced steady-state, then promoted longer intestinal villi and recuperative hepatopancreases of shrimp with enhanced digestive enzyme activities to increase nutrient absorption after long-term exposure. Meanwhile, the enhanced resistance against V. parahemolyticus under gradual-low pH would probably inhibit disease outbreak in the shrimp farming.

Seawater pearl hydrolysate inhibits photoaging via decreasing oxidative stress, autophagy and apoptosis of Ultraviolet B-induced human skin keratinocytes.

BACKGROUND: Ultraviolet (UV) is the main reason to cause photoaging skin which not only hinders beauty, brings the patients with psychological burden, but also pathologically leads to the occurrence of tumors in skin. OBJECTIVE: This study goes into the inhibitory effect and mechanism of seawater pearl hydrolysate (SPH) to address human skin keratinocytes photoaging induced by UVB. METHODS: The photoaging model of Hacat cell was constructed by UVB irradiation, the levels of oxidative stress, apoptosis, aging, autophagy and autophagy-related protein and signal pathway expression were assessed to characterize the inhibitory effect and mechanism of SPH on photoaging Hacat cell. RESULTS: Seawater pearl hydrolysate significantly accelerated (p < 0.05) the activities of superoxide dismutase, catalase, and glutathione peroxidase, and markedly reduced (p < 0.05) the contents of reactive oxygen species (ROS), malondialdehyde, protein carbonyl compound and nitrosylated tyrosine protein, aging level, apoptosis rate in Hacat cell induced by 200 mJ cm-2 UVB after 24 and 48 h of culture; high dose SPH significantly raised (p < 0.05) relative expression level of p-Akt, p-mTOR proteins, and markedly decreased (p < 0.05) relative expression level of LC3II protein, p-AMPK, and autophagy level in Hacat cell induced by 200 mJ cm-2 UVB, or in combination with the intervention of PI3K inhibitor or AMPK overexpression after 48 h of culture. CONCLUSION: Seawater pearl hydrolysate can effectively inhibit 200 mJ cm-2 UVB-induced photoaging of Hacat cells. The mechanism indicates removing the excessive ROS through increasing the antioxidation of photoaging Hacat cells. Once redundant ROS is eliminated, SPH works to reduce AMPK, increase PI3K-Akt pathway expression, activate mTOR pathway to lowdown autophagy level, and as a result, inhibit apoptosis and aging in photoaging Hacat cells.

Study on the Mechanism of Hydrolyzed Seawater Pearl Tablet in Treating Chronic Sleep Deprivation Mice Model.

BACKGROUND: Modern lifestyle increasingly deprives people from sleep to different degrees. Long-term sleep deprivation will facilitate body's pathological behaviors, such as lethargy, depression, and anorexia. OBJECTIVE: This study is an investigation into the mechanism of hydrolyzed seawater pearl tablet in treating chronic sleep deprivation mice model. METHODS: The chronic sleep deprivation model was established involving C57BL/6mice; the body weight, behavioral characteristics, hippocampal structure, oxidative stress, apoptosis-related protein expression, and intestinal bacteria in mice were assessed to characterise hydrolyzed seawater pearl tablet. RESULTS: Hydrolyzed seawater pearl tablet significantly accelerated body weight, open field test score, and sugar water preference rate (P < 0.05), alleviated the structural damage of hippocampus, reduced the content of MDA (P < 0.05), Bax protein expression, increased the content of GSH (P < 0.05), the activities of SOD, GSH-Px, and Bcl-2 protein expression in the hippocampus, increased the Escherichia coli, Bacteroides, Bifidobacterium and Lactobacillus (P < 0.05), which are beneficial bacteria in the intestine, in chronic sleep deprivation mice, and reduced the amount of Clostridium perfringens (P < 0.05), which are harmful bacteria in the intestine. CONCLUSION: Hydrolyzed seawater pearl tablet can improve the depression-like mental state of mice caused by chronic sleep deprivation. The mechanism involves improving the antioxidant activity of the hippocampus to eliminate the excessive ROS, which inhibits cell apoptosis and alleviates tissue structure damage. Meanwhile, it may also be involved in adjusting the microbiota level and improving the mental and behavioral activities of chronic sleep deprivation mice through the intestine-brain axis.

