Inhibition of HMG-CoA reductase activity and cholesterol permeation through Caco-2 cells by caffeoylquinic acids from Vernonia condensata leaves

ABSTRACT The aim of this study was to provide scientific knowledge to support the use of Vernonia condensata Baker, Asteraceae, beverages for their alleged hypocholesterolemic properties by testing their action as HMG-CoA reductase inhibitors and their capacity to lower dietary cholesterol permeation. Chlorogenic acid, and other caffeoylquinic acids derivatives were identified as the main components of these beverages by LC–MS/MS. No changes in the composition were notice after the in vitro gastrointestinal digestion and no toxicity against Caco-2 and HepG2 cell lines was detected. Cholesterol permeation through Caco-2 monolayers was reduced in 37% in the presence of these herbal teas, and the caffeoylquinic acids permeated the monolayers in 30–40% of their initial amount in 6 h. HMG-CoA reductase activity was reduced with these beverages, showing an IC50 of 217 µg ml−1. It was concluded that caffeoylquinic acids, the major components, justified 98% of the enzyme inhibition measured.

Extrato de plantas medicinais como carrapaticida de Rhipicephalus (Boophilus) microplus / Herbal extract against Rhipicephalus (Boophilus) microplus ticks

O uso de plantas medicinais tem sido uma prática antiga da humanidade, contribuindo para a divulgação das virtudes terapêuticas de extratos de diferentes vegetais. Na busca de alternativas naturais eficazes para males que prejudicam indiretamente o homem, as plantas medicinais têm sido utilizadas na veterinária na tentativa de eliminar ou reduzir a ação dos carrapatos B. microplus, que podem trazer prejuízos a bovinos. Durante anos têm sido utilizado produtos químicos nesse controle, no entanto, os carrapatos adquirem resistência aos fármacos em decorrência do uso contínuo. Assim, objetivou-se avaliar o efeito de hidrolato e extratos aquosos de carqueja [Baccharis trimera (Less). D.C.], alfavaca (Ocimum gratissimum L.), necroton [Vernonia condensata (Backer) H. Rob.] camomila [Chamomilla recutita (L.) Rauschert], além do óleo essencial de alfavaca (Ocimum gratissimum L.). Os ensaios para larvas de B. microplus foram realizados com impregnação das substâncias em papel filtro. Os resultados obtidos demonstraram que todos os extratos aquosos foram ineficazes; o hidrolato de carqueja e de necroton apresentaram eficiência em torno de 30%, necessitando novos testes para comprovação. Dentre os resultados obtidos, destaca-se o hidrolato de alfavaca que apresentou eficiência de 76,7% na concentração de 100% e o óleo essencial puro de alfavaca que apresentou ação larvicidade 100% indicando o potencial carrapaticida dessa planta, especificamente no combate de B.microplus.

The use of medicinal plants has been a longstanding practice of mankind, helping to spread the therapeutic virtues of different plant extracts, due to their medicinal effects. In the search for effective natural alternatives for ailments that indirectly affect man, medicinal plants have been used in veterinary medicine, in an attempt to eliminate or reduce the action of B. microplus ticks, which can cause damage to cattle. For many years, chemical products have been used in this control. However, after some time ticks acquire drug resistance, as a result of continuous use. Thus, the objective of this paper was to evaluate the effect of hydrolates and aqueous extracts of carqueja [Baccharis trimera (Less). DC], alfavaca (Ocimum gratissimum L.), necroton [Vernonia condensata (Baker) H. Rob.], chamomile [Chamomilla recutita (L.) Rauschert] and also the essential oil of alfavaca (Ocimum gratissimum L.). The assays for larvae of B. microplus were carried out by impregnating the paper filter with the substances. The results showed that all the aqueous extracts were ineffective; the hydrolate of carqueja and necroton presented efficiencies around 30%, requiring further tests to prove. Among the results, we observed that the alfavaca hydrolate showed an efficiency of 76.7% at a concentration of 100% and the pure alfavaca oil showed a larvicidal action of 100%, indicating this plant's potential to reduce ticks, specifically in the control of B. microplus.

Antinociceptive and acute toxicity evaluation of Vernonia condensata Baker leaves extracted with different solvents and their mixtures.

Extract of Vernonia condensata (Asteraceae = Compositae) leaves has different uses in Brazilian folk medicine, which includes analgesic and antiinflamatory agent. The aim of this study was to apply a modified simplex-centroid mixture design to evaluate the best extractor system for the antinociceptive activity, evaluated by writhing test. Different solvents (acetone, dichloromethane, ethanol and ethyl acetate) as well as their binary, ternary and quaternary mixtures were used. For comparison, aqueous extract was also evaluated. LD50 was estimated and qualitative phytochemical screening, conducted. The extracts with antinociceptive activity were: aqueous, acetone, dicloromethane (DCM), ethanol (ETOH), acetone-DCM, acetone-ETOH, acetone-ethyl acetate, ETOH-ethyl acetate, acetone-DCM-ethyl acetate, acetone-ETOH-ethyl acetate and DCM-ETOH-ethyl acetate. The higher margin of safety (LD50/ED50) was for acetone > acetone-ETOH-ethyl acetate > aqueous > ETOH = acetone-ETOH > DCM > acetone-ethyl acetate > DCM-ETOH-ethyl acetate > acetone-DCM > acetone-DCM-ethyl acetate. Phytochemical screening showed that all the extracts contained alkaloids, phenolic compounds, flavonoids, tannins and saponins. In conclusion, the extractor system influences both the pharmacological activity and acute toxicity of leaves from V. condensata. Acetone and the ternary mixture, acetone-ETOH-ethyl acetate extracts showed higher margin of safety than aqueous extract.