Protective effects and mechanism of chemical- and plant-based selenocystine against cadmium-induced liver damage.

Although selenium (Se) and cadmium (Cd) often coexist naturally in the soil of China, the health risks to local residents consuming Se-Cd co-enriched foods are unknown. In the present study, we investigated the effects of chemical-based selenocystine (SeCys2) on cadmium chloride-induced human hepatocarcinoma (HepG2) cell injury and plant (Cardamine hupingshanensis)-derived SeCys2 against Cd-induced liver injury in mice. We found that chemical- and plant-based SeCys2 showed protective effects against Cd-induced HepG2 cell injury and liver damage in mice, respectively. Compared with Cd intervention group, co-treatment with chemical- or plant-based SeCys2 both alleviated liver toxicity and ferroptosis by decreasing ferrous iron, acyl-CoA synthetase long-chain (ACSL) family member 4, lysophosphatidylcholine acyltransferase 3, reactive oxygen species and lipid peroxide levels, and increasing ACSL3, peroxisome proliferator-activated receptor α, solute carrier family 7 member 11 (SLC7A11) and glutathione and glutathione peroxidase 4 (GPX4) levels. In conclusion, chemical- and plant-based SeCys2 alleviated Cd-induced hepatotoxicity and ferroptosis by regulating SLC7A11/GPX4 signaling and lipid peroxidation. Our findings indicate that potential Cd toxicity from consuming foods grown in Se- and Cd-rich soils should be re-evaluated. This study offers a new perspective for the development of SeCys2-enriched agricultural products.

Effects of selenium-cadmium co-enriched Cardamine hupingshanensis on bone damage in mice.

Selenium (Se) and cadmium (Cd) usually co-existed in soils, especially in areas with Se-rich soils in China. The potential health consequences for the local populations consuming foods rich in Se and Cd are unknown. Cardamine hupingshanensis (HUP) is Se and Cd hyperaccumulator plant that could be an ideal natural product to assess the protective effects of endogenous Se against endogenous Cd-caused bone damage. Male C57BL/6 mice were fed 5.22 mg/kg cadmium chloride (CdCl2) (Cd 3.2 mg/kg body weight (BW)), or HUP solutions containing Cd 3.2 mg/kg BW and Se 0.15, 0.29 or 0.50 mg/kg BW (corresponding to the HUP0, HUP1 and HUP2 groups) interventions. Se-enriched HUP1 and HUP2 significantly decreased Cd-induced femur microstructure damage and regulated serum bone osteoclastic marker levels and osteogenesis-related genes. In addition, endogenous Se significantly decreased kidney fibroblast growth factor 23 (FGF23) protein expression and serum parathyroid hormone (PTH) levels, and raised serum calcitriol (1,25(OH)2D3). Furthermore, Se also regulated gut microbiota involved in skeletal metabolism disorder. In conclusion, endogenous Se, especially with higher doses (the HUP2 group), positively affects bone formation and resorption by mitigating the damaging effects of endogenous Cd via the modulation of renal FGF23 expression, circulating 1,25(OH)2D3 and PTH and gut microbiota composition.

Protective effects of epigallocatechin-3-o-gallate combined with organic selenium against transforming growth factor-beta 1-induced fibrosis in LX-2 cells.

In this study, we investigated the protective effects and possible mechanism of epigallocatechin-3-o-gallate (EGCG) combined with organic selenium in transforming growth factor (TGF)-ß1-activated LX-2 cells. After 12 h of starvation, LX-2 cells were treated with 10 ng/ml of recombinant TGF-ß1 and different concentrations of EGCG, L-selenomethionine (L-SeMet), or L-selenomethylcysteine (L-SeMC) for 24 h. We found that 100 and 200 µM EGCG combined with 1 mM L-SeMet or L-SeMC showed a synergistic effect in decreasing the survival rate of activated LX-2 cells. In addition, the combination of 100 mM EGCG and 1 mM L-SeMet or L-SeMC promoted the apoptosis of activated LX-2 cells. Compared with the EGCG treatment group, the combination intervention group had significantly suppressed levels of hepatic stellate cell activation markers including alpha-smooth muscle actin, collagen type I alpha 1, collagen type III alpha 1, 5-hydroxytryptophan (5-HT), and 5-HT receptors 2A and 2B. Moreover, interleukin-10 levels were decreased, while TGF-ß1 levels were increased after TGF-ß1 activation in LX-2 culture medium, whereas the combin1ation intervention reversed this phenomenon. The combination treatment had a more pronounced effect than any single treatment at the same dose. These results demonstrated that the combination of EGCG and organic selenium synergistically improves the TGF-ß1-induced fibrosis of LX-2 cells to some extent by promoting apoptosis and inhibiting cell activation. PRACTICAL APPLICATIONS: Here, we found that the effects of epigallocatechin-3-o-gallate (EGCG) + L-selenomethionine or L-selenomethylcysteine were more pronounced than those of EGCG alone. Future studies should investigate the protective effects of green tea and selenium-enriched green tea against hepatic fibrosis and explore the differences in their molecular mechanisms. The results of this study will be helpful for the development and utilization of selenium-enriched tea for food processing and health supplement production.

