Publications by authors named "Paulo F V Bizerra"

Previous research has revealed that mitochondria are an important target for photodynamic therapy (PDT), which might be employed as a therapeutic approach for several malignancies, including hepatocellular carcinoma (HCC). In this study, we investigated both intrinsic toxicity and photodynamic effects of the photosensitizer (PS) aluminum chloride phthalocyanine (AlClPc) on mitochondrial functions. Several aspects of mitochondrial bioenergetics, structure, and oxidative state were investigated in the isolated mitochondria obtained from rat liver by differential centrifugation.

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Overall health relies on features of skeletal muscle that generally decline with age, partly due to mechanisms associated with mitochondrial redox imbalance and bioenergetic dysfunction. Previously, aged mice genetically devoid of the mitochondrial NAD(P) transhydrogenase (NNT, encoded by the nicotinamide nucleotide transhydrogenase gene), an enzyme involved in mitochondrial NADPH supply, were shown to exhibit deficits in locomotor behavior. Here, by using young, middle-aged, and older NNT-deficient (Nnt) mice and age-matched controls (Nnt), we aimed to investigate how muscle bioenergetic function and motor performance are affected by NNT expression and aging.

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Cyclic AMP is produced in cells by two different types of adenylyl cyclases: at the plasma membrane by the transmembrane adenylyl cyclases (tmACs, ADCY1~ADCY9) and in the cytosol by the evolutionarily more conserved soluble adenylyl cyclase (sAC, ADCY10). By employing high-resolution extracellular flux analysis in HepG2 cells to study glycogen breakdown in real time, we showed that cAMP regulates glycogen metabolism in opposite directions depending on its location of synthesis within cells and the downstream cAMP effectors. While the canonical tmAC-cAMP-PKA signaling promotes glycogenolysis, we demonstrate here that the non-canonical sAC-cAMP-Epac1 signaling suppresses glycogenolysis.

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Clomipramine, a tricyclic antidepressant used to treat depression and obsessive-compulsive disorder, has been linked to a few cases of acute hepatotoxicity. It is also recognized as a compound that hinders the functioning of mitochondria. Hence, the effects of clomipramine on mitochondria should endanger processes that are somewhat connected to energy metabolism in the liver.

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Toluidine blue O (TBO) is a phenothiazine dye that, due to its photochemical characteristics and high affinity for biomembranes, has been revealed as a new photosensitizer (PS) option for antimicrobial photodynamic therapy (PDT). This points to a possible association with membranous organelles like mitochondrion. Therefore, here we investigated its effects on mitochondrial bioenergetic functions both in the dark and under photostimulation.

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Imidacloprid (IMD) is a neonicotinoid insecticide used in large quantities worldwide in both veterinary and agronomic applications. Several studies have shown adverse effects of IMD on non-target organisms, with the liver being identified as the main affected organ. This study aimed to evaluate the effects of IMD on human hepatoblastoma (HepG2) cells.

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Background: The present study aimed to characterize the intrinsic and photodynamic effects of azure B (AB) on mitochondrial bioenergetics, as well as the consequences of its intrinsic effects on hepatic energy metabolism.

Methods: Two experimental systems were utilized: (a) isolated rat liver mitochondria and (b) isolated perfused rat liver.

Results: AB interacted with mitochondria regardless of photostimulation, but its binding degree was reduced by mitochondrial energization.

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Azure A (AA) is a cationic molecule of the class of phenothiazines that has been applied in vitro as a photosensitising agent in photodynamic antimicrobial chemotherapy. It is a di-demethylated analogue of methylene blue (MB), which has been demonstrated to be intrinsically and photodynamically highly active on mitochondrial bioenergetics. However, as far as we know, there are no studies about the photodynamic effects of AA on mammalian mitochondria.

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Diazinon (DZN) is a broad-spectrum insecticide extensively used to control pests in crops and animals. Several investigators demonstrated that DZN produced tissue toxicity especially to the liver. In addition, the mitochondrion was implicated in DZN-induced toxicity, but the precise role of this organelle remains to be determined.

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Testosterone is the predominant androgen in men and the lack of it can be a trigger to the development of the metabolic syndrome. Here we review the relationship between testosterone deficiency, metabolic syndrome, and hepatic steatosis reported by studies with men and rodents. The prevalence of metabolic syndrome and testosterone deficiency is higher among older subjects.

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According to the literature, methylene blue (MB) is a photosensitizer (PS) with a high affinity for mitochondria. Therefore, several studies have explored this feature to evaluate its photodynamic effects on the mitochondrial apoptotic pathway under normoxic conditions. We are aware only of limited reports regarding MB's photodynamic effects on mitochondrial energy metabolism, especially under hypoxic conditions.

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Imidacloprid (IMD) is a neonicotinoid insecticide widely used in crops, pets, and on farm animals for pest control, which can cause hepatotoxicity in animals and humans. In a previous study using isolated rat liver mitochondria, we observed that IMD inhibited the activity of FF-ATP synthase. The aim of this study was to evaluate the effects of IMD on rat isolated hepatocytes and perfused rat liver, besides the influence of its biotransformation on the toxicological potential.

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There is no use restriction associated with bees for many fungicides used in agriculture; however, this does not always mean that these pesticides are harmless for these nontarget organisms. We investigated whether the fungicide pyraclostrobin, which acts on fungal mitochondria, also negatively affects honey bee mitochondrial bioenergetics. Honey bees were collected from 5 hives and anesthetized at 4 °C.

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The toxic effects of the insecticide fipronil on the sperm production and oxidative damage in the testis were evaluated, as well as the protective action of vitamin E. Male rats received vehicle or fipronil 5 mg/kg and fipronil 5 mg/kg + vitamin E 100 mg/kg for 14 days. Thereafter, the sperm concentration in the epididymis and parameters of oxidative damage in the homogenate of testicles were assessed.

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Silkworm cocoon production has been reduced due to a number of problems other than those inherent in sericulture, such as diseases, malnutrition, and inappropriate management. The use of pesticides in areas surrounding mulberry fields can contaminate these plants and consequently harm caterpillars. The aim of this study was to evaluate whether the application of the fungicide pyraclostrobin in mulberry plants interferes with the mitochondrial bioenergetics and the productive performance of silkworms.

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Imidacloprid (IMD) is a neonicotinoid insecticide widely used in crops, pets, and on farm animals for pest control. Several studies were conducted examining the adverse effects of IMD on animals often exhibiting hepatic damage. The aim of this study was to determine the effects of IMD on bioenergetics of mitochondria isolated from rat liver.

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Background: Gossypol is a chemical present in the seeds of cotton plants (Gossypium sp.) that reduces fertility in farm animals. Vitamin E is an antioxidant and may help to protect cells and tissues against the deleterious effects of free radicals.

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