Antiproliferative Effects of Pterodon pubescens Extract and Isolated Diterpenes in HaCaT Cells.

Pterodon pubescens fruits are popularly used because of their analgesic and anti-inflammatory actions, which are attributed to the isolated compounds with a vouacapan skeleton. This work aimed to evaluate the antiproliferative and anti-inflammatory effects of a P. pubescens fruit dichloromethane extract and the vouacapan diterpene furan isomer's mixture (1 : 1) (6α-hydroxy-7ß-acetoxy-vouacapan-17ß-oate methyl ester and 6α-acetoxy-7ß-hydroxy-vouacapan-17ß-oate methyl ester isomers) in HaCaT cells using the cell migration and the BrDU incorporation assay. Levels of IL-8 were measured by ELISA after TNF-α stimulation. HPLC/DAD analysis of the extract revealed the expressive presence of vouacapan diterpene furan isomer's mixture. P. pubescens extract (1.5625 - 25 µg/mL) and vouacapan diterpene furan isomer's mixture (3.125 - 50 µM) inhibited cell proliferation as indicated by a decreased BrdU-incorporation. For the evaluation of cell migration, time-lapse microscopy was used. P. pubescens presented inhibition on cell migration at all concentrations tested (3.125 - 12.5 µg/mL), whereas for the VDFI mixture, the inhibition was only observed at the highest concentrations (12.5 and 25 µM) tested. Furthermore P. pubescens extract and vouacapan diterpene furan isomer's mixture significantly decreased IL-8 levels. Our results showed antiproliferative and anti-inflammatory effects on HaCaT cells treated with the extract and the vouacapan isomer's mixture, without affecting cell viability. These activities could be attributed to the voucapan molecular structures. In conclusion, topical products developed of P. pubescens extract or the voucapan isomer's mixture should be further studied as a potential product for local treatment against hyperproliferative lesions as in psoriasis vulgaris, representing an alternative treatment approach.

Evaluation of the Intestinal Absorption Mechanism of Casearin X in Caco-2 Cells with Modified Carboxylesterase Activity.

The clerodane diterpene casearin X (1), isolated from the leaves of Casearia sylvestris, is a potential new drug candidate due to its potent in vitro cytotoxic activity. In this work, the intestinal absorption mechanism of 1 was evaluated using Caco-2 cells with and without active carboxylesterases (CES). An LC-MS method was developed and validated for the quantification of 1. The estimation of permeability coefficients was possible only under CES-inhibited conditions in which 1 is able to cross the Caco-2 cell monolayer. The mechanism is probably by active transport, with no significant efflux, but with a high retention of the compound inside the cells. The enzymatic hydrolysis assay demonstrates the susceptibility of 1 to first-pass metabolism as substrate for specific CES expressed in human intestine.

Evaluation of intestinal permeability of vicenin-2 and lychnopholic acid from Lychnophora salicifolia (Brazilian arnicão) using Caco-2 cells.

Lychnophora salicifolia, commonly known as "arnicão", is used as an anti-inflammatory agent and as a flavoring agent in the Brazilian traditional spirit "cachaça". In this work, the permeation process of vicenin-2 (1) and lychnopholic acid (2) (major secondary metabolites from the hydroalcoholic extract) was investigated using Caco-2 cells. For this investigation, a new HPLC-DAD method was developed and validated for the quantification step. It was observed that 2 crosses the Caco-2 cell monolayer by passive diffusion. On the other hand, 1 was not transported, suggesting no absorption and no efflux of this compound in Caco-2 cells.

Assessment of sedative effects of Passiflora edulis f. flavicarpa and Passiflora alata extracts in mice, measured by telemetry.

Several Passiflora species have been used widely as a folk medicine due to their sedative and anxiolytic activities. In Brazil, a number of native plants of the genus Passiflora exist, but only Passiflora edulis f. flavicarpa (PE) and Passiflora alata (PA) are of commercial value. Thus, the aim of the present study was to investigate the sedative effects of aqueous extracts obtained from the pericarp as well as from the leaves of PE and PA in mice using radiotelemetry. Aqueous extracts from PE and PA were tested for effects on locomotion over 180 min in 300 mg/kg, 600 mg/kg and 1200 mg/kg, in male C57BL/6J mice after oral administration. For validation of the telemetry system, caffeine (negative control) and midazolam (positive control) were used. All tested extracts decreased locomotor activity in a dose-dependent manner in comparison to the control group. The two lower concentrations of each extract showed the highest decrease in locomotion after 24 min, while 1200 mg/kg had a significant sedative effect already after 18 min. Interestingly, aqueous extracts of PA were more active in comparison to aqueous extracts of PE and the pericarp extracts of both plants showed more pronounced effects on locomotor activity if compared to leaf extracts. In conclusion, the present study represents an innovative, objective approach to measure sedative effects of plant extracts with minimized handling-related stress and remote data collection.

Isolation and HPLC quantitative analysis of antioxidant flavonoids from Alternanthera tenella Colla.

Phytochemical analysis of the antioxidant ethanolic extract of Alternanthera tenella Colla led to the isolation of six flavonoids, acacetin 8-C-[alpha-L-rhamnopyranosyl-(1 --> 2)-beta-D-glucopyranoside] (1), 2"-O-alpha-L-rhamnopyranosyl-vitexin (2), 2"-O-beta-D-glucopyranosyl-vitexin (3), vitexin (4), quercetin (5) and kaempferol (6). All the structures were established by ESI-MS and NMR spectroscopic methods. Antioxidant capacity of extract, fractions and isolated compounds was determined using the oxygen radical absorbance capacity (ORAC) assay and extract, fractions and flavonoids isolated showed antioxidant activity in vitro. Moreover, the total soluble phenolic contents of the extract and fractions were measured using the Folin-Ciocalteau reagent and the quantitative analysis of flavone C-glycosides major constituents was performed by HPLC.