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Oxysophocarpine (OSC), a quinolizidine alkaloid, shows neuroprotective potential, though its mechanisms are unclear. The aim of the present study was to investigate the neuroprotective effects of OSC through the nuclear factor erythroid 2−related factor 2 (Nrf2)/ heme oxygenase−1 (HO–1) signaling pathway using the HT–22 cell line. Assessments of cell viability were conducted utilizing the 3−(4,5−dimethylthiazol−2−yl)−2,5−diphenyltetrazolium bromide (MTT) assay. Assessments of oxidative stress (OS) were conducted through the quantification of reactive oxygen species (ROS). The integrity of the mitochondrial membrane potential (MMP) was scrutinized using fluorescent probe technology. Apoptosis levels were quantified using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The trafficking of Nrf2 within the cell nucleus was examined through immunofluorescence analysis. Furthermore, Western blotting (WB) was applied to evaluate the expression levels of proteins implicated in apoptosis and the Nrf2/HO–1 pathway. To further probe the influence of OSC on the overexpression of antioxidant enzymes, cells were subjected to transfection with HO–1 siRNA. The results showed that OSC inhibited glutamate-induced OS, as evidenced by reduced cell viability and ROS levels. Furthermore, the apoptotic condition induced by glutamate in HT–22 cells was significantly reduced following OSC treatment. More interestingly, the Nrf2/HO–1 signaling pathway was upregulated following OSC treatment. These results suggest that OSC can exert neuroprotective effects by regulating the Nrf2/HO–1 pathway to inhibit neuronal cell apoptosis, potentially aiding in the treatment of neurodegenerative diseases.

Artemisia japonica Thunb. has been used as a traditional Chinese medicine and a vegetable for thousands of years in China. However, there are few reports on the chemical composition and biological activity of its leaves. Thus, this study aimed to evaluate the chemical composition, antioxidant and anti-inflammatory effects of water extracts of A. japonica leaves and their underlying mechanisms. A total of 48 compounds were identified in the water extract using UPLC-QTOF-MS2 analysis, with phenolic acids, particularly chlorogenic acid compounds, being the predominant components. The ethyl acetate fraction (EAF) contained most of the total phenolic content (385.4217 mg GAE/g) and displayed superior antioxidant capacity with the IC50DPPH•, IC50ABTS•+, and OD0.5reducing power at 10.987 μg/mL, 43.630 μg/mL and 26.883 μg/mL, respectively. Furthermore, EAF demonstrated potent antioxidant and anti-inflammatory effects in LPS-induced RAW264.7 cells by upregulating the Nrf2/HO-1 signal pathway. These findings highlight that A. japonica leaves possess remarkable abilities to mitigate inflammation and oxidative stress, suggesting their potential utilization as medicinal agents and food additives for promoting human health. [ABSTRACT FROM AUTHOR]

