Algal sterols are as effective as β-sitosterol in reducing plasma cholesterol concentration

The present study examined the cholesterol-lowering activity of sterol extract (SE) derived from alga Schizochytrium sp. and its interaction with gene expression of transporters, receptors, and enzymes involved in cholesterol absorption and metabolism. GC-MS analyses found that SE was a mixture of various sterols including lathosterol, ergosterol, stigmasterol, 24-ethylcholesta-5,7,22-trienol, stigmasta-7,24(24(1))-dien-3β-ol, and cholesterol. Results showed that SE at doses of 0.06 and 0.30 g/kg diet were able to decrease plasma cholesterol concentration by 19.5 and 34%, respectively, compared with the control, in hamsters maintained on a 0.1% high-cholesterol diet. SE at a dose of 0.30 g/kg diet was as effective as β-sitosterol in reducing plasma total cholesterol (TC). SE-induced reduction in plasma TC was accompanied by down-regulation of intestinal acyl-CoA:cholesterol acyltransferase 2 (ACAT2) and hepatic 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase and up-regulation of hepatic low-density lipoprotein (LDL) receptor. Addition of SE to the diet increased the excretion of total fecal sterols. It was concluded that SE possessed the same cholesterol-lowering activity as β-sitosterol and the underlying mechanisms were mediated by increasing sterol excretion and decreasing cholesterol absorption and synthesis.

Impaired hepatic and intestinal ATP-binding cassette transporter G5/8 was associated with high exposure of β-sitosterol and the potential risks to blood-brain barrier integrity in diabetic rats

OBJECTIVES

Plant sterols are thought to treat hypercholesterolemia via inhibiting intestinal cholesterol absorption. The aim of this study was to evaluate the contribution of impaired ATP-binding cassette transporter G5/8 (ABCG5/8) expression by diabetes to the increased β-sitosterol (BS) exposure and impact of increased BS on integrity of blood-brain barrier (BBB).

METHODS

Basal BS level in tissues of streptozotocin-inducted rats and ABCG5/8 protein levels in liver and intestine were investigated; pharmacokinetics of BS was studied following oral dose; and primarily cultured rat brain microvessel endothelial cells (rBMECs) were used to study BS transportation across BBB and effect of BS on BBB integrity.

KEY FINDINGS

Diabetic rats showed greatly upgraded basal levels of BS in plasma, intestine, cerebral and hippocampus, accompanied by impairment of ABCG5/8 protein expression in liver and intestine. Pharmacokinetics studies demonstrated higher AUC0-48 and Cmax , and lower faecal recoveries of BS after oral administration, indicating enhancement of absorption or efflux impairment. In-vitro data showed increased ratio of BS/cholesterol in high levels BS-treated rBMECs was associated with increased BBB permeability of some biomarkers including BS itself.

CONCLUSIONS

Impaired ABCG5/8 protein expression by diabetes led to increase in BS exposure, which may be harmful to BBB function.

β-sitosterol in different parts of Saraca asoca and herbal drug ashokarista: Quali-quantitative analysis by liquid chromatography-mass spectrometry

β-sitosterol is an important component in food and herbal products and beneficial in hyperlipidemia. Its higher concentrations in serum may lead to coronary artery disease in case of sitosterolemia. Therefore, it is essential to determine the quantity of β-sitosterol in food and herbal drugs. Saraca asoca and its preparations have been widely used by traditional healers are also a source of β-sitosterol. In the present study, quantitative estimation of β-sitosterol present in hot and cold water extracts of bark, regenerated bark, leaves and flowers of the S. asoca and Ashokarista drugs were carried out first time using high performance liquid chromatography coupled (HPLC) with quadrupole time-of-flight mass spectrometry. Different concentrations of β-sitosterol and crude extracts were estimated by HPLC and targeted mass spectrometry. Standard curve for β-sitosterol was prepared from the intensities of transitions (397.50 → 147.0987 m/z) having regression coefficient (r (2)) 0.9952. Out of eight extracts and two drugs used in the study bark water, leaves water and leaves hot water extracts were found to have a considerable quantity of β-sitosterol, i.e. 170, 123.5 and 19.3 ng/mL, respectively. The results showed significant differences in the distribution of β-sitosterol among different organs of S. asoca and drugs prepared from its bark. HPLC/electrospray ionizationmass spectroscopy method is accurate, reproducible and requires less specimen, sample preparation and analysis time over HPLC assay. This type of approaches could be helpful for the quality control of herbal medicines and provides necessary information for the rational utilization of plant resources.

