A potent synthetic nanobody with broad-spectrum activity neutralizes SARS-CoV-2 virus and the Omicron variant BA.1 through a unique binding mode.

The major challenge to controlling the COVID pandemic is the rapid mutation rate of the SARS-CoV-2 virus, leading to the escape of the protection of vaccines and most of the neutralizing antibodies to date. Thus, it is essential to develop neutralizing antibodies with broad-spectrum activity targeting multiple SARS-CoV-2 variants. Here, we report a synthetic nanobody (named C5G2) obtained by phage display and subsequent antibody engineering. C5G2 has a single-digit nanomolar binding affinity to the RBD domain and inhibits its binding to ACE2 with an IC50 of 3.7 nM. Pseudovirus assays indicated that monovalent C5G2 could protect the cells from infection with SARS-CoV-2 wild-type virus and most of the viruses of concern, i.e., Alpha, Beta, Gamma and Omicron variants. Strikingly, C5G2 has the highest potency against Omicron BA.1 among all the variants, with an IC50 of 4.9 ng/mL. The cryo-EM structure of C5G2 in complex with the spike trimer showed that C5G2 binds to RBD mainly through its CDR3 at a conserved region that does not overlap with the ACE2 binding surface. Additionally, C5G2 binds simultaneously to the neighboring NTD domain of the spike trimer through the same CDR3 loop, which may further increase its potency against viral infection. Third, the steric hindrance caused by FR2 of C5G2 could inhibit the binding of ACE2 to RBD as well. Thus, this triple-function nanobody may serve as an effective drug for prophylaxis and therapy against Omicron as well as future variants.

Whole body vibration activates AMPK/CPT1 signaling pathway of skeletal muscle in young and aging mice based on metabolomics study.

Whole-body vibration (WBV) can improve skeletal muscle function in aging mice, but whether the effect on young and aging skeletal muscle is consistent has not been studied. We selected C57BL/6J mouse models, which were divided into young control group (YC), young vibration group (YV), aging control group (AC) and aging vibration group (AV). After 12 weeks of WBV, we found that compared with the YC group, the pathways of linoleic acid metabolism, biosynthesis of unsaturated fatty acids, arachidonic acid metabolism, nicotinate and nicotinamide metabolism, glycine, serine and threonine metabolism, and arginine and proline metabolism improved significantly in the YV group. Compared with the AC group, the pathways of arachidonic acid metabolism, alpha-linolenic acid metabolism, biosynthesis of unsaturated fatty acids, pentose and glucuronate interconversions and pentose phosphate pathway improved significantly in the AV group. Furthermore, we found that WBV decreased triglyceride (TG), total cholesterol (TC), and free fatty acid (FFA) levels in aging mice, improved mitochondrial membrane potential, and increased the expression of phosphorylated activated protein kinase (p-AMPK), peroxisome proliferator-activated receptor coactivator-1α (PGC-1α) and carnitine palmitoyl transferase 1B (CPT1B) in the skeletal muscle of young and aging mice. Our study revealed that WBV mainly improved lipid metabolism and amino acid metabolism pathways of skeletal muscle in young mice and mainly improved lipid metabolism and glucose metabolism pathways of skeletal muscle in aging mice. WBV can activate the AMPK/CPT1 signaling pathway and improve mitochondrial function in skeletal muscle in both young and aging mice.

Medium & long-chain acylcarnitine's relation to lipid metabolism as potential predictors for diabetic cardiomyopathy: a metabolomic study.

