Bénédicte Berké

Bisulfite addition to anthocyanins: revisited structures of colourless adducts

Abstract Decolourization of anthocyanins by sulfur dioxide is investigated through the reaction between sodium bisulfite and malvidin 3- O -glucoside. The structural elucidation of the C-4 sulfonate adducts is established by 1 H, 13 C and 33 S NMR spectroscopies.

Prevention of type 2 diabetes induced by high fat diet in the C57BL/6J mouse by two medicinal plants used in traditional treatment of diabetes in the east of Algeria.

AIM OF THE STUDY The preventive effect of the hydro-alcoholic extracts of Artemisia herba-alba Asso (AHA), and Centaurium erythraea Rafn (CE), two medicinal plants used in traditional treatment of diabetes in the north-eastern Algeria, were evaluated in animal models of type 2 diabetic induced with a standardised high fat diet (HFD). MATERIALS AND METHODS Plant extracts were administered orally by gavage at a dose of 2g/kg bodyweight daily for 20 weeks to male C57BL/6J mice fed HFD. Animals were weighed and plasma glucose measured weekly and insulin at the end of study using standard ELISA methods. RESULTS After 6 weeks, blood glucose levels increased in HFD control mice. At end of study (20 weeks) in groups treated with AHA or CE extracts vs. HFD control group there was a significant reduction in mean (+/-SD) fasting blood glucose (respectively 108.0+/-42.0 and 120.4+/-45.1 vs. 183.1+/-19.1mg/dl, p<0.05), triglyceride concentrations (26.9+/-6.7 and 27.9+/-17.8 vs. 48.9+/-12.1mg/dl, p<0.05) and serum insulin levels (1.1+/-1.0 and 0.6+/-0.7 vs. 3.1+/-1.8 ng/ml, p<0.05). Plant extracts also markedly reduced insulin resistance as measured by the homeostasis model assessment (HOMA) compared to HFD controls (AHA: 4.4+/-5.3, CE: 3.0+/-3.3 vs. HFD control 38.3+/-26.6, p<0.05). The plant extracts had no effect on calorie intake or body weight. CONCLUSION AHA had been shown to have a hypoglycaemic effect in diabetes but this is the first demonstration of a preventive effect of AHA and CE on HFD-induced diabetes.

DNA triplex stabilization property of natural anthocyanins.

The DNA triplex stabilization property of seven natural anthocyanins (five monoglucosides and two diglucosides) has been measured by the mean of triplex thermal denaturation experiments. We have noticed a difference between the diglucosides that do not modify this melting temperature and the monoglucosides (namely 3-O-beta-D-glucopyranoside of malvidin, peonidin, delphinidin, petunidin and cyanidin) which present a weak but significant stabilizing effect. It appears clearly that the difference between the two series could be due to the supplementary sugar moiety at the 5 position for the diglucosylated compounds, that would make them too crowded to allow interaction with the triplex. Among the monoglucoside series, the most active compounds are the only ones to embody a catechol B-ring in their structure that could be important for such an interaction. The need to have pure and fully characterized compounds to run these measurements, made it possible for us to unambiguously assign the 1H and 13C NMR spectra with the help of 2D NMR experiments. Thus, missing data of compounds not totally described earlier, are provided herein.

Antihypertensive effects of Ocimum basilicum L. (OBL) on blood pressure in renovascular hypertensive rats

Ocimum basilicum L. (OBL), sweet basil, is a medicinal herb used in traditional Chinese medicine to treat cardiovascular diseases including hypertension. The objective of the study was to investigate the possible antihypertensive effects of OBL extract in renovascular hypertensive rats. The two-kidney one-clip (2K1C) Goldblatt model of renovascular hypertension was used in Wistar rats. Rats were randomized into sham, untreated 2K1C, captopril- (30 mg kg−1 per day orally) and OBL- (100, 200, 400 mg kg−1 per day orally) (low (L)-, medium (M)-, high (H)-OBL) treated 2K1C groups (n=10–12 per group), followed up for 4 weeks. Blood pressure, heart weight/body weight, plasma angiotensin-II and endothelin (ET)-1 were studied. OBL reduced systolic and diastolic blood pressure by about 20 and 15 mm Hg, respectively, compared with 35 and 22 mm Hg for captopril, from the lowest dose tested with no dose dependency. Cardiac hypertrophy was reduced from 3.6±0.7 mg g−1 for untreated 2K1C to 3.0±0.6, 2.9±0.6 and 2.4±0.4 mg g−1 for L-, M- and H-OBL, respectively, compared with 2.6±0.5 for sham and 3.1±0.4 mg g−1 for captopril (P<0.05). Renal function was improved with captopril. Angiotensin was reduced to a lesser extent than with captopril. ET was reduced to lower concentrations (78±15, 80±22, 82±15 pg ml−1 for L-, M-, H-OBL, respectively) than in sham (116±31 pg ml−1), untreated 2K1C (174±72 pg ml−1) or captopril (117±72 pg ml−1) groups. The effects of OBL on blood pressure, cardiac hypertrophy and ET, are consistent with an effect on ET-converting enzyme, and warrant further exploration.