Objective To investigate the effect and its mechanism of emodin on the ferroptosis of chondrocytes in rats with knee osteoarthritis (KOA). Methods A total of 96 SD rats were divided into the sham operation (sham) group, the KOA group, the emodin (EMO) group and the emodin+Nrf2 inhibitor (EMO+ML385) group, with 24 rats in each group. Except for the sham group, KOA rat models were established by modified Hulth method in each group. The tumor necrosis factor-α (TNF-α), nitric oxide (NO) and prostaglandin E2 (PGE2) levels were detected by enzyme-linked immunosorbent assay (ELISA). General morphology of knee joint was observed with naked eyes. The pathological morphology of knee joint cartilage was observed with safranine O-solid green staining. Apoptosis rate of chondrocytes of knee joint was detected by TdT-mediated dUTP nick end labeling (TUNEL) staining. Malondialdehyde (MDA), reactive oxygen species (ROS), glutathione (GSH) and ferrous ion (Fe2+) levels in knee joint cartilage were detected by biochemical reagent kit. Expression levels of matrix metalloproteinase (MMP)-3, MMP-13, collagen type II α1 (COL2A1), prostaglandin-endoperoxide synthase 2 (PTGS2), glutathione peroxidase 4 (GPX4), acyl-CoA synthetase long chain family member 4 (ACSL4), nuclear factor E2- related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) mRNA or protein in knee joint cartilage were detected by real-time fluorescence quantitative PCR (qRT-PCR), Western blot assay or immunohistochemistry. Results Compared with the sham group, the serum TNF-α, NO and PGE2 levels, Osteoarthritis Research Society International (OARSI) score, apoptosis rate, mRNA expression of MMP-3, MMP-13 and PTGS2, MDA, ROS, and Fe2+ levels, proportion of ACSL4 positive cells, and protein expression of ACSL4, nuclear Nrf2 and HO-1 increased in the KOA group. GSH levels, mRNA expression of COL2A1, proportion of GPX4 positive cells, and protein expression of GPX4 and cytoplasmic Nrf2 decreased (P<0.05). The articular cartilage was obviously damaged. EMO can improve the inflammatory reaction, knee joint cartilage tissue injury and chondrocyte ferroptosis of KOA rats, and further activate Nrf2/HO-1 signal pathway. ML385 not only inhibited the activation of Nrf2/HO-1 signal pathway, but also attenuated the improvement of EMO on knee joint cartilage tissue injury and chondrocyte ferroptosis of KOA rats. Conclusion Emodin can activate Nrf2/HO-1 signal pathway, inhibit chondrocyte ferroptosis and protect knee articular cartilage of KOA rats. [ABSTRACT FROM AUTHOR]

Objective: Periostin is important for the maintenance of periodontal tissue, but its role in periodontitis is controversial. This research investigated the effect of periostin in periodontitis and the underlying mechanism. Design: Mouse periodontitis models in vivo and inflammation model in vitro which were induced by Porphyromonas gingivalis lipopolysaccharide were established to evaluate periostin expression. Human periodontal ligament fibroblasts (PDLFs) were treated with lipopolysaccharide and N‐acetylcysteine, fluorescence staining, flow cytometry, Western blot, and qRT‐PCR were used to detect reactive oxygen species (ROS), periostin expression, and apoptosis‐related makers. The periostin gene was successfully transfected into PDLFs to verify the effect of periostin on apoptosis. Then, the Nrf2 inhibitor was added to clarify the mechanism. Results: Periostin expression decreased in the periodontal ligaments of mouse periodontitis models and lipopolysaccharide‐induced PDLFs. Lipopolysaccharide promoted the activation of ROS and apoptosis in PDLFs, whereas N‐acetylcysteine reversed this condition. Overexpression of periostin suppressed apoptosis of PDLFs and reversed the inhibitory effect of lipopolysaccharide on nuclear Nrf2 expression. Moreover, the Nrf2 inhibitor attenuated the protective effect of periostin on lipopolysaccharide‐induced apoptosis. Conclusions: Lipopolysaccharide induced apoptosis in PDLFs by inhibiting periostin expression and thus Nrf2/HO‐1 pathway, indicating that periostin could be a potential therapeutic target for periodontitis. [ABSTRACT FROM AUTHOR]

Artemisia japonica Thunb. has been used as a traditional Chinese medicine and a vegetable for thousands of years in China. However, there are few reports on the chemical composition and biological activity of its leaves. Thus, this study aimed to evaluate the chemical composition, antioxidant and anti-inflammatory effects of water extracts of A. japonica leaves and their underlying mechanisms. A total of 48 compounds were identified in the water extract using UPLC-QTOF-MS2 analysis, with phenolic acids, particularly chlorogenic acid compounds, being the predominant components. The ethyl acetate fraction (EAF) contained most of the total phenolic content (385.4217 mg GAE/g) and displayed superior antioxidant capacity with the IC50DPPH•, IC50ABTS•+, and OD0.5reducing power at 10.987 μg/mL, 43.630 μg/mL and 26.883 μg/mL, respectively. Furthermore, EAF demonstrated potent antioxidant and anti-inflammatory effects in LPS-induced RAW264.7 cells by upregulating the Nrf2/HO-1 signal pathway. These findings highlight that A. japonica leaves possess remarkable abilities to mitigate inflammation and oxidative stress, suggesting their potential utilization as medicinal agents and food additives for promoting human health.

