Antiproliferative potential of solidagenone isolated of Solidago chilensis

ABSTRACT Plants are considered among the main sources of biologically active chemicals. The species Solidago chilensis Meyen, Asteraceae, is native to the southern parts of South America, where the aerial parts of the plant are commonly used for the treatment of inflammatory conditions. However, the effects of S. chilensis on human cancer cells remain to be elucidated. In this study, we evaluated the antiproliferative effects of the hydroalcoholic and dichloromethane extracts of S. chilensis, as well as their chemical constituents quercitrin and solidagenone against the five human tumor cell lines in vitro. The dichloromethane extract showed a promisor antiproliferative effects in vitro, especially against glioma cell line. Besides, the hydroalcoholic extract and quercitrin were inactive. The diterpene solidagenone showed highly potent antiproliferative effects against breast (MCF-7), kidney (786-0), and prostate cancer (PC-3) cells (total growth inhibition: TGI < 6.25 µg/ml). Solidagenone meets the theoretical physico-chemical criteria for bioavailability of drugs, according to the "Rule of Five" and, by theorical studies, the observed biological effects were probably related to the interaction of the molecule with nuclear receptors and as an enzymatic inhibitor. This study contributes to chemical study and to the identification of antiproliferative molecules in S. chilensis.

Effects of hydroalcoholic extract of Celtis iguanaea on markers of cardiovascular diseases and glucose metabolism in cholesterol-fed rats

ABSTRACT Celtis iguanaea (Jacq.) Sarg., Cannabaceae, is popularly used in the treatment of diabetes mellitus. However, chemical and pharmacological investigations are lacking. In this study, we investigated the effects of the hydroalcoholic extract from C. iguanaea on markers of cardiovascular diseases and the glucose metabolism in cholesterol-fed rats. Therefore, hypercholesterolemic rats (1% cholesterol) were orally treated with C. iguanaea extract (C-150, CI-300, or CI-600 mg/kg) or simvastatin (4 mg/kg) (n = 6) once a day (30 days) with a hypercholesterolemic diet. A control group (C) was given saline. C. iguanaea extract showed significant decreases in serum levels of total cholesterol, LDL-cholesterol, HMG-CoA-reductase, interleukin-1 and 6, TNF-α and IFN-γ when compared to group C (p < 0.001). Hypoglycemic effects were observed along with a decrease of the activity of sucrase (CI-600), maltase (CI-150, CI-300), and an increase in muscle glycogen levels (CI-300). Antioxidant effects were observed in plasma by the decrease of TBARS and increase of nonprotein thiols levels (CI-600). The histopathological analysis showed a significant decrease in the liver fat area for C. iguanaea extract compared to group C (p < 0.001). Our results suggest that the biological effects of C. iguanaea extract could be related to the flavonoids that possibly exert antioxidant, enzymatic inhibitory, and insulin-mimetic effects.

Antiproliferative effects of pinostrobin and 5,6-dehydrokavain isolated from leaves of Alpinia zerumbet

Abstract Natural products are a major source of drugs for the treatment of cancer. The species Alpinia zerumbet (Pers.) B.L. Burtt & R.M. Sm, Zingiberaceae, is widely distributed in Brazil where it is known as "colônia". The leaves are commonly used in the treatment of hypertension and dyspepsia, however, the effects of A. zerumbet extracts and isolated substances on human cancer cells remain to be elucidated. This study was designed to identify the chemical constituents of hydroalcoholic and dichloromethane extracts from A. zerumbet leaves and to investigate their in vitro antiproliferative activity. The isolated phytochemicals included kaempferol, dihydro-5,6-dehydrokavain, 5,6-dehydrokavain, and pinostrobin. The hydroalcoholic extract inhibited cellular proliferation only at high concentrations, while the dichloromethane extract showed a moderate antiproliferative effect against leukemia and lung tumor cell lines. 5,6-Dehydrokavain showed potent cytostatic activity against glioblastoma cells and a moderate effect on all other tumor cell lines. Pinostrobin showed potent activity against leukemia and breast tumor cell lines and moderate cytostatic effect against ovarian cell. Furthermore, this is the first report on the isolation of kaempferol and pinostrobin from A. zerumbet leaves. Moreover, the purification process described in this study was effective. These results suggest that A. zerumbet leaves are a promising source of anticancer compounds.