BACKGROUND: Acylcarnitine is an intermediate product of fatty acid oxidation. It is reported to be closely associated with the occurrence of diabetic cardiomyopathy (DCM). However, the mechanism of acylcarnitine affecting myocardial disorders is yet to be explored. This current research explores the different chain lengths of acylcarnitines as biomarkers for the early diagnosis of DCM and the mechanism of acylcarnitines for the development of DCM in-vitro. METHODS: In a retrospective non-interventional study, 50 simple type 2 diabetes mellitus patients and 50 DCM patients were recruited. Plasma samples from both groups were analyzed by high throughput metabolomics and cluster heat map using mass spectrometry. Principal component analysis was used to compare the changes occurring in the studied 25 acylcarnitines. Multivariable binary logistic regression was used to analyze the odds ratio of each group for factors and the 95% confidence interval in DCM. Myristoylcarnitine (C14) exogenous intervention was given to H9c2 cells to verify the expression of lipid metabolism-related protein, inflammation-related protein expression, apoptosis-related protein expression, and cardiomyocyte hypertrophy and fibrosis-related protein expression. RESULTS: Factor 1 (C14, lauroylcarnitine, tetradecanoyldiacylcarnitine, 3-hydroxyl-tetradecanoylcarnitine, arachidic carnitine, octadecanoylcarnitine, 3-hydroxypalmitoleylcarnitine) and factor 4 (octanoylcarnitine, hexanoylcarnitine, decanoylcarnitine) were positively correlated with the risk of DCM. Exogenous C14 supplementation to cardiomyocytes led to increased lipid deposition in cardiomyocytes along with the obstacles in adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) signaling pathways and affecting fatty acid oxidation. This further caused myocardial lipotoxicity, ultimately leading to cardiomyocyte hypertrophy, fibrotic remodeling, and increased apoptosis. However, this effect was mitigated by the AMPK agonist acadesine. CONCLUSIONS: The increased plasma levels in medium and long-chain acylcarnitine extracted from factors 1 and 4 are closely related to the risk of DCM, indicating that these factors can be an important tool for DCM risk assessment. C14 supplementation associated lipid accumulation by inhibiting the AMPK/ACC/CPT1 signaling pathway, aggravated myocardial lipotoxicity, increased apoptosis apart from cardiomyocyte hypertrophy and fibrosis were alleviated by the acadesine.

Bioremediation of marine oil spills by immobilized oil-degrading bacteria and nutrition emulsion.

The combination of bioaugmentation and biostimulation was used to speed up the bioremediation of marine oil spills. A novel carrier material that consisted of puffed panicum miliaceum (PPM), calcium alginate and chitosan was prepared. The porous structure and low density of PPM ensured this carrier material not only had appropriate physical and biological properties for the aggregation of microorganisms but also was biodegradable and floating on the seawater surface for bioremediation of oil pollution. An oil-degrading bacterial consortium was immobilized via adsorption on the carrier material. The immobilized bacteria were observed with scanning electron microscopy. The number of viable cells immobilized on the material was approximately 1.12 × 108 CFU/g. To solve the problem of nutrients supplementation in seawater, an emulsion formed with urea solution, soybean lecithin, alcohol and oleic acid was prepared as oleophilic fertilizer. The results from laboratory and field mesocosm experiments showed that the combination of immobilized bacteria and the emulsion achieved a higher oil removal efficiency compared with the use of them separately. The results of field mesocosm experiments conducted in the coastal seawater showed that most of the petroleum pollutant (> 98%) was removed from the surface of seawater in 24 h. GC-MS analysis showed that most components of petroleum pollutants had been removed. This formula with immobilized bacteria and emulsion can be exploited further for the bioremediation of marine oil spills.

Metabolomics Study of Whole-body Vibration on Lipid Metabolism of Skeletal Muscle in Aging Mice.

