Shear Resistance of Siltous Sands Improved with Bridelia Tannins

The ruin of several civil engineering works occurs due to shear rupture of the ground. When the stress is greater than the shear resistance, the internal friction angle and the cohesion of the soil loosen and rupture occurs. Cement and lime are often used to stabilize soils and improve soil strength. The costs and environmental problems of these technologies raise concerns and challenge researchers to innovate with clean, inexpensive materials, accessible to the most disadvantaged social classes. The question that this study seeks to answer is whether the binders derived from plant tannins, which also stabilize soils, improve the shear resistance of these soils. To do this, we determined for silty sand the shear parameters, notably the cohesion and the angle of internal friction in the non-stabilized state and when they are stabilized with the powder of the bark of the Bridelia under different water states. The results show that the addition of Bridelia powder to silty sand increases the cohesion of the soil by nearly 70.71% and the friction angle by 4.31%. But in unfavourable water conditions, the cohesion and internal friction angle of the silty sand material improved with Bridelia bark powder drops drastically by nearly 81.56%. but does not dissolve completely as for the same material. When it is not stabilized. This information is an invaluable contribution in the search for solutions to increase the durability of earthen constructions by improving the water-repellent properties of soils.

Acute and Sub-Chronic Toxicity Evaluation of the Crude Methanolic Bark Extract of Bridelia micrantha (Hochst.) Baill. (Phyllanthaceae) and Its Fraction

Bridelia micrantha, commonly known as coastal golden leaf, is a member of the family Phyllanthaceae. In preliminary studies nine fractions, named F1 - F9, were obtained by fractionating the crude methanol extract of the stem bark of Bridelia micrantha using column chromatographic techniques. The fraction F6 was the most active when tested for antibacterial activity. Thus, toxicity of this fraction was investigated for further use. The present study evaluated the acute and sub-chronic toxicity of the crude methanolic bark extract of Bridelia micrantha and its fraction. The acute toxicity was carried out according to the experimental protocol of Organization for Economic Co-operation and Development (OECD). The plant extract or the fraction F6 was administered orally to female mice at a single dose of 2000 mg/kg and the animals were observed for any behavioral changes or mortality for 14 days. In the sub-chronic toxicity study, the extract and fraction were administered orally at 200, 400 and 800 mg/kg bw/day for 28 days to healthy Wistar rats. The general behavior and body weight of the rats were recorded daily. At the end of the experimental period, hematological and biochemical analyses, changes in vital organ weight (liver, lung, heart, spleen and kidney), and histopathological examination of the liver and kidney were performed. No mortality or adverse effects were noted at the 2000 mg/kg dose during the oral acute toxicity test. In the sub-chronic study, the crude methanolic bark extract of Bridelia micrantha and the fraction F6 induced no mortality or treatment-related adverse effects on body weight, general behavior, relative organ weights, hematological and biochemical parameters. Histopathological examination of the liver and kidney showed normal architecture suggesting no morphological alterations. In conclusion, the oral administration of the crude methanolic bark extract of Bridelia micrantha and the fraction F6 for 28 days at a dosage of up to 800 mg/kg did not induce toxicological damage in rats. From acute toxicity study, the median lethal dose (LD50) of the crude methanolic bark extract of Bridelia micrantha and the fraction F6 was estimated to be more than 2000 mg/kg.

Screening of ethyl acetate extract of Bridelia micrantha for hepatoprotective and anti-oxidant activities on Wistar rats