The pericarp of Zanthoxylum bungeanum maxim (PZM) is a commonly used spice and herbal medicine in China. In the present study, the structural characteristics of PPZM were investigated by saccharide mapping after enzymatic digestion by using high-performance thin layer chromatography (HPTLC) and polysaccharide analysis by using carbohydrate gel electrophoresis (PACE). The mechanisms of protective effects of PPZM on Aβ25–35-induced oxidative damage were explored in PC12 cells. The results showed that PPZM contained 1,4-α-D-galactosidic, 1,4-α-D-galactosiduronic, and (1→4)-β-D-glucosidic linkages. Pretreatment with PPZM significantly increased the cell viability of Aβ25–35-injured PC12 cells. Flow cytometry and Hoechst/PI staining indicated that PPZM gradually relieved the apoptosis of the Aβ25–25-treated cells. PPZM markedly decreased the ROS level of PC12 cells and suppressed Aβ25–35-induced oxidative stress by increasing the SOD level, and decreasing the level of MDA and LDH. The mRNA expressions of caspase-3 and Bax were significantly downregulated, and Bcl-2 expression was upregulated by treatment with PPZM. PPZM significantly increased the mRNA expression of Nrf2 and HO-1 in Aβ25–35 treated cells. The results indicated that PPZM alleviated apoptosis and oxidative stress induced by Aβ25–25 through the inhibition of mitochondrial dependent apoptosis and activation of Nrf2/HO-1 pathway. PPZM can be used as a potential protective agent against Aβ25–25-induced neurotoxicity. [ABSTRACT FROM AUTHOR]

Oxidative stress is closely linked to the etiology of temporomandibular joint osteoarthritis. (TMJ-OA) and is an important therapeutic target. Cerium oxide nanoparticles (CNPs) have been broadly studied owing to their powerful antioxidant properties and potential preventive and therapeutic effects against chronic diseases. The current study was designed to explore the protective effects of CNPs on the progression of TMJ-OA and their potential mechanisms. We detected the ability of CNPs to eliminate reactive oxygen species (ROS) in chondrocytes. Moreover, their protective effects on chondrocytes were detected in the level of gene and protein. Furthermore, TUNEL assay, histology and safranin O-fast green staining were used to detect the beneficial effects of CNPs on cartilage explants. The mechanism of CNPs, protecting condylar cartilage by reducing inflammation, was further explored by knocking down the Nuclear factor-erythroid 2-related factor (Nrf2) gene. CNPs could reduce the ROS levels in chondrocytes and cartilage explants and reverse the IL-1β-induced imbalance of cartilage matrix metabolism and apoptosis. The protective effects of CNPs on cartilage were lost after key antioxidant factors including Nrf2 and heme-oxygenase 1(HO-1) were significantly reduced. In conclusion, this study demonstrated for the first time that activating the Nrf2/HO-1 signaling pathway by CNPs might have therapeutic potential for TMJ-OA.

Oxysophocarpine (OSC), a quinolizidine alkaloid, shows neuroprotective potential, though its mechanisms are unclear. The aim of the present study was to investigate the neuroprotective effects of OSC through the nuclear factor erythroid 2-related factor 2 (Nrf2)/ heme oxygenase-1 (HO-1) signaling pathway using the HT-22 cell line. Assessments of cell viability were conducted utilizing the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Assessments of oxidative stress (OS) were conducted through the quantification of reactive oxygen species (ROS). The integrity of the mitochondrial membrane potential (MMP) was scrutinized using fluorescent probe technology. Apoptosis levels were quantified using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The trafficking of Nrf2 within the cell nucleus was examined through immunofluorescence analysis. Furthermore, Western blotting (WB) was applied to evaluate the expression levels of proteins implicated in apoptosis and the Nrf2/HO-1 pathway. To further probe the influence of OSC on the overexpression of antioxidant enzymes, cells were subjected to transfection with HO-1 siRNA. The results showed that OSC inhibited glutamate-induced OS, as evidenced by reduced cell viability and ROS levels. Furthermore, the apoptotic condition induced by glutamate in HT-22 cells was significantly reduced following OSC treatment. More interestingly, the Nrf2/HO-1 signaling pathway was upregulated following OSC treatment. These results suggest that OSC can exert neuroprotective effects by regulating the Nrf2/HO-1 pathway to inhibit neuronal cell apoptosis, potentially aiding in the treatment of neurodegenerative diseases.

