Gabriel de Oliveira Isac Moraes

Hypotensive effect of aqueous extract of Averrhoa carambola L. (Oxalidaceae) in rats: An in vivo and in vitro approach

AIM OF THE STUDY Averrhoa carambola L. (Oxalidaceae) leaves are used in Brazilian traditional medicine to treat hypertension. This study was conducted to evaluate the hypotensive effect of the aqueous extract of Averrhoa carambola (AEAc) and its underlying mechanisms in the isolated rat aorta. MATERIALS AND METHODS The effect of AEAc on the mean arterial pressure (MAP) was determined in vivo in anesthetized rats. In vitro, thoracic aortic rings were isolated and suspended in organ baths, and the effects of AEAc were studied by means of isometric tension recording experiments. In HPLC analysis, the fingerprint chromatogram of AEAc was established. RESULTS In normotensive rats, AEAc (12.5-50.0 mg/kg, i.v.) induced dose-dependent hypotension. In vitro, AEAc caused a depression in the E(max) response to phenylephrine without a change in sensibility. Also, in a depolarized Ca(2+)-free medium, AEAc inhibited CaCl(2)-induced contractions and caused a concentration-dependent rightward shift of the response curves, indicating that AEAc inhibited the contractile mechanisms involving extracellular Ca(2+) influx. CONCLUSIONS These results demonstrate the hypotensive effects of AEAc, and these effects may, in part, be due to the inhibition of Ca(2+), which supports previous claims of its traditional use.

Green banana pasta diet prevents oxidative damage in liver and kidney and improves biochemical parameters in type 1 diabetic rats

OBJECTIVE In this study, the effects of a green banana pasta diet on the oxidative damage from type 1 diabetes mellitus (DM) were investigated. MATERIALS AND METHODS Formulations containing 25 (F25), 50 (F50), and 75% (F75) of green banana pasta were prepared and included in a 12-week diet of Wistar rats with alloxan-induced type 1 DM. The effects of these formulations in preventing oxidative damage in kidneys and liver homogenates of rats were evaluated using the TBARS assay (lipid peroxidation in liver) and the DNPH assay (protein oxidation in liver and kidneys). Furthermore, the effects of the formulations on the fasting glycemia, fructosamine levels, renal function (creatinine), liver function (enzymes aspartate aminotransferase [AST] and alanine aminotransferase [ALT]), and lipid profile (total cholesterol and fractions) in the serum of rats were evaluated in addition to the evaluation of the centesimal composition and microbiological analysis of the produced green banana pasta. RESULTS An F75 diet prevented hyperglycemia in diabetic rats (p < 0.05) compared to the diabetic rats fed a standard diet (commercial feed). Notably, the protein oxidation in both the liver and kidneys were prevented in diabetic rats on the F50 or F75 diets compared to the control group, whereas the lipid peroxidation was only prevented in the liver (p < 0.05). Moreover, all formulations prevented an increase in the amount of triglycerides in the serum of the rats. The F25 and F50 diet prevented the increase of cholesterol, and the F75-based diet of ALT and fructosamine (p < 0.05) supported the anti-hyperglycemic effects and the protection against oxidative damage. CONCLUSION The green banana pasta (F75) diet showed great potential for preventing complications associated with diabetes.

Photodynamic therapy for Schistosoma mansoni: Promising outcomes

The purpose of this study was to assess, for the very first time, the effects of photodynamic therapy (PDT) on Schistosoma mansoni in vitro by measuring reactive oxygen species (ROS) generation throughout the treatment, as well as the behavior of the parasites (mating, motility and contraction/shortening), and damage to their tegument and excretory systems. The parasites were divided into 4 groups: control, photosensitizer, laser and PDT. Light irradiation was delivered with an InGaAlP low-level laser device operating at 660nm, with 40mW and 100J/cm2. For PDT, different toluidine blue dye (TBO) concentrations and times of exposure were utilized. Interestingly, TBO-mediated PDT was able to kill S. mansoni (P<0.001) due to the significant amount of ROS released that inflicted damages in the tegument and excretory system, as well as contraction and cessation of motility. In addition, males of S. mansoni were shown to be more sensitive to PDT if compared to their corresponding females when the optimal TBO concentration of 31.2μL was considered (P=0.0126). PDT presents two major advantages: not inducing microbial resistance and also lacking adverse effects. Therefore, PDT may become a promising therapeutic alternative for schistosomiasis in the near future, especially for cases of allergy and resistance to praziquantel.