Lactoferrin improves hepatic insulin resistance and pancreatic dysfunction in high-fat diet and streptozotocin-induced diabetic mice.

Lactoferrin (Lf) is an iron-binding glycoprotein with potentially beneficial biological functions. However, the interaction between Lf and type 2 diabetes mellitus (T2DM) remains unclear. We hypothesized that Lf would improve hepatic insulin resistance and pancreatic dysfunction in diabetic mice. Male C57BL/6J mice were fed a high-fat diet for 15 weeks and injected with streptozotocin (STZ) for 5 consecutive days to establish a T2DM model. One week after STZ injection, mice with ≥11.1 mmol/L fasting blood glucose concentration were considered T2DM mice. These mice received 0.5% or 2% Lf solution for another 12 weeks. Biochemical parameters were measured, and histopathological examination of the pancreas and liver was performed. Hepatic protein expression related to the insulin signalling pathway was also assessed. Diabetic mice showed insulin resistance and abnormal glucolipid metabolism. Lf decreased serum concentrations of glycated serum protein, fasting insulin, cholesterol, and triglyceride and increased liver insulin sensitivity. Hematoxylin-eosin staining showed that Lf reversed the abnormal pancreatic islets of diabetic mice. Lf improved pancreatic dysfunction by reducing oxidative stress and inflammation responses. Furthermore, Lf upregulated the protein expression of insulin receptor, insulin receptor substrate-1, glucose transporter 4, phosphor phosphatidylinositol 3-kinase/phosphatidylinositol 3-kinase (PI3K), and phosphor protein kinase B/protein kinase B (AKT) in the liver. This study indicated that Lf supplementation improved hepatic insulin resistance and pancreatic dysfunction, possibly by regulating the PI3K/AKT signaling pathway in T2DM mice.

The Protective Effects of Zornia diphylla (L.) Pers. Against Acute Liver Injury Induced by Carbon Tetrachloride in Mice.

Background: Zornia diphylla (L.) Pers. (ZDP) is a traditional Chinese herbal medicine that has been used for several decades to treat patients with liver diseases. Whether ZDP is best administered as a single agent or adjunctive therapy has yet to be determined as does the mechanism whereby it exerts its effects on antagonizing acute liver injury (ALI). Aim of the study: To investigate the protective effects of ZDP on ALI induced by carbon tetrachloride (CCl4) and the potential underlying mechanisms. Materials and Methods: Sixty adult mice were randomized into six study groups (n = 10/group). Three groups were treated with different concentrations of ZDP (2.5, 1.25, 0.625 g/kg), one with bifendate (0.0075 g/kg) alone (positive control) and one with physiologic saline (normal, negative control). All groups were treated for 14 days. Two hours after the last administration, the normal group received an intraperitoneal injection of peanut oil, and the other five groups received an intraperitoneal injection of an equal dose of CCl4 peanut oil solution. At 24 h, the liver index, histology and serum or tissue levels and/or protein expression of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TBIL), alkaline phosphatase (ALP), superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT), glutathione (GSH), Akt, phosphorylated Akt (p-Akt), nuclear factor kappa B p65 (NF-κB p65), inhibitor of NF-κB α (IκB-α), interleukin-1 ß (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), E-cadherin and vimentin were determined. Results: Compared to the model controls, the degree of inflammatory cell infiltration and hepatocyte injury of liver tissue was relieved in the bifendate and three ZDP groups; liver index in the ZDP (2.5, 1.25 g/kg) groups and serum liver function indices in the ZDP (2.5, 1.25 and 0.625 g/kg) groups were decreased; antioxidants SOD, CAT and GSH in liver tissue were increased but the lipid peroxidation index MDA was decreased; protein expression of inflammatory cytokines Akt, p-Akt, NF-κB p65, IκB-α, IL-1ß, IL-6 and TNF-α in the liver was ameliorated, and E-cadherin expression was increased. The results of liver histopathology also showed that ZDP had a significant effect on ALI. Conclusion: ZDP has obvious protective effects on CCl4-induced ALI as a single therapy and appears to act by inhibiting oxidation, reducing the release of inflammatory factors and promoting hepatocyte repair.

