Is there a common pathophysiological mechanism between COVID-19 and depression?

COVID-19 is a disease caused by SARS-CoV-2 and was initially considered to cause serious damage to the respiratory system. Over time, it has been found to affect other organs due to its ability to bind to the ACE2 receptor (type 2 angiotensin-converting enzyme), which can be found in various tissues, including the central nervous system. In addition, a large formation of pro-inflammatory cytokines responsible for various lesions was observed during the evolution of this disease. Our objective was to demonstrate the molecular mechanisms involved in the infection that may demonstrate the relationship between COVID-19 and the development of depressive conditions. Based on the main medical databases (LiLacs, SciELO, Bireme, Scopus, EBSCO, and PubMed) and using the terms 'coronavirus infections' AND 'Inflammation' AND 'depression' AND 'cytokines', we conducted an integrative review of articles published in 2020. Considering this stage of Covid-19 and the inflammatory component of depression, this review showed a relationship between these two conditions based on common pathophysiological mechanisms indicating possible depressive disorders in surviving patients, especially in the most severe cases. The role of inflammatory cytokines and the presence of ACE-2 receptors on the cell surface appear to be the common pathophysiological mechanism between COVID-19 and depression.

Antidepressant activity of rose oxide essential oil: possible involvement of serotonergic transmission.

Rose oxide (RO) is a monoterpene found in rose oil fragrances. This monoterpene has been reported to possess anti-inflammatory activity, however, little is known regarding its pharmacological activity. The present study was carried out to evaluate its antidepressant action and possible mechanisms of action. Analysis of ADMET pharmacokinetic properties (absorption, distribution, metabolism, excretion and toxicity) of rose oxide was performed by computational prediction analysis. Behavioral tests were performed to assess the interaction between rose oxide and the central nervous system and antidepressant effect that includes: forced swim test (FST), tail suspension test (TST), open field test (OFT) and rota-rod test. The results of pharmacokinetic and toxicological properties indicate that rose oxide could be used orally, since it has good intestinal absorption as well as pharmacological and toxicological properties that can be similar to pharmacological compounds (regular hepatic metabolism and low toxicity). Treatment with 50 mg/kg of rose oxide was able to decrease the immobility time of animals not affected by FST and TST and was not able to alter the motor activity of the OFT and rota-rod test, suggesting modulation and antidepressant activity. Docking data suggest that rose oxide can bind to receptors in the serotonergic pathway. The results described here suggest that rose oxide has antidepressant activity, modulating the serotonergic pathway.

Watermelon and others plant foods that trigger headache in migraine patients.

Background: Food is already recognized as a trigger for migraine, but its mechanism of action has not been fully clarified. There is evidence that they act on the pathogenesis of migraine, interfering with meningeal inflammation, vasodilation and cerebral glucose metabolism.Aim: The aim of this study was to know which plant foods are triggers for migraine and the latency time for the onset of pain.Method: We interviewed patients with migraine and tension-type headache about plant foods that trigger headache and onset time of the headache. We studied 3,935 migraine patients and 1,163 with tension-type headache.Results: There were headaches triggered by plant foods after 90.5 ± 7.9 minutes of ingestion in 40.3% (1,584/3,935) of migraine patients and none with tension-type headache. Headaches triggered by plant foods intake are distributed in the following order of frequency: watermelon (29.5%), passion fruit (3.73%), orange (2.01%), pineapple (1.52%), grape (0.51%), banana (0.46%), cucumber (0.43%), acerola (0.25%) and papaya (0.25%).Conclusions: Many plant foods, especially watermelon, may trigger headache attacks in migraine patients within a few minutes.

Anti-Inflammatory, Antinociceptive, and Antioxidant Properties of Anacardic Acid in Experimental Models.

Anacardic acid (AA), a compound extracted from cashew nut liquid, exhibits numerous pharmacological activities. The aim of the current investigation was to assess the anti-inflammatory, antinociceptive, and antioxidant activities of AA in mouse models. For this, Swiss albino mice were pretreated with AA (10, 25, 50 mg/kg, intraperitoneally, ip) 30 min prior to the administration of carrageenan, as well as 25 mg/kg of prostaglandin E2, dextran, histamine, and compound 48/80. The antinociceptive activity was evaluated by formalin, abdominal, and hot plate tests, using antagonist of opioid receptors (naloxene, 3 mg/kg, ip) to identify antinociceptive mechanisms. Results from this study revealed that AA at 25 mg/kg inhibits carrageenan-induced edema. In addition, AA at 25 mg/kg reduced edema and leukocyte and neutrophilic migration to the intraperitoneal cavity, diminished myeloperoxidase activity and malondialdehyde concentration, and increased the levels of reduced glutathione. In nociceptive tests, it also decreased licking, abdominal writhing, and latency to thermal stimulation, possibly via interaction with opioid receptors. Taken together, these results indicate that AA exhibits anti-inflammatory and antinociceptive actions and also reduces oxidative stress in acute experimental models, suggesting AA as a promising compound in the pharmaceutical arena.

