Development and Evaluation of Virola oleifera Formulation for Cutaneous Wound Healing.

In regions adjacent to the Brazilian Atlantic Forest, Virola oleifera (VO) resin extract has been popularly used for decades as a skin and mucosal healing agent. However, this antioxidant-rich resin has not yet been investigated in wound healing, whose physiological process might also be aggravated by oxidative stress-related diseases (e.g., hypertension/diabetes). Our aim, therefore, was to investigate whether VO resin presents healing effects through an innovative cream for topical applications. For this, adult male Wistar rats were divided into four groups. Then, four 15 mm excisions were performed on the shaved skin. All treatments were applied topically to the wound area daily. At the end of experiments (0, 3rd, and 10th days) macroscopic analysis of wound tissue contraction and histological analysis of inflammatory cell parameters were performed. The group treated with VO cream showed the best wound contraction (15%, p < 0.05) and reduced levels of lipid peroxidation and protein oxidation (118% and 110%, p < 0.05, respectively) compared to the control group. Our results demonstrated the healing capacity of a new formulation prepared with VO, which could be, at least in part, justified by antioxidant mechanisms that contribute to re-epithelialization, becoming a promising dermo-cosmetic for the treatment of wound healing.

DNA damage and repair on hematopoietic stem cells: impact of oxidative stress in renovascular hypertension.

BACKGROUND: This study investigated oxidative damage to bone marrow cells in the pathogenesis of renovascular hypertension (RH). METHODS: Male C57BL/6 J mice (10-week-old and ~23 g) were divided into two groups: Sham-operated and 2K1C, which has a stainless-steel clip placed around the left renal artery. After twenty-eight days, the animals were anesthetized for hemodynamic measurements and bone marrow cells isolation. The intracellular production of ROS, DNA damage, and DNA repair kinetics were evaluated. RESULTS: Our results show that RH increases HSCs ROS production and that the 2K1C group showed a significant reduction of HSCs in the G0/G1 phase, increased p53 expression, DNA fragmentation, low DNA repair capacity, and a higher percentage of apoptotic cells when compared with the Sham group. CONCLUSIONS: Our data imply that RH can compromise the hematopoiesis by increased oxidative stress leading to impaired DNA repair activity. Furthermore, this study provides new insights into the influence of hypertension on bone marrow homeostasis. This study showed for the first time that RH leads to oxidative damage, including genotoxic, to bone marrow cells. Thus, these findings provide new insights into the consequences of RH on bone marrow cells.

Mechanisms of Action of Kefir in Chronic Cardiovascular and Metabolic Diseases.

The gut microbiota maintains a complex mutual interaction with different organs of the host. Whereas in normal conditions this natural community of trillions of microorganisms greatly contributes to the human health, gut dysbiosis is related with onset or worsening of diverse chronic systemic diseases. Thus, the reestablishment of gut microbiota homeostasis with consumption of prebiotics and probiotics may be a relevant strategy to prevent or attenuate several cardiovascular and metabolic complications. Among these functional foods, the synbiotic kefir, which is a fermented milk composed of a mixture of bacteria and yeasts, is currently the most used and has attracted the attention of health care professionals. The present review is focused on reports describing the feasibility of kefir consumption to provide benefits in cardiometabolic diseases, including hypertension, vascular endothelial dysfunction, dyslipidemia and insulin resistance. Interestingly, recent studies show that mechanisms of actions of kefir in cardiometabolic diseases include recruitment of endothelial progenitor cells, improvement of the balance vagal/sympathetic nervous system, diminution of excessive generation of reactive oxygen species, angiotensin converting enzyme inhibition, anti-inflammatory cytokines profile and alteration of the intestinal microbiota. These findings provide a better understanding about the mechanisms of the beneficial actions of kefir and motivate further investigations to determine whether the use of this synbiotic could also be translated into clinical improvements in cardiometabolic diseases.

Increased ROS production and DNA damage in monocytes are biomarkers of aging and atherosclerosis

BACKGROUND: New evidence demonstrates that aging and dyslipidemia are closely associated with oxidative stress, DNA damage and apoptosis in some cells and extravascular tissues. However, in monocytes, which are naturally involved in progression and/or resolution of plaque in atherosclerosis, this concurrence has not yet been fully investigated. In this study, we evaluated the influence of aging and hypercholesterolemia on serum pro-inflammatory cytokines, oxidative stress, DNA damage and apoptosis in monocytes from apolipoprotein E-deficient (apoE-/-) mice compared with age-matched wild-type C57BL/6 (WT) mice. Experiments were performed in young (2-months) and in old (18-months) male wild-type (WT) and apoE-/- mice. RESULTS: Besides the expected differences in serum lipid profile and plaque formation, we observed that atherosclerotic mice exhibited a significant increase in monocytosis and in serum levels of pro-inflammatory cytokines compared to WT mice. Moreover, it was observed that the overproduction of ROS, led to an increased DNA fragmentation and, consequently, apoptosis in monocytes from normocholesterolemic old mice, which was aggravated in age-matched atherosclerotic mice. CONCLUSIONS: In this study, we demonstrate that a pro-inflammatory systemic status is associated with an impairment of functionality of monocytes during aging and that these parameters are fundamental extra-arterial contributors to the aggravation of atherosclerosis. The present data open new avenues for the development of future strategies with the purpose of treating atherosclerosis.

