Dengue viruses, mosquito-borne members of the Flaviviridae family, are the causative agents of dengue fever and its associated complications, dengue haemorrhagic fever and dengue shock syndrome. To date, more than 2.5 billion people in over 100 countries are at risk of infection, and approximately 20 million infections were reported annually. There is currently no treatment or vaccine available for dengue infection. This study employed a whole-cell organism model or in vitro methods to study the inhibitory property of the flavanoid-derived compounds against DENV2 activity. Results showed that at concentration not exceeding the maximum non-toxic dose (MNTD), these compounds completely prevented DENV2 infection in HepG2 cells as indicated by the absence of cytophatic effects. The in vitro antiviral activity assessed in HepG2 cells employing virus inhibition assay showed high inhibitory activity in a dose dependent manner. At concentration below MNTD, compounds exhibited inhibitory activity against DENV2 with a range of potency strengths of 72% to 100%. The plaque forming unit per ml (pfu/ml) was reduced prominently with a maximum reduction of 98% when the infected HepG2 cells were treated with the highest non-toxic dose of compounds. The highly potent activity of the compounds against DENV2 infection strongly suggests their potential as a lead antiviral agent for dengue.

The presented study was designed to probe the toxicity potential of newly identified compound naphthalen-2-yl 3,5-dinitrobenzoate (SF1). Acute, subacute toxicity and teratogenicity studies were performed as per Organization of economic cooperation and development (OECD) 425, 407, and 414 test guidelines, respectively. An oral dose of 2000 mg/kg to rats for acute toxicity. Furthermore, 5, 10, 20, and 40 mg/kg doses were administered once daily for 28 days in subacute toxicity study. Teratogenicity study was performed with 40 mg/kg due to its excellent anti-Alzheimer results at this dose. SF1 induced a significant rise in Alkaline Phosphatases (ALP), bilirubin, white blood cells (WBC), and lymphocyte levels with a decrease in platelet count. Furthermore, the reduction in urea, uric acid, and aspartate transaminase (AST) levels and an increase in total protein levels were measured in subacute toxicity. SF1 increased spermatogenesis at 5 and 10 mg/kg doses. Teratogenicity study depicted no resorptions, early abortions, cleft palate, spina bifida and any skeletal abnormalities in the fetuses. Oxidative stress markers (Superoxide dismutase (SOD), