Oligomeric proanthocyanidins ameliorates osteoclastogenesis through reducing OPG/RANKL ratio in chicken's embryos.

Skeletal disorders can seriously threaten the health and the performance of poultry, such as tibial dyschondroplasia (TD) and osteoporosis (OP). Oligomeric proanthocyanidins (OPC) are naturally occurring polyphenolic flavonoid compounds that can be used as potential substances to improve the bone health and the growth performance of poultry. Eighty 7-day-old green-eggshell yellow feather layer chickens were randomly divided into 4 groups: basal diet and basal diet supplementation with 25, 50, and 100 mg/kg OPC. The results have indicated that the growth performance and bone parameters of chickens were significantly improved supplementation with OPC in vivo, including the bone volume (BV), the bone mineral density (BMD) and the activities of antioxidative enzymes, but ratio of osteoprotegerin (OPG)/receptor activator of NF-κB (RANK) ligand (RANKL) was decreased. Furthermore, primary bone marrow mesenchymal stem cells (BMSCs) and bone marrow monocytes/macrophages (BMMs) were successfully isolated from femur and tibia of chickens, and co-cultured to differentiate into osteoclasts in vitro. The osteogenic differentiation derived from BMSCs was promoted treatment with high concentrations of OPC (10, 20, and 40 µmol/L) groups in vitro, but emerging the inhibition of osteoclastogenesis by increasing the ratio of OPG/RANKL. In contrary, the osteogenic differentiation was also promoted treatment with low concentrations of OPC (2.5, 5, and 10 µmol/L) groups, but osteoclastogenesis was enhanced by decreasing the ratio of OPG/RANKL in vitro. In addition, OPG inhibits the differentiation and activity of osteoclasts by increasing the autophagy in vitro. Dietary supplementation of OPC can improve the growth performance of bone and alter the balance of osteoblasts and osteoclasts, thereby improving the bone health of chickens.

Baicalin and N-acetylcysteine regulate choline metabolism via TFAM to attenuate cadmium-induced liver fibrosis.

(Background): Cadmium is an environmental pollutant associated with several liver diseases. Baicalin and N-Acetylcysteine have antioxidant and hepatoprotective effects. (Purpose): However, it is unclear whether baicalin and N-Acetylcysteine can alleviate Cadmium -induced liver fibrosis by regulating metabolism, or whether they exert a synergistic effect. (Study design): We treated Cadmium-poisoned mice with baicalin, N-Acetylcysteine, or baicalin+ N-Acetylcysteine. We studied the effects of baicalin and N-Acetylcysteine on Cadmium-induced liver fibers and their specific mechanisms. (Methods): We used C57BL/6 J mice, and AML12, and HSC-6T cells to establish in vitro assays and in vivo models. (Results): Metabolomics was used to detect the effect of baicalin and N-Acetylcysteine on liver metabolism, which showed that compared with the control group, the Cadmium group had increased fatty acid and amino acid levels, with significantly reduced choline and acetylcholine contents. Baicalin and N-Acetylcysteine alleviated these Cadmium-induced metabolic changes. We further showed that choline alleviated Cadmium -induced liver inflammation and fibrosis. In addition, cadmium significantly promoted extracellular leakage of lactic acid, while choline alleviated the cadmium -induced destruction of the cell membrane structure and lactic acid leakage. Western blotting showed that cadmium significantly reduced mitochondrial transcription factor A (TFAM) and Choline Kinase α(CHKα2) levels, and baicalin and N-Acetylcysteine reversed this effect. Overexpression of Tfam in mouse liver and AML12 cells increased the expression of CHKα2 and the choline content, alleviating and cadmium-induced lactic acid leakage, liver inflammation, and fibrosis. (Conclusion): Overall, baicalin and N-Acetylcysteine alleviated cadmium-induced liver damage, inflammation, and fibrosis to a greater extent than either drug alone. TFAM represents a target for baicalin and N-Acetylcysteine, and alleviated cadmium-induced liver inflammation and fibrosis by regulating hepatic choline metabolism.

Puerarin alleviates cadmium-induced oxidative damage to bone by reducing autophagy in rats.

Autophagy is a regulatory mechanism involved in cadmium (Cd)-induced bone toxicity and is suppressed by various stimuli, including oxidative stress. Puerarin is an isoflavonoid compound isolated from Pueraria, a plant used in traditional Chinese medicine. The underlying mechanisms of action of puerarin remain unclear. The objective of this study was to explore the mitigating effects of puerarin on cadmium-induced oxidative damage in the bones of rats. Cadmium exposure increased oxidative damage in rat bones; this was markedly decreased by puerarin treatment, as demonstrated by changes in the activity of antioxidative enzymes. Cadmium-induced blockage of the expression of key bone regulatory proteins, autophagy-related markers, and signaling molecules was also alleviated by puerarin treatment. Additionally, cadmium reduced expression of the autophagic protein Rab7 and of late endosomal/lysosomal adaptor and MAPK and mTOR activator 1 (LAMTOR1); the decrease in these proteins was not restored by puerarin treatment. We speculate that puerarin relieves the inhibition of fusion of autophagosomes with lysosomes that is induced by cadmium; however, this specific effect of puerarin and downstream effects on bone regulatory mechanisms require further investigation. In conclusion, puerarin alleviates cadmium-induced oxidative damage in the bones of rats by attenuating autophagy, which is likely associated with the antioxidant activity of puerarin.

