Xiaoxia Liang

Quantification of metallothionein on the liver and kidney of rats by subchronic lead and cadmium in combination

The combined subchronic effects of exposure to lead acetate and cadmium chloride on oxidative stress and metallothionein (MT) gene expression were detected in the liver and kidney of rats to investigate the hazards of environmentally relevant, low-dose exposure to these compounds. Pb and Cd co-induced oxidative stress in liver and kidney tissues. This result was indicated by a significant (P<0.01) increase in the maleic dialdehyde level and decreased levels of reduced glutathione, superoxide dismutase, catalase, and glutathione peroxidase. MT mRNA and protein significantly increased (P<0.01) in the liver and kidney of rats. Furthermore, the expression levels of MT-1 mRNA and MT-2 mRNA differed between the liver and kidney. The findings indicate that Pb combined with Cd induced oxidative damage in the liver and kidney of rats, and MT may be a biochemical environmental indicator.

Acaricidal activity of petroleum ether extract of neem (Azadirachta indica) oil and its four fractions separated by column chromatography against Sarcoptes scabiei var. cuniculi larvae in vitro.

The petroleum ether extract of neem oil and its four fractions separated by column chromatography was diluted at different concentrations with liquid paraffin. The acaricidal bioassay was conducted using a dipping method. The results indicated that the median lethal concentration (LC50) of the petroleum ether extract (at the concentration of 500.0ml/l) was 70.9ml/l, 24h after treatment. At concentrations of 500.0, 250.0, 125.0, 62.5 and 31.2ml/l, the median lethal times (LT50) of the petroleum ether extract were 8.7, 8.8, 10.8, 11.5 and 13.1h, respectively. Thin-layer chromatography (TLC) showed that the petroleum ether extract of neem oil separated into four fractions (F1-F4). Acaricidal activity of 68.3% and 100.0% in the F2 and F4 was confirmed. These results suggest that petroleum ether extracts of neem oil and its four fractions possess useful acaricidal activity in vitro.

The enhancement of immune function and activation of NF-κB by resveratrol-treatment in immunosuppressive mice.

Resveratrol, a kind of natural product found in over 70 plants, possesses both immunomodulatory and anticancer effects. Many reports have shown that resveratrol has the bidirectional regulation effects on antigen presenting and cellular immunity. However, few reports have evaluated the effects of resveratrol on reinforcing immunity recovery via activating nuclear factor -κappa B (NF-κB). In the present study, we investigated the effects of resveratrol on recovery and reconstruction of immune function by detecting nonspecific and specific immunity in immunosuppressive mice. We found that, compared to the immunosuppressive mice, the spleen index and spleen lymphocyte proliferation of resveratrol-treated mice (30 mg/kg body weight) were enhanced. After resveratrol-treatment (15 mg/kg body weight), the function of peritoneal macrophages was enhanced and the CD4+ cells were increased in peripheral blood. The expressions of serum cytokines related to immune function, including interleukin (IL)-1α/β, IL-2, tumor necrosis factor-α and NF-κB were up-regulated in a dose-dependent manner. The expression of the transcription factor NF-κB in spleen was enhanced after resveratrol-treatment. The immuno-enhancement effects of resveratrol were similar to that of levamisole (served as positive control). These results demonstrated that resveratrol had potent immune enhancement activity in immunosuppressive mice, and one possible mechanism of action was to activate the NF-κB.

Toxicological evaluation of neem (Azadirachta indica) oil: acute and subacute toxicity.

Neem (Azadirachta indica), popularly known as traditional medicine is a native plant in India. Neem oil is a vegetable oil derived from seeds or fruits of the neem tree through pressing or solvent extraction, and largely used in popular medicine to have antifungal, antibacterial, antimalarial, antiparasitic, anti-inflammatory, as well as immunemodulatory properties in different animal species. In the present study, acute and 28-day subacute toxicity tests were carried out. In the acute toxicity test, the LD50 values of neem oil were found to be 31.95g/kg. The subacute treatment with neem oil failed to change body weight gain, food and water consumption. Serum biochemistry analysis showed no significant differences in any of the parameters examined under the dose of 1600mg/kg/day. Histopathological exams showed that the target organs of neem oil were testicle, liver and kidneys up to the dose of 1600mg/kg/day.

