<bold>Interaction between Pyridostigmine Bromide and Oxidative Stress</bold>

In this chapter the following topics will be addressed: (1) actions of the cholinergic system in the nervous system, commenting on acetylcholine metabolism and acetylcholinesterase metabolism; (2) acetylcholinesterase inhibitors as subtitle in this topic: pharmacological characterization of pyridostigmine bromide, mechanism of action, and therapeutic effect of the drug; (3) use of pyridostigmine bromide in Persian Gulf War; and (4) potential effect of pyridostigmine bromide in oxidative stress, addressing as subtitle the influence of pyridostigmine bromide on the superoxide-hydrogen peroxide imbalance model. Studies indicate that the interaction between pyridostigmine bromide and stressors could trigger genotoxicity, the mechanism associated with the induction of oxidative stress that leads to this side effect of this drug; however, this discussion needs to be better elucidated and may be more discussed as there is interaction between the pyridostigmine bromide and an endogenous oxidative imbalance caused by it or even by the possible interaction of this with genetic variations present in the antioxidant metabolism

Human adipose-derived stem cells obtained from lipoaspirates are highly susceptible to hydrogen peroxide mediated cytogenotoxicity

There is evidence that H2O2 can induce the proliferation, migration, and regeneration of stem cells, as well as that of adipose-derived stem cells (ASCs). This could be useful to expand the possible uses of ASCs in therapeutic applications. &nbsp;However, the safety profile of H2O2 use in stem cells is not clear yet. Therefore, the present study evaluated the acute cytotoxic, oxidative and genotoxic effects of different concentrations of H2O2 on ASCs obtained from human lipoaspirates. The ASCs were treated with 1–1000 μM H2O2 for two hours. Cell viability was evaluated by double-strand DNA determination. Apoptosis induction was analyzed measuring active levels of caspases 1, 3 and 8. Biochemical oxidative stress markers were analyzed and genotoxic effects were assessed by DNA comet assay. All H2O2 concentrations increased ASC mortality rates with approximately 100% mortality achieved at ≥ 200 μM. Active caspases 1, 3 and 8, oxidative stress, as well as oxidative damage as assessed by lipid peroxidation increased dose‐dependently. There was also an approximate 50% increase in catalase levels in cells exposed to all H2O2 tested concentrations. H2O2 concentrations of ≥ 10 μM were genotoxic. These results suggest that ASCs are highly sensitive to H2O2 exposition. In addition, DNA damage in the surviving cells may affect their proliferative and differentiation capacity, as well as their safety profile for therapeutic use

Regenerative potential of the cartilaginous tissue in mesenchymal stem cells: update, limitations, and challenges

ABSTRACT Advances in the studies with adult mesenchymal stem cells (MSCs) have turned tissue regenerative therapy into a promising tool in many areas of medicine. In orthopedics, one of the main challenges has been the regeneration of cartilage tissue, mainly in diarthroses. In the induction of the MSCs, in addition to cytodifferentiation, the microenvironmental context of the tissue to be regenerated and an appropriate spatial arrangement are extremely important factors. Furthermore, it is known that MSC differentiation is fundamentally determined by mechanisms such as cell proliferation (mitosis), biochemical-molecular interactions, movement, cell adhesion, and apoptosis. Although the use of MSCs for cartilage regeneration remains at a research level, there are important questions to be resolved in order to make this therapy efficient and safe. It is known, for instance, that the expansion of chondrocytes in cultivation, needed to increase the number of cells, could end up producing fibrocartilage instead of hyaline cartilage. However, the latest results are promising. In 2014, the first stage I/II clinical trial to evaluate the efficacy and safety of the intra-articular injection of MSCs in femorotibial cartilage regeneration was published, indicating a decrease in injured areas. One issue to be explored is how many modifications in the articulate inflammatory environment could induce differentiation of MSCs already allocated in that region. Such issue arose from studies that suggested that the suppression of the inflammation may increase the efficiency of tissue regeneration. Considering the complexity of the events related to the chondrogenesis and cartilage repair, it can be concluded that the road ahead is still long, and that further studies are needed

Xanthine-Catechin Mixture Enhances Lithium-Induced Anti-Inflammatory Response in Activated Macrophages In Vitro