The Ciji-Hua'ai-Baosheng II Formula Attenuates Chemotherapy-Induced Anorexia in Mice With H22 Hepatocellular Carcinoma.

Background: Ciji-Hua'ai-Baosheng II Formula (CHB-II-F) is a traditional Chinese medicine formula, which specifically targets different aspects of chemotherapy-induced adverse effects in patients with cancer. In our clinical application, CHB-II-F significantly alleviated chemotherapy-induced anorexia (loss of appetite) and improved the quality of life for patients with tumor during and after chemotherapy. However, the mechanism of CHB-II-F in alleviation of chemotherapy-induced anorexia remains to be further investigated. Aim of Study: To explore the therapeutic effect and mechanism of CHB-II-F on chemotherapy-induced anorexia in the mice model of H22 hepatoma. Materials and Methods: A total of 72 Kunming mice of SPF grade were inoculated subcutaneously with H22 hepatoma cells into the right anterior armpit of the mice. After 1 week of seeding, mice were injected intraperitoneally with a high dose of 5-fluorouracil (200 mg/kg 5-FU) to establish the model of chemotherapy. The mice were randomly divided into six groups: untreated group, 5-FU group, 5-FU plus Yangzheng Xiaoji capsule (YZXJC) group, and three groups of 5-FU plus different concentrations of CHB-II-F. All the mice in each group were treated for 14 days. The body weight, food intake, tumor volume, and tumor weight of mice were measured, and pathological examinations of tumor tissue, stomach, and duodenum were carried out. Expressions of serum Leptin, Neuropeptide Y (NPY), epidermal cell growth factor (EGF), Motilin (MTL), Orexin A (OXA), Gastrin (GAS), Ghrelin, Prostaglandin E2 (PGE2), and jejunum superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were examined. The protein and mRNA levels of proopiomelanocortin (POMC), Orexin receptor 1 (OX1R), neuropeptide Y (NPY), cocaine and amphetamine regulated transcript peptide (CART), Agouti gene-related protein (AgRP), Leptin receptor (Ob-R), and Ghrelin receptor (GHSR) were examined in hypothalamus, and the protein levels of substance P (SP) and 5-hydroxytryptamine (5-HT) in duodenum were measured. Results: The combination of CHB-II-F and 5-FU could enhance the inhibitory effect of 5-FU on tumor. The tumor inhibition rates of 5-FU group, YZXJC group, CHB-II-F(H) group, CHB-II-F(M) group, and CHB-II-F(L) group were 58.88, 28.08, 54.96, 37.69, and 28.61%, respectively. Compared with untreated group and 5-FU group, CHB-II-F significantly increased the body weight and food intake of tumor-bearing mice; increased the content of NPY, Orexin A, Ghrelin, GAS, MTL, EGF, and PGE2 in serum and the activity of SOD in jejunum; and decreased the content of Leptin in serum and the content of MDA in jejunum. Compared with untreated group and 5-FU group, CHB-II-F also enhanced the expression of OX1R, GHSR, NPY, and AgRP protein and gene and decreased the expression of Ob-R, POMC, and CART protein and gene in hypothalamus of mice, and the gene expression was consistent with the protein expression. In addition, CHB-II-F decreased the expression of 5-HT and SP protein in duodenum. Conclusion: In the murine model of H22 hepatocellular carcinoma (HCC) receiving chemotherapy, CHB-II-F enhances the inhibitory effect of 5-FU on tumor, significantly improves the pathological injury of gastrointestinal tract caused by chemotherapy, and regulates the secretion of gastrointestinal hormones. It may alleviate chemotherapy-induced anorexia by affecting appetite regulatory factors in the feeding area of hypothalamus central nervous system and peripheral appetite regulatory factors.

Protective effects of Lycium barbarum polysaccharide on ovariectomy­induced cognition reduction in aging mice.

