A new polyacetylene glucoside from Vernonia scorpioides and its potential antihyperglycemic effect.

Natural polyacetylene compounds have been found mainly in seven botanical families and remain underexplored and understudied, despite its inherent chemical and biological reactivity, due to the presence of conjugated triple bonds. Some polyacetylene glucosides have been found to stimulate glucose uptake in C5BL/ks-db/db obese diabetic mice, and since polyacetylene glucosides previously found in Vernonia scorpioides showed little to none cytotoxicity, in this study the antihyperglycemic potential of a new V. scorpioides polyacetylene glucoside has been accessed in order to shine a new light on the biological activity of this unique scaffold. For the isolation of this new compound an optimized method of Centrifugal Partition Chromatography (CPC) is for the first time described together with its X-ray data. The results demonstrate that 3,4-dihydrovernoniyne-4-O-ß-glucoside has significant effect on glycaemia at low dose 0.5 mg/kg, and pointing that the anti-hyperglycemic effect may be due in part to the inhibition of intestinal disaccharidases.

Polyacetylenes from the leaves of Vernonia scorpioides (Asteraceae) and their antiproliferative and antiherpetic activities.

Polyacetylenes constitute an underexplored and unstable class of compounds that are found mainly in the Apiaceae, Araliaceae and Asteraceae families. Vernonia scorpioides (Lam.) Pers., Asteraceae is a lianous neotropical herb that usually grows in soils that have been deforested and are of poor quality. It is used in folk medicine for the treatment of several skin conditions. This study addresses the characterisation of eight polyacetylenes isolated from the leaves of V. scorpioides. Their structures were established on the basis of 1D and 2D NMR spectroscopy and MS analysis. Ab initio calculations including solvent effects were employed to aid the elucidation of the absolute configurations of the compounds. The in vitro antiproliferative and anti-herpetic activities of the polyacetylenes were determined. The isolated compounds presented no inhibitory effect against a human cell line of non-small cell lung cancer, but presented a mild non-selective in vitro antiviral activity, although their corresponding glycosides were inactive.

Effects of the topical application of an ethyl acetate fraction from Vernonia scorpioides on excisional wounds infected with Staphylococcus aureus in rats

We investigated the healing process on excisional wounds infected with Staphylococcus aureus in rats, treated with 50 µL of ethyl acetate III from Vernonia scorpioides (Lam.) Pers., Asteraceae, rifamycin diethylamide B 25 mg, or saline. The lesions were measured daily and after seven days were surgically removed and histologically processed. The results indicate a favorable action of the EAIII, demonstrated by the increased wound contraction, smaller area of necrotic tissue, good development of granulation tissue, extensive extracellular matrix deposition and epithelial regeneration. This sub-fraction was phytochemically investigated in parallel studies, revealing the presence of sesquiterpene lactones (glaucolides and hirsutinolides) such as diacethylpiptocarphol and related hirsutinolides, flavonoids and cinnamic acid derivatives and also a new polyacetylene, which have been previously published. Results support the effectiveness of V. scorpioides antimicrobial activity in infected wound healing in rats.

Evaluation of the proliferative activity of methanol extracts from six medicinal plants in murine spleen cells

A number of natural compounds have been used as immunomodulatory agents, enabling the function of the immune system to be modified by stimulating or suppressing it. There has been increasing interest in the study of therapeutic action of plant extracts regarding their immunomodulatory activity. The aim of this study was to identify and evaluate the action of extracts of the medicinal plants Calophyllum brasiliense, Ipomoea pes-caprae, Matayba elaeagnoides, Maytenus robusta, Rubus imperialis and Vernonia scorpioides on the development of spleen cells from mice, using the in vitro cellular proliferation assay. The cells, obtained by mechanical rupture of mice spleen (5x10(4) cells/mL), were incubated with methanol extracts (10, 50, 100 and 200 µg/mL) and phytohemagglutinin (PHA, 5 µg/mL). The basal control for proliferation consisted of cells alone, while the positive control consisted of cells and PHA. The cell culture was kept at 37 ºC in 5 percent CO2 for 72 hours, and cell proliferation was revealed by the blue tetrazolium reduction assay (MTT). The results were expressed as percentage of growth and were analyzed using the Kruskal-Wallis and Mann-Whitney tests. The C. brasiliense, I. pes-caprae and M. elaeagnoides extracts showed dose-dependent induction of cell proliferation, with a significant increase in cell proliferation (p<0.03) and percentage growth of 88.2 percent, 73.1 percent and 52.7 percent, respectively, suggesting T lymphocyte stimulation. By contrast, M. robusta, R. imperialis and V. scorpioides extracts showed significance only with a negative percentage of growth, suggesting inhibition of cell proliferation (p<0.04). Further biomonitoring studies will enable the fractions and isolated substances responsible for the immunomodulatory activities to be identified.

