Hypolipidemic effect of arborium plus in experimentally induced hypercholestermic rabbits

Physiological Responses to Multiple Low-Doses of Bacillus anthracis Spores in the Rabbit Model of Inhalation Anthrax

Bacillus anthracis spores that are re-aerosolized from surface deposits after initial contamination present significant health risks for personnel involved in decontamination. To model repeated exposure to low dose B. anthracis spores, three groups of seven rabbits were challenged with multiple low-doses of B. anthracis spores 5 days a week for 3 weeks. Mortality, body temperature, heart and respiration rates, hematology, C-reactive protein, bacteremia, and serum protective antigen were monitored for 21 days post-exposure after the last of multiple doses. All rabbits exposed to a mean daily dose of 2.91 × 10² colony forming units (CFU) survived and showed minimal physiological changes attributable to exposure. One of seven rabbits receiving a mean daily dose of 1.22 × 10³ CFU died and four of seven receiving a mean daily dose of 1.17 × 10⁴ CFU died. The LD₅₀ was calculated to be 8.1 × 10³ CFU of accumulated dose. Rabbits that succumbed to the higher dose exhibited bacteremia and increases above baseline in heart rate, respiration rate, and body temperature. Two rabbits in the mean daily dose group of 1.17 × 10⁴ CFU exhibited clinical signs of inhalation anthrax yet survived. This study provides a description of lethality, pathophysiology, and pathology in a controlled multiple low-dose inhalation exposure study of B. anthracis in the rabbit model. The data suggest that the accumulated dose is important in survival outcome and that a subset of rabbits may show clinical signs of disease but fully recover without therapeutic intervention

The effect of hydroalcoholic extract of Teucrium polium L. on the inflammatory markers and lipid profile in hypercholesterolemic rats

Background

Cardiovascular diseases are among the most common causes of mortality worldwide. Therefore, it is necessary to control the risk factors of these patients. Since the level of inflammatory markers and lipid profiles has increased in cardiovascular diseases and due to the increasing role of plants in the treatment of diseases, the current study aimed to investigate the effect of hydroalcoholic extract of Teucrium polium on inflammatory markers and lipid profile in hypercholesterolemic rats.

Materials and methods

A total of 24 adult male Wistar rats were randomly divided into four groups of six each and treated with oral administration for 8 weeks. The control group received normal diet, the sham group received high-cholesterol diet and experimental groups 1 and 2 received high-cholesterol diet in the 8 weeks and doses of 85 and 170 mg/kg, respectively, of the T. polium hydroalcoholic extract (TPHAE) in the second 4 weeks. At the beginning and the end of the study, rats were examined for biochemical parameters. The mean level of variables for each group was presented as mean ± standard error of mean.

Results

The results of this study showed that, after administration of TPHAE, there was a significant decrease in the mean of inflammatory markers in all groups compared to sham group (P<0.001). Also, administration of the extract significantly reduced the serum levels of triglyceride, cholesterol and LDL-cholesterol and significantly increased the serum HDL-cholesterol levels. In addition, the 170 mg/kg dose of TPHAE was the most effective in reducing serum levels of inflammatory and lipid markers.

Conclusion

Treatment with TPHAE caused dose-dependent decrease in serum levels of inflammatory markers and lipid profile in hypercholesterolemic rats. Therefore, it can be applied as a natural product for the management of cardiovascular diseases.

Rhododendron oldhamii leaf extract improves fatty liver syndrome by increasing lipid oxidation and decreasing the lipogenesis pathway in mice