Inhibitory Effect of Resveratrol against Duck Enteritis Virus In Vitro

Duck viral enteritis (DVE) is an acute, contagious herpesvirus infection of ducks, geese, and swans of all ages and species. This disease has been responsible for significant economic losses in domestic and wild waterfowl as a result of mortality, and decreased egg production. Resveratrol is a naturally occurring phytoalexin in specific plants and exhibits inhibitory activity against many kinds of virus. In this paper, resveratrol was found to inhibit duck enteritis virus (DEV) replication in a dose-dependent manner, with a 50% inhibition concentration of 3.85 μg/mL. The inhibition in virus multiplication in the presence of resveratrol was not attributed to direct inactivation or inhibition of virus attachment to the host cells, but to the inhibition of viral multiplication in host cells. The assay of the time of addition limited the drug effect during the first 8 h of infection. This conclusion was supported by the ultrastructure images of the early stage of DEV infection, which showed that the replication of virus nucleic acid and the formation of the capsid in the cell nucleus were suppressed. In the indirect immunofluorescence assay, proteins expression in DEV infected duck embryo fibroblasts (DEFs) within 24 h post-infection (p.i.) was also effectively suppressed by resveratrol. In summary, the resveratrol has a good activity against DEV infection in vitro, which could be attributed to that fact that several essential immediate early viral proteins for virus replication were impacted by resveratrol.

The antibacterial mechanism of berberine against Actinobacillus pleuropneumoniae.

This study demonstrated berberine to be a potential natural compound against Actinobacillus pleuropneumoniae. Liquid doubling dilution, transmission electron microscopy (TEM), SDS-PAGE and 4′,6-diamidino-2-phenylindole (DAPI) staining were employed to elucidate the antibacterial activity and mechanism of berberine. The minimal inhibitory concentration of berberine was 0.3125 mg/mL, and time–kill curves showed concentration and time dependence. The TEM micrographs displayed damaged cell wall, concentrated cytoplasm, cytoplasmic content leakage and cell death. SDS-PAGE and DAPI assays revealed that berberine can restrain DNA and protein syntheses. Berberine inhibited the synthesis of proteins associated with the growth and cleavage of bacteria and then blocked the division and development of bacteria. The compound ultimately induced cytoplasm pyknosis and bacterial death.

Acute and subchronic toxicity as well as evaluation of safety pharmacology of Galla chinensis solution.

Galla chinensis has been popularly used in traditional Chinese medicine which is beneficial for the treatment of various diseases, such as inflammation, dysentery, toxicosis and sore. However, it has not previously been evaluated for safety through systematic toxicological studies. In the present study, acute and subchronic oral toxicity studies and safety pharmacology evaluation of Galla chinensis solution (GCS) were conducted in specific pathogen-free (SPF) Sprague-Dawley (SD) rats. Acute administration of GCS was done as single dose from 3333 mg to 6912 mg per kg/bodyweight (bw) and subchronic toxicity study for 30 days was done by daily oral administration of GCS at doses of 500, 1500 and 2500 mg/kg body weight in SPF SD rats. The acute toxicity study showed the LD50 of GCS was greater than 5000 mg/kg. The results of sunchronic toxicity study showed that the no-observed effect level of GCS was lesser than 1500 mg/kg bw day, which suggested three times higher than that of recommended dose for clinical applications (500 mg/kg bw day). The dose at 2500 mg/kg bw day of GCS may slow down the growth of rats and lead to degeneration and necrosis of tissue cells to some extent. In the safety pharmacology study, GCS did not produce any side effects to rats in central nervous system, cardiovascular system and respiratory system. Therefore, from the results of the study presented herein, it could be concluded that the use of appropriate levels (one to three times of recommended dose for clinical applications) of GCS as a topical preparations is considered safe.

