Evaluation of homeopathic medicine in rats subjected to a hypercaloric diet and stress

Introduction: The factors related to obesity are complex, involving biologic, environmental and neuropsychological mechanisms[1-3]. Among the factors which influence the gain of weight, we can consider the stressful factors. Aims: The aim of this experiment was to evaluate the influence of the commercial homeopathic product compound by Fucus vesiculosus 1cH, Thyroidinum 5cH and Calcarea carbonica 5cH (Besomed®) in the gain of weight in animals submitted to hypercaloric diet and stress. Materials and Methods 40 male freshly weaned Wistar rats, ingesting hypercaloric food, were divided into 4 groups, being two groups submitted to stress by standstill, being one group treated and the other one for control (vehicle) and two more groups without stress being one treated and the other one for control. All were given the drink water ad libidum, in blind, for 2 months. The general activity was evaluated by the Open Field method in 2 steps, one after stress and one after 1 month of treatment. The weekly gain of weight was measured during the whole period of treatment. The data were analyzed by the ANOVA method of two ways followed by the Bonferroni test[4], being p≤0,05. Results: The treatment with Besomed® was effective in reducing only the gain of weight in the animals submitted to stress (p≤0,05); the evaluation of general activity in the Open Field showed increase in the time of freezing of these same animals after receiving the stressful stimulus. Discussion: The medicine is used as auxiliary in obesity treatment, and has the same both endogenous highdiluted molecules as the medicine used by similarity, which is the case of Calcarea carbonica, which, among others is indicated for obesity and hyperlipidemia[5], being observed in this study that the homeopathic complex group gained less weight than the other groups. Stress is capable of disturbing the physiological and psychological homeostasia of an individual, and when the stress is caused by standstill, it may induce behavior of the anxious type. There are also studies relating anxiety and feeding behavior in chronically stressed[6] individuals, showing that consuming a hypercaloric diet induces an anxious behavior[7] in male rats. In this study was not observed any change in the motor activity of animals which passed stress, however the time of freezing of the animals which took Besomed® was the lowest (p≤0,05) after stress, if compared to the control groups, demonstrating the absence of an anxious behavior. Conclusion: The medicine evaluated was effective in reducing weight and in inducing an adaptive behavior only in the stressed animals, reducing the evaluated parameters to the same levels observed in the control group.

Preliminary Study of Body Temperature Emissivity in Rabbits Selected for Litter Size Residual Variability

A divergent selection for litter size residual variability has been carried out in rabbits during 12 generations. Litter size residual variability was estimated as phenotypic variance of litter size within females after correcting for the year-season and the parity-lactation status effects. Stress causes an increase in core body temperature. Infrared thermography (IRT) has been shown to be a useful technique for identifying changes in body temperature emissivity. The aim of this work is to study the correlated response to selection for litter size residual variability in body temperature emissivity at natural mating. Natural mating can be considered a stressful stimulus for does. Temperature was measured in the eyeball by IRT before mating (basal temperature) and after 5 min, 30 min, and 60 min in does of the lines selected to decrease and to increase litter size residual variability (i.e., the Low and the High lines). Both lines showed similar basal temperature. Eyeball temperature was increased slightly in the Low line from basal state to 5 min after stressful stimulus (from 35.69 °C to 36.32 °C), and this increase remained up to 60 min after stress (36.55 °C). The High line showed a higher temperature than the Low line at 30 min (+0.96 °C, p = 0.99). At 60 min, temperature was similar between lines. The evolution of temperature was different between lines: the High line reached the peak of temperature later than the Low line (at 30 min vs. 5 min), and its peak was higher compared to the Low line (36.95 °C vs. 36.32 °C). In conclusion, the does selected for reducing litter size variability showed a lower increase in temperature after a stressful stimulus, therefore showing lower stress and consequently better welfare.

The evolution of the concept of stress and the framework of the stress system

Stress is a central concept in biology and has now been widely used in psychological, physiological, social, and even environmental fields. However, the concept of stress was cross-utilized to refer to different elements of the stress system including stressful stimulus, stressor, stress response, and stress effect. Here, we summarized the evolution of the concept of stress and the framework of the stress system. We find although the concept of stress is developed from Selye’s “general adaptation syndrome”, it has now expanded and evolved significantly. Stress is now defined as a state of homeostasis being challenged, including both system stress and local stress. A specific stressor may potentially bring about specific local stress, while the intensity of stress beyond a threshold may commonly activate the hypothalamic-pituitary-adrenal axis and result in a systematic stress response. The framework of the stress system indicates that stress includes three types: sustress (inadequate stress), eustress (good stress), and distress (bad stress). Both sustress and distress might impair normal physiological functions and even lead to pathological conditions, while eustress might benefit health through hormesis-induced optimization of homeostasis. Therefore, an optimal stress level is essential for building biological shields to guarantee normal life processes.