Anti-ulcerative colitis activity of compounds from Euphorbia granuleta Forssk

The aim of the present study was to evaluate the anti-ulcerative colitis (UC) activity of the total alcohol extracts of Euphorbia granuleta Forssk. (Euphorpiaceae), isolate and identify the active compounds that could be responsible for the activity, in addition to determination of the possible mechanism of action. Six compounds were isolated and identified from this plant: three phenolic compounds (kampferol, kampferol-3-glucoside and kampferol-3-galactoside) in addition to three steroidal compounds (1-ethoxypentacosane, heptacosan-1-ol and β-sitosterol). Three compounds (heptacosan-1-ol, β-sitosterol and kampferol-3-galactoside) were found to be responsible for the anti-UC activity of E. granuleta extract. The anti-UC activity of these compounds may be explained by reducing the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-α), in addition to reduction of colonic malondialdehyde (MDA) contents. No side effects were reported on liver and kidney functions. The active compounds reduced both serum TNF-α and mucosal MDA levels.

Antiobesity effect of Stellaria media against drug induced obesity in Swiss albino mice

The whole plant of Stellaria media (family: Caryophyllaceae) has been tested for its antiobesity activity by using progesterone-induced obesity model in female albino mice. The effect of S. media on food consumption pattern, change in body weight, thermogenesis, lipid metabolism, and histology of fat pad. were examined. Methanolic and alcoholic extracts of the S. media were used in the study. Methanolic extract of S. media (MESM) have prevented the increase in body weight, adipose tissue weight and size, and upturned obesity and associated complications. MESM has also shown promising effects compared with alcoholic extract of S. media may be because of its multiple mechanisms. These findings suggest that antiobesity activity produced by MESM is because of its anorexic property mediated by saponin and flavonoid and partly of by its β-sitosterol content. β-Sitosterol in the plant extract was confirmed by thin-layer chromatography study. β-sitosterol is plant sterol having structural similarity with dietary fat which do the physical competition in the gastrointestinal tract and reduces fat absorption. Before carrying in vivo activity detail pharmacognostic and phytochemical analysis of the extracts was carried out. The plant has shown the presence of saponin, flavonoids, steroids and triterpenoids, glycosides, and anthocynidine. By this study, it can be concluded that, MESM is beneficial in suppression of obesity induced by progesterone.

Comparison of the chemical compositions and nutritive values of various pumpkin (Cucurbitaceae) species and parts

Pumpkins have considerable variation in nutrient contents depending on the cultivation environment, species, or part. In this study, the general chemical compositions and some bioactive components, such as tocopherols, carotenoids, and β-sitosterol, were analyzed in three major species of pumpkin (Cucurbitaceae pepo, C. moschata, and C. maxima) grown in Korea and also in three parts (peel, flesh, and seed) of each pumpkin species. C. maxima had significantly more carbohydrate, protein, fat, and fiber than C. pepo or C. moschata (P < 0.05). The moisture content as well as the amino acid and arginine contents in all parts of the pumpkin was highest in C. pepo. The major fatty acids in the seeds were palmitic, stearic, oleic, and linoleic acids. C. pepo and C. moschata seeds had significantly more γ-tocopherol than C. maxima, whose seeds had the highest β-carotene content. C. pepo seeds had significantly more β-sitosterol than the others. Nutrient compositions differed considerably among the pumpkin species and parts. These results will be useful in updating the nutrient compositions of pumpkin in the Korean food composition database. Additional analyses of various pumpkins grown in different years and in different areas of Korea are needed.

Chemical constituents and biological studies of Origanum vulgare Linn

Bioassay-guided isolation of methanolic extract of the leaves of Origanum vulgare Linn., yielded two protocatechuic acid ester derivatives, origanol A (1) and origanol B (2) along with ursolic acid (3), oleanolic acid (4), β-sitosterol (5), and triacontanol (6). Structures of the compound were established based on physical and spectral data (UV, IR, ¹H and ¹³C NMR and mass). Origanol A (1) showed significant mushroom tyrosinase inhibition activity.