Objective:To explore the hepatoprotective and anti-oxidant activities of the methanolic leaf extract of Bridelia micrantha(B.micrantha) on paracetamol induced liver damage in Wistar rats. Methods:Parameters were measured including alanine aminotransaminase(ALT),aspartate aminotransferase(AST),alkaline phosphatase(ALP),bilirubin and total protein.The anti-oxidant effects were studied using the 1,l-Diphenynl-2-Picrylhydrazyl(DPPH) and Ferric Reducing Antioxidant Power(FRAP) assay methods.Results:B.micrantha extract decreased the level of AST in the rats given PCM from(129.47±0.921) IU/L to(57.78±1.71) IU/L(P【0.05).This was lower than the value for Silymarin which was(59.92±1.41) IU/L.ALT concentration was reduced from (150.18±2.23) IU/L to(79.10±2.01) IU/L(P【0.05).ALP was reduced from(49.86±0.85) IU/L to(29.64±1.53) IU/L(P【0.05).Total bilirubin was reduced from(2.14±0.10 mg/dL) to(0.18±0.07) mg/dL (P【0.05) while total protein was increased from(4.26±0.30) mg/dL to(6.20±0.19) mg/dL(P【0.05). Concentrations ranging from 10 - 400μg/mL of B.micrantha were assayed for antioxidant activities.The DPPH assay showed 98%antioxidant activity at concentration of 400μg/mL. The FRAP values were 0.016,0.39,0.455,0.601 and 1.382μM at 10.50,100,200 and 400μg/ mL respectively.Conclusions:Results suggest that B.micrantha has hepatoprotective and anti oxidant potentials.However,further work involving fractionation needs to done to isolate the active compound responsible for the hepatoprotective activity.

Two New Flavonol Glycosides from Bridelia tomentosa

Two new flavonol glycosides, tamarixetin 3-O-β-D-xylopyranosyl-（1-2）-α-L-ribopyranoside （1） and tamarixetin 3-O-α-L-ribopyranoside （2） were isolated from the leaves of Bridelia tomentosa. Their structures were elucidated by 1D and 2D NMR analysis, as well as MS and IR spectra.

The antihyperglycemic effect of Bridelia ndellensis ethanol extract and its fractions is mediated by an insulinotropic action

Backgroung: Bridelia ndellensis (Euphorbiaceae) is used as a traditional plant treatment of diabetes. The aim of the present study was to investigate the mechanism involved in the antihyperglycemic effects of this plant. Methods: An intestinal perfusion technique was used to study the effect of the ethanol extract of B. ndellensis on the intestinal absorption of glucose in normal rats fasted for 36 h. The effect of the extract (50 and 100 mg/kg) on Insulin secretion was evaluated using BRIN-BD11 pancreatic cells. Results: In a perfused rat intestinal preparation in situ, the plant extract at a concentration of 5 mg/ml did not show any inhibitory effects on glucose absorption when compared with control animals. Ouabain which is an inhibitor of glucose transport across the small intestine significantly (p < 0.001) decreased the glucose absorption during the whole perfusion period compared with the control group. On the other hand, the plant extract inhibited the gastrointestinal motility induced by Barium sulphate milk in rats. The ethanol extract of B. ndellensis at concentrations of 50 and100mg/ml stimulated in a concentration-dependent manner the insulin secretion from BRIN-BD11 cells in vitro. The induction of insulin release was significantly different when compared to control with the concentration of 100 μg/ml (P < 0.001). Alanine (10 mM) used as positive control, significantly (p < 0.001) stimulated insulin release from BRIN-BD11 cells. Conclusion: The present study has revealed that B. ndellensis ethanol extract stimulates insulin secretion and does not affect the glucose absorption, and it has suggested that the antihyperglycemic effects of B. ndellensis is partly mediated by the stimulation of insulin secretion.

Flavonoids from the Leaves of <i>Bridelia stipularis</i>with <i>in Vitro</i>Antioxidant and Cytotoxicity Activity

Methanolic extract of the leaves of Bridelia stipularis was studied. From this study, we isolated three known flavonoids. They were identified as 7-O-methyl luteolin, apigenin and 5, 7, 2’, 5’ tetrahydroxyflavone by NMR spectroscopic studies. All of them are first time documented for this plant. Different solvent fractions were subjected to in vitro antioxidant and cytotoxicity studies. Both apigenin and ethyl acetate soluble fraction of Bridelia stipularis showed strong antioxidant activity having IC50 value of 8.005, 8.77 μg/mL respectively. Chloroform soluble fraction of Bridelia stipularis exerted the highest toxicity to brine shrimp and petroleum ether soluble fraction showed moderate toxicity having LC50 value of 1.05, 1.71 μg/mL respectively.

