Determination of preclinical safety of oil obtained from Pachira aquatica Aublet (Malvaceae) seeds: histopathological, biochemical, hematological, and genetic toxicity studies in rats.

Pachira aquatica is a species used for medicinal and food purposes and has numerous phytochemicals that may have systemic toxic effects and damage to genetic material. This study aimed to evaluate acute and short-term oral toxicity, as well as genotoxic and clastogenic effects of oil extracted from P. aquatica (PASO) seeds in rats and Drosophila melanogaster. The results obtained with biochemical and hematological analyses did not show significant changes in any evaluated parameters when compared with reference values for the species used in the study. Data from the histopathological analysis corroborated results found in this study. These findings indicate low acute and short-term toxicity following oral PASO exposure in rats under the experimental conditions tested. Tests performed in rats showed that PASO did not present significant genotoxic or clastogenic effects on the cells analyzed with the three doses tested. Treatment with PASO in the offspring of HB crossing, which showed high cytochrome P450 levels, did not exhibit genotoxic activity, as demonstrated by the SMART test. These results suggest that products from the hepatic oil metabolism did not show genotoxicity under the conditions tested. Together, the results indicate that, under the experimental conditions tested, PASO is safe for repeated intake. As PASO exhibited low potential to cause harmful effects on living organisms, our study encourages further research aimed at assessing its pharmacological activity, since it is a widely consumed plant.

The ethanolic extract obtained from Campomanesia pubescens (D.C.) O.BERG fruits exerts anxiolytic and antidepressant effects on chronic mild stress model and on anxiety models in Wistar rats: Behavioral evidences.

Objectives: Campomanesia pubescens (DC) O.BERG (Myrtaceae) fruits contain high levels of flavonoids and are widely consumed by the South American population. In the central nervous system (CNS), some flavonoids act as modulators of GABA-A receptors and monoamine oxidase inhibitors, resulting in anxiolytic antidepressants effects, respectively. The objective of the present study was to evaluate the anxiolytic and antidepressant effects of ethanolic extract of C. pubescens fruits (EEFCP) in rats.Methods: In order to prove the antidepressant effect of the EEFCP, rats were submitted to the chronic mild stress model, to the sucrose preference test (SPT), and the forced swimming test. To test the anxiolytic effects, the Elevated plus-maze (EPM), open field (OF), and Marble-Burying models were used.Results: After 2 weeks of treatment, imipramine 25 mg/kg, EEFCP 250 mg/kg, and EEFCP 500 mg/kg reversed the anhedonic behavior measured by SPT and significantly reduced the immobility time of animals under stress. In addition, treatment with diazepam 2 mg/kg, EEFCP 250 mg/kg, and EEFCP 500 mg/kg increased the percentage of entries and time spent on the open arms of the EPM, increased locomotion, rearing, and reduced the grooming time in OF.Discussion: The chemical analysis of the EEFCP indicated high content of flavonoids and the behavioral analysis revealed an antidepressant and anxiolytic effect, suggesting that these phytochemicals may be involved with these actions in the CNS.

Evaluation of the effect of alpha-tocopherol on anxiety and the neuroinflammatory process during alcohol withdrawal in a model of forced and chronic self-administration of liquid diet containing ethanol: Behavioral and neurochemical evidence.

Alcoholism affects about 2 billion people worldwide. Withdrawal causes a neuroinflammatory response that increases anxiety. α-tocopherol is the most important antioxidant that has its in vivo action currently known. Therefore, this study aimed to evaluate the effect of α-tocopherol on the neuroinflammatory process in brain regions involved in anxiety and its anxiolytic potential during alcohol withdrawal. For this, male Wistar rats were divided into four groups and submitted to a procedure of forced and chronic self-administration of liquid diet containing 6% and 8% ethanol for 15 days, followed by abrupt interruption of treatment. Animals in the control group received the liquid diet without ethanol. Twenty-four or 48 h after ethanol discontinuation, and 30 min after the last administration of α-tocopherol or saline, animals were evaluated in the elevated plus maze, light/dark box, and open field tests. At the end of the tests, each experimental group underwent brain tissue collection for analysis of cytokine levels. The results showed that: alcohol induces the neuroinflammatory process and anxiety; the stress generated by withdrawal can induce oxidative stress, which alters the production of inflammatory cytokines in the amygdaloid nuclei (AN) and medial hypothalamic nucleus (mHN); α-tocopherol exhibited anxiolytic and anti-inflammatory activity, attenuating the anxious behavior of abstinent animals and reducing neuroinflammation in AN and mHN; and the intensity of the anxiolytic and anti-inflammatory effect of α-tocopherol is dose-dependent. These results identify α-tocopherol as a potential therapeutic target supporting the fight against relapse during alcohol withdrawal.

