Phytochemical Screening, Study of Acute Toxicity and Hypoglycemic and Antihyperglycemic Activities of Silver Nanoparticles from Guibourtia tessmannii (Harms) J. Leonard (Caesalpiniaceae)

According to the World Health Organization, diabetes affects approximately 347 million people worldwide. Its management is not within the reach of all social classes, therefore medicinal plants are still the first resort for many populations in Africa. The biological material used in this study was the trunk bark of Guibourtia tessmannii. 50 g of trunk bark powder were decocted in 500 ml of distilled water for 5 minutes were carried out. The method used for the synthesis of silver nanoparticles (AgNps) was an organometallic bio-reduction of silver nitrate salts mediated by various secondary metabolites contained in the plant extract. The study of the toxicity acute was conducted according to guideline 423 of the OECD protocol. The pharmacological activities were each carried out with 28 female rats divided into 7 groups of four rats. It was a question for the hypoglycemic activity of administering various doses of silver nanoparticles and other substances to the rats thirty minutes after the carbohydrate intake and for the anti-hyperglycemic activity of administering the same substances to the rats thirty minutes before the carbohydrate intake. The extraction yield was 8.76%. Only the alkaloid test was negative. After acute toxicity study, the LD50 was greater than 2000 mg/kg. Blood sugar tests revealed that glibenclamide 5 mg/kg, which is the reference molecule, lowered blood sugar more than the other treatments applied in the other batches. It was followed by treatment with silver nanoparticles at a dose of 400 μg/kg in both tests. It was therefore concluded that silver nanoparticles from G. tessmannii are good for the formulation of improved traditional medicines and bring up their afficacity .

The methanolic extract ofGuibourtia tessmannii(Caesalpiniaceae)improves sexual parameters in high fat diet-induced obese sexually sluggish rats

Objective:To evaluate the effects of the methanolic extract ofGuibourtia tessmannii (G. tesmannii) on sperm parameters, lipid profile and testosterone level in obese rats.Methods: A total of 193 male Wistar rats were fed either with palm oil diet (n=185) or standard diet (n=8) for 16 wk. At the end of this feeding period, 90 obese rats were selected and randomly divided into 18 groups of five rats each and treated with distilled water (10 mL/kg), vitamin E (75 mg/kg), clomiphene citrate (2 mg/kg) or methanolic extract ofG. tessmannii (55, 110 or 220 mg/kg) for 7, 21 or 56 d. At the end of each treatment period, sperm parameters, lipid profile and testosterone level were evaluated. Data were analyzed using ANOVA for repeated measures followed by post-hoc Tukey HSD (P<0.05) for multiple comparisons.Results: Feeding of rats for 16 wk with palm oil diet significantly damaged sperm parameters. The methanolic extract ofG. tesmannii improved sperm viability, motility and normality after 21 or 56 d of treatment. The sperm normality increased significantly in rats treated with the methanolic extract ofG. tesmannii for 7 (110 mg/kg,P<0.01) and 56 d (110 and 220 mg/kg,P<0.05) compared to control group. Triglycerids, total cholesterol, low and very low density lipoproteins cholesterol levels were lower in rats treated with the plant extract for 56 d.G. tesmannii also significantly increased the high density lipoprotein cholesterol and testosterone levels in the plasma after 56 d of treatment.Conclusions: The methanolic extract ofG. tesmannii can improve sperm parameters, lipid profile and testosterone level in obese rats. These findings may justify the folkloric use ofG. tesmannii as a reproductive performance enhancer.

Preliminary studies of acute and sub-chronic toxicity of the aqueous extract of Guibourtia tessmannii(Harms) J.Leonard stem barks (Caesalpiniaceae) in mice and rats

Objective: To investigate the toxicity of aqueous extract of Guibourtia tessmannii(Harms) J. Leonard(G. tessmannii) and evaluate its safety.Methods: NMRI mice were used to determine the acute toxicity of G. tessmannii.Increasing concentrations of the plant extracts were administered intraperitoneally or by force-feeding. General behavior and death were monitored and recorded daily for 7 days.In order to determine the sub-acute toxicity of the extract, several doses were administered by oral gavage daily for 28 days in adult Wistar rats. Different parameters were assessed including body weight, food and water intake, biochemical parameters and several vital organ weights.Results: LD50 of 328.78 mg/kg was obtained by i.p. route and more than 5 000 mg/kg was obtained in acute toxicity by oral route. In sub-acute toxicity, no significant alteration was observed in body weight or vital organs, food and water intake, and biochemical parameters.Conclusions: The results showed that the aqueous extract of G. tessmannii has low toxicity intraperitoneally and no sub-acute toxicity via oral intake.

4种常用装饰装修木材表面特性分析

对筒状非洲楝、水曲柳、古夷苏木和杉木4种常用装饰装修木材表面特性进行测定分析,结果表明:在CIE(1976)L*a*b*色空间中,筒状非洲楝和古夷苏木明度L*平均值较低,属于深材色树种;杉木明度L*平均值为70.28,属于较高明度。从整体分布情况来看,4种常用装饰装修木材的a*和b*都分布在0以上,明度分布在40以上,色调标号都分布在YR的区间;古夷苏木和水曲柳木材表面润湿性大于筒状非洲楝和杉木。

3种木材涂饰前后表面视觉性质差异的研究

测定分析了筒状非洲楝Entandrophragma cylindricum,古夷苏木Guibourtia tessmannii和水曲柳Fraxinus mandschurica木材醇酸清漆涂饰前后表面视觉性质的差异。结果表明,涂饰处理降低了3种木材表面的明度(L*)和红绿轴色品指数(a*)值,其中,古夷苏木的L*变化差异最大,明度降低明显;水曲柳的红绿轴色品指数差(Δa*)绝对值最大,相比处理前更偏向绿色;3种木材透明涂饰后的黄蓝轴色品指数(b*)均有所升高,黄蓝轴色品指数差(Δb*)绝对值由大到小分别为水曲柳>古夷苏木>筒状非洲楝,数值越大越趋于黄色;总体色差(ΔE*)变化差异不大,涂饰对3种木材的总体色差影响不明显。