Ageing increases the occurrence and development of many diseases. Exercise is believed to be an effective way to improve ageing and skeletal muscle atrophy. However, many elderly people are unable to engage in active exercise. Whole-body vibration is a passive way of moving that is especially suitable for the elderly and people who find it inconvenient to exercise. Metabolomics is the systematic study of metabolic changes in small molecules. In this study, metabolomics studies were performed to investigate the regulatory effect of whole-body vibration on the skeletal muscles of ageing mice. After 12 weeks, we found that whole-body vibration had the most obvious effect on lipid metabolism pathways (such as linoleic acid, α-linolenic acid metabolism, glycerophospholipid metabolism pathways) in skeletal muscle of ageing mice. Through further research we found that whole-body vibration decreased the levels of triglycerides, total cholesterol, low-density lipoprotein cholesterol and very low-density lipoprotein in blood; decreased the lipid deposition in skeletal muscle; decreased the protein expression of monocyte chemoattractant protein-1 and interleukin-6; improved the protein levels of phosphorylated insulin receptor substrate-1, phosphate phosphoinositide 3-kinase and p-AKT; improved the protein levels of klotho; and decreased the protein expression of p53. These findings reveal that whole-body vibration might postpone senility by attenuating lipid deposition and reducing chronic inflammation and the insulin resistance of skeletal muscle.

A novel nanobody-based HER2-targeting antibody exhibits potent synergistic antitumor efficacy in trastuzumab-resistant cancer cells.

Human epithelial growth factor receptor-2 (HER2) plays an oncogenic role in numerous tumors, including breast, gastric, and various other solid tumors. While anti-HER2 therapies are approved for the treatment of HER2-positive tumors, a necessity persists for creating novel HER2-targeted agents to resolve therapeutic resistance. Utilizing a synthetic nanobody library and affinity maturation, our study identified four anti-HER2 nanobodies that exhibited high affinity and specificity. These nanobodies recognized three distinct epitopes of HER2-ECD. Additionally, we constructed VHH-Fc and discovered that they facilitated superior internalization and showed moderate growth inhibition. Compared to the combination of trastuzumab and pertuzumab, the VHH-Fc combos or their combination with trastuzumab demonstrated greater or comparable antitumor activity in both ligand-independent and ligand-driven tumors. Most remarkably, A9B5-Fc, which targeted domain I of HER2-ECD, displayed significantly enhanced trastuzumab-synergistic antitumor efficacy compared to pertuzumab under trastuzumab-resistant conditions. Our findings offer anti-HER2 nanobodies with high affinity and non-overlapping epitope recognition. The novel nanobody-based HER2-targeted antibody, A9B5-Fc, binding to HER2-ECD I, mediates promising receptor internalization. It possesses the potential to serve as a potent synergistic partner with trastuzumab, contributing to overcoming acquired resistance.

Correlation between Acylcarnitine and Peripheral Neuropathy in Type 2 Diabetes Mellitus.

OBJECTIVE: In patients with type 2 diabetes mellitus (T2DM), it is unknown whether acylcarnitine changes in the patient's plasma as diabetic peripheral neuropathy (DPN) occurs. The purpose of the present study was to investigate the correlation between acylcarnitines and DPN in Chinese patients with T2DM. METHODS: A total of 508 patients admitted to the First Affiliated Hospital of Jinzhou Medical University were included in this study, and all of whom were hospitalized for T2DM from January 2018 to December 2020. The diagnostic criteria for DPN were based on the 2017 Chinese Guidelines for the Prevention of Type 2 Diabetes. The contents of 25 acylcarnitine metabolites in fasting blood were determined by mass spectrometry. The measured acylcarnitines were classified by factor analysis, and the factors were extracted. To determine the correlation between acylcarnitines and DPN, binary logistic regression analysis was applied. RESULTS: Among the 508 T2DM patients, 270 had DPN. Six factors were extracted from 25 acylcarnitines, and the cumulative contribution rate of variance was 61.02%. After the adjustment for other potential confounding factors, such as other carnitines and conventional risk factors, Factor 2 was positively associated with an increased risk of DPN (OR: 1.38, 95% CI: 1.13-1.69). Factor 2 contained acetylcarnitine (C2), propionylcarnitine (C3), butylcarnitine (C4), and isovalerylcarnitine (C5). CONCLUSIONS: Plasma levels of short-chain acylcarnitines (C2, C3, C4, and C5) were positively associated with DPN risk.

Curcumin Conjugated Gold Nanoclusters as Perspective Therapeutics for Diabetic Cardiomyopathy.

