TNF-α inhibition, antioxidant effects and chemical analysis of extracts and fraction from Brazilian guaraná seed powder.

Paullinia cupana Kunth., commonly named Guaraná, is a plant from Brazil used as stimulant. The aim of this study was to evaluate the potential of extracts and tannins-rich and methylxanthines-free fraction from guaraná in the anti-inflammatory and antioxidant effect in vitro. Extract 1 obtained good yields of tannins and methylxanthines and was used to identify a type-A procyanidin trimer by LC-ESI-MS. Fraction 4 was rich in tannins and absent of methylxanthines. The extracts and fraction exhibited strong capacity for scavenging DPPH radical with IC50 between 5.88 and 42.75-µg/mL and inhibited TNF-α release by LPS-activated THP-1 cells when compared with control cells and did not present toxicity to THP-1 cells. The fraction 4, rich in tannins, was highly active, with IC50 5.88 µg/mL by DPPH method and inhibited TNF-α release in 83.50% at 90 µg/mL. These results reinforced potential anti-inflammatory of guaraná and data for new therapeutic approaches.

Pharmacological activity of the hydroalcoholic extract from Hovenia dulcis thunberg fruit and the flavonoid dihydromyricetin during hypercholesterolemia induced in rats

Cerebrovascular accidents and coronary artery disease are the leading causes of cardiovascular mortalities in Brazil and high levels of LDL cholesterol are one of the main risk factors. In this context, several plant extracts and natural substances have shown promise as cholesterol-lowering. The objective of this study was to evaluate the potential of the hydroalcoholic extract of the fruit of H. dulcis and of dihydromyricetin in cholesterol reduction in hypercholesterolemic rats. Forty-two Wistar male rats were distributed into seven groups of six animals that received diets supplemented with 1% cholesterol and 0.3% cholic acid, with the exception of the control group, which received conventional diets. Animals were treated with oral suspensions containing: atorvastatin 1.0 mg/kg; H. dulcis extract at 50.0 and 100.0 mg/kg and dihydromyricetin at 25.0 and 50.0 mg/kg vehicle (control group). The following biochemical markers were evaluated; total cholesterol, HDL-C, LDL-C, triglycerides, AST, ALT, and alkaline phosphatase. The hypercholesterolemic diet was effective in inducing hypercholesterolemia, increasing total cholesterol by 112.7% relative to the control group. The treatments with two doses of the extract proved to be promising hypocholesterolemic agents, as they were able to substantially reduce total cholesterol and LDL-C, without significantly altering triglycerides, hepatic transaminases, and alkaline phosphatase, thereby encouraging the studies with the plant H. dulcis. The groups treated with the flavonoid dihydromyricetin, although they showed a significant reduction in total cholesterol and LDL-C, and found increases in triglycerides and hepatic transaminases, which is unwanted in the context of hypercholesterolaemia.

No Brasil, o acidente vascular cerebral e a doença arterial coronariana constituem as principais causas de mortalidade cardiovascular, sendo os altos níveis de colesterol LDL um dos principais fatores de risco. Nesse contexto, diversos extratos vegetais e substâncias naturais isoladas têm se mostrado promissoras como hipocolesterolemiantes. O objetivo do trabalho foi avaliar o potencial do extrato hidroalcoólico dos frutos de Hovenia dulcis e do flavonóide diidromiricetina na redução do colesterol em ratos hipercolesterolêmicos. Quarenta e dois ratos Wistar machos, foram distribuídos em 7 grupos de 6 animais, que receberam dieta suplementada com 1% de colesterol e 0,3% de ácido cólico, à exceção do grupo controle, que recebeu ração convencional. Posteriormente, os animais foram tratados com suspensões orais contendo: atorvastatina 1,0 mg/kg; extrato de H. dulcis de 50,0 e 100,0 mg/kg; diidromiricetina de 25,0 e 50,0 mg/kg e veículo (grupo controle). Avaliaram-se os parâmetros bioquímicos: colesterol total, HDL-C, LDL-C, triglicérides, AST, ALT e fosfatase alcalina. A dieta hipercolesterolêmica foi efetiva na indução da hipercolesterolemia, aumentando o colesterol total em 112,7% em relação ao controle. Os tratamentos com as duas doses do extrato mostraram-se promissores como agentes hipocolesterolemiantes, já que foram capazes de reduzir substancialmente o colesterol total e LDL-C, sem alterar significativamente triglicérides, as transaminases hepáticas e a fosfatase alcalina, incentivando, assim, a continuidade de estudos com a planta H. dulcis. Já os grupos tratados com o flavonóide diidromiricetina, apesar de apresentarem redução significativa do colesterol total e de LDL-C, apresentaram elevações nos triglicérides e nos parâmetros hepáticos, resultado indesejável no âmbito das hipercolesterolemias.