Computer aided screening and evaluation of herbal therapeutics against MRSA infections

Methicillin resistant Staphylococcus aureus (MRSA), a pathogenic bacterium that causes life threatening outbreaks such as community-onset and nosocomial infections has emerged as ‘superbug’. The organism developed resistance to all classes of antibiotics including the best known Vancomycin (VRSA). Hence, there is a need to develop new therapeutic agents. This study mainly evaluates the potential use of botanicals against MRSA infections. Computer aided design is an initial platform to screen novel inhibitors and the data finds applications in drug development. The drug-likeness and efficiency of various herbal compounds were screened by ADMET and docking studies. The virulent factor of most of the MRSA associated infections are Penicillin Binding Protein 2A (PBP2A) and Panton-Valentine Leukocidin (PVL). Hence, native structures of these proteins (PDB: 1VQQ and 1T5R) were used as the drug targets. The docking studies revealed that the active component of Aloe vera, β-sitosterol (3S, 8S, 9S, 10R, 13R, 14S, 17R) ­17­ [(2R, 5R)-5-ethyl-6-methylheptan-2-yl] -10, 13-dimethyl 2, 3, 4, 7, 8, 9, 11, 12, 14, 15, 16, 17- dodecahydro-1H-cyclopenta [a] phenanthren-3-ol) showed best binding energies of -7.40 kcal/mol and ­6.34 kcal/mol for PBP2A and PVL toxin, respectively. Similarly, Meliantriol (1S-1-[ (2R, 3R, 5R)-5-hydroxy-3-[(3S, 5R, 9R, 10R, 13S, 14S, 17S)-3-hydroxy 4, 4, 10, 13, 14-pentamethyl-2, 3, 5, 6, 9, 11, 12, 15, 16, 17-decahydro-1H-cyclopenta[a] phenanthren-17-yl] oxolan-2-yl] -2- methylpropane-1, 2 diol), active compound in Azadirachta indica (Neem) showed the binding energies of ­6.02 kcal/mol for PBP2A and ­8.94 for PVL toxin. Similar studies were conducted with selected herbal compound based on pharmacokinetic properties. All in silico data tested in vitro concluded that herbal extracts of Aloe-vera, Neem, Guava (Psidium guajava), Pomegranate (Punica granatum) and tea (Camellia sinensis) can be used as therapeutics against MRSA infections.

A New coumarin from Citrus paradisi Macf

Phytochemical examination of the peel of grapefruit resulted in the isolation of five compounds namely friedelin, β -sitosterol, 7(3’,7’,11’,14’-tetramethy)pentadec-2’,6’,10’-trienyloxycoumarin, limonin and cordialin B. These compounds have been characterized on the basis of spectral data, and 7(3’,7’,11’,14’-tetramethy)pentadec-2’,6’,10’-trienyloxycoumarin is a hitherto unreported compound.

Effect of an isolated active compound (Cg-1) of Cassia glauca leaf on blood glucose, lipid profile, and atherogenic index in diabetic rats

Objectives:

The objective of present study was to evaluate the effect of active principle (Cg-1) from Cassia glauca leaf on serum glucose and lipid profile in normal and diabetic rats.

Materials and Methods:

Diabetes was induced by streptozotocin in neonates. Oral administration of petroleum ether, chloroform, acetone, and methanol of C. glauca leaf (100 mg/kg, p.o.) for 21 days caused a decrease in fasting blood glucose (FBG) in diabetic rats. Among all the extracts, acetone extract was found to lower the FBG level significantly in diabetic rats. Glibenclamide was used as standard antidiabetic drug (5 mg/kg, p.o). Acetone extract was subjected to column chromatography that led to isolation of an active principle, which was given trivial name Cg-1. Cg-1 (50 mg/kg, p.o.) was studied for its hypoglycemic and hypolipidemic potential. The unpaired t-test and analysis of variance (ANOVA) followed by post hoc test was used for statistical analysis.

Results:

Cg-1 caused a significant reduction in FBG level. It also caused reduction in cholesterol, triglycerides, and LDL levels and improvement in the atherogenic index and HDL level in diabetic rats.

Conclusion:

Improvement in the FBG and the atherogenic index by Cg-1 indicates that Cg-1 has cardioprotective potential along with antidiabetic activity and provides a scientific rationale for the use as an antidiabetic agent.

