In vitro antioxidant potential and in vivo effects of Schinus terebinthifolia Raddi leaf extract in diabetic rats and determination of chemical composition by HPLC-ESI-MS/MS.

The present study investigated the in vitro and in vivo antioxidant potential and phytochemical composition of Schinus terebinthifolia, which is widely used in folk medicine for various therapeutic purposes. The in vitro analyses indicated that the hydroethanolic extract (HE) had 312.50 ± 0.50 mg GAE/g of total phenols. It also presented anti-DPPH• and anti-ABTS•+ activity, reduced phosphomolybden and metal ions and blocked the bleaching of ß-carotene. The HE at concentrations of 3.0 and 2.0 µg/mL had TRAP values of 2.223 ± 0.018 and 1.894 ± 0.026 µM Trolox, respectively. The HE increased the availability of antioxidants in plasma in treated animals in vivo. HPLC-ESI-MS/MS indicated the presence of 11 phenols: cumaric acid, (+)-catechin, myricetin-3-O-glicuronide, kaempferol-3-O-glucoside, myricetin, myricitrin, quercetin, gallic acid, methyl galate, pentagalloyl glucose and ethyl galate. Thus, S. terebinthifolia has potential for the prevention or treatment of diseases that are related to oxidative stress, such as diabetes mellitus.

Larvicidal potential of piperovatine in the control of cattle tick.

Rhipicephalus (Boophilus) microplus is one of the most important ectoparasites in cattle breeding worldwide, causing direct and indirect losses to animals and producers. Chemical acaricides are utilized in the control of cattle tick and the increase in the development of resistance by ectoparasites makes new alternative necessary. Therefore, research studies have been carried out using bioactive molecules that are quickly degraded and that reduce poisoning to appliers and non-target organisms, environmental contamination and development of resistance. Thus, this study aimed to isolate piperovatine from the roots of Piper corcovadensis, a native species to Brazil, and to evaluate the larvicidal activity against Rhipicephalus (Boophilus) microplus by larval packet test and in ex situ in an open environment. Piperovatine was isolated by classical column chromatography, and identified by 1H and 13C NMR. The lethal concentration (LC) of piperovatine that killed 50% (LC50) and 99% (LC99) of the larvae was determined by Probit analysis. The results indicated LC50 5.17 and LC99 25.41 µg/mL. LC99 was tested in ex situ in an open environment, and an efficiency of 96.63% was found, indicating that piperovatine kept the larvicidal action determined in in vitro test and in open environment. Therefore, this study shows new perspectives to develop products that can be applied in natural conditions to control this ectoparasite.

Evaluation of Chemical Composition and Antileishmanial and Antituberculosis Activities of Essential Oils of Piper Species.

Essential oils from fresh Piperaceae leaves were obtained by hydrodistillation and analyzed by gas chromatography mass spectrometry (GC-MS), and a total of 68 components were identified. Principal components analysis results showed a chemical variability between species, with sesquiterpene compounds predominating in the majority of species analyzed. The composition of the essential oil of Piper mosenii was described for the first time. The cytotoxicity of the essential oils was evaluated in peritoneal macrophages and the oils of P. rivinoides, P. arboretum, and P. aduncum exhibited the highest values, with cytotoxic concentration at 50% (CC50) > 200 µg/mL. Both P. diospyrifolium and P. aduncum displayed activity against Leishmania amazonensis, and were more selective for the parasite than for the macrophages, with a selectivity index (SI) of 2.35 and >5.52, respectively. These SI values were greater than the 1 for the standard drug pentamidine. The antileishmanial activity of the essential oils of P. diospyrifolium and P. aduncum was described for the first time. P. rivinoides, P. cernuum, and P. diospyrifolium displayed moderate activity against the Mycobacterium tuberculosis H37Rv bacillus, with a minimum inhibitory concentration (MIC) of 125 µg/mL. These results are relevant and suggests their potential for therapeutic purposes. Nevertheless, further studies are required to explain the exact mechanism of action of these essential oils.