Antiproliferative activity, antioxidant capacity and chemical composition of extracts from the leaves and stem of Chresta sphaerocephala

AbstractIn this study, antiproliferative and antioxidant activities of crude extracts (hexane, ethyl acetate and methanol) from leaves and stem of Chresta sphaerocephala DC., Asteraceae, were investigated. Antiproliferative activity was tested in vitro against ten human cancer cells and against VERO (no cancer cell). Antioxidant activities were determined using DPPH and ORAC-FL assays and the total phenolic content was estimated by Folin–Ciocalteu method. Hexane and ethyl acetate extracts (leaves and stem) exhibited antiproliferative activity against cancer cell lines with total growth inhibition (TGI) between 50.40 and 250 µg/ml. For VERO cell, TGI values were >250 µg/ml for all extracts, except to hexane extract of the stem (TGI 80.92 µg/ml). In an initial evaluation, ethyl acetate and methanol extracts (leaves and stem) have shown levels of phenolic compounds between 6.94 and 30.96 mg GAE/kg in Folin–Ciocalteu assay, DPPH free-radical scavenging activity with SC50 in the range of 75.22 and 400 µg/ml and antioxidant capacity between 290.08 and 1088 µmol TE/g of extract in ORAC-FL assay. HPLC-DAD and ESI-MS analysis allowed the identification of flavonoids in the methanol extract from the leaves of C. sphaerocephala. Three steroids and nine triterpenoids were identified in the bioactive hexane extracts using HRGC.

Evaluation of immunomodulatory and anti-inflammatory effects and phytochemical screening of Alternanthera tenella Colla (Amaranthaceae) aqueous extracts

Alternanthera tenella Colla extracts are used in Brazilian traditional folk medicine to treat a variety of infectious diseases as well as inflammation and fever. In this work, the immunomodulatory, anti-inflammatory and potential toxic effects of cold (CAE) and hot (HAE) aqueous extracts of A. tenella were investigated in vivo. In addition, we analyzed the phytochemical properties of both extracts. BALB/c mice were immunized in vivo with sheep red blood cells and concomitantly inoculated intraperitoneally (i.p.) with each extract (50, 100 or 200 mg/kg). Specific antibody-producing cells were enumerated using plaque-forming cell assays (PFC) and anti-SRBC IgG and IgM serum levels were measured via enzyme-linked immunosorbent assay. Body and lymphoid organ weights were determined after treatments in order to evaluate toxic effects. Carrageenan-induced paw edema was employed to investigate anti-inflammatory activity in mice inoculated i.p. with CAE or HAE (200 or 400 mg/kg). Phytochemical screening was performed using spectrometric and chromatographic approaches and revealed that CAE possessed higher tannin and flavonoid levels than HAE. PFC numbers were increased after treatment with CAE (100 mg/kg) four days after immunization, as were the serum antibody titers after four and seven days, suggesting immunostimulatory activity through modulation of B lymphocyte functions. Body and organ weights did not show major changes, suggesting that extracts administered to mice did not induce significant toxicity. Both extracts had significant anti-inflammatory activity in the paw edema assay. These results suggested that aqueous extracts from A. tenella contained several chemical compounds that possess positive and/or negative modulator effects on the immune system, which appeared to correlate with tannin and flavonoid levels in those extracts. In summary, these studies provide important insight into the biological activities of A. tenella.

Effect of extracts and isolated compounds from Chresta scapigera on viability of Leishmania amazonensis and Trypanosoma cruzi

Fractionation of bioactive crude extracts of Chresta scapigera led to the isolation of four triterpenes and five flavonoids, among them beta-amyrin acetate (1), 11alpha,12alpha-oxidetaraxeryl acetate (2) and lupeol (3), as well as the flavonoids apigenin (6), kaempferol (7), crysoeriol (8) and luteolin (9) were active against Leishmania amazonensis amastigotes-like stages, while only the flavonoids (6), (7) and (9) showed toxicity towards bloods trypomastigote forms of Trypanosoma cruzi.

O fracionamento dos extratos bioativos de Chresta scapigera proporcionou o isolamento de triterpenos e flavonóides, dentre os quais acetato de beta-amirina (1), acetate de 11alfa,12-oxidotaraxeril (2) e lupeol (3), assim como os flavonóides apigenina (6), caenferol (7), crisoeriol (8) e luteolina (9) mostraram-se ativos contra formas amastigotas de Leishmania amazonensis, enquanto, apenas os flavonóides (6), (7) e (9) apresentaram toxicidade contra as formas tripomastigotas de Trypanosoma cruzi.

Biological activities and chemical composition of crude extracts from Chresta exsucca

As atividades tripanocida, leishmanicida, antibacteriana e antifungica dos extratos brutos de Chresta exsucca foram investigadas. Formas tripomastigotas do Trypanosoma cruzi, formas amastigotas de Leishmania amazonensis e vinte cepas de microrganismos, incluindo bactérias Gram-positivas, Gram-negativas e leveduras, foram utilizadas nos ensaios biológicos. Os melhores resultados foram obtidos para a atividade leishmanicida. A composição química dos extratos hexânicos e etanólicos dessa espécie foi determinada empregando-se técnicas cromatográficas como HRGC e HPLC-ESI-MS, respectivamente. Esteróides, triterpenos e flavonóides foram identificados.

Constituents of Moquinia kingii

A extração da planta total (partes aéreas e raiz) de Moquinia kingii forneceu três flavonóides, descritos pela primeira vez na tribo Moquinieae, além de lactona sesquiterpênica e triterpenos. As estruturas foram determinadas por estudos espectroscópicos.