COVID-19 and its genomic variants: Molecular pathogenesis and therapeutic interventions.

Coronavirus disease-19 (COVID-19), caused by a ß-coronavirus and its genomic variants, is associated with substantial morbidities and mortalities globally. The COVID-19 virus and its genomic variants enter host cells upon binding to the angiotensin converting enzyme 2 receptors that are expressed in a variety of tissues, but predominantly in the lungs, heart, and blood vessels. Patients afflicted with COVID-19 may be asymptomatic or present with critical symptoms possibly due to diverse lifestyles, immune responses, aging, and underlying medical conditions. Geriatric populations, especially men in comparison to women, with immunocompromised conditions, are most vulnerable to severe COVID-19 associated infections, complications, and mortalities. Notably, whereas immunomodulation, involving nutritional consumption, is essential to protecting an individual from COVID-19, immunosuppression is detrimental to a person with this aggressive disease. As such, immune health is inversely correlated to COVID-19 severity and resulting consequences. Advances in genomic and proteomic technologies have helped us to understand the molecular events underlying symptomatology, transmission and, pathogenesis of COVID-19 and its genomic variants. Accordingly, there has been development of a variety of therapeutic interventions, ranging from mask wearing to vaccination to medication. This review summarizes the current understanding of molecular pathogenesis of COVID-19, effects of comorbidities on COVID-19, and prospective therapeutic strategies for the prevention and treatment of this contagious disease.

Allylpyrocatechol, isolated from betel leaf ameliorates thyrotoxicosis in rats by altering thyroid peroxidase and thyrotropin receptors.

Allylpyrocatechol (APC) was isolated from betel leaf and its possible role in L-thyroxin (L-T4)-induced thyrotoxic rats was evaluated. The disease condition, thyrotoxicosis was confirmed by higher levels of thyroid hormones and low thyrotropin (TSH) in serum. Increased hepatic activities of 5'-mono-deiodinase(5'D1), glucose-6-phospatase (G-6-Pase); serum concentrations of alanine transaminase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase(LDH) and tumour necrosis factor-alpha(TNF-α) were observed in thyrotoxic rats. Hepatic lipid peroxidation(LPO) was also increased and the endogenous antioxidants were depleted in these rats. In western blot analysis thyroid peroxidase expression was found to be reduced, whereas thyrotropin receptor(TSHR) expression was enhanced in thyroid gland of these animals. On the other hand, APC treatment in thyrotoxic rats decreased the levels of serum thyroid hormones, ALT, AST, TNF-α and LDH, as well as hepatic 5' D1 and G-6-Pase activities. However, it increased the serum TSH levels. APC also reduced the hepatic LPO and increased the cellular antioxidants in thyrotoxic rats. However, expression of TSHR was inhibited and TPO was increased by APC. The test compound also improved histological features in both liver and thyroid. Present report appears to be the first one that indicates the positive role of APC in ameliorating T4-induced thyrotoxicosis.

Influence of bilateral eyestalk ablation on gonads of fresh water prawn, Macrobrachium dayanum.

The study was carried out in laboratory for one month to know the effect of bilateral eyestalk ablation on gonads of Macrobrachium dayanum. Healthy specimens of Macrobrachium dayanum in the size group of (4-6 cm in length) were taken for the experiment. The eyestalk ablation was done by cutting away the eyestalks from their bases with sterilized scissor. The results here obtained indicated positive effects of eyestalk ablation on ovary and testes of Macrobrachium dayanum. The histological details of the female prawns which were ablated showed post-vitellogenic oocytes; where as unablated females prawn never developed beyond pre-vitellogenic oocytes. Similarly in males, testes showed pronounced development of different cells as compared to unablated ones. Fully developed spermatozoa were seen in ablated ones. Gonadosomatic studies also showed that ovarian and testicular cells developed better as compared to control and these findings suggest the fact that the eyestalks of M. dayanum contain ovary and testis inhibiting factors.

Role of feeding time and food amount in the reproduction of spotted Munia.

It was observed that food restriction significantly increase gonadal development for about two months indicating that hypothalamo hypophyseal gonadal axis becomes more sensitive to feeding stress during the early breeding period than the other reproductive phases. Normal testicular development was also not seen in the spotted munia in which food was restricted for two times each of 3 hour duration, despite the fact that daily food consumption was not significantly less (only by 6.60%) compared to the control group. This suggests that daily restriction in feeding for a longer period (total 6 h or more) may also alter the reproductive function in wild birds.