The pericarp of Zanthoxylum bungeanum maxim (PZM) is a commonly used spice and herbal medicine in China. In the present study, the structural characteristics of PPZM were investigated by saccharide mapping after enzymatic digestion by using high-performance thin layer chromatography (HPTLC) and polysaccharide analysis by using carbohydrate gel electrophoresis (PACE). The mechanisms of protective effects of PPZM on Aβ25–35-induced oxidative damage were explored in PC12 cells. The results showed that PPZM contained 1,4-α-D-galactosidic, 1,4-α-D-galactosiduronic, and (1→4)-β-D-glucosidic linkages. Pretreatment with PPZM significantly increased the cell viability of Aβ25–35-injured PC12 cells. Flow cytometry and Hoechst/PI staining indicated that PPZM gradually relieved the apoptosis of the Aβ25–25-treated cells. PPZM markedly decreased the ROS level of PC12 cells and suppressed Aβ25–35-induced oxidative stress by increasing the SOD level, and decreasing the level of MDA and LDH. The mRNA expressions of caspase-3 and Bax were significantly downregulated, and Bcl-2 expression was upregulated by treatment with PPZM. PPZM significantly increased the mRNA expression of Nrf2 and HO-1 in Aβ25–35 treated cells. The results indicated that PPZM alleviated apoptosis and oxidative stress induced by Aβ25–25 through the inhibition of mitochondrial dependent apoptosis and activation of Nrf2/HO-1 pathway. PPZM can be used as a potential protective agent against Aβ25–25-induced neurotoxicity.

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.

• Ferroptosis plays an important role in DSS-induced ulcerative colitis. • Ferroptosis could effectively ameliorate DSS-induced UC by blocking of Nrf2/HO-1 signaling. • These data provide new perspectives for comprehending the molecular mechanism and developing novel therapeutic strategies for UC. Ulcerative colitis (UC) is an inflammatory disease characterized by an uncontrolled inflammatory response. Previous study showed that the immunological impairment elicted the alteration of inflammatory mediators, and ferroptosis was implicated with the lethal accumulation of reactive oxygen species (ROS). Therefore, this study aimed to investigate the role of ferroptosis in dextran sulfate sodium (DSS)-induced UC. The animal model was established and the molecular markers of ferroptosis were detected by using western blot. The results suggested that the expression of COX2 and ACSL4 was increased dramatically, while the level of GPX4 and FTH1 was deceased in 3% DSS group compared with Control group (P < 0.05). Meanwhile, the body weight and colon length were significantly increased, and the inflammation indexes and MDA levels were reduced in 3% DSS+ ferrostatin-1 group, 3% DSS+ liproxstatin-1 group and 3% DSS+ deferprone group compared to 3% DSS group (P < 0.05). Additionally, the mRNA and protein level of COX2 and ACSL4 were obviously upregulated, but the GPX4 and FTH1 expression were downregulated in 3% DSS group (P < 0.05); however, the expression level of COX2, ACSL4, GPX4 and FTH1 was revered after ferrostatin-1, liproxstatin-1 (Lip-1) or deferprone (DFP) administration. The immunohistochemical assay showed that the staining intensity of COX2 was decreased and the staining intensity of GPX4 was increased in 3% DSS+ Ferr-1 group compared with 3% DSS group (P < 0.05). Moreover, the nuclear factor erythoid 2-related 2 (Nrf2) and HO-1 expression were lower in 3% DSS+ Ferr-1 group than 3% DSS group (P < 0.05). These data revealed that suppressing ferroptosis could effectively ameliorate DSS-induced UC involved in blocking Nrf2/HO-1 signaling pathway. [ABSTRACT FROM AUTHOR]