Re-evaluation for systematic reviews of traditional Chinese medicine in the treatment of chronic bronchitis.

BACKGROUND: Chronic bronchitis (CB) is a common clinical chronic respiratory disease, which has a high incidence in the middle aged and elderly population. With the development of the disease, the number of acute attacks becomes more and more frequent, which leads to the continuous decrease of lung function. If not treated in time, it will lead to a variety of complications and seriously affect the quality of life of patients. Traditional Chinese medicine (TCM) or TCM combined with western medicine is highly effective in the treatment of CB disease. In recent years, there are many systematic reviews on the use of TCM therapy in the treatment of CB, and the efficacy and safety of TCM in the treatment of CB diseases are evaluated. The aim of this study was to re-evaluate the Meta analysis/Systematic reviews (MAs/SRs) of TCM for the treatment of CB, aiming to provide a clinical basis for the treatment of CB by TCM. METHODS: Retrieval among Chinese and English databases such as China National Knowledge Infrastructure, Wanfang database, China Scientific Journals Database, SinoMed, PubMed, Web of Science, The Cochrane Library and EMbase, etc. were conducted within the duration from database establish Tion date to March 2023.The included research was independently conducted by 2 researchers for literature screening, data extraction, and quality evaluation. The AMSTAR 2 scale was used to evaluate the quality of the report, the PRISMA 2020 statement evaluated the quality of the report, the ROBIS tool evaluated the risk of bias, and the GRADE quality evaluation tool evaluated the quality of the evidence. RESULTS: Fifteen MAs/SRs were included, for a total of 224 studies involving 20,710 patients with CB. The 15 studies included in AMSTAR 2 are of very low quality. The ROBIS evaluation results showed that 8 MAs/SRs were considered to have high risk and 7 with low risk. The PRISMA 2020 report quality showed evaluation results of the included studies scores between 24 and 30, among them 13 with high quality and 2 with low quality. The GRADE system results showed that, within 70 outcome indicators, only 14 of them have moderate quality for evidence, with 31 for low quality, 25 for very low quality, and none for high quality. CONCLUSION: The MAs/SRs methodological quality of using TCM for treatment CB is generally poor, the quality of reports as well as evidence are generally low, and the risk of bias is high, therefore we should treat these results with caution.

Effect and mechanism of pearl on ovarian function of rats with premature ovarian failure induced by tripterygium glycosides.

Background and aim: Recent studies show that combination of apoptosis and oxidative stress forms a "vicious circle" in the process of premature ovarian failure (POF). Pearl extract has a good effect for anti-oxidation and anti-aging in vitro and vivo and can be used to treat various aging diseases. However, reports about effect and mechanism of pearl on ovarian function of premature ovarian failure (POF)are limited. Experimental procedure: The effect and mechanism of pearl on ovarian function of rats with POF were evaluated using rats with premature ovarian failure induced by tripterygium glycosides. The estrous cycle, contents of serum reproductive hormones, tissue structure, oxidative stress level, autophagy and apoptotic protein expression, and MAPK signaling pathway of ovary were assessed to characterise pearl. Result and conclusion: Low, medium and high-dose pearl improved the estrous cycle in POF rats, and high-dose pearl was the best in terms of recovery effect; high-dose pearl significantly increased (P < 0.05) contents of E2, AMH and GSH, activities of SOD, CAT and GSH-PX and follicular development, while significantly decreased (P < 0.05)contents of FSH, LH and ROS and MDA in POF rats; low, medium and high-dose pearl notably reduced (P < 0.05) the apoptotic protein cleaved-caspase 3 and Bax expression, and MAPK signaling pathway of ERK1/2, p38 and JNK in POF rats, among which high-dose pearl behaved best. Medium and high-dose pearl apparently raised (P < 0.05)expressions of autophagy protein LC3II, Beclin-1 and p62 in POF rats. Therefore, pearl can effectively enhance ovarian function of POF rats. The optimal concentration was found to be 740 mg kg-1 at a high dose. The mechanism may be related with the enhanced follicular development through improving granulosa cell autophagy and inhibiting granulosa cell apoptosis by inhibition of MAPK signaling pathway after scavenging excessive ROS. Section: 1. Natural Products. Taxonomy classification by EVISE: Ovarian Cancer, Chinese Herbal Medicine, Traditional Medicine, Oxidative Stress, Antioxidant Studies, Rat, Autophagy.