Women experience cognitive decline as they age due to the decrease in estrogen levels following menopause. Currently, effective pharmaceutical treatments for age­related cognitive decline are lacking; however, several Traditional Chinese medicines have shown promising effects. Lycium barbarum polysaccharides (LBPs) were found to exert a wide variety of biological activities, including anti­inflammatory, antioxidant and anti­aging effects. However, to the best of our knowledge, the neuroprotective actions of LBP on cognitive impairment induced by decreased levels of estrogen have not yet been determined. To evaluate the effects of LBP on learning and memory impairment in an animal model of menopause, 45 female ICR mice were randomly divided into the following three groups: i) Sham; ii) ovariectomy (OVX); and iii) OVX + LBP treatment. The results of open­field and novel object recognition tests revealed that mice in the OVX group had learning and memory impairments, and lacked the ability to recognize and remember new objects. Notably, these deficits were attenuated following LBP treatment. Immunohistochemical staining confirmed the protective effects of LBP on hippocampal neurons following OVX. To further investigate the underlying mechanism of OVX in mice, mRNA sequencing of the hippocampal tissue was performed, which revealed that the Toll­like receptor 4 (TLR4) inflammatory signaling pathway was significantly upregulated in the OVX group. Moreover, reverse transcription­quantitative PCR and immunohistochemical staining demonstrated that OVX induced hippocampal injury, upregulated the expression levels of TLR4, myeloid differentiation factor 88 and NF­κB, and increased the expression of TNF­α, IL­6 and IL­1ß inflammatory factors. Conversely, LBP treatment downregulated the expression levels of mRNAs and proteins associated with the TLR4/NF­κB signaling pathway, decreased the inflammatory response and reduced neuronal injury in mice that underwent OVX. In conclusion, the findings of the present study indicated that oral LBP treatment may alleviate OVX­induced cognitive impairments by downregulating the expression levels of mRNAs and proteins associated with the TLR4/NF­κB signaling pathway, thereby reducing neuroinflammation and damage to the hippocampal neurons. Thus, LBP may represent a potential agent for the prevention of learning and memory impairments in patients with accelerated aging caused by estrogen deficiency.

Role of Traditional Chinese Medicine in the Management of Viral Pneumonia.

Viral pneumonia is one kind of acute respiratory tract infection caused by the virus. There have been many outbreaks of viral pneumonia with high contagiousness and mortality both in China and abroad, such as the great influenza in 1918, the severe acute respiratory syndrome (SARS) coronavirus in 2003, the Influenza A (H1N1) virus in 2009, and the Middle East Respiratory Syndrome coronavirus (MERS-CoV) in 2012 and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2019. These outbreaks and/or pandemic have significant impact on human life, social behaviors, and economic development. Moreover, no specific drug has been developed for these viruses. Traditional Chinese medicine (TCM) plays an important role in the treatment of viral pneumonia during these outbreaks especially in SARS and SARS-CoV-2 because studies suggest that TCM formulations may target several aspects of the disease and may have lesser side effects than manufactured pharmaceuticals. In recent years, a lot of clinicians and researchers have made a series of in-depth explorations and investigations on the treatment of viral pneumonia with TCM, which have understood TCM therapeutic mechanisms more specifically and clearly. But critical analysis of this research in addition to further studies are needed to assess the potential of TCM in the treatment of viral pneumonia.

p-Coumaric acid as a prophylactic measure against normobaric hypoxia induced pulmonary edema in mice.

AIMS: Previous studies indicate that the anti-hypoxia effects of Tibetan Turnip (Brassica rapa ssp. rapa) were closely related to its characteristic components being p-coumaric acid (CA) and p-coumaric acid­ß­d­glucopyranoside (CAG). Since CAG would be converted to CA in vivo, this study aims to further examine the efficacy and mechanism of CA against pulmonary edema induced by normobaric hypoxia. MAIN METHODS: Male ICR mice were assigned to the normoxia group and several hypoxia groups, given sterile water, CA or dexamethasone orally, once daily for four consecutive days. One hour after the final gavage, mice in the above hypoxia groups were put into the normobaric hypoxia chamber (9.5% O2) for 24 h while mice in normoxia group remained outside the chamber. After hypoxia exposure, lung water content (LWC), pulmonary vascular permeability, the protein content of bronchoalveolar lavage fluid (BALF), plasma total nitrate/nitrite (NOx) and endothelin-1 (ET-1) content, histological and ultra-microstructure analyses were performed. Expression of occludin was assayed by immunohistochemistry. KEY FINDINGS: In a hypoxic environment of 9.5% O2, mice treated with 100 mg/kg body wt CA had significantly lower LWC and BALF protein content than mice in the hypoxia vehicle group. Meanwhile, mice in CA group showed intact lung blood-gas-barrier, increased levels of plasma total NO, decreased levels of plasma ET-1 and upregulation of occludin expression. SIGNIFICANCE: CA exerts preventive effects against normobaric hypoxic pulmonary edema in mice, its mechanisms involved improving the integrity of the lung barrier, inhibiting oxidative stress and inflammation.