Protective effect of sildenafil on the genotoxicity and cytotoxicity in apolipoprotein E-deficient mice bone marrow cells.

BACKGROUND: The pharmacological inhibitor of phosphodiesterase 5 (PDE5), sildenafil, is a promising candidate for antioxidant therapy that can result in cardiovascular protection. In addition to its known effects on the cardiovascular system, hypercholesterolemia leads to increased oxidative stress and DNA damage in the bone marrow, which is a non-classical target organ of atherosclerosis. In the present study, we evaluate oxidative stress and assess the effect of genomic instability on cell cycle kinetics in atherosclerotic animals and determine if sildenafil reverses these detrimental effects in bone marrow cells. METHODS: Experiments were performed in male wild-type (WT) and apolipoprotein E knockout mice (apoE(-/-)) (9 weeks of age). apoE(-/-) mice were randomly distributed into the following 2 groups: sildenafil-treated (40 mg/kg/day for 3 weeks, n = 8) and vehicle-treated (n = 8), by oral gavage. After treatment, bone marrow cells were isolated to assess the production of superoxide anions and hydrogen peroxide, determine cell cycle kinetics and evaluate the presence of micronucleated cells. RESULTS: Sildenafil treatment reduced the cytoplasmic levels of superoxide anion (~95% decrease, p < 0.05) and decreased hydrogen peroxide (~30% decrease, p < 0.05). Moreover, we observed protective effects on the DNA of bone marrow cells, including normal cell cycling, decreased DNA fragmentation and a diminished frequency of micronucleated cells. CONCLUSION: Our data reveal that the excessive production of ROS in atherosclerotic mice overcome the DNA repair pathways in bone marrow cells. The novelty of the present study is that the administration of sildenafil reduced ROS to baseline levels and, consequently, reverted the DNA damage and its outcomes in bone marrow cells.

Reactive oxygen species contribute to dysfunction of bone marrow hematopoietic stem cells in aged C57BL/6 J mice.

BACKGROUND: Stem cells of intensely regenerative tissues are susceptible to cellular damage. Although the response to this process in hematopoietic stem cells (HSCs) is crucial, the mechanisms by which hematopoietic homeostasis is sustained are not completely understood. Aging increases reactive oxygen species (ROS) levels and inflammation, which contribute to increased proliferation, senescence and/or apoptosis, leading to self-renewal premature exhaustion. In this study, we assessed ROS production, DNA damage, apoptosis, senescence and plasticity in young, middle and aged (2-, 12- and 24-month-old, respectively) C57BL/6 J mice. RESULTS: Aged HSCs showed an increase in intracellular superoxide anion (1.4-fold), hydrogen peroxide (2-fold), nitric oxide (1.6-fold), peroxynitrite/hidroxil (2.6-fold) compared with young cells. We found that mitochondria and NADPHox were the major sources of ROS production in the three groups studied, whereas CYP450 contributed in middle and aged, and xanthine oxidase only in aged HSCs. In addition, we observed DNA damage and apoptosis in the middle (4.2- and 2-fold, respectively) and aged (6- and 4-fold, respectively) mice; aged mice also exhibited a significantly shorter telomere length (-1.8-fold) and a lower expression of plasticity markers. CONCLUSION: These data suggest that aging impairs the functionality of HSCs and that these age-associated alterations may affect the efficacy of aged HSC recovery and transplantation.

Renovascular hypertension leads to DNA damage and apoptosis in bone marrow cells.

Angiotensin II (Ang II), which plays a pivotal role in the pathophysiology of the two-kidney, one-clip (2K1C) Goldblatt hypertension, has been associated with augmented generation of reactive oxygen species (ROS) in some cells and tissues. In the present study, we evaluated the influence of 2K1C hypertension on oxidative stress, DNA fragmentation, and apoptosis of bone marrow (BM) cells. Two weeks after the renal artery clipping or Sham operation, flow cytometry analysis showed a higher production of superoxide anions (approximately sixfold) and hydrogen peroxide (approximately twofold) in 2K1C hypertensive than in Sham normotensive mice. 2K1C mice also showed an augmented DNA fragmentation (54%) and apoptotic cells (21%). Our data show that the 2K1C renovascular hypertension is characterized by an increased production of ROS, DNA damage, and apoptosis of BM, which is a fundamental source of the cells involved in tissue repair.