Therapeutic potential of N-acetyl cysteine (NAC) in preventing cytokine storm in COVID-19: review of current evidence.

Since November 2019, SARS Coronavirus 2 disease (COVID-19) pandemic has spread through more than 195 nations worldwide. Though the coronavirus infection affects all age and sex groups, the mortality is skewed towards the elderly population and the cause of death is mostly acute respiratory distress syndrome (ARDS). There are data suggesting the role of excessive immune activation and cytokine storm as the cause of lung injury in COVID-19. The excessive immune activation and cytokine storm usually occurs due to an imbalance in redox homeostasis of the individuals. Considering the antioxidant and free radical scavenging action of N acetyl cysteine (NAC), its use might be useful in COVID-19 patients by decreasing the cytokine storm consequently decreasing the disease severity. Therefore, we reviewed all the available resources pertaining to the role of reactive oxygen species (ROS) in cytokine storm and the mechanism of action of NAC in preventing ROS. We also reviewed the use of NAC in COVID-19.

Protective effect of aqueous suspension of dried latex of Calotropis procera against oxidative stress and renal damage in diabetic rats

Calotropis species have been used in the traditional medicinal system for the treatment of diseases of the liver and abdomen. In view of the antioxidant and anti-hyperglycemic properties of an aqueous suspension obtained from the dried latex of Calotropis procera, the present study was carried out to evaluate its efficacy in affording protection against alloxan induced changes in rat kidney. A single intraperitoneal injection of alloxan (150 mg/kg) in rats produced hyperglycemia within 3 days and altered kidney functions over a period of 90 days. Daily oral administration of the aqueous suspension (100 and 400 mg/kg) in diabetic rats produced anti-hyperglycemic effect that was comparable to that of glibenclamide (10 mg/kg). Unlike glibenclamide, the aqueous suspension did not increase the serum insulin levels in diabetic rats. However, it produced a marked reduction in the levels of urinary glucose and protein and normalized the renal tissue levels of thiobarbituric acid-reactive substances (TBARS) and glutathione (GSH) in diabetic rats and the effect was comparable to that of glibenclamide. The protection afforded by the aqueous suspension was also evident from the histological analysis of the renal tissue. Our study shows that by exhibiting antioxidant and anti-hyperglycemic property the aqueous suspension of dried latex of C. procera affords protection against the complications associated with diabetes

Protective effect of aqueous suspension of dried latex of Calotropis procera against oxidative stress and renal damage in diabetic rats

Calotropis species have been used in the traditional medicinal system for the treatment of diseases of the liver and abdomen. In view of the antioxidant and anti-hyperglycemic properties of an aqueous suspension obtained from the dried latex of Calotropis procera, the present study was carried out to evaluate its efficacy in affording protection against alloxan induced changes in rat kidney. A single intraperitoneal injection of alloxan (150 mg/kg) in rats produced hyperglycemia within 3 days and altered kidney functions over a period of 90 days. Daily oral administration of the aqueous suspension (100 and 400 mg/kg) in diabetic rats produced anti-hyperglycemic effect that was comparable to that of glibenclamide (10 mg/kg). Unlike glibenclamide, the aqueous suspension did not increase the serum insulin levels in diabetic rats. However, it produced a marked reduction in the levels of urinary glucose and protein and normalized the renal tissue levels of thiobarbituric acid-reactive substances (TBARS) and glutathione (GSH) in diabetic rats and the effect was comparable to that of glibenclamide. The protection afforded by the aqueous suspension was also evident from the histological analysis of the renal tissue. Our study shows that by exhibiting antioxidant and anti-hyperglycemic property the aqueous suspension of dried latex of C. procera affords protection against the complications associated with diabetes

Protective effect of aqueous suspension of dried latex of Calotropis procera against oxidative stress and renal damage in diabetic rats

Calotropis species have been used in the traditional medicinal system for the treatment of diseases of the liver and abdomen. In view of the antioxidant and anti-hyperglycemic properties of an aqueous suspension obtained from the dried latex of Calotropis procera, the present study was carried out to evaluate its efficacy in affording protection against alloxan induced changes in rat kidney. A single intraperitoneal injection of alloxan (150 mg/kg) in rats produced hyperglycemia within 3 days and altered kidney functions over a period of 90 days. Daily oral administration of the aqueous suspension (100 and 400 mg/kg) in diabetic rats produced anti-hyperglycemic effect that was comparable to that of glibenclamide (10 mg/kg). Unlike glibenclamide, the aqueous suspension did not increase the serum insulin levels in diabetic rats. However, it produced a marked reduction in the levels of urinary glucose and protein and normalized the renal tissue levels of thiobarbituric acid-reactive substances (TBARS) and glutathione (GSH) in diabetic rats and the effect was comparable to that of glibenclamide. The protection afforded by the aqueous suspension was also evident from the histological analysis of the renal tissue. Our study shows that by exhibiting antioxidant and anti-hyperglycemic property the aqueous suspension of dried latex of C. procera affords protection against the complications associated with diabetes.

Drug repositioning: re-investigating existing drugs for new therapeutic indications.