Inhibition of Cell Growth and Cellular Protein, DNA and RNA Synthesis in Human Hepatoma (HepG2) Cells by Ethanol Extract of Abnormal Savda Munziq of Traditional Uighur Medicine

Abnormal Savda Munziq (ASMq) is a traditional Uighur medicinal herbal preparation, commonly used for the treatment and prevention of cancer. We tested the effects of ethanol extract of ASMq on cultured human hepatoma cells (HepG2) to explore the mechanism of its putative anticancer properties, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) bromide, neutral red and lactate dehydrogenase (LDH) leakage assays, testing the incorporation of 3[H]-leucine and 3[H]-nucleosides into protein, DNA and RNA, and quantifying the formation of malondialdehyde-thiobarbituric acid (MDA) adducts. ASMq ethanol extract significantly inhibited the growth of HepG2 and cell viability, increased the leakage of LDH after 48 hours or 72 hours treatment, in a concentration- and time-dependent manner (P < .05). Cellular protein, DNA and RNA synthesis were inhibited in a concentration- and time-dependent manner (P < .05). No significant MDA release in culture medium and no lipid peroxidation in cells were observed. The results suggest that the cytotoxic effects of ASMq ethanol extract might be related to inhibition of cancer cell growth, alteration of cell membrane integrity and inhibition of cellular protein, DNA and RNA synthesis.

Treatment of high fat diet induced type 2 diabetes in C57BL/6J mice by two medicinal plants used in traditional treatment of diabetes in the east of Algeria.

AIM OF THE STUDY Hydro-alcoholic extracts of Centaurium erythraea Rafn (CE), Gentianaceae and Artemisia herba-alba Asso (AHA), Asteraceae, medicinal plants used in traditional treatment of diabetes in north-eastern Algeria, were tested in established type 2 diabetes induced with a standardized high fat diet (HFD) in mice. MATERIALS AND METHODS After confirmation of diabetes (17th week), plant extracts were administered orally by gavage at a dose of 2 g/kg daily for 18 weeks to male C57BL/6J mice fed HFD. Animals were weighed, food intake and plasma glucose measured weekly, insulin and lipid profile at study end. RESULTS At 35 weeks, groups treated with AHA or CE vs. HFD control had a significant reduction in mean (±SD) fasting blood glucose concentrations (143.8±23.9 and 139.5±14.2 vs. 229.0±20.8 mg/dL, p<0.05, respectively), triglyceride (18.9±11.1 and 16.0±6.5 vs. 62.8±18.3 mg/dL, p<0.05), total cholesterol (1.2±0.1 and 1.2±0.3 vs. 1.8±1.1 g/L, p<0.05) and serum insulin concentrations (1.7±0.7 and 0.9±0.7 vs. 3.3±14.3 ng/mL, p<0.05). Plant extracts also markedly reduced insulin resistance as compared to HFD controls (AHA: 15.6±9.1, CE: 9.0±7.7 vs. HFD control 38.5±30.3, p<0.05). The plant extracts decreased calorie intake and had little effect on body weight or HDL-cholesterol. CONCLUSION AHA has already been shown to have a antihyperglycaemic and antihyperlipidemic effect but this is the first demonstration of an effect of AHA and CE on established HFD-induced diabetes.

Anti-inflammatory, immunomodulatory, and heme oxygenase-1 inhibitory activities of ravan napas, a formulation of uighur traditional medicine, in a rat model of allergic asthma.