CLC-2 is a positive modulator of oligodendrocyte precursor cell differentiation and myelination.

Oligodendrocytes (OLs) are myelin-forming cells that are present within the central nervous system. Impaired oligodendrocyte precursor cell (OPC) differentiation into mature OLs is a major cause of demyelination diseases. Therefore, identifying the underlying molecular mechanisms of OPC differentiation is crucial to understand the processes of myelination and demyelination. It has been acknowledged that various extrinsic and intrinsic factors are involved in the control of OPC differentiation; however, the function of ion channels, particularly the voltage­gated chloride channel (CLC), in OPC differentiation and myelination are not fully understood. The present study demonstrated that CLC­2 may be a positive modulator of OPC differentiation and myelination. Western blotting results revealed that CLC­2 was expressed in both OPCs and OLs. Furthermore, CLC­2 currents (ICLC­2) were recorded in both types of cells. The inhibition of ICLC­2 by GaTx2, a blocker of CLC­2, was demonstrated to be higher in OPCs compared with OLs, indicating that CLC­2 may serve a role in OL differentiation. The results of western blotting and immunofluorescence staining also demonstrated that the expression levels of myelin basic protein were reduced following GaTx2 treatment, indicating that the differentiation of OPCs into OLs was inhibited following CLC­2 inhibition. In addition, following western blot analysis, it was also demonstrated that the protein expression of the myelin proteins yin yang 1, myelin regulatory factor, Smad­interacting protein 1 and sex­determining region Y­box 10 were regulated by CLC­2 inhibition. Taken together, the results of the present study indicate that CLC­2 may be a positive regulator of OPC differentiation and able to contribute to myelin formation and repair in myelin­associated diseases by controlling the number and open state of CLC-2 channels.

Neurochemical and Behavior Deficits in Rats with Iron and Rotenone Co-treatment: Role of Redox Imbalance and Neuroprotection by Biochanin A.

Increasing evidences show that the etiology of Parkinson's disease (PD) is multifactorial. Studying the combined effect of several factors is becoming a hot topic in PD research. On one hand, iron is one of the essential trace metals for human body; on the other hand, iron may be involved in the etiopathogenesis of PD. In our present study, the rats with increased neonatal iron (120 µg/g bodyweight) supplementation were treated with rotenone (0.5 mg/kg) when they were aged to 14 weeks. We observed that iron and rotenone co-treatment induced significant behavior deficits (time-dependent) and striatal dopamine depletion in the male and female rats, while they did not do so when they were used alone. No significant change in striatal 5-hydroxytryptamine content was observed in the male and female rats with iron and rotenone co-treatment. Also, iron and rotenone co-treatment significantly decreased substantia nigra TH expression in the male rats. Furthermore, co-treatment with iron and rotenone significantly induced malondialdehyde increase and glutathione decrease in the substantia nigra of male and female rats. There was no significant change in cerebellar malondialdehyde and glutathione content of the rats co-treated with iron and rotenone. Interestingly, biochanin A significantly attenuated striatal dopamine depletion and improved behavior deficits (dose-dependently) in the male and female rats with iron and rotenone co-treatment. Biochanin A treatment also significantly alleviated substantia nigra TH expression reduction in the male rats co-treated with iron and rotenone. Finally, biochanin A significantly decreased malondialdehyde content and increased glutathione content in the substantia nigra of male and female rats with iron and rotenone co-treatment. Our results indicate that iron and rotenone co-treatment may result in aggravated neurochemical and behavior deficits through inducing redox imbalance and increased neonatal iron supplementation may participate in the etiopathogenesis of PD. Moreover, biochanin A may exert dopaminergic neuroprotection by maintaining redox balance.

Effects of Tibetan turnip (Brassica rapa L.) on promoting hypoxia-tolerance in healthy humans.