Accumulation of lipids in the myocardium contributes to the development of cardiac dysfunctions and various chronic diseases, such as diabetic cardiomyopathy (DCM). Curcumin (Cur) can relieve lipid accumulation problems, but its efficiency is limited by poor water solubility and biocompatibility. Herein, gold nanoclusters (AuNCs) were used to improve the efficiency of Cur, and the conjugates Curcumin-AuNCs (AuCur) were developed. In the treatment of high-fat-induced myocardial cell damage, we found that AuCur could effectively reduce intracellular lipid accumulation, the increase of reactive oxygen species (ROS), the increase of mitochondrial division, and the increase of apoptosis compared with Cur. AuCur decreased the expression of the peroxisome proliferator-activated receptors-α subtype (PPARα), and the therapeutic effect of AuCur was canceled when the expression of PPARα was enhanced. For the above reasons, AuCur treated the toxic effect of high lipid on cardiomyocytes by regulating PPARα, providing a new idea and method for the treatment of DCM.

Preparation of chitosan-collagen-alginate composite dressing and its promoting effects on wound healing.

The present study aimed to prepare a composite dressing composed of collagen, chitosan, and alginate, which may promote wound healing and prevent from seawater immersion. Chitosan-collagen-alginate (CCA) cushion was prepared by paintcoat and freeze-drying, and it was attached to a polyurethane to compose CCA composite dressing. The swelling, porosity, degradation, and mechanical properties of CCA cushion were evaluated. The effects on wound healing and seawater prevention of CCA composite dressing were tested by rat wound model. Preliminary biosecurity was tested by cytotoxicity and hemocompatibility. The results revealed that CCA cushion had good water absorption and mechanical properties. A higher wound healing ratio was observed in CCA composite dressing treated rats than in gauze or chitosan treated ones. On the fifth day, the healing rates of CCA composite dressing, gauze, and chitosan were 48.49%±1.07%, 28.02%±6.4%, and 38.97%±8.53%, respectively. More fibroblast and intact re-epithelialization were observed in histological images of CCA composite dressing treated rats, and the expressions of EGF, bFGF, TGF-ß, and CD31 increased significantly. CCA composite dressing showed no significant cytotoxicity, and favorable hemocompatibility. These results suggested that CCA composite dressing could prevent against seawater immersion and promote wound healing while having a good biosecurity.

Radioprotective effects of cimetidine on rats irradiated by long-term, low-dose-rate neutrons and 60Co γ-rays.

BACKGROUND: Cimetidine, an antagonist of histamine type II receptors, has shown protective effects against γ-rays or neutrons. However, there have been no reports on the effects of cimetidine against neutrons combined with γ-rays. This study was carried out to evaluate the protective effects of cimetidine on rats exposed to long-term, low-dose-rate neutron and γ-ray combined irradiation (n-γ LDR). METHODS: Fifty male Sprague-Dawley (SD) rats were randomly divided into 5 groups: the normal control group, radiation model group, 20 mg/(kg · d) cimetidine group, 80 mg/(kg · d) cimetidine group and 160 mg/(kg · d) cimetidine group (10 rats per group). Except for the normal control group, 40 rats were simultaneously exposed to fission neutrons (252Cf, 0.085 mGy/h) for 22 h every day and γ-rays (60Co, 0.097 Gy/h) for 1.03 h once every three days, and the cimetidine groups were administered intragastrically with cimetidine at doses of 20, 80 and 160 mg/kg each day. Peripheral blood WBC of the rats was counted the day following exposure to γ-rays. The rats were anesthetized and sacrificed on the day following exposure to 252Cf for 28 days. The spleen, thymus, testicle, liver and intestinal tract indexes were evaluated. The DNA content of bone marrow cells and concanavalin A (ConA)-induced lymphocyte proliferation were measured. The frequency of micronuclei in polychromatic erythrocytes (fMNPCEs), superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) in the serum and liver tissues were detected. RESULTS: The peripheral blood WBC in the cimetidine groups was increased significantly on the 8th day and the 26th day compared with those in the radiation model group. The spleen, thymus and testicle indexes of the cimetidine groups were higher than those of the radiation model group. The DNA content of bone marrow cells and lymphocyte proliferation in the cimetidine groups were increased significantly, and fMNPCE was reduced 1.41-1.77 fold in cimetidine treated groups. The activities of SOD and GSH-Px in the cimetidine groups were increased significantly, and the content of MDA in the cimetidine groups was decreased significantly. CONCLUSIONS: The results suggested that cimetidine alleviated damage induced by long-term, low-dose-rate neutron and γ combined irradiation via antioxidation and immunomodulation. Cimetidine might be useful as a potent radioprotector for radiotherapy patients as well as for occupational exposure workers.

