Catechins: Therapeutic Perspectives in COVID-19-Associated Acute Kidney Injury.

Data obtained from several intensive care units around the world have provided substantial evidence of the strong association between impairment of the renal function and in-hospital deaths of critically ill COVID-19 patients, especially those with comorbidities and requiring renal replacement therapy (RRT). Acute kidney injury (AKI) is a common renal disorder of various etiologies characterized by a sudden and sustained decrease of renal function. Studies have shown that 5-46% of COVID-19 patients develop AKI during hospital stay, and the mortality of those patients may reach up to 100% depending on various factors, such as organ failures and RRT requirement. Catechins are natural products that have multiple pharmacological activities, including anti-coronavirus and reno-protective activities against kidney injury induced by nephrotoxic agents, obstructive nephropathies and AKI accompanying metabolic and cardiovascular disorders. Therefore, in this review, we discuss the anti-SARS-CoV-2 and reno-protective effects of catechins from a mechanistic perspective. We believe that catechins may serve as promising therapeutics in COVID-19-associated AKI due to their well-recognized anti-SARS-CoV-2, and antioxidant and anti-inflammatory properties that mediate their reno-protective activities.

Mechanistic Aspects and Therapeutic Potential of Quercetin against COVID-19-Associated Acute Kidney Injury.

The inflammatory mediator and oxidant agent storm caused by the SARS-CoV-2 infection has been strongly associated with the failure of vital organs observed in critically ill patients with coronavirus disease 2019 (COVID-19) and the death of thousands of infected people around the world. Acute kidney injury (AKI) is a common renal disorder characterized by a sudden and sustained decrease in renal function with a critical influence on poor prognosis and lethal clinical outcomes of various etiologies, including some viral infection diseases. It is known that oxidative stress and inflammation play key roles in the pathogenesis and development of AKI. Quercetin is a natural substance that has multiple pharmacological properties, such as anti-inflammatory action, and is used as a dietary supplement. There is evidence of the anti-coronavirus activities of this compound, including against the target SARS-CoV-2 3CLpro. The ability to inhibit coronavirus and its inflammatory processes is strongly desired in a new drug for the treatment of COVID-19. Therefore, in this review, the dual effect of quercetin is discussed from a mechanistic perspective in relation to AKI kidney injury and its nephroprotective potential to SARS-CoV-2 patients.

Antidepressant Potential of Cinnamic Acids: Mechanisms of Action and Perspectives in Drug Development.

Depression is a health problem that compromises the quality of life of the world's population. It has different levels of severity and a symptomatic profile that affects social life and performance in work activities, as well as a high number of deaths in certain age groups. In the search for new therapeutic options for the treatment of this behavioral disorder, the present review describes studies on antidepressant activity of cinnamic acids, which are natural products found in medicinal plants and foods. The description of the animal models used and the mechanisms of action of these compounds are discussed.

Vaccinium macrocarpon Aiton Extract Ameliorates Inflammation and Hyperalgesia through Oxidative Stress Inhibition in Experimental Acute Pancreatitis.

We evaluated the effect of the hydroethanolic extract of fruits of Vaccinium macrocarpon (HEVm) in a model of acute pancreatitis (AP) in mice. AP was induced by two injections of L-arginine and animals were treated with HEVm (50, 100, and 200 mg/kg, p.o.) or vehicle (saline) every 24 h, starting 1 h after the induction of AP. Phytochemical analysis of the extract and measurement of inflammatory and oxidative stress parameters, as well as abdominal hyperalgesia, were performed. Catechin, epicatechin, rutin, and anthocyanins were identified in HEVm. Treatment with HEVm decreased L-arginine-induced abdominal hyperalgesia (from 48 to 72 h). Also, treatment with HEVm decreased L-arginine-induced pancreatic edema, pancreatic and pulmonary neutrophil infiltration, and levels of tumor necrosis factor-α, interleukin-1ß, and interleukin-6, after 72 h of induction. L-arginine-induced hyperamylasemia and hyperlipasemia were also reduced by the treatment with HEVm in comparison to vehicle-treated group. Moreover, lipoperoxidation, carbonyl radicals, nonprotein sulfhydryl groups, and activity of catalase and superoxide dismutase, but not glutathione peroxidase, were restored by the treatment with HEVm. These results show that treatment with HEVm decreased hyperalgesia and pancreatic/extrapancreatic inflammation and oxidative damage in L-arginine-induced AP, making this extract attractive for future approaches designed to treat this condition.

Structure­activity relationship of terpenes with anti-inflammatory profile ­ a systematic review.

Inflammation is a complex biological response that in spite of having available treatments, their side effects limit their usefulness. Because of this, natural products have been the subject of incessant studies, among which the class of terpenes stands out. They have been the source of study for the development of anti-inflammatory drugs, once their chemical diversity is well suited to provide skeleton for future anti-inflammatory drugs. This systematic review reports the studies present in the literature that evaluate the anti-inflammatory activity of terpenes suffering any change in their structures, assessing whether these changes also brought changes in their effects. The search terms anti-inflammatory agents, terpenes, and structure­activity relationship were used to retrieve English language articles in SCOPUS, PUBMED and EMBASE published between January 2002 and August 2013. Twenty-seven papers were found concerning the structural modification of terpenes with the evaluation of antiinflammatory activity. The data reviewed here suggest that modified terpenes are an interesting tool for the development of new anti-inflammatory drugs.