BACKGROUND: Studies have confirmed that long-term regular aerobic exercise can effectively reduce blood glucose level and improve insulin resistance. It is an important measure for diabetic nephropathy, but the specific mechanism is unknown. OBJECTIVE: To investigate the effect of aerobic exercise on renal oxidative stress injury in mice with diabetic nephropathy, and explore its relationship with nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) signal pathway. METHODS: Male C57/BL6 mice were randomly divided into normal control group, model group, and aerobic exercise group, 8 mice in each group. Except for the control group, mice in the other two groups were intraperitoneally injected with 40 mg/kg streptozotocin for 5 consecutive days to induce diabetes. After 4 weeks, the 24-hour urine protein content > 30 mg suggested a successful modeling of diabetic nephropathy. After 8 weeks of modeling, mice in the aerobic exercise group underwent treadmill aerobic exercise for 8 weeks, 1 hour daily, 5 days per week. After 8 weeks of treatment, systolic blood pressure of the tail artery, 24-hour urinary microalbumin excretion rate, blood glucose, blood lipid, serum creatinine, and blood urea nitrogen levels were measured. The content of malondialdehyde and the activity of total superoxide dismutase of renal tissue homogenate were determined. The glomerular mesangial extracelluar matrix deposition, the level of reactive oxygen and the expression levels of Nrf2 and HO-1 in renal tissue were detected. Ethic approval was obtained from the Experimental Animal Ethic Committee of Henan Academy of Chinese Medicine in China (approval No. HPHT2015019). RESULTS AND CONCLUSION: Compared with the control group, the 24-hour urinary microalbumin excretion rate, levels of blood glucose, serum creatinine, blood urea nitrogen, total cholesterol, triglyceride, and low-density lipoprotein-cholesterol, and systolic blood pressure of the tail artery in the model group were significantly increased (P < 0.05), the glomerular mesangial extracelluar matrix was significantly accumulated (P < 0.05), and the levels of reactive oxygen species and malondialdehyde were significantly increased. Compared with the model group, the above-mentioned parameters were significantly decreased in the aerobic exercise group. Aerobic exercise significantly increased the activity of total superoxide dismutase, decreased the accumulation of glomerular mesangial extracelluar matrix, and up-regulated the expression of Nrf2 and HO-1 in the renal tissue. To conclude, aerobic exercise can alleviate renal oxidative stress injury in diabetic nephropathy mice, which may be related to the activation of Nrf2/HO-1 pathway. [ABSTRACT FROM AUTHOR]

Spinal cord injury (SCI) often induces severe sensory and motor dysfunction. Oxidative stress is an important pathophysiological process of secondary SCI, and its inhibition could facilitate the alleviation of the injury. Resveratrol is a natural plant polyphenol compound that has significant antioxidant and anti-inflammatory effects. It can inhibit oxidative stress by activating the Nrf2/HO-1 signal pathway. In this report, we analyze the antioxidant effect of resveratrol in SCI, clarify the specific mechanism of action and provide a theoretical basis for the clinical employment of resveratrol for SCI. [Display omitted] [ABSTRACT FROM AUTHOR]

Oxidative stress is closely linked to the etiology of temporomandibular joint osteoarthritis. (TMJ-OA) and is an important therapeutic target. Cerium oxide nanoparticles (CNPs) have been broadly studied owing to their powerful antioxidant properties and potential preventive and therapeutic effects against chronic diseases. The current study was designed to explore the protective effects of CNPs on the progression of TMJ-OA and their potential mechanisms. We detected the ability of CNPs to eliminate reactive oxygen species (ROS) in chondrocytes. Moreover, their protective effects on chondrocytes were detected in the level of gene and protein. Furthermore, TUNEL assay, histology and safranin O-fast green staining were used to detect the beneficial effects of CNPs on cartilage explants. The mechanism of CNPs, protecting condylar cartilage by reducing inflammation, was further explored by knocking down the Nuclear factor-erythroid 2-related factor (Nrf2) gene. CNPs could reduce the ROS levels in chondrocytes and cartilage explants and reverse the IL-1β-induced imbalance of cartilage matrix metabolism and apoptosis. The protective effects of CNPs on cartilage were lost after key antioxidant factors including Nrf2 and heme-oxygenase 1(HO-1) were significantly reduced. In conclusion, this study demonstrated for the first time that activating the Nrf2/HO-1 signaling pathway by CNPs might have therapeutic potential for TMJ-OA., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Xiong, Bao, Li, Gu, Li, Yin, Li, Miao and Liu.)

