Alexandre Roberto Hickmann

Effect of pterostilbene complexed with cyclodextrin on rat liver: potential reduction of oxidative damage and modulation redox-sensitive proteins

The objectives of this study were to promote the aqueous solubility of pterostilbene (PTS) by complexation with hydroxypropyl-β-cyclodextrin (HPβCD), characterize the complex under physical aspects, to make its oral administration feasible in biological tests, and to investigate their pharmacological properties. For 14 days, rats received daily PTS:HPΒCD complex at doses of 25, 50, or 100 mg kg−1 per day orally. The results showed no kidney or liver damage, nor any induction of apoptosis by the administered doses. Also, the complex showed dose-dependent antioxidant effects in the rat liver, as evidenced by a reduction in lipid peroxidation and reactive oxygen species, as well as an increase in non-enzymatic antioxidant. PTS:HPΒCD complex also increased the expression of sensitive redox proteins such as AKT and GSK-3β related to the insulin signaling pathway in the liver. Thus, the complexation demonstrated to be able to increase the apparent solubility of PTS making feasible dose curve administration and could be a food alternative complementary to antioxidant therapeutic. Therefore, the PTS:HPβCD complex can be used for prevention of diseases related to oxidative damage and insulin signaling.

Sulforaphane effects on oxidative stress parameters in culture of adult cardiomyocytes

The aim of this study was to analyse the effect of sulforaphane (SFN) in cultures of adult cardiomyocytes, evaluating oxidative stress at different times. Cells were isolated, cultured, and divided into 4 groups: Control, SFN (5μM), H2O2 (5μM), and SFN+H2O2 (5μM both), and subdivided into groups undergoing 1 or 24 h of SFN incubation. After 1 h of incubation, reactive oxygen species production was 40% lower in the SFN group than the Control, and lipid peroxidation was 63% higher in the H2O2 group than the Control, and it was reduced in both of the SFN groups. The SOD activity was 59% higher in groups incubated for 24 h than in those incubated for 1 h. Protein expression of SOD-1 and SOD-2 was higher in the 24-h groups compared to the 1-h groups (55% and 24%, respectively). The Nrf2 protein expression in the 1-h groups was 17% higher than in the 24-h groups, and the SFN + H2O2 group had 40% more Nrf2 than the Control in the 1-h groups. Unlike Nrf2, the PGC-1α expression was 69% higher in the 24-h groups in relation to the 1-h groups. Regarding the 24-h groups, the SFN and SFN+H2O2 groups were higher than the Control (32% and 33%, respectively), and the SFN+H2O2 group was increased (21%) compared to H2O2. SFN had a protective action against oxidative damage, but had no effect on the antioxidant enzymes analyzed. The different responses in the expression of Nrf2 and PGC-1α in relation to the incubation times, draws attention to the importance of establishing a timeline of the action of SFN, since there appears to be a temporal difference in its mechanism in adult cardiomyocytes.