Lithium (Li) is a chemical element used for treating and preventing bipolar disorder (BD) and exerts positive effects such as anti-inflammatory effects as well as undesirable side effects. These effects of Li can be influenced by interaction with some nutritional elements. Therefore, we investigated the potential effects of xanthine (caffeine and theobromine) and catechin molecules present in some food beverages broadly consumed worldwide, such as coffee and tea, on Li-induced anti-inflammatory effects. In the present study, we concomitantly exposed RAW 264.7 macrophages to Li, isolated xanthine and catechin molecules, and a xanthine-catechin mixture (XC mixture). We evaluated the effects of these treatments on cell proliferation, cell cycle progression, oxidative and antioxidant marker expression, cytokine levels, gene expression, and GSK-3β enzyme expression. Treatment with the XC mixture potentialized Li-induced anti-inflammatory effects by intensification of the following: GSK-3β inhibitory action, lowering effect on proinflammatory cytokines (IL-1β, IL-6, and TNFα), and increase in the levels of IL-10 that is an anti-inflammatory cytokine. Despite the controversial nature of caffeine consumption by BD patients, these results suggested that consumption of caffeine, in low concentrations, mixed with other bioactive molecules along with Li may be safe

Xanthine-Catechin Mixture Enhances Lithium-Induced Anti-Inflammatory Response in Activated Macrophages In Vitro

Lithium (Li) is a chemical element used for treating and preventing bipolar disorder (BD) and exerts positive effects such as anti-inflammatory effects as well as undesirable side effects. These effects of Li can be influenced by interaction with some nutritional elements. Therefore, we investigated the potential effects of xanthine (caffeine and theobromine) and catechin molecules present in some food beverages broadly consumed worldwide, such as coffee and tea, on Li-induced anti-inflammatory effects. In the present study, we concomitantly exposed RAW 264.7 macrophages to Li, isolated xanthine and catechin molecules, and a xanthine-catechin mixture (XC mixture). We evaluated the effects of these treatments on cell proliferation, cell cycle progression, oxidative and antioxidant marker expression, cytokine levels, gene expression, and GSK-3β enzyme expression. Treatment with the XC mixture potentialized Li-induced anti-inflammatory effects by intensification of the following: GSK-3β inhibitory action, lowering effect on proinflammatory cytokines (IL-1β, IL-6, and TNFα), and increase in the levels of IL-10 that is an anti-inflammatory cytokine. Despite the controversial nature of caffeine consumption by BD patients, these results suggested that consumption of caffeine, in low concentrations, mixed with other bioactive molecules along with Li may be safe

Guaraná (Paullinia cupana) improves the proliferation and oxidative metabolism of senescent adipocyte stem cells derived from human lipoaspirates

AbstractCellular senescence is a limiting factor in the proliferative expansion and quality of adult mesenchymal stem cells, often making them unviable in regenerative clinical practice. In vitro supplementation by antioxidant food extract of senescent mesenchymal stem cells could reverse these undesirable characteristics. To evaluate this hypothesis, senescent adipocyte-mesenchymal cells (ASCs) obtained from human lipoaspirates were exposed at different concentrations of hydro-alcoholic guaraná (Paullinia cupana) extract for 72h. After the incubation, we performed a proliferative assay. Oxidative stress indicators and antioxidant enzymes (biochemical activity and gene expression by qRT-PCR analysis) in these senescent cells were also evaluated. In senescent cells exposed to guaraná at 5mg/g concentration increased cellular proliferation occurred compared to untreated senescent cells (79.1±15.7%). Concomitantly, a decrease in several oxidative stress indicators was observed in senescent cells treated with guaraná. A genomic effect of guaraná exposure was observed when the modulation of antioxidant enzymes genes was analyzed. The results described here suggest that the food extract supplementation could reverse the initial senescence processes in ASCs. These results have potential application in regenerative medicine

Human adipose-derived stem cells obtained from lipoaspirates are highly susceptible to hydrogen peroxide mediated cytogenotoxicity

There is evidence that H2O2 can induce the proliferation, migration, and regeneration of stem cells, as well as that of adipose-derived stem cells (ASCs). This could be useful to expand the possible uses of ASCs in therapeutic applications. &nbsp;However, the safety profile of H2O2 use in stem cells is not clear yet. Therefore, the present study evaluated the acute cytotoxic, oxidative and genotoxic effects of different concentrations of H2O2 on ASCs obtained from human lipoaspirates. The ASCs were treated with 1–1000 μM H2O2 for two hours. Cell viability was evaluated by double-strand DNA determination. Apoptosis induction was analyzed measuring active levels of caspases 1, 3 and 8. Biochemical oxidative stress markers were analyzed and genotoxic effects were assessed by DNA comet assay. All H2O2 concentrations increased ASC mortality rates with approximately 100% mortality achieved at ≥ 200 μM. Active caspases 1, 3 and 8, oxidative stress, as well as oxidative damage as assessed by lipid peroxidation increased dose‐dependently. There was also an approximate 50% increase in catalase levels in cells exposed to all H2O2 tested concentrations. H2O2 concentrations of ≥ 10 μM were genotoxic. These results suggest that ASCs are highly sensitive to H2O2 exposition. In addition, DNA damage in the surviving cells may affect their proliferative and differentiation capacity, as well as their safety profile for therapeutic use