Efficacy and adverse event profile of cannabidiol and medicinal cannabis for treatment-resistant epilepsy: Systematic review and meta-analysis.

This paper aimed to systematically examine the efficacy and adverse event (AE) profile of cannabidiol and medicinal cannabis by analyzing qualitative and meta-analytic data. We used the terms ("Cannabidiol" OR "Cannabis") AND "Epilepsy" AND ("Treatment" OR "Therapeutics") as keywords to retrieve studies indexed on PubMed, ScienceDirect, and CENTRAL databases. The inclusion criteria were as follows: clinical studies with a longitudinal observational design and intervention using cannabinoid derivatives, especially cannabidiol and medicinal cannabis, whereby some results involved the frequency of epileptic seizures. We used Cochrane Collaboration's Review Manager software (RevMan 5.1.6) for the meta-analysis and dichotomized the articles to a confidence interval of 95%. From 236 articles, we selected 16 for descriptive analysis; we selected only 4 for the meta-analysis. According to the results, a statistically meaningful effect of cannabidiol compared with placebo was observed (p < 0.00001). When comparing treatment with cannabidiol or medicinal cannabis, significance was not found for the AE profile (p = 0.74). As AEs for cannabidiol were more common under short-term than under long-term treatment (p < 0.00001), this approach was favorable in the long term. Furthermore, cannabidiol is more effective than placebo, regardless of the etiology of epileptic syndromes and dosage. Overall, the AE profile did not differ across treatments with cannabidiol or medicinal cannabis, though it did differ favorably for long-term than for short-term treatment.

Antidepressant-like effect of anacardic acid in mice via the L-arginine-nitric oxide-serotonergic system.

Depression, a multifactorial neuronal disorder with high morbidity/mortality, is associated with psychological, psychosocial, hereditary, and environmental etiologies, where reactive species exert pathophysiological functions. Anacardic acid (AA), a natural compound obtained from cashew nut liquid, has several pharmacological activities, including antioxidant and anticonvulsant. The aim of the present study was to evaluate the antidepressant-like effect of AA and the involvement of serotonergic, noradrenergic, and L-arginine-nitric oxide (NO) in tail suspension and forced swim tests and, more so, to investigate its antioxidant effect in Saccharomyces cerevisiae and in male Swiss mice (n = 8). In order to identify the antidepressant mechanisms, AA (10, 25, or 50 mg/kg, p.o.) was given 30 min before clonidine (2-adrenergic receptor agonist), L-arginine (NO precursor), propranolol (ß-adrenergic receptor antagonist), and several other agonists or antagonists used. On the other hand, clonidine, noradrenoreceptor, noradrenaline, and L-arginine were used to identify the antidepressant mechanisms. Results suggest that AA exerts antidepressant-like activity, especially at higher doses, possibly by inhibiting serotonin and 5HT-1A reuptake receptors and by inhibiting NO synthetase and guanylyl cyclase enzymes. Additionally, AA exhibited antioxidant effect in S. cerevisiae. This antioxidant capacity may be linked to its antidepressant-like effect but does not interact with α- and ß-adrenoceptor receptors. In conclusion, AA may be used as a promising agent to treat depression, especially which arises from oxidative stress.

Anticonvulsant effect of anacardic acid in murine models: Putative role of GABAergic and antioxidant mechanisms.

Epilepsy is a neurological disease affecting people of all ages worldwide. Side effects of antiepileptic drugs and their association with oxidative stress stimulate the search for new drugs, which would be more affordable with fewer adverse effects. Accordingly, the aim of the present work is to evaluate the anticonvulsant effect of anacardic acid (AA), a natural compound extracted from cashew liquid (Anacardium occidentalis), in murine models, as well as its antioxidant actions in Saccharomyces cerevisiae. AA (>90% purity) was tested, in vivo, in male Swiss mice (25-30 g) with four convulsive models, (1) pentylenetetrazole, (2) pilocarpine, (3) electroshock, and (4) kainic acid, at doses of 25, 50, and 100 mg/kg, body weight (B.W.) Additionally, the effective dose, toxic dose, and protective index studies were also performed. Results revealed that AA exhibits anticonvulsive effects in models 1, 3, and 4, with a mean effective dose (ED50) of 39.64 (model 1) >100 mg/kg, B.W. (model 2), and 38.36 (model 3); furthermore, AA displays a protection index of 1.49 (model 1), <0.6 (model 2, and 1.54 (model 3). In addition, AA showed antioxidant activities in S. cerevisiae mutated for superoxide dismutases (SOD). In conclusion, these results show that AA exhibits significant anticonvulsant and antioxidant activities and may be used as a promising natural product for the treatment of epilepsy.