Beneficial effects of a novel shark-skin collagen dressing for the promotion of seawater immersion wound healing.

BACKGROUND: Wounded personnel who work at sea often encounter a plethora of difficulties. The most important of these difficulties is seawater immersion. Common medical dressings have little effect when the affected area is immersed in seawater, and only rarely dressings have been reported for the treatment of seawater-immersed wounds. The objective of this study is to develop a new dressing which should be suitable to prevent the wound from seawater immersion and to promote the wound healing. METHODS: Shark skin collagen (SSC) was purified via ethanol de-sugaring and de-pigmentation and adjusted for pH. A shark skin collagen sponge (SSCS) was prepared by freeze-drying. SSCS was attached to an anti-seawater immersion polyurethane (PU) film (SSCS + PU) to compose a new dressing. The biochemical properties of SSC and physicochemical properties of SSCS were assessed by standard methods. The effects of SSCS and SSCS + PU on the healing of seawater-immersed wounds were studied using a seawater immersion rat model. For the detection of SSCS effects on seawater-immersed wounds, 12 SD rats, with four wounds created in each rat, were divided into four groups: the 3rd day group, 5th day group, 7th day group and 12th day group. In each group, six wounds were treated with SSCS, three wounds treated with chitosan served as the positive control, and three wounds treated with gauze served as the negative control. For the detection of the SSCS + PU effects on seawater-immersed wounds, 36 SD rats were divided into three groups: the gauze (GZ) + PU group, chitosan (CS) + PU group and SSCS + PU group, with 12 rats in each group, and two wounds in each rat. The wound sizes were measured to calculate the healing rate, and histomorphology and the immunohistochemistry of the CD31 and TGF-ß expression levels in the wounded tissues were measured by standard methods. RESULTS: The results of Ultraviolet-visible (UV-vis) spectrum, Fourier-transform infrared (FTIR) spectrum, circular dichroism (CD) spectra, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and amino acid composition analyses of SSC demonstrated that SSC is type I collagen. SSCS had a homogeneous porous structure of approximately 200 µm, porosity rate of 83.57% ± 2.64%, water vapor transmission ratio (WVTR) of 4500 g/m2, tensile strength of 1.79 ± 0.41 N/mm, and elongation at break of 4.52% ± 0.01%. SSCS had significant beneficial effects on seawater-immersed wound healing. On the 3rd day, the healing rates in the GZ negative control, CS positive control and SSCS rats were 13.94% ± 5.50%, 29.40% ± 1.10% and 47.24% ± 8.40%, respectively. SSCS also enhanced TGF-ß and CD31 expression in the initial stage of the healing period. The SSCS + PU dressing effectively protected wounds from seawater immersion for at least 4 h, and accelerated re-epithelialization, vascularization and granulation formation of seawater-immersed wounds in the earlier stages of wound healing, and as well as significantly promoted wound healing. The SSCS + PU dressing also enhanced expression of TGF-ß and CD31. The effects of SSCS and SSCS + PU were superior to those of both the chitosan and gauze dressings. CONCLUSIONS: SSCS has significant positive effects on the promotion of seawater-immersed wound healing, and a SSCS + PU dressing effectively prevents seawater immersion, and significantly promotes seawater-immersed wound healing.

γ-H2AX responds to DNA damage induced by long-term exposure to combined low-dose-rate neutron and γ-ray radiation.