Evaluation of the toxic potential of the aqueous extract from Mangifera indica Linn. (Anacardiaceae) in rats submitted to experimental models of acute and subacute oral toxicity.

ETHNOPHARMACOLOGICAL RELEVANCE: The population has traditionally used the Mangifera indica plant leaves to treat diseases such as Diabetes Mellitus and alleviate signs and symptoms such as inflammation, diarrhea, and dysentery. In a previous study, we demonstrated that the flavonoids present in the aqueous extract from M. indica leaves (EAMI) exhibited a potent hypoglycemic effect in diabetic rats, promoting the widespread use of the plant by the population and highlighting the importance of investigating its oral toxicity. AIM OF THE STUDY: The present study aimed to assess the toxic potential of EAMI in rats submitted to experimental models of acute and subacute (short-term) oral toxicity. MATERIAL AND METHODS: For the acute toxicity test, female Wistar rats received a single oral dose of 2000 mg/kg body weight of EAMI and were observed for 14 days. In the short-term toxicity test, male and female Wistar rats received repeated oral EAMI doses of 125, 250, 500 or 1000 mg/kg body weight and observed for 28 days. RESULTS: The phytochemical analysis of EAMI demonstrated that the extract has high levels of flavonoids. No animals died in the acute toxicity test, and no clinical changes were observed that show signs of toxicity in the animals. There was no significant change in the weight of the organs of the animals submitted to tests with the EAMI, suggesting that LD50 is greater than 2000 mg/kg. In the conditions and doses tested in the short-term toxicity experiments, the treatment did not produce significant changes in the physiological, biochemical, hematological, and histopathological parameters in the animals evaluated. CONCLUSIONS: Our study demonstrated that high doses of EAMI administered acutely, as well as all doses evaluated in the short-term oral toxicity model, should be considered safe during traditional therapeutic use.

Aqueous extract from Mangifera indica Linn. (Anacardiaceae) leaves exerts long-term hypoglycemic effect, increases insulin sensitivity and plasma insulin levels on diabetic Wistar rats.

BACKGROUND: Diabetes mellitus is one of the most common todays public health problems. According to a survey by the World Health Organization, this metabolic disorder has reached global epidemic proportions, with a worldwide prevalence of 8.5% in the adult population. OBJECTIVES: The present study aimed to investigate the hypoglycemic effect of aqueous extract of Mangifera indica (EAMI) leaves in streptozotocin-induced diabetic rats. METHODS: Sixty male rats were divided into 2 groups: Normoglycemic and Diabetic. Each group was subdivided into negative control, glibenclamide 3 or 10 mg/kg, EAMI 125, 250, 500, and 1000 mg/kg. Intraperitoneal injection of streptozotocin 100 mg/kg was used to DM induction. The hypoglycemic response was assessed acutely after two and four weeks of treatment. After a 6-hour fasting period, the fasting blood glucose of animals was verified, and 2.5 g/kg glucose solution was orally administered. The insulin tolerance test and plasma insulin levels assessment were performed in the morning after fasting of 12 to 14 hours. RESULTS AND CONCLUSION: The chemical analysis of EAMI showed high levels of phenolic compounds. There was no significant difference in fasting blood glucose between normoglycemic and diabetic groups, and that EAMI did not have an acute effect on diabetes. After two and four weeks of treatment, the extract significantly reduced blood glucose levels, exceeding glibenclamide effects. EAMI was effective in maintaining the long-term hypoglycemic effect, as well as, significantly increased the sensitivity of diabetic animals to insulin and the plasma insulin level.

Molecular aspects of depression: A review from neurobiology to treatment.

