Hypoglycemic and antioxidant activities of the hydroethanolic leaf extract of Byrsocarpus coccineus Schumach. & Thonn. (Connaraceae) / 中国天然药物

AIM@#Diabetes Mellitus is associated with significant morbidity and mortality worldwide. The need for enhanced efficacy and safety, and cheaper and more readily available new drugs has increased the search for new antidiabetic drugs from plants. This study was conducted to investigate the antidiabetic activity of the hydroethanolic leaf extract of B. coccineus in rats.@*METHODS@#The effect of B. coccineus extract (100-800 mg · kg(-1), p.o.) on blood glucose levels in normal and glucose loaded rats, and alloxan-induced diabetic rats was determined. After 10 days of treatment, blood samples were collected from rats for lipid and insulin profiling. Animals were thereafter sacrificed and the kidneys, heart, and liver were harvested for antioxidant indices assay.@*RESULTS@#In normal rats, B. coccineus did not cause significant reduction in blood glucose. At the dose of 800 mg · kg(-1), significant increase in blood glucose level was not observed 30 min. after glucose load. B. coccineus administered acutely did not generally produce significant reduction in blood glucose level in diabetic rats. Administered subacutely, the extract significantly reduced blood glucose level in diabetic rats from the 3(rd) day with peak effect observed at the dose of 800 mg · kg(-1) on the 10(th) day. The extract generally preserved in vivo antioxidant levels in the kidneys, heart, and liver, increased the level of high density lipoprotein and insulin, and reduced the level of triglycerides and low density lipoprotein compared to diabetic control.@*CONCLUSION@#The findings in this study suggest that the hydroethanolic leaf extract Byrsocarpus coccineus possesses antidiabetic activity possibly mediated through inhibition of intestinal glucose absorption, in vivo antioxidant activity, and enhancement of regeneration of beta cells of the pancreas and insulin secretion.

Antibacterial, allelopathic and antioxidant activity of extracts and compounds from Rourea induta Planch. (Connaraceae).

This study evaluated some biological activities of the leaves from Rourea induta Planch., Connaraceae. Fractions of the ethanolic extract from leaves of this species were obtained by liquid/liquid partition and their antibacterial, allelophatic and antioxidant activities were analyzed. By the agar diffusion method the ethyl acetate, chloroform fractions and hyperin showed antimicrobial activity against Staphylococcus epidermidis with an inhibition halo of 15.0, 12.3 and 9.3 mm respectively, and Staphylococcus aureus with 7.6 mm for the fractions. For antioxidant activity all samples have demonstrated a significant potential, especially the chloroform, ethyl acetate fractions and the hyperin which IC50 were, 5.33 ±0.19; 3.21 ± 0.00 and 3.89 ± 0,02 respectively. This result is close to the standards vitamin C and rutin. In the allelopathic activity the hexane fraction at 0.8 mg and 0.4 mg, inhibited 33.24% and 20.54% the hipocotyl’s growth of Lactuca sativa seeds, and the compound tetracosane inhibited 18.05% the hipocotyl’s growth at 0.4 mg. The obtained results stimulate the continuity of this study.

Chemical constituents of Rourea doniana

The chromatography fractionation of the hexane, chloroform and ethyl acetate extracts from the leaves and stems of Rourea doniana Baker, Connaraceae, resulted in the isolation of five triterpenes (lupeol, lupenone, α-amyrenone, β-amyrenone, and taraxerol), a flavonol (7,4'-dimethylkaempferol), a coumarin (scopoletin) and four phytosteroids (β-sitosterol, stigmasterol, β-sitosteryl-3-O-β- D-glucopyranoside and stigmasteryl-3-O-β-D-glucopyranoside). All compounds are being for the first time in this species and all triterpenes and the flavonol are being described for the first time in the family Connaraceae. These compounds were identified on basis of their IR and NMR (¹H, 13C, DEPT, HSQC, HMBC, and NOESY) spectral data and by comparison with literature data.

Phytochemical constituents and preliminary toxicity evaluation of leaves from Rourea induta Planch. (Connaraceae) / Constituintes fitoquímicos e avaliação preliminar de toxicidade folhas de Rourea Induta Planch. (Connaraceae)

Most active plants are toxic at high doses and it is therefore important to investigate the preliminary toxicity of plant extracts. The Rourea induta species is a potential drug with no phytochemical or biological studies registered in the literature. Thus, a phytochemical study and a toxicity analysis of the ethanolic extract obtained from the leaves of Rourea induta Planch., Connaraceae, was run. A long chain hydrocarbon, n-tetracosane, and four flavonoids were identified: quercetin, and three glycosylated derivates, quercetin-3-O-α-arabinofuranoside, quercetin-3-O-β-xyloside and quercetin-3-O-β-galactoside. This is the first time these have been isolated in this species. The structures were elucidated by 13C NMR, ¹H NMR, UV and IR spectroscopy. The toxicity evaluation of extracts was performed by the brine shrimp method and determination of hemolytic activity. The samples demonstrated no toxic potential by the analyzed methods.

A maioria das plantas ativas é tóxica em doses elevadas, portanto, é importante a investigação da toxicidade preliminar dos extratos das plantas. A espécie Rourea induta é uma droga potencial que não apresenta estudo fitoquímico ou biológico descrito na literatura. Assim, um estudo fitoquímico e análises toxicológicas foram realizados com o extrato etanólico obtido das folhas de Rourea induta Planch., Connaraceae. Foram obtidos um hidrocarboneto de cadeia longa, n-tetracosano, e quatro flavonóides, quercetina e três derivados glicosilados, quercetina-3-O-α-arabinofuranosideo, quercetina-3-O-β-xilosideo e quercetina-3-O-β-galactosideo. Esta é a primeira vez que estes compostos são isolados nesta espécie. As estruturas foram elucidadas por espectroscopia de RMN-13C, RMN-¹H, ultravioleta e infravermelho. A avaliação da toxicidade dos extratos foi analisada pelo método da Artemia salina e atividade hemolítica. Nenhuma das amostras testadas apresentou um potencial tóxico pelos métodos analisados.

Connaraceae endémicas del Perú

La familia Connaraceae es reconocida en el Perú por presentar tres géneros y 20 especies (Brako & Zarucchi, 1993; Ulloa Ulloa et al., 2004), principalmente lianas y arbustos. En este trabajo reconocemos tres especies endémicas en tres géneros. Las especies endémicas ocupan la región Bosques Húmedos Amazónicos, entre los 100 y 400 m de altitud. Una de estas especies está representada dentro del Sistema Nacional de Áreas Naturales Protegidas por el Estado.

The Connaraceae are represented in Peru by 20 species in three genera (Brako & Zarucchi, 1993; Ulloa Ulloa et al., 2004), mainly lianas and trees. Here we recognize three endemic species in three genera. Endemic species are found in Humid Lowland Amazonian Forests region, between 100 and 400 m elevation. One of these species has been recorded within Peru´s protected areas system.