Byrsonima sericea Ethanol Extract Protected PC12 Cells from the Oxidative Stress and Apoptosis Induced by 6-Hydroxydopamine.

Parkinson's disease is characterized by the progressive loss of dopaminergic neurons in the nigrostriatal pathway and oxidative stress is one of the main mechanisms that lead to neuronal death in this disease. Previous studies have shown antioxidant activity from the leaves of Byrsonima sericea, a plant of the Malpighiaceae family. This study aimed to evaluate the cytoprotective activity of the B. sericea ethanolic extract (BSEE) against the cytotoxicity induced by 6-hydroxydopamine (6-OHDA) in PC12 cells, an in vitro model of parkinsonism. The identification of phenolic compounds in the extract by HPLC-DAD revealed the presence of geraniin, rutin, isoquercetin, kaempferol 3-O-ß-rutinoside, and quercetin. The BSEE (75-300 µg/mL) protected PC12 cells from toxicity induced by 6-OHDA (25 µg/mL), protected cell membrane integrity and showed antioxidant activity. BSEE was able to decrease nitrite levels, glutathione depletion, and protect cells from 6-OHDA-induced apoptosis. Thus, we suggest that the BSEE can be explored as a possible cytoprotective agent for Parkinson's disease due to its high antioxidant capacity and anti-apoptotic action.

Palmatine, a natural alkaloid, attenuates memory deficits and neuroinflammation in mice submitted to permanent focal cerebral ischemia.

Ischemic stroke is one of the major causes of human morbidity and mortality. The pathophysiology of ischemic stroke involves complex events, including oxidative stress and inflammation, that lead to neuronal loss and cognitive deficits. Palmatine (PAL) is a naturally occurring (Coptidis rhizome) isoquinoline alkaloid that belongs to the class of protoberberines and has a wide spectrum of pharmacological and biological effects. In the present study, we evaluated the impact of Palmatine on neuronal damage, memory deficits, and inflammatory response in mice submitted to permanent focal cerebral ischemia induced by middle cerebral artery (pMCAO) occlusion. The animals were treated with Palmatine (0.2, 2 and 20 mg/kg/day, orally) or vehicle (3% Tween + saline solution) 2 h after pMCAO once daily for 3 days. Cerebral ischemia was confirmed by evaluating the infarct area (TTC staining) and neurological deficit score 24 h after pMCAO. Treatment with palmatine (2 and 20 mg/kg) reduced infarct size and neurological deficits and prevented working and aversive memory deficits in ischemic mice. Palmatine, at a dose of 2 mg/kg, had a similar effect of reducing neuroinflammation 24 h after cerebral ischemia, decreasing TNF-, iNOS, COX-2, and NF- κB immunoreactivities and preventing the activation of microglia and astrocytes. Moreover, palmatine (2 mg/kg) reduced COX-2, iNOS, and IL-1ß immunoreactivity 96 h after pMCAO. The neuroprotective properties of palmatine make it an excellent adjuvant treatment for strokes due to its inhibition of neuroinflammation.

Prevalence of depressive symptoms among dental students is influenced by sex, academic performance, smoking exposure, and sexual orientation: cross-sectional study

Aim: To estimate the prevalence and associated factors of self-reported depressive symptoms in undergraduate and graduate dental students. Methods: The Depression, Anxiety and Stress Scale (DASS-21) was applied, and only the depression domain was verified. A structured questionnaire was used to collect sociodemographic, behavioral, and COVID-19 pandemic-related fear variables. Academic performance was assessed based on academic records, ranging from 0 (worst possible grade) to 10 (best possible grade). Respondents included 408 regularly enrolled dental students. Bi- and multivariate analyses were performed using Poisson regression with robust variance to verify the association between at least moderate depressive symptoms and independent variables. Results: The prevalence of at least moderate depression was 40.5% among undergraduate students and 26% among graduate students. The prevalence of fear and anxiety due to the COVID-19 pandemic was 96.1% among undergraduate students and 93.5% among graduate students. In the final multivariate analysis, being female (prevalence ratio [PR]:2.01; 95% confidence interval [95%CI]:1.36­2.96) was associated with a higher PR for depression. Conversely, no exposure to smoking (PR:0.54; 95%CI:0.36­0.82) and a final academic performance average ≥7.0 (PR:0.56; 95%CI:0.41­0.76) was associated with a lower PR for depression. Finally, among graduate students, a non-heterosexual orientation was associated with a higher PR for depression (PR:6.70; 95%CI:2.21­20.29). Conclusion: Higher rates of depression symptoms were observed in female undergraduates, students with lower academic performance and smoking exposure, and graduate dental students with a non-heterosexual orientation