Inhibitory potentials of phenolic-rich extracts from Bridelia ferruginea on two key carbohydrate-metabolizing enzymes and Fe^(2＋)-induced pancreatic oxidative stress

Objective： The current study was designed to evaluate the various antioxidant potentials and inhibitory effects of phenolic-rich leaf extracts of Bridelia ferruginea（BF） on the in vitro activities of some key enzymes involved in the metabolism of carbohydrates.Methods： In this study, BF leaf free and bound phenolic-rich extracts were used. We quantified total phenolic and flavonoid contents, and evaluated several antioxidant activities using assays for ferric reducing antioxidant power, total antioxidant activity（phosphomolybdenum reducing ability）, 1,1-diphenyl-2-picrylhydrazyl and thiobarbituric acid reactive species. Also, extracts were tested for their ability to inhibit a-amylase and α-glucosidase activity.Results： The total phenolic and total flavonoid contents in the free phenolic extract of BF were significantly greater than in the bound phenolic extract. Also, all the antioxidant activities considered were significantly greater in the free phenolic extract than in the bound phenolic extract. In the same vein, the free phenolic-rich extract had a significantly higher percentage inhibition against α-glucosidase activity（IC50= 28.5 mg/mL） than the bound phenolic extract（IC50= 340.0 mg/mL）. On the contrary, the free phenolic extract（IC50= 210.0 mg/mL） had significantly lower inhibition against α-amylase than the bound phenolic-rich extract（IC50= 190.0 mg/mL）.Conclusion： The phenolic-rich extracts of BF leaves showed antioxidant potentials and inhibited two key carbohydrate-metabolizing enzymes in vitro.

土蜜树果实化学成分的研究

目的：研究土蜜树Bridelia tomentosa的化学成分。方法：运用硅胶柱色谱进行分离纯化，通过理化性质和波谱分析鉴定结构。结果：从中分离得到了10个化合物，分别鉴定为异柽柳素（tamarixetin，1），槲皮素（quercetin，2），没食子酸乙酯（ethylgallate，3），没食子酸（gallic acid，4），3，3’，4-O-三甲基鞣花酸（3，3’，4-tri-O-methylellagic acid，5），短叶苏木酚酸乙酯（ethyl brevifolincarboxylate，6），β-香树脂醇（β-amyrin，7），无羁萜（friedelin，8），β-谷甾醇（9），豆甾醇（10）。结论：化合物1，3—7是首次从该属中分离得到，化合物2为首次从该植物中分离得到。

大叶土蜜树化学成分及抗神经炎活性研究

为研究大叶土蜜树(Bridelia retusa)茎的化学成分及其抗神经炎活性,采用色谱技术从大叶土蜜树茎部分95%乙醇提取物中分离得到11个化合物。通过核磁共振波谱、质谱以及与文献数据比较,化合物结构鉴定为没食子酸(1)、木栓酮(2)、阿魏酸二十七烷脂(3)、芥子醛(4)、丁香醛(5)、丁香脂素(6)、补骨脂素(7)、补骨脂酚(8)、二十五烷酸(9)、亚油酸(10)和1-Linoleoylglycerol(11)。其中化合物3～11为首次从土蜜树属中分离得到。对化合物1～11的抗神经炎活性进行评价,发现化合物4、5、10和11对LPS诱导BV-2细胞NO生成具有显著抑制作用,其IC50分别为12. 57、8. 41、5. 86、5. 86μM。

土蜜树叶化学成分的研究

目的 研究土蜜树Bridelia tomentosa叶的化学成分。方法 运用硅胶柱色谱进行分离纯化，通过理化性质和波谱分析鉴定结构。结果 从土蜜树叶中分离得到了7个化合物，分别鉴定为小麦黄素（1），cappariloside A（2），表木栓醇（3），木栓酮（4），异柽柳素（5），萨谷甾醇（6），豆甾醇（7）。结论 首次从该植物中分离得到化合物1和2。