Major depressive disorder (MDD), also known as unipolar depression, is one of the leading causes of disability and disease worldwide. The signs and symptoms are low self­esteem, anhedonia, feeling of worthlessness, sense of rejection and guilt, suicidal thoughts, among others. This review focuses on studies with molecular-based approaches involving MDD to obtain an integrated, more detailed and comprehensive view of the brain changes produced by this disorder and its treatment and how the Central Nervous System (CNS) produces neuroplasticity to orchestrate adaptive defensive behaviors. This article integrates affective neuroscience, psychopharmacology, neuroanatomy and molecular biology data. In addition, there are two problems with current MDD treatments, namely: 1) Low rates of responsiveness to antidepressants and too slow onset of therapeutic effect; 2) Increased stress vulnerability and autonomy, which reduces the responses of currently available treatments. In the present review, we encourage the prospection of new bioactive agents for the development of treatments with post-transduction mechanisms, neurogenesis and pharmacogenetics inducers that bring greater benefits, with reduced risks and maximized access to patients, stimulating the field of research on mood disorders in order to use the potential of preclinical studies. For this purpose, improved animal models that incorporate the molecular and anatomical tools currently available can be applied. Besides, we encourage the study of drugs that do not present "classical application" as antidepressants, (e.g., the dissociative anesthetic ketamine and dextromethorphan) and drugs that have dual action mechanisms since they represent potential targets for novel drug development more useful for the treatment of MDD.

Preclinical safety evaluation of the aqueous extract from Mangifera indica Linn. (Anacardiaceae): genotoxic, clastogenic and cytotoxic assessment in experimental models of genotoxicity in rats to predict potential human risks.

ETHNOPHARMACOLOGICAL RELEVANCE: Medicinal plants widely used by the population contain significant concentrations of biologically active compounds and, although they have proven pharmacological properties, can cause DNA damage and develop fatal diseases. AIM OF THE STUDY: The present study aimed to evaluate the genotoxic, cytotoxic potential and clastogenic effects of the aqueous extract from Mangifera indica leaves (EAMI) on rats submitted to experimental genotoxicity models and through the SMART test performed in Drosophila melanogaster. MATERIAL AND METHODS: The comet assay and the micronucleus test were performed on peripheral and bone marrow blood, respectively, of Wistar rats, orally treated with EAMI at doses of 125, 250, 500 and 1000 mg/kg/bw for 28 days. In the SMART test, the standard cross between three mutant D. melanogaster strains was used. Larvae were treated with EAMI at different concentrations, and the wings of adult flies were evaluated for the presence/frequency of mutant spots and compared to the negative control group. RESULTS: Phytochemical analysis of EAMI indicated high levels of flavonoids. The tests performed in rats showed that EAMI did not present significant genotoxic or clastogenic effects. The results showed a critical dose-dependent cytoprotective effect exerted by EAMI. This result was attributed to the high content of polyphenols and flavonoids. The biotransformation metabolites of EAMI did not present genotoxic activity, as demonstrated by the SMART test. CONCLUSIONS: These results are relevant since they provide safety information about a plant species of great therapeutic, economical, nutritious and ethnopharmacological value for the population.

Preclinical safety evaluation of the ethanolic extract from Campomanesia pubescens (Mart. ex DC.) O.BERG (guavira) fruits: analysis of genotoxicity and clastogenic effects.

Genotoxicity studies of plants with medicinal and nutritional properties are recommended by international regulatory agencies as part of the risk assessment. Due to their consumption as food, nutraceutical use and ethnopharmacological relevance, Campomanesia pubescens represents one of these plants to be studied. The aim of the present study was to evaluate the genotoxic, cytotoxic potential and clathogenic effects of the ethanolic extract obtained from the pulp of C. pubescens (EEFCP) fruits on rats submitted to experimental genotoxicity models and through the SMART test performed in Drosophila melanogaster. The comet assay and the micronucleus test were performed on peripheral and bone marrow blood, respectively, of Wistar rats orally treated with EEFCP at doses of 125, 250, 500 and 1000 mg per kg per bw for 28 days. In the SMART test, the standard cross between three mutant D. melanogaster strains was used. Larvae were treated with EEFCP at different concentrations and the wings of adult flies were evaluated for the presence/frequency of mutant spots and compared to the negative control group. Phytochemical analysis of EEFCP indicated high levels of flavonoids. The tests performed in rats showed that EEFCP did not present significant genotoxic or clastogenic effects. The biotransformation metabolites of EEFCP did not present genotoxic activity, as demonstrated by the SMART test. Together, all results indicate that, under the experimental conditions used, EEFCP did not reveal any preclinical genetic toxicity. Therefore, the safe consumption can be fomented increasing, consequently, the economic liquidity in the industrial market from the fruits of guavira.