Effect of Erythrina variegata seed extract on hyperlipidemia elicited by high-fat diet in wistar rats

OBJECTIVE

To investigate the effect of the methanolic extract of Erythrina variegata (Linn.) var Orientalis (Fabaceae) seeds (MEEV) in reducing the cholesterol levels and as well as antioxidant in experimentally induced hyperlipidemic rats.

MATERIALS AND METHODS

Doses of 200 and 400 mg/kg of the extract were evaluated for its effect on lipid profile, HMG-CoA reductase, and on antioxidant enzymes in high-fat diet (HFD) induced hyperlipidemia.

RESULTS AND CONCLUSION

The elevated levels of total cholesterol, triglycerides, low-density lipoprotein, and very low density lipoprotein due to HFD was reduced by concurrent treatment with MEEV (200 and 400 mg/kg) significantly (P<0.001). A significant reduction (P<0.001) in high-density lipoprotein was noticed in HFD fed groups; however, a nonsignificant increment was produced by the administration of MEEV (200 and 400 mg/kg). The HMG-CoA reductase activity was increased in HFD fed animals significantly (P<0.001) and was reduced by MEEV 400 mg/kg significantly (P<0.001). There was a noticed increase in the body weight and mesenteric fat pad weight in HFD fed group (P<0.001), which was reduced by the administration of MEEV (200 and 400 mg/kg). The antioxidant enzymes such as superoxide dismutase and catalase were reduced significantly in the HFD fed group, whose levels were increased significantly (P<0.001) by the administration of MEEV (200 and 400 mg/kg). Lipid peroxidation was increased in HFD fed animals, which was reduced significantly (P<0.001) by the treatment with MEEV (200 and 400 mg/kg).

β-Sitosterol: supercritical carbon dioxide extraction from sea buckthorn (Hippophae rhamnoides L.) seeds

Supercritical fluid extraction represents an efficient and environmentally friendly technique for isolation of phytosterols from different plant sources. Sea buckthorn (Hippophae rhamnoides L.) seeds were extracted with supercritical carbon dioxide at pressures ranging from 15–60 MPa and temperatures of 40–80 °C. Oil and β-sitosterol yields were measured in the extraction course and compared with Soxhlet extraction with hexane. The average yield of β-sitosterol was 0.31 mg/g of seeds. The maximum concentration of β-sitosterol in the extract, 0.5% w/w, was achieved at 15 MPa, 40 °C, and a carbon dioxide consumption of 50 g/g of seeds. The extraction rate was maximal at 60 MPa and 40 °C. Both β-sitosterol yield and its concentration in the extract obtained with hexane were lower than with carbon dioxide.

Protective effect of Cassia glauca Linn. on the serum glucose and hepatic enzymes level in streptozotocin induced NIDDM in rats

OBJECTIVE

The objective of the present study was to investigate the hypoglycemic and hepatoprotective effect of Cassia glauca leaf extracts on normal and non insulin dependent diabetes mellitus (NIDDM) in rats. The study was further carried out to investigate the effect of different fractions of the active extract of Cassia glauca, on normal and NIDDM rats, and the effect of active fraction on the blood glucose and hepatic enzymes level.

METHODS

Diabetes was induced by streptozotocin (STZ) at a dose of 90mg/kg, i.p. in neonates. Different extracts of cassia glauca (100mg/kg, p.o.) were administered to the diabetic rats. Acetone extract was found to lower the serum glucose level significantly in diabetic rats. Further, the acetone extract was subjected to column chromatography and four fractions were obtained on the basis of TLC. All the four fractions (100mg/kg, p.o.) were administered to the diabetic rats. Fraction 1 (F1) caused the maximum reduction in the blood glucose level. The results of the test were compared with the standard antidiabetic drug glibenclamide (5mg/kg, p.o.).

RESULTS

Fraction 1 of acetone extract caused a significant reduction in the levels of hepatic enzyme Aspartate transaminase (AST), alanine transaminase (ALT), creatine kinase (CK), and lactate dehydrogenase (LDH) in STZ-induced diabetic rats.

CONCLUSION

Improvement in the blood sugar level and normalization of liver functions by Cassia glauca indicates that the plant has hepatoprotective potential, along with antidiabetic activity, and it provides a scientific rationale for the use of Cassia glauca as an antidiabetic agent.