Inhibitory Effect of Seawater Pearl Hydrolysate on UVA-Induced Photoaging of Human Skin Fibroblasts.

This study is an investigation into the inhibitory effect of seawater pearl hydrolysate (SPH) on the UVA-induced photoaging of human skin fibroblast (HSF) cells, and the mechanism thereof. HSF cells were cultured and irradiated with a UVA 0-50 J·cm-2 dose gradient. The cell inhibition rate was detected using the CCK8 method, and the half-inhibitory dose was determined. Based on this, the dose of UVA irradiation for the follow-up experiment was selected to establish a photoaging model of the HSF cells. The cells were divided into a normal (N) group, UVA-irradiated (UVA) group, SPH low dose (SPHL) group, SPH medium dose (SPHM) group, and SPH high dose (SPHH) group. The photoaging model of HSF cells was established by UVA irradiation in the UVA, SPHL, SPHM, and SPHH groups; the SPHL, SPHM, and SPHH groups were treated with SPH at concentrations of 50, 100, and 200 mg·L-1, respectively, at the same time. After 24 and 48 h of culture, the reactive oxygen species (ROS) level of the HSF cells was detected by flow cytometry, and the required culture time of the HSF cells for the follow-up experiment was selected. The malondialdehyde and glutathione contents, as well as the activities of the superoxide dismutase, catalase, and glutathione peroxidase in the HSF cells, were detected by biochemical methods. The levels of expression of MMP-1 and collagen I protein in HSF cells were detected by the western blot test, the extent of aging of HSF cells was detected by ß-galactosidase staining, and the apoptosis level of HSF cells was detected by flow cytometry. The results show that SPH inhibits the UVA-induced photoaging of HSF cells in a dose-dependent manner within a certain concentration range, and the effect of a concentration of 200 mg·L-1 was the most significant. The mechanism is related to improving the antioxidant activity of photoaging HSF cells to eliminate excessive ROS. It can inhibit apoptosis, reduce the protein expression of MMP-1, and effectively control the degradation of collagen I protein in photoaging HSF cells. Therefore, SPH offers potential for use in sunscreen cosmetics.

Hydrolyzed seawater pearl tablet modulates the immunity via attenuating Th1/Th2 imbalance in an immunosuppressed mouse model.

OBJECTIVE: To investigate whether Hydrolyzed Seawater Pearl tablet (HSPT) could modulate the Th1/Th2 imbalance in an immunosuppressed mouse model with Th1 to Th2 shift induced by Cyclosporine A (CsA) which can be used in the clinical treatment of Th2 to Th1 shift diseases, and explore the possible mechanism for the adjuvant therapeutic efficacy of HSPT on recurrent respiratory infections (RRI) and acquired immune deficiency syndrome (AIDS). METHODS: The mice were randomly divided into six groups of five animals each, namely normal group, model group, lentinan polysaccharide tablet (LPT) group and three HPST treated groups. HPST treated groups were administered with HPST (0.51, 1.02, 2.04 g/kg) via intragastric gavage (i.g) for 30 consecutive days. LPT used as reference drug for positive control, LPT group was administered with LPT (8.2 mg/kg) for 30 consecutive days. Normal group and model group were received distilled water. The animals in model group, LPT group and HPST treated groups were injected intraperitoneally with CsA (50 mg/kg) to establish the immunosuppressed mice model with Th1 to Th2 shift on the 20th, 22nd and 24th day, one hour after the administration of the respective treatment. Animals were sacrificed one hour after the last administration to collect blood and splenic tissue. The proportion of T cells including CD8+ and CD4+ T cells, Th1 and Th2 in peripheral blood of experimental mice were measured by flow cytometric. The protein level in serum and mRNA level in splenic tissue of experimental mice for interleukin (IL)-2, IL-12, interferon-γ (IFN-γ), IL-4, IL-6, IL-10 and IL-13 were measured by enzyme linked immunosorbent assay and fluorescence quantitative polymerase chain reaction respectively. RESULTS: HSPT elevated the proportion of T cells including both CD8+ and CD4+ T cells, in which the proportion of Th1 and Th2 cells increased, while the ratio of Th1/Th2 cells decreased in peripheral blood of the immunosuppressed mouse model with Th1 to Th2 shift induced by CsA. Furthermore, HSPT elevated both protein and mRNA level of Th1-type cytokines IL-2 and IFN-γ, while had no significant effect on protein and mRNA level of Th1-type cytokine IL-12 and Th2-type cytokines IL-4, IL-6, IL-10, IL- 13 in mouse model. CONCLUSION: Our findings suggest that HSPT can increase proportion of T cells including both CD8+ and CD4+ T cells and induce Th2 to Th1 shift in both cells and cytokines, which probably was the mechanism to account for the adjuvant therapeutic efficacy of HSPT on RRI and AIDS.