Skeletal muscle diseases have become to be the most common complication in patients with type 2 diabetic mellitus (T2DM). However, the effective therapies against skeletal muscle diseases are not yet available. Sulforaphane (SFN) is an organic isothiocyanate found in cruciferous plants. Our aim was to explore whether SFN could attenuate the skeletal muscle diseases in spontaneous type 2 diabetic db/db mice. The db/m and littermate db/db mice were treated with SFN or dimethyl sulfoxide. The grip strength of mice was measured by a grasping forcing machine. The electron transmission microscopy was used to perform the skeletal muscle. The western blot was used to detect the nuclear factor E2-related factor 2/heme oxygenase 1 (Nrf2/HO-1) signal pathway related proteins, and inflammatory and apoptotic associated proteins. The mRNA levels of anti-inflammatory and anti-oxidative relative genes were detected by RT-QPCR. We found that SFN could significantly increase the grip strength of the db/db mice. The lean mass and gastrocnemius mass were increased in the db/db mice after administration with SFN. Additionally, the db/db mice restored the skeletal muscle fiber organization after SFN treatment. Mechanistically, SFN could activate the Nrf2/HO-1 signal pathway, and downregulate the expression of inflammatory and apoptotic associated proteins. Furthermore, SFN could also regulate the mRNA levels of anti-inflammatory and anti-oxidative related genes. Our results demonstrated that SFN can protect against skeletal muscle diseases in db/db type 2 diabetic mice and provide a potential drug to prevent skeletal muscle dysfunction in T2DM patients. SFN could protect against skeletal muscle diseases in db/db type 2 diabetic mice. Mechanistically, SFN can activate the Nrf2/HO-1 signal pathway and inhibit the expression of inflammatory and apoptotic associated genes. Unlabelled Image [ABSTRACT FROM AUTHOR]

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 H 2 O 2 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., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Jiang, Zhou, Zhang, Wang, Yang and Li.)

In the present study, to investigate the prevention mechanism of proanthocyanidins from lotus seedpod (LSPCs) on methyl mercuric chloride (MMC) induced neurotoxicity, neuron/astrocyte cells were co-cultured to simulate the microenvironment in vivo to the greatest extent. The results showed that, compared with MMC group, pretreatment with LSPCs not only improved cell survival rate, decreased the release of lactate dehydrogenase (LDH), decreased the intracellular reactive oxygen species (ROS) level, and prevented the increase of intracellular [Ca2+]i, but also significantly increased the total anti-oxidation capacity (T-AOC) (p ＜0.05), the levels of glutathione peroxidase (GSH-Px) (p ＜0.05), glutathione (GSH) (p ＜0.05), and mitochondrial membrane potential (MMP) (p ＜0.01). Besides, LSPCs up-regulated the expression of transcriptional factor Nrf2/HO-1 in a concentration-dependent manner. Moreover, LSPCs reduced the expression of Bax protein, significantly increased the expression of Bcl-xl, Bcl-2, β-Ⅲ-Tubulin, SYN, and Arc proteins. The expression of these proteins is mainly regulated by genes and reflects the changes of genes functions. Taken together, these results suggested that LSPCs could enhance cellular antioxidant defense capacity through regulating the activation of Nrf2/HO-1, and involving the inhibition of mitochondria-mediated apoptotic signaling pathway. • LSPCs possess significant protective effects on MMC induced neurotoxicity. • The mechanism of LSPCs protecting against MMC induced neurotoxicity was studied. • Nrf2/HO-1 signaling pathway is considered to be a target of neurological diseases. [ABSTRACT FROM AUTHOR]