Ravan Napas (RN) is a traditional formula used to treat pulmonary symptoms and diseases such as coughing, breathing difficulty, and asthma in traditional Uighur medicine. The purpose of this study was to investigate the anti-inflammatory, and immuno-modulatory activity of RN in a well-characterized animal model of allergic asthma. Rats were sensitized with intraperitoneal (ip) ovalbumin (OVA) and alum, and then challenged with OVA aerosols. The asthma model rats were treated with RN; saline- and dexamethasone- (DXM-) treated rats served as normal and model controls. The bronchoalveolar lavage fluid (BALF) cellular differential and the concentrations of sICAM-1, IL-4, IL-5, TNF-α, INF-γ, and IgE in serum were measured. Lung sections underwent histological analysis. The immunohistochemistry S-P method was used to measure the expression of ICAM-1 and HO-1 in the lung. RN significantly reduced the number of inflammatory cells in BALF and lung tissues, decreased sICAM-1, IL-4, IL-5, TNF-α, and IgE in serum, and increased serum INF-γ. There was a marked suppression of ICAM-1 and HO-1 expression in the lung. Our results suggest that RN may have an anti-inflammatory and immuneregulatory effect on allergic bronchial asthma by modulating the balance between Th1/Th2 cytokines.

NMR and simulated annealing investigations of bradykinin in presence of polyphenols.

Abstract Epidemiological studies have shown that the incidence of some cardiovascular degenerative diseases appears to be lower in populations with regular but moderate drinking of red wine rich in polyphenols. One of the most important properties of polyphenols is to form complexes with proteins. The linear nonapeptide hormone bradykinin (H-Arg1-Pro2-Pro3-Gly4- Phe5-Ser6-Pro7-Phe8-Arg9-OH) is involved in a variety of physiological processes such as the cardiovascular processes. Thus, the goal of this work was to study the effects of tannins on the peptide structure by NMR investigations and molecular modeling. The results of these investigations show that in the presence of catechin, the peptide conformation is not affected and is in a random coil structure. On the contrary, the peptide structure is modified by the addition of dimeric proanthocyanidin B3 (catechin 4α→8 catechin). The dimer leads to the formation of a large flexible turn between the 6–9 residues. Thus, the biological activities of bradykinin in the presence of polyphenols could be affected.

Abnormal Savda Munziq, an Herbal Preparation of Traditional Uighur Medicine, May Prevent 1,2-dimethylhydrazine-Induced Rat Colon Carcinogenesis

The study tried to assess the chemoprotective effect of abnormal Savda Munziq (ASMq) on 1,2-dimethylhydrazine (DMH)-induced rat colon carcinogenesis. Male F344 rats were randomized into eight groups: Group 1 was served as control, no DMH injection was given and treated daily with normal saline. Rats in Groups 2–8 were given a single intraperitoneal injection of DMH (20 mg/kg body weight) at the beginning of the study. Group 2 was served as negative control, administered with normal saline until the end of the experiment after the single DMH injection. Groups 3–5 were served as pretreatment group, administered with ASMq ethanol extract at 400, 800 and 1600 mg/kg body weight, respectively, until the 45th day, continued by normal saline administration for another 45 days. Groups 6–8 were served as the treatment group, administered with normal saline for the first 45 days from the day of DMH injection, ASMq ethanol extract at three different doses to be administered until the end of the second 45th day. All rats were sacrificed at 91st day and the colons were analyzed for aberrant crypt foci (ACF) formation and crypt multiplicity. Results showed that ASMq ethanol extract reduced the number of ACF, AC and crypt multiplicity significantly (P < .05). It suggested that ASMq ethanol extract had chemoprotective effects on DMH-induced colon carcinogenesis, by suppressing the development of preneoplastic lesions, and probably exerted protection against the initiation and promotion steps of colon carcinogenesis.

Acute and sub-chronic (28days) oral toxicity evaluation of hydroethanolic extract of Bridelia ferruginea Benth root bark in male rodent animals.

The present investigation was carried out to evaluate the safety of hydro-ethanol extract of Bridelia ferruginea Benth (Euphorbiaceae) root bark. For acute toxicity study, a single dose of 2000 and 5000 mg/kg of the B. ferruginea root bark extract was given orally to healthy male Wistar rats and Balb/c mice. The animals were observed for mortality and clinical signs for 3 h and then daily for 14 days. In the sub-chronic toxicity study, the extract was administered orally at doses of 250, 500 and 1000 mg/kg/day for 28 days to male Wistar rats. Animals were sacrificed to examine their organs, and urine and blood serum were analyzed. In the acute toxicity study, B. ferruginea root bark extract caused neither significant visible signs of toxicity, nor mortality in Wistar rats and Balb/c mice. In sub-chronic toxicity study, administration of the B. ferruginea root bark extract at 250, 500, and 1000 mg/kg for 28 consecutive days to Wistar rats did not produce mortality. No significant differences were found in relative organ weights, biochemical studied parameters in treated groups compared to control group. No obvious histological changes were observed in organs of B. ferruginea extract treated animals compared to controls.