Preclinical safety evaluation of the ethanolic extract from guavira fruits (Campomanesia pubescens (D.C.) O. BERG) in experimental models of acute and short-term toxicity in rats.

Campomanesia pubescens is a fruit plant widely distributed in South America and used by the population for medicinal and nutritional purposes, with important economic and cultural value. This study evaluated the toxic potential of the ethanolic extract from C. pubescens (EEFCP) fruits through acute and short-term toxicity tests. For the acute toxicity test, female rats received a single oral dose of 2000 mg/kg body weight of EEFCP and were observed for 14 days. In the short-term toxicity test, male and female rats received repeated oral doses of 125, 250, 500 or 1000 mg/kg of EEFCP, being treated and observed for 28 days, and after the treatment period, a satellite and satellite control group remained under observation for another 14 days. No mortality, clinical and organ weight alterations were observed, indicating that LD50 is greater than 2000 mg/kg body weight. In addition, the doses tested did not produce significant changes in the behavioral, physiological, hematological or histopathological parameters of animals. These results demonstrate the low acute and short-term toxicity of EEFCP in rats. The data obtained are of great relevance since they provide important information about a plant species of great economic, nutritional and ethnopharmacological value.

Oral acute and subchronic toxicity studies of the oil extracted from pequi (Caryocar brasiliense, Camb.) pulp in rats.

The Caryocar brasiliense (pequi) is a Brazilian fruit of important geographic distribution and of broad popular use for nutritional purposes. This study aimed to evaluate the toxicological potential of pequi through the acute and subchronic toxicity tests. For the acute toxicity test, female Wistar rats received, orally, a single dose of 2000 mg/kg/bw of pequi oil and were observed for 14 days. In subchronic toxicity test, Wistar male and female rats received, orally, repeated doses of 125, 250, 500 or 1000 mg/kg/bw of the oil, being treated and observed for 28 days. In the acute toxicity test, no changes as well as no mortality were observed, indicating that the LD50 is higher than 2000 mg/kg/bw. In the subchronic toxicity test, the tested doses produced no significant changes in behavioral, physiological, biochemical or histopathologic parameters in animals. Some hematological abnormalities were found after subchronic exposure and need to be clarified. These results demonstrate the low toxicity of acute and subchronic to the oil of pequi in rats. However, additional studies are required in order to verify if the hematological abnormalities have any relation to the oil exposure and also provide sufficient safety evidence for the use of the oil in humans.

GABA(B) receptor agonist only reduces ethanol drinking in light-drinking mice.

Baclofen, a GABA(B) agonist, reduces ethanol intake in animals and humans, but the contrary or no effect was also reported. Our previous study demonstrated that mice characterized as "loss of control over ethanol intake" had different Gabbr1 and Gabbr2 transcription levels, which express, respectively, the GABA(B1) and GABA(B2) subunits in brain areas related to addictive behavior. In the present study, we tested baclofen on ethanol intake in mice exposed to the free-choice paradigm. Adult male Swiss mice, individually housed, had free access to three bottles: ethanol (5% and 10%) and water. The protocol had four phases: acquisition (AC, 10 weeks), withdrawal (W, 4 cycles during 2 weeks of 2 day-free-choice and 2 day-only-water), reexposure (RE, 2 weeks), and adulteration of ethanol solutions with quinine (AD, 2 weeks). Mice characterized as "loss of control" (A, n=11, preference for ethanol in AC and maintenance of ethanol intake levels in AD), heavy (H, n=11, preference for ethanol in AC and reduction of ethanol intake levels in AD), and light (L, n=16, preference for water in all phases) drinkers were randomly distributed into two subgroups receiving either intraperitoneal injections of all doses of baclofen (1.25, 2.5, and 5.0mg/kg, given each dose twice in consecutive days) or saline, being exposed to free-choice. Fluid consumption was measured 24h later. Baclofen reduced ethanol intake in group L. In group H a reduction compared to AC was observed. Group A maintained their high ethanol intake even after baclofen treatment. Activation of the GABA(B) receptor depends on the precise balance between the GABA(B1) and GABA(B2) subunits, so the disproportionate transcription levels, we reported in group A, could explain this lack of response to baclofen. These data highlight the importance to test baclofen in individuals with different ethanol drinking profiles, including humans.