Várias substâncias de origem natural têm sido utilizadas como agentes imunomoduladores, permitindo modificar a função do sistema imune e propiciando o estudo de atividades terapêuticas de extratos de plantas. Este trabalho objetivou identificar a atividade imunomodulatória dos extratos de seis plantas medicinais da flora brasileira, Calophyllum brasiliense, Ipomoea pes-caprae, Matayba elaeagnoides, Maytenus robusta, Rubus imperialis e Vernonia scorpioides, sobre a proliferação de células esplênicas de camundongos. As células esplênicas murinas obtidas por ruptura mecânica do baço (5x14³ células/mL) foram incubadas com os extratos metanólicos das plantas (10, 50, 100, 200 µg/mL) e fito-hemaglutinina (PHA, 5 µg/mL). O controle basal de proliferação foi constituído de células apenas e o controle positivo formado por células e PHA. O cultivo celular foi mantido a 37 ºC, 5 por cento de CO2, 72 horas, com quantificação da proliferação celular pelo ensaio de redução do azul de tetrazólio. Os resultados expressos em percentagem de crescimento foram analisados pelos testes de Kruskal-Wallis e Mann-Whitney. Os extratos de C. brasiliense, I. pes-caprae e M. elaeagnoides mostraram indução dose-dependente da proliferação celular (p<0,03), com percentagem de crescimento de, respectivamente, 88,2 por cento, 73,1 por cento e 52,7 por cento, sugerindo estímulo de linfócitos T. Contrariamente, os extratos de M. robusta, R. imperialis e V. scorpioides apresentaram significância apenas com percentagem de crescimento negativa, indicando inibição da proliferação celular (p<0,04). A continuidade no estudo biomonitorado permitirá a identificação das frações e substâncias isoladas responsáveis pelas atividades imunomoduladoras.

Cytotoxic activity of the sub-fraction 2125 from Vernonia scorpioides against Sarcoma 180 tumor cells in mice / Ação citotóxica da sub-fração 2125 de Vernonia scorpioides contra células do Sarcoma 180 em camundongos

The effect of the selected sub-fraction SF-2125 of the Vernonia scorpioides leaf extract on Sarcoma 180 (S180) ascitic tumor-bearing mice was investigated. The animals were treated with SF-2125 at a concentration of 5 mg/kg, administered intraperitoneally and intravenous during the development of the tumor. Treatment with SF-2125 5 mg/kg i.p. increased the lifespan of the animals, maintained their body and the ascitic tumor showed no development. Intravenous treatment did not reduce the tumor volume.

O efeito da sub-fração SF-2125 obtida do extrato das folhas de Vernonia scorpioides foi investigado em camundongos portadores do tumor ascítico Sarcoma 180 (S180). Os animais foram tratados com SF-2125 na concentração de 5 mg/kg, administrada por vias intraperitoneal e intravenosa durante o desenvolvimento do tumor. O tratamento com SF-2125 5 mg/kg i.p. aumentou o tempo de vida dos animais, manteve seu peso corporal e o tumor na forma ascítica não teve desenvolvimento. O tratamento intravenoso não reduziu o volume do tumor.

Effects of the topical application of the extract of Vernonia scorpioides on excisional wounds in mice

Vernonia scorpioides is traditionally widely used in Brazil to treat skin problems, including healing of chronic wounds, such as ulcers of the lower limbs and diabetic wounds. This work investigated the healing process on excisional wounds in the skin of mice, treated daily with an ointment containing 20 percent of the ethanol extract of the leaves of Vernonia scorpioides, compared with the control. A skin wound area of about 4 mm was excised on anaesthetised mice, and after 3, 7 and 14 days of treatment, the lesions were surgically removed and histologically processed. Wound healing activity was determined by the percentage of necrosis area, mononuclear inflammatory cells, fibroblasts and blood vessels. In the acute phase of healing, treatment with piracá extract enlarged the lesions and intensified the necrosis area, compared with the control group. However, the treatment did not inhibit either the recruitment and stimulation of inflammatory cells or the repair process. The results obtained indicate a harmful action of the extract immediately after tissue excision, demonstrated by the increased area of necrotic tissue, clotting and exudates formed in the treated groups. However, the extract did not inhibit the formation of granulation tissue.