Alkaloid and acetogenin-rich fraction from Annona crassiflora fruit peel inhibits proliferation and migration of human liver cancer HepG2 cells.

Plant species from Annonaceae are commonly used in traditional medicine to treat various cancer types. This study aimed to investigate the antiproliferative potential of an alkaloid and acetogenin-rich fraction from the fruit peel of Annona crassiflora in HepG2 cells. A liquid-liquid fractionation was carried out on the ethanol extract of A. crassiflora fruit peel in order to obtain an alkaloid and acetogenin-rich fraction (AF-Ac). Cytotoxicity, proliferation and migration were evaluated in the HepG2 cells, as well as the proliferating cell nuclear antigen (PCNA), vinculin and epidermal growth factor receptor (EGFR) expression. In addition, intracellular Ca2+ was determined using Fluo4-AM and fluorescence microscopy. First, 9 aporphine alkaloids and 4 acetogenins that had not yet been identified in the fruit peel of A. crassiflora were found in AF-Ac. The treatment with 50 µg/mL AF-Ac reduced HepG2 cell viability, proliferation and migration (p < 0.001), which is in accordance with the reduced expression of PCNA and EGFR levels (p < 0.05). Furthermore, AF-Ac increased intracellular Ca2+ in the HepG2 cells, mobilizing intracellular calcium stores, which might be involved in the anti-migration and anti-proliferation capacities of AF-Ac. Our results support the growth-inhibitory potential of AF-Ac on HepG2 cells and suggest that this effect is triggered, at least in part, by PCNA and EGFR modulation and mobilization of intracellular Ca2+. This study showed biological activities not yet described for A. crassiflora fruit peel, which provide new possibilities for further in vivo studies to assess the antitumoral potential of A. crassiflora, especially its fruit peel.

Antioxidant compounds from Banisteriopsis argyrophylla leaves as α-amylase, α-glucosidase, lipase, and glycation inhibitors.

Banisteriopsis argyrophylla belongs to the Malpighiaceae family, which is a species from Cerrado, also known as "cipó-prata" or "cipó-folha-de-prata." Several species of this family present biological potential. This work reports the chemical identification of the ethanol extract (EE) and its fractions from B. argyrophylla leaves and shows the analysis of the antioxidant activity and inhibitory effects on activities of α-amylase, α-glucosidase and lipase, and non-enzymatic glycation. The ethyl acetate fraction (EAF) and n-butanol fraction (BF) showed antioxidant activity, with IC50 values of 4.1 ± 0.1 and 4.8 ± 0.1 µg mL-1, respectively, by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, and IC50 values of 6046.3 ± 174.2 and 6264.2 ± 32.2 µmol Trolox eq g-1 by the oxygen radical absorbance capacity (ORAC) method. Furthermore, the DPPH method with these fractions presented electroactive species with antioxidant potential, as shown by the differential pulse voltammetry (DPV) method. The inhibitory effects of the EAF and BF were demonstrated by the following results: IC50 of 5.1 ± 0.3 and 2.5 ± 0.2 µg mL-1 for α-amylase, IC50 of 1093.5 ± 26.0 and 1250.8 ± 21.9 µg mL-1 for α-glucosidase, IC50 of 8.3 ± 4.1 and 4.4 ± 1.0 µg mL-1 for lipase, and IC50 of 1.3 ± 0.1 and 0.9 ± 0.1 µg mL-1 for glycation. Some bioactive compounds were identified by (-)-ESI-MS/MS, such as catechin, procyanidins, glycosylated flavonoids, kaempferol, and megastigmane glucosides. The antidiabetic activity of B.argyrophylla has been reported for the first time.

Potential Benefits of Nitrate Supplementation on Antioxidant Defense System and Blood Pressure Responses after Exercise Performance.

Nitrate (NO3 -) supplementation is associated with exercise performance, oxygen uptake, blood flow, and blood pressure improvement, and it can act as an antioxidant agent. This study evaluated the effects of sodium nitrate supplementation on oxidative stress markers and blood pressure responses after aerobic exercise performance in physically active males. Fourteen subjects aged 22 ± 3 years and with a BMI of 23 ± 1 kg/m2 were submitted to four exercise tests in intervals of 5 days. Nitrate supplementation (NO session) and placebo supplementation (PL session) were acute (AC) and over a period of 5 days (FD) in random order with a crossover design. Saliva was collected at basal (0'); 60 min after supplementation (60'); immediately after exercise (90'); and 15, 30, and 60 min after the test (105', 120', and 150'). The NO session had higher concentrations (P < 0.05) of salivary nitrite in both AC and FD treatments when compared with the PL session. There was a reduction in systolic blood pressure (SBP) only after FD in the NO session. Furthermore, uric acid and total antioxidant capacity (FRAP) salivary concentrations increased, while SOD activity and TBARS levels decreased after FD but not after AC in the NO session. The results suggest that nitrate supplemented over a period of 5 days reduced SBP and indirectly acted as an antioxidant in healthy nonsedentary young men.