Drug discovery and development is an expensive, time-consuming, and risky enterprise. In order to accelerate the drug development process with reduced risk of failure and relatively lower costs, pharmaceutical companies have adopted drug repositioning as an alternative. This strategy involves exploration of drugs that have already been approved for treatment of other diseases and/or whose targets have already been discovered. Various techniques including data mining, bioinformatics, and usage of novel screening platforms have been used for identification and screening of potential repositioning candidates. However, challenges in clinical trials and intellectual property issues may be encountered during the repositioning process. Nevertheless, such initiatives not only add value to the portfolio of pharmaceutical companies but also provide an opportunity for academia and government laboratories to develop new and innovative uses of existing drugs for infectious and neglected diseases, especially in emerging countries like India.

Issues in pharmacotherapy of 2009 H1N1 influenza infection.

The pandemic caused by the 2009 H1N1 influenza A virus has been a cause of great concern for healthcare professionals and the scientific community worldwide. Due to the widespread resistance of the virus to adamantanes, pharmacotherapy is currently limited to neuraminidase inhibitors, oseltamivir and zanamivir. The use of neuraminidase inhibitors in India is primarily associated with issues of patient and physician awareness, variability in disease management guidelines, safety and efficacy in the Indian population, need for active drug safety monitoring, and development of resistance due to possible misuse. In addition, other issues like availability of the drugs in retail and stockpiling by the public health authorities need careful introspection. The development of influenza vaccines in India and its adequate availability to the country's populace also poses significant challenges in the management of the pandemic. In light of the limited therapeutic options available for the management of the disease, research on novel targets and pharmacological agents would also be beneficial in addressing the challenges of future outbreaks.

Calotropis procera latex affords protection against carbon tetrachloride induced hepatotoxicity in rats.

In the present study, latex of Calotropis procera possessing potent antioxidant and anti-inflammatory properties was evaluated for its hepatoprotective effect against carbon tetrachloride (CCl(4)) induced hepatotoxicity in rats. Subcutaneous injection of CCl(4,) administered twice a week, produced a marked elevation in the serum levels of aspartate transaminase (AST), alanine transaminase (ALT) and tumor necrosis factor alpha (TNF-alpha). Histological analysis of the liver of these rats revealed marked necro-inflammatory changes that were associated with increase in the levels of TBARS, PGE(2) and catalase and decrease in the levels of glutathione (GSH), superoxide dismutase (SOD) and glutathione peroxidase (GPx). Daily oral administration of aqueous suspension of dried latex (DL) of Calotropis procera at 5, 50 and 100mg/kg doses produced a dose-dependent reduction in the serum levels of liver enzymes and inflammatory mediators and attenuated the necro-inflammatory changes in the liver. The DL treatment also normalized various biochemical parameters of oxidative stress. Our study shows that the antioxidant and anti-inflammatory effects of DL and silymarin were comparable and suggests that DL could be used as a hepatoprotective agent.

A comparative study on the efficacy of rofecoxib in monoarticular arthritis induced by latex of Calotropis procera and Freund's complete adjuvant.

The role of prostaglandins in Calotropis procera latex induced inflammation and hyperalgesia has been well established. The acute inflammation induced by the dried latex (DL) of this plant could be effectively ameliorated by standard anti-inflammatory drugs. In present study we have evaluated the efficacy of rofecoxib, a COX-2 inhibitor in monoarthritis induced by intra-articular injection of DL and compared it with that against Freund's Complete Adjuvant (FCA). DL and FCA were injected into the right ankle joint of the rat and the joint diameter was measured by a micrometer screw gauge on day 0, 4, 8, 12, 20 and 28. Concomitantly the hyperalgesic response was also evaluated by motility test, stair climbing ability test, dorsal flexion pain test and compression test. The effect of rofecoxib was evaluated on these parameters in both the models. Both DL and FCA produced peak inflammation on day 4 that was associated with decreased pain threshold and functional impairment. Although rofecoxib was more effective in improving motility in the DL model, its effect on joint inflammation, hyperalgesia and stair climbing ability was comparable in both the models. Thus, our study indicates that DL induced monoarthritis could be used as a model for the screening and evaluation of anti-inflammatory and anti-arthritic drugs.

Antioxidant and protective effect of latex of Calotropis procera against alloxan-induced diabetes in rats.

In the present study, dry latex (DL) of Calotropis procera possessing potent anti-inflammatory activity was evaluated for its antioxidant and anti-hyperglycemic effects against alloxan-induced diabetes in rats. Daily oral administration of DL at 100 and 400 mg/kg doses produced a dose-dependent decrease in the blood glucose and increase in the hepatic glycogen content. DL also prevented the loss of body weight in diabetic rats and brought down the daily water consumption to values comparable to normal rats. DL also produced an increase in the hepatic levels of the endogenous antioxidants, namely superoxide dismutase (SOD), catalase and glutathione, while it brought down the levels of thiobarbituric acid-reactive substances (TBARS) in alloxan-induced diabetic rats. The efficacy of DL as an antioxidant and as an anti-diabetic agent was comparable to the standard anti-diabetic drug, glibenclamide.