Depression is a neuropsychiatric disorder associated with persistent stress and disruption of neuronal function. Persistent stress causes neuronal atrophy, including loss of synapses and reduced size of the hippocampus and prefrontal cortex. These alterations are associated with neural dysfunction, including mood disturbances, cognitive impairment, and behavioral changes. Synaptic plasticity is the fundamental function of neural networks in response to various stimuli and acts by reorganizing neuronal structure, function, and connections from the molecular to the behavioral level. In this review, we describe the alterations in synaptic plasticity as underlying pathological mechanisms for depression in animal models and humans. We further elaborate on the significance of phytochemicals as bioactive agents that can positively modulate stress-induced, aberrant synaptic activity. Bioactive agents, including flavonoids, terpenes, saponins, and lignans, have been reported to upregulate brain-derived neurotrophic factor expression and release, suppress neuronal loss, and activate the relevant signaling pathways, including TrkB, ERK, Akt, and mTOR pathways, resulting in increased spine maturation and synaptic numbers in the neuronal cells and in the brains of stressed animals. In clinical trials, phytochemical usage is regarded as safe and well-tolerated for suppressing stress-related parameters in patients with depression. Thus, intake of phytochemicals with safe and active effects on synaptic plasticity may be a strategy for preventing neuronal damage and alleviating depression in a stressful life.

Objective: To investigate the pharmacological potential of Argemone mexicana in treating constipation and emesis by using in vitro and in vivo models.Methods: The spasmogenic and spasmolytic effects were evaluated on isolated rabbit jejunum fragments loaded in a tissue organ bath. The response was recorded with an isotonic transducer attached with Power Lab Data Acquisition System. The laxative and antiemetic activities were assessed in BALB-c mice and poultry chicks challenged with carbamylcholine and copper sulphate stimulated emesis, respectively. Results: The total phenolic and total flavonoids contents of the extract were (267.75 ± 5.77) mg GAE/g and (73.86 ± 6.01) mg QE/g, respectively. Argemone mexicana extract exerted spasmogenic effect on isolated rabbit jejunum segments with an EC50 value of 0.016 mg/mL, which was blocked by atropine (0.3 μM). Argemone mexicana extract exerted spasmolytic effect in atropine treated jejunum fragments with an EC50 value of 2.185 mg/mL. Furthermore, Argemone mexicana extract relaxed potassium (80 mM)-induced contractions (EC50: 9.07 mg/mL), similar to a standard drug verapamil. The calcium channel blocker activity was confirmed by a rightward shift of concentration-response curve of calcium in the presence of Argemone mexicana extract (1-5 mg/mL) and verapamil (0.1-1 μM). In addition, the extract increased the distance travelled by a charcoal in the gastrointestinal tract and exhibited antiemetic effect on copper sulphate induced emesis in chicks. Conclusions: Argemone mexicana shows cholinergic agonist and calcium channel blocker activities, as well as antiemetic effect. It may be used as a potential agent for treating gastrointestinal disorders.

This paper reports a presumptive severe acute respiratory syndrome coronavirus 2 (SARSCoV-2) infection in a cat. A cat with respiratory disease living with three individuals with coronavirus disease 2019 showed bilateral ground-glass opacities in the lung on X-ray and computed tomography. The clinical swabs were negative for SARS-CoV-2 RNA, but the serum was positive for SARS-CoV-2 antibodies. Interstitial pneumonia and prominent type 2 pneumocyte hyperplasia were noted on histopathology. Respiratory tissues were negative for SARS-CoV-2 RNA or antigen, but the cat was positive for feline parvovirus DNA. In conclusion, the respiratory disease and associated pathology in this cat could have been due to exposure to SARS-CoV-2.

Objective: To investigate the pharmacological potential of Argemone mexicana in treating constipation and emesis by using in vitro and in vivo models. Methods: The spasmogenic and spasmolytic effects were evaluated on isolated rabbit jejunum fragments loaded in a tissue organ bath. The response was recorded with an isotonic transducer attached with Power Lab Data Acquisition System. The laxative and antiemetic activities were assessed in BALB-c mice and poultry chicks challenged with carbamylcholine and copper sulphate stimulated emesis, respectively. Results: The total phenolic and total flavonoids contents of the extract were (267.75 ± 5.77) mg GAE/g and (73.86 ± 6.01) mg QE/g, respectively. Argemone mexicana extract exerted spasmogenic effect on isolated rabbit jejunum segments with an EC50 value of 0.016 mg/mL, which was blocked by atropine (0.3 μM). Argemone mexicana extract exerted spasmolytic effect in atropine treated jejunum fragments with an EC50 value of 2.185 mg/mL. Furthermore, Argemone mexicana extract relaxed potassium (80 mM)-induced contractions (EC50: 9.07 mg/mL), similar to a standard drug verapamil. The calcium channel blocker activity was confirmed by a rightward shift of concentration-response curve of calcium in the presence of Argemone mexicana extract (1-5 mg/mL) and verapamil (0.1-1 μM). In addition, the extract increased the distance travelled by a charcoal in the gastrointestinal tract and exhibited antiemetic effect on copper sulphate induced emesis in chicks. Conclusions: Argemone mexicana shows cholinergic agonist and calcium channel blocker activities, as well as antiemetic effect. It may be used as a potential agent for treating gastrointestinal disorders.