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 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.