Risk estimates for low-dose radiation (LDR) remain controversial. The possible involvement of DNA repair-related genes in long-term low-dose-rate neutron-gamma radiation exposure is poorly understood. In this study, 60 rats were divided into control groups and irradiated groups, which were exposed to low-dose-rate n-γ combined radiation (LDCR) for 15, 30, or 60 days. The effects of different cumulative radiation doses on peripheral blood cell (PBC), subsets of T cells of peripheral blood lymphocytes (PBL) and DNA damage repair were investigated. Real-time PCR and immunoblot analyses were used to detect expression of DNA DSB-repair-related genes involved in the NHEJ pathway, such as Ku70 and Ku80, in PBL. The mRNA level of H2AX and the expression level of γ-H2AX were detected by real-time PCR, immunoblot, and flow cytometry. White blood cells (WBC) and platelets (PLT) of all ionizing radiation (IR) groups decreased significantly, while no difference was seen between the 30 day and 60 day exposure groups. The numbers of CD3(+), CD4(+) T cells and CD4(+)/CD8(+) in the PBL of IR groups were lower than in the control group. In the 30 day and 60 day exposure groups, CD8(+) T cells decreased significantly. Real-time PCR and immunoblot results showed no significant difference in the mRNA and protein expression of Ku70 and Ku80 between the control groups and IR groups. However, the mRNA of H2AX increased significantly, and there was a positive correlation with dose. There was no difference in the protein expression of γ-H2AX between 30 day and 60 day groups, which may help to explain the damage to PBL. In conclusion, PBL damage increased with cumulative dose, suggesting that γ-H2AX, but neither Ku70 nor Ku80, plays an important role in PBL impairment induced by LDCR.

Isolation, characterization, and radiation protection of Sipunculus nudus L. polysaccharide.

Sipunculus nudus Linnaeus polysaccharide (SNP) was purified from S. nudus L. via NaOH extraction, trichloroacetic acid deproteination, DEAE-cellulose 52 and Sephacryl S-300 chromatography. The monosaccharide analysis and molecular weight was detected with HPLC. FT-IR, 1H spectrum and 13C NMR spectrum were performed to detect the chemical characteristics. The antioxidant activity was assayed in vitro. The radiation protection effects were detected on mice. The results showed that SNP was composed of mannose, rhamnose, galacturonic acid, glucose, arabinose and fucose, and the average molecular weight was 680 kDa. Above the concentration of 10 mg/mL, SNP showed powerful scavenging activity on hydroxyl radical. In the animals irradiated with a 7.5 Gy γ-rays, the 90 mg/kg and the 270 mg/kg SNP groups survived significantly longer than the radiation control group. In the animals irradiated with a 4.0 Gy γ-rays, SNP showed significant protection effect. The contents of DNA in bone marrow cells were significantly increased by SNP treatment, and the micronucleus rates of 30 mg/kg and 270 mg/kg SNP groups were decrease significantly compared to the radiation control group. These findings suggest that SNP possesses marked antioxidant and bone marrow damage protection capacity which play important roles in the prevention of radiation damage.

Radioprotective effects of Sipunculus nudus L. polysaccharide combined with WR-2721, rhIL-11 and rhG-CSF on radiation-injured mice.