Therapeutic Effect of Seawater Pearl Powder on UV-Induced Photoaging in Mouse Skin.

The objective of this study was to investigate the therapeutic effect of seawater pearl powder (SPP) on ultraviolet (UV) irradiation-induced photoaging in mouse skin. The protein and trace elements in SPP were detected by liquid chromatography-mass spectrometry, atomic fluorescence spectrometry, and inductively coupled plasma-atomic emission spectrometry. The effect of SPP on treating skin damage resulting from UV-induced photoaging was observed by gross physical appearance and histopathological analysis. Oxidative stress and melanin synthesis were analyzed using biochemical method. Western blotting was applied to analyze the phosphorylation and expression levels of matrix metalloproteinase-1 (MMP-1), collagen I, and proteins involved in the mitogen-activated protein kinase (MAPK) signaling pathways (p38, ERK, and JNK). The results show that SPP has a significant therapeutic effect on UV-induced photoaging of skin and improves and restores appearance and tissue structure of mouse skin. The major mechanism may be related to reduction of expression level of MMP-1 and enhancement of collagen I production via inhibition of MAPK signaling pathway after scavenging of excess reactive oxygen species (ROS) in the UV-induced photoaged skin of mice. Meanwhile, it may also be involved in reducing melanin content by inhibiting tyrosinase activity after scavenging excess ROS in the UV-induced photoaged skin of mice. Therefore, SPP could be a good substance to treat photoaging skin. Taking cost-effectiveness and efficacy into consideration, the optimal concentration of SPP for treating photoaging skin could be 100 mg/g.

Immunomodulatory Effects of Hydrolyzed Seawater Pearl Tablet (HSPT) on Th1/Th2 Functionality in a Mice Model of Chronic Obstructive Pulmonary Disease (COPD) Induced by Cigarette Smoke.

Chronic obstructive pulmonary disease (COPD) is predicted to become the third leading cause of death around the world. The present study is designed to investigate whether hydrolyzed seawater pearl tablet (HSPT) has immunoregulatory effects on the Th1/Th2 functionality in cigarette smoke-induced COPD model mice. The determination of the amino acid composition of HSPT was carried out by high-performance liquid chromatography (HPLC) with precolumn phenylisothiocyanate (PITC) derivatization. COPD model mice were constructed by cigarette smoking (CS) treatment and HSPT was administered. HSPT inhibited the infiltration of inflammation in the airway of the lung, reduced influx of eosinophils (EOSs), lymphocytes (LYMs), neutrophils (NEUs), and macrophages (MACs) in the bronchoalveolar lavage fluid (BALF), decreased the levels of IFN-γ, IL-2, IL-4, and IL-10 in the serum and lung, and decreased the expression of aforementioned cytokines in the spleen and lung in CS-treated mice. Besides, HSPT also had the ability to reduce the amount of CD3+CD4+ T cells and modulate the Th1/Th2 balance. Taken together, this study supports the consensus that CS is a critical factor to induce and aggravate COPD. HSPT could regulate the balance of Th1/Th2 in CS-induced COPD model mice, indicating its effects on inhibiting the development of COPD.