ETHNOPHARMACOLOGICAL RELEVANCE: Tibetan turnip (Brassica rapa L.), widely distributed in Tibet region, is an edible and medical plant with effects of "tonic and anti-hypoxia" "heat-clearing and detoxification" and "alleviating fatigue" according to traditional Tibetan medical books. AIM OF THE STUDY: This research systematically studied the effects of Tibetan turnip on promoting hypoxia-tolerance in humans and the mechanisms. MATERIALS AND METHODS: A 7-d, self-control and single-blind human feeding trial was conducted among 27 healthy subjects with 8 males and 10 females in feeding group fed with 7.5g turnip powder 2 times daily while 4 males and 5 females in control group fed with 7.5g radish powder twice a day. Subjects were required to undergo a hypoxia tolerance test (7.1% O2) and a cardiopulmonary function evaluation (Bruce treadmill protocol) before (1st day) and after (9th day) the trial. Simultaneously, the anti-oxidative activities (SOD, CAT, GSH-Px, MDA), routine and biochemical analyses of blood samples were evaluated. RESULTS: The females' SpO2 increased significantly by 6.4% at the end of the hypoxia tolerance test after taking turnips (p<0.05), and the hypoxia symptoms in most of the subjects were alleviated as well. The anaerobic threshold, peak O2 pulse and peak VO2/kg were significantly improved after 7-d turnip consumption during the Bruce treadmill test (p<0.05). As for the blood analysis, anti-oxidative activities were boosted effectively after the 7-d treatments. Moreover, mean corpuscular hemoglobin concentration (MCHC) in the males of feeding group increased significantly (p<0.05). However, little changes of all variables were observed in the control group. CONCLUSIONS: Consumption of Tibetan turnips for 7 days likely contributed to the hypoxia tolerance in healthy humans, which could be due to its abilities of improving oxygen uptake and delivery, enhancing body antioxidant capacity and increasing MCHC. However, further studies with larger samples and double-blind design are warranted, and future studies covering more diverse populations (unhealthy, athletic) would be also considered. Moreover, researches on identifying Tibetan turnip's active compounds are desired as well.

Oxymatrine protects against myocardial injury via inhibition of JAK2/STAT3 signaling in rat septic shock.

Oxymatrine (OMT), an alkaloid extracted from Sophora japonica (kushen), is used to treat inflammatory diseases and various types of cancer in traditional Chinese medicine. However, the cellular and molecular mechanisms underlying the anti­inflammatory activity of OMT remain poorly understood. The present study explored the protective effect of OMT on myocardial injury in rats with septic shock by inhibiting the activation of the janus kinase­signal transducer and activator of transcription (JAK/STAT) signaling pathway. OMT treatment was found to significantly inhibit the activation of JAK2 and STAT3 in myocardial tissue. It also attenuated the expression of pro­inflammatory cytokines, including interleukin­1ß and tumor necrosis factor­α. In addition, OMT exhibited anti­inflammatory properties as heart function and myocardial contractility was improved and pathological and ultrastructural injury was prevented in myocardial tissue induced by septic shock. The results indicate that OMT exhibits substantial therapeutic potential for the treatment of septic shock­induced myocardial injury through inhibition of the JAK2/STAT3 signaling pathway.

[Protective effects and mechanisms of OSR on primary cultured hippocampus neurons subjected to anoxic injury in neonatal rat].

OBJECTIVE: To investigate the protective effects of oxysophoridine (OSR) on primary cultured hippocampus neurons subjected to anoxia injury in neonatal rats and its mechanism. METHOD: The model of anoxia injury of hippocampus neurons in neonatal rats were primarily cultured in vitro by physical oxygen deficiency using glucose-free culture fluid. The survival rate of neurons, the leaking rate of lactate dehydrogenase (LDH), the intracellular contents of malondialdehyde (MDA) and nitric oxide (NO), the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and nitric oxide synthase (NOS) were measured. The intracellular free calcium concentration ([Ca2+]i) in hippocampus neurons were detected with Ca(2+)-sensitive dual wavelength fluorescence spectrophotometer. RESULT: Neuron death occurred in the anoxia injury model group with increase of LDH leaking rate, the contents of NO, MDA, intracellular [Ca2+] and the elevated activity of NOS while decreased activities of SOD and GSH-PX. The hippocampus neurons subjected to anoxia injury were alleviated in OSR (0.625, 5, 10 microg x L(-1)) group. CONCLUSION: OSR has significant protective effects on hippocampus neurons subjected to anoxic injury. The mechanism of its protective effect may relate to its reduction of calcium overload and against oxidation injury.