Acute and chronic effects of exams week on cortisol production in undergraduate students

ABSTRACTUndergraduate students experience many levels of stress throughout their university trajectory. The pressure to achieve good results highlight the exams week in the Universities as a stimulus that triggers psychosocial stress and increased release of cortisol. Considering the increasingly experience an undue amount of stress, we aimed in this study to investigate the short- and long-term effects of exams week on HPA axis in undergraduates by the cortisol production. Twenty-eight undergraduates aged 18-24 years from biological sciences during the final exams’ week at the end of the school year collected hair and saliva for cortisol measures. Hair cortisol was significantly higher in exams month. They exhibited cortisol rhythmicity and preserved CAR (cortisol awakening response) even under psychosocial stress. The exams week is a trigger for psychosocial stress, however, did not generate significant short-term changes in cortisol rhythmicity. Thus, it is evident that young people adapt to the stressful stimulus, avoiding a possible trigger for mental illness.

A role for cerebral cortex in the suppression of innate defensive behavior

The cerebral cortex is involved in the control of cognition and the processing of learned information and it appears to have a role in the adaptation of behavior in response to unpredictable circumstances. In addition, the cortex may have a role in the regulation of innate responses since rodents, cats or primates with surgical removal or accidental destruction of cortical regions show excessive irritability, aggression and rage elicited by threatening stimuli. However, it remains unclear whether cortex has an acute role in suppressing innate threat responses because the imprecision and chronic nature of these lesions leaves open the possibility that compensatory processes may underlie some of these phenotypes. In the present study we used pharmacogenetic inhibition to precisely, rapidly and reversibly suppress cortical pyramidal neuron function and examine its contribution to defensive behaviors elicited by a variety of innately aversive stimuli. Inhibition of cortex caused an increase of defensive responses elicited by an aggressive conspecific, a novel prey, and a physically stressful stimulus. These findings are consistent with a role of cortex in the acute inhibition of innate defensive behaviors.

Diene Valepotriates fromValeriana glechomifoliaPrevent Lipopolysaccharide-Induced Sickness and Depressive-Like Behavior in Mice

Valeriana glechomifolia, a native species from southern Brazil, presents antidepressant-like activity and diene valepotriates (VAL) contribute to the pharmacological properties of the genus. It is known that depression can develop on an inflammation background in vulnerable patients and antidepressants present anti-inflammatory properties. We investigated the effects of VAL (10 mg/kg, p.o.) on sickness and depressive-like behaviors as well as proinflammatory cytokines (IL-1βand TNF-α) and BDNF expression in the cortex of mice exposed to a 5 min swimming session (as a stressful stimulus) 30 min before theE. coliLPS injection (600 µg/kg, i.p.). The forced swim + LPS induced sickness and depressive-like behaviors, increased the cortical expression of IL-1βand TNF-α, and decreased BDNF expression. VAL was orally administered to mice 1 h before (pretreatment) or 5 h after (posttreatment)E. coliLPS injection. The pretreatment with VAL restored the behavioral alterations and the expression of cortical proinflammatory cytokines in LPS-injected animals but had no effects on BDNF expression, while the posttreatment rescued only behavioral alterations. Our results demonstrate for the first time the positive effects of VAL in an experimental model of depression associated with inflammation, providing new data on the range of action of these molecules.

Neurobiology of Posttraumatic Stress Disorder (PTSD) and its Frontostriatal Implications: a short review

Throughout its evolutionary course, stress has remained as an adaptive response to stimuli that may jeopardize the integrity of an organism. Within this perspective, we can classify the stressors as psychological,physical or harmful to cardiovascular stability. However, when intense stressful events occur, there is a possibility of developing PTSD. This disorder makes use of the hypothalamic-pituitary-adrenal axis, which is commonly activated during stress and is kept activated even when the stressful stimulus has ended months ago. The consequences of this condition are observed at the neuroendocrine, neurochemical and anatomical level. This review aims to give a brief report of the neurobiology of stress, PTSD, and its implications in various structures,such as the amygdala, hippocampus and prefrontal cortex.

Dental anxiety in relation to aggressive characteristics of patients

Dental anxiety is defined as the response to a stressful stimulus that is specific to a dental context. The dental treatment itself may provoke excitation and aggressive response relating to multiple sources of motivation that have been examined by the literature.The hypothesis to test in the present paper is to what extent dental anxiety can be explained by looking at patients’ characteristics solely or by considering latent aggressiveness that could be manifested before and during the dental treatment.The results of the study should give some indications to dentists to better understand the presence of a greater or lesser anxiety associated with orthodontic treatment in order to provide an appropriate assistance and, eventually, to help patients in developing coping strategies. As a consequence, it should be clear how intervening on each component of dental anxiety and/or aggressiveness may have a positive impact on the outcome of dental treatment.

Maternal depression and foetal responses to novel stimuli: insights from a socio-economically disadvantaged Indian cohort

Maternal stress during pregnancy has pervasive effects on stress responsivity in children. This study is the first to test the hypothesis that maternal prenatal depression, as observed in South India, may be associated with how foetuses respond to a potentially stressful stimulus. We employed measures of foetal heart rate at baseline, during exposure to a vibroacoustic stimulus, and post-stimulation, to study patterns of response and recovery in 133 third trimester foetuses of depressed and non-depressed mothers. We show that the association between maternal depression and foetal stress responsivity is U-shaped with foetuses of mothers with high and low depression scores demonstrating elevated responses, and poorer recovery, than foetuses of mothers with moderate levels. The right amount of intra-uterine stimulation is important in conditioning foetuses towards optimal regulation of their stress response. Our results imply that, in certain environmental contexts, exposure to moderate amounts of intra-uterine stress may facilitate this process.