This study investigated the radioprotective effect of Sipunculus nudus L. polysaccharide (SNP) in combination with WR-2721, rhIL-11 and rhG-CSF on irradiated mice. A total of 70 Imprinting Control Region (ICR) mice were divided into seven groups: the control group, the model group and five administration groups. All groups, except the control group, were exposed to a 5 Gy (60)Co γ-ray beam. Blood parameters [including white blood cell (WBC), red blood cell (RBC) and platelet counts and hemoglobin level] were assessed three days before irradiation, and the on the 3rd, 7th and 14th days after irradiation. Spleen, thymus and testicular indices, DNA contents of bone marrow cells, bone marrow nucleated cells, sperm counts, superoxide dismutase (SOD), malondialdehyde (MDA), testosterone and estradiol levels in the serum were assessed on the 14th day after irradiation. The combined administration of SNP, WR-2721, rhIL-11 and rhG-CSF exerted synergistic recovery effects on peripheral blood WBC, RBC and platelet counts and hemoglobin levels in irradiated mice, and synergistic promotion effects on spleen, thymus, testicle, bone marrow nucleated cells and sperm counts in irradiated mice. The synergistic administration increased the serum SOD activities and serum testosterone content of irradiated mice, but synergy decreased the content of serum MDA and estradiol in irradiated mice. These results suggest that the combined administration of SNP, WR-2721, rhIL-11 and rhG-CSF should increase the efficacy of these drugs for acute radiation sickness, protect immunity, hematopoiesis and the reproductive organs of irradiated-damaged mice, and improve oxidation resistance in the body.

Protective effects of polysaccharides from Sipunculus nudus on Beagle dogs exposed to γ-radiation.

The aim of the study is to investigate the radioprotective effect of polysaccharide extract from Sipunculus nudus (SNP). Beagle dogs were randomly divided into the following six groups. Group-1: Un-treated and un-irradiated controls. Group-2: Exposed to a single acute dose of 2 Gy γ-radiation alone. Groups-3, 4 and 5: Oral administration of SNP at 50, 100 or 200 mg/kg body weight once a day for 7 days followed by a single acute whole body exposure to 2 Gy γ-radiation. The same doses of SNP were administered for further 27 days. Group-6: Positive controls treated with 1.6 mg/kg Nilestriol by gavage after radiation. Blood parameters including white/red cells and platelet counts, as well as hemoglobin level, were assessed every other day for 34 days (7 days before and 27 days of experiment). Serum separated from aliquots of the same blood sample was used to estimate enzyme activity of antioxidant superoxide-dismutase, and to determine levels of free radical, nitric oxide, hydroxyl and superoxide anion. At the end of the experiment, all dogs were euthanized to weigh the organs for organ co-efficient calculation. Pathological changes were assessed in the bone marrow. The results showed that the dogs exposed to γ-radiation alone exhibited a typical hematopoietic syndrome. In contrast, at the end of 27 days experiment, dogs received oral administration of SNP+γ-radiation showed: (i) a much improved blood picture as indicated by shorter duration of leucopenia, neutropenia, thrombocytopenia (platelet counts), as well as hemoglobin levels, (ii) significantly improved hematopoietic activity in the bone marrow, (iii) substantial decrease in nitric oxide levels, and notable increase in activity of antioxidant superoxide dismutase. The results suggested that oral administration of SNP in Beagle dogs was effective in facilitating the recovery of hematopoietic bone marrow damage induced by γ-radiation.

Growth inhibition and induction of early apoptosis by arenicolsterol A, a novel cytotoxic enolic sulphated sterol from the marine annelid, Arenicola cristata.

Arenicolsterol A (ASA), a novel cytotoxic enolic sulphated sterol, was isolated from the marine annelid, Arenicola cristata (AC). Growth inhibition of this compound on cancer cell lines was determined by MTT assay and suppression of tumour stem cells colony formation. The results showed that ASA was selectively cytotoxic on HeLa cell line (IC(50) = 6.00 +/- 1.16 micromol L(- 1) on HeLa cell line, IC(50) = 10.85 +/- 0.97 micromol L(- 1) on 929 cell line and 14.72 +/- 1.55 micromol L(- 1) on NCI-h6 cell line). In addition, the apoptosis induced by ASA was verified from monitoring the stainability with Annexin V and propidium iodine by a fluorescence-activated cell sorter. The experimental data confirmed that ASA could induce apoptosis in HeLa cells by arresting early stage in apoptosis. Meanwhile, the apoptosis was found to be correlative with the inhibition of the protein tyrosine phosphatases (cdc25A, cdc25B, JSP1, etc). Therefore, ASA might be a novel promising precursor of anticancer medicines.