Some members of Rhododendron genus are traditionally used as medicinal plants for arthritis, acute and chronic bronchitis, asthma, pain, inflammation, rheumatism, hypertension and metabolic diseases. To the best of our knowledge, there is no report on the protective effects of R. oldhamii leaf extract on non-alcoholic fatty liver disease (NAFLD) in vivo and in vitro. In this study, the effects of R. oldhamii leaf extract on inhibiting the free fatty acid (FFA)-induced accumulation of fat in HepG2 cells and on improving fatty liver syndrome in mice with high fat diet (HFD)-induced NAFLD were investigated. For the in vitro assay, HepG2 cells were treated with FFAs (oleate/palmitate = 2:1) with or without treatment with R. oldhamii leaf ethyl acetate (EtOAc) fraction to observe lipid accumulation using Nile red and oil red O stains. For the in vivo assay, C57BL/6 mice were randomly assigned to three groups (n = 5), including the normal diet group, the HFD group and the HFD+EtOAc group. After 11 weeks, body weight, serum biochemical indices and the mRNA expressions of the liver tissue, as well as the outward appearance, weight and histopathological analysis of liver and adipose tissues were evaluated. Among the fractions derived from R. oldhamii leaf, the EtOAc fraction exhibited a strong fat-accumulation inhibitory activity. Following reverse-phase high-performance liquid chromatography (HPLC), four specific phytochemicals, including (2R, 3R)-astilbin (AS), hyposide (HY), guaijaverin (GU) and quercitrin (QU), were isolated and identified from the EtOAc fraction of R. oldhamii leaf extract. Among them, AS and HY showed excellent fat-accumulation inhibitory activity. Thus, the EtOAc fraction of R. oldhamii leaf and its derived phytochemicals have great potential in preventing FFA-induced fat accumulation. In addition, the EtOAc fraction of R. oldhamii leaf significantly improved fatty liver syndrome and reduced total cholesterol (TC) and triglyceride (TG) in HFD-induced NAFLD mice at a dosage of 200 mg/kg BW. These results demonstrated that the methanolic extracts from R. oldhamii leaf have excellent inhibitory activities against fat accumulation and anti-NAFLD activities and thus have great potential as a natural health product.

A 4-week study of four 3-monochloropropane-1,2-diol diesters on lipid metabolism in C57BL/6J mice

3-Monochloropropane-1,2-diol (3-MCPD) esters have been detected in many foods, which have become a new safety issue worldwide. In the study, we investigated the effect of four 3-MCPD diesters (palmitate diester: CDP; stearate diester: CDS; oleate diester: CDO; linoleate diester: CDL) on lipid metabolism in C57BL/6J mice. The results showed that CDP, CDS, CDO and CDL significantly increased the serum TC, LDL-C levels and liver TG, TC levels at dose of 16.5μmol/kg/day. These results indicated that 3-MCPD diesters could potentially cause hyperlipidemia in C57BL/6J mice. Moreover, oil red O staining confirmed fat accumulation in liver induced by 3-MCPD diesters. Our work will provide more information for safety evaluation of 3-MCPD diesters. However, whether free 3-MCPD or free fatty acids or combined action compensates for the hyperlipidemia effects should be elucidated in the future.

Antihyperglycemic and antihyperlipidemic activity of ethyl acetate fraction of Rhododendron arboreum Smith flowers in streptozotocin induced diabetic rats and its role in regulating carbohydrate metabolism

OBJECTIVE

To explore and identify the most potent antihyperglycemic fraction from the ethanol extract of Rhododendron arboreum (R. arboreum) flowers.

METHODS

Normal and streptozotocin induced diabetic rats were treated with all four fractions of R. arboreum flowers for short term and with fraction 3 for long term study. On completion of the treatment, a range of indicators were tested including fasting blood glucose, plasma protein, haemoglobin A1C, insulin secretion, body weight, blood lipid profile and carbohydrate metabolism regulating enzymes of liver.

RESULTS

In short term study, the fraction 3 (Active fraction) produced a significant (P<0.000 1) reduction (73.6%) in blood glucose level at a dose of 200 mg/kg after the treatment in the diabetic rats. Administration of active fraction (200 and 400 mg/kg) once daily for 30 d in streptozotocin diabetic rats resulted in a significant (P<0.001 to P<0.000 1) fall in blood glucose level, hemoglobin A1C, serum urea and creatinine with significant but a increase in insulin level similar to standard drug glybenclamide. Further, the active fraction showed antihyperlipidemic activity as evidenced by significant (P<0.001 to P<0.000 1) decreases in serum serum total cholesterol, triglycerides, low density lipoprotein cholesterol and very low density cholesterol levels coupled together with elevation of high density lipoprotein cholesterol in the diabetic rats.

CONCLUSIONS

The active fraction of R. arboreum flowers decreases streptozotocin induced hyperglycemia by promoting insulin secretion and glycolysis and by decreasing gluconeogenesis.