Quercetin and Allicin Can Alleviate the Hepatotoxicity of Lead (Pb) through the PI3K Signaling Pathway.

Lead (Pb) is a common toxic heavy metal pollutant in the environment that seriously endangers the health of animals. The liver is a key target organ affected by Pb toxicity. Plant extracts allicin and quercetin have a strong antioxidant capacity that can promote the excretion of heavy metals by improving the body's antioxidant defense and chelating heavy metal ions. To explore the preventive and therapeutic effects of allicin and quercetin on Pb poisoning in chickens, 96 chickens were randomly divided into eight groups: control, Pb, allicin, quercetin, allicin + quercetin, Pb + allicin, Pb + quercetin, and Pb + allicin + quercetin groups. The chickens were given feed containing the above treatments for 90 days. The results indicated that Pb can affect the growth and development of the liver, damage the circulatory system, destroy the structure of mitochondria and nuclei in liver cells, cause an imbalance in the oxidation system, inhibit PI3K protein, and activate the mitochondrial apoptotic pathway. Allicin and quercetin, alone or in combination, can improve the antioxidant capacity of the liver and alleviate liver tissue damage caused by Pb. In summary, allicin and quercetin could alleviate oxidative damage and apoptosis in the Pb-poisoned chicken liver through the PI3K signaling pathway, with stronger effects achieved by their combination.

Puerarin Restores Autophagosome-Lysosome Fusion to Alleviate Cadmium-Induced Autophagy Blockade via Restoring the Expression of Rab7 in Hepatocytes.

Autophagic dysfunction is one of the main mechanisms by which the environmental pollutant cadmium (Cd) induces cell injury. Puerarin (Pue, a monomeric Chinese herbal medicine extract) has been reported to alleviate Cd-induced cell injury by regulating autophagy pathways; however, its detailed mechanisms are unclear. In the present study, to investigate the detailed mechanisms by which Pue targets autophagy to alleviate Cd hepatotoxicity, alpha mouse liver 12 (AML12) cells were used to construct a model of Cd-induced hepatocyte injury in vitro. First, the protective effect of Pue on Cd-induced cell injury was confirmed by changes in cell proliferation, cell morphology, and cell ultrastructure. Next, we found that Pue activated autophagy and mitigated Cd-induced autophagy blockade. In this process, the lysosome was further activated and the lysosomal degradation capacity was strengthened. We also found that Pue restored the autophagosome-lysosome fusion and the expression of Rab7 in Cd-exposed hepatocytes. However, the fusion of autophagosomes with lysosomes and autophagic flux were inhibited after knocking down Rab7, and were further inhibited after combined treatment with Cd. In addition, after knocking down Rab7, the protective effects of Pue on restoring autophagosome-lysosome fusion and alleviating autophagy blockade in Cd-exposed cells were inhibited. In conclusion, Pue-mediated alleviation of Cd-induced hepatocyte injury was related to the activation of autophagy and the alleviation of autophagy blockade. Pue also restored the fusion of autophagosomes and lysosomes by restoring the protein expression of Rab7, thereby alleviating Cd-induced autophagy blockade in hepatocytes.

Effects of RANKL, osteoprotegerin, calcium and phosphorus on survival and activation of Muscovy duck osteoclasts in vitro.

The aim of this study was to determine whether receptor activator of nuclear factor NF-kappaB ligand (RANKL), osteoprotegerin (OPG) and a calcium:phosphorus (Ca:P) ratio of 2:1 could affect survival and activation of Muscovy duck osteoclasts (OCs). Bone marrow cells were obtained from 5-day-old Muscovy ducks and cultured with (Group A) No added factors, (B) 30ng/mL soluble RANKL (sRANKL), (C) 30ng/mL sRANKL and 10ng/mL OPG, (D) 10ng/mL OPG, (E) 50ng/mL OPG, (F) 100ng/mL OPG and (G) 30ng/mL sRANKL, 6mmol/L Ca and 3mmol/L P. sRANKL promoted the survival of OCs on day 2, whereas the number of OCs decreased with addition of OPG in a dose-dependent manner. OPG and Ca:P (2:1) both inhibited OC survival induced by RANKL. RANKL stimulated bone resorption by OCs, whereas OPG, but not Ca:P (2:1), inhibited the activity of OCs induced by RANKL. RANKL promotes the survival and activation of OCs from Muscovy ducks, whereas OPG and, to a lesser extent, Ca:P (2:1) reduce the life span and inhibited the activation of OCs induced by RANKL.