Antiviral effect of sulfated Chuanmingshen violaceum polysaccharide in chickens infected with virulent Newcastle disease virus

Newcastle disease virus (NDV) belonging to the Paramyxovirinae subfamily is one of the most devastating pathogens in poultry. Although vaccines are widely applied to control the infection, outbreaks of Newcastle disease (ND) repeatedly happen. Currently, there are no alternative control measures available for ND. In the present study, we found that sulfated Chuanmingshen violaceum polysaccharide (sCVPS) were potent inhibitors of NDV in specific pathogen free chickens infected with a virulent strain. With sCVPS treatment, the survival rate increased by almost 20% and virus titers in test organs, including brain, lung, spleen and thymus, were significantly decreased. The sCVPS also exhibited the ability to prevent viral transmission by reducing the amount of virus shed in saliva and feces. Higher concentrations of interferon α and γ in serum were detected in chickens treated with sCVPS, indicating that one of the antiviral mechanisms may be attributed to the property of immunoenhancement. Histopathological examination showed that sCVPS could alleviate the tissue lesions caused by NDV infection. These results suggest that sCVPS are expected to be a new alternative control measure for NDV infection and further studies could be carried out to evaluate the antiviral activity of sCVPS against other paramyxoviruses.

Antiviral activity of sulfated Chuanmingshen violaceum polysaccharide against Newcastle disease virus.

Newcastle disease virus (NDV) is a member of Paramyxovirinae subfamily and can infect most species of birds causing severe economic losses. The current control measure is vaccination, but infections cannot be completely prevented. It remains a constant threat to the poultry industry and new control measures are urgently needed. This study demonstrates that sulfated Chuanmingshen violaceum polysaccharides (sCVPSs) were potent inhibitors of NDV, with 50 % inhibitory concentrations (IC50) ranging from 62.55 to 76.31 µg ml(-1) in Baby hamster kidney fibroblasts clone 21 (BHK-21) and from 101.57 to 125.90 µg ml(-1) in chicken embryo fibroblasts (CEF). sCVPS is more effective than heparan sulfate (HS; as a positive control) with IC50 values of 99.28 µg ml(-1) in BHK-21 and 118.79 µg ml(-1) in CEF. sCVPSs and HS exhibit anti-NDV activity by prevention of the early stages of viral life. The mechanism of action study indicated that virus adsorption in BHK-21, and both virus adsorption and penetration in CEF were inhibited by sCVPSs. When the number of viruses was increased to an m.o.i. of 0.1 in the immunofluorescence study and to an m.o.i. of 1 in the fluorescent quantitative PCR study, viral infection was also significantly suppressed; the antiviral activity of sCVPSs was independent of the m.o.i. sCVPSs also prevented the cell-to-cell spread of NDV. In vivo tests carried out on specific pathogen-free (SPF) chickens showed that sCVPSs also inhibited virus multiplication in heart, liver, spleen, lung and kidney. These results indicated that sCVPSs perform more effectively than HS as antiviral agents against NDV, and can be further examined for their potential as an alternative control measure for NDV infection.

Diterpenoid alkaloids from the root of Aconitum sinchiangense W. T. Wang with their antitumor and antibacterial activities

Abstract A phytochemical study of the root barks of Aconitum sinchiangense W. T. Wang, a traditional Chinese herb medicine, led to the isolation of 15 diterpenoid alkaloids, including one new C19-diterpenoid alkaloid, sinchiangensine A (1), whose structure was determined by spectral methods including 2D NMR. Additionally, sinchiangensine A and its known analogue 3 were first reported as potential antitumor and antibacterial diterpenoid alkaloids, which showed significant antitumor activities against tumour cells (HL-60, A-549, SMCC-7721, MCF-7 and SW480), with IC50 comparable to cisplatin, and significant antibacterial activities against Staphylococcus aureus ATCC-25923 with MIC value of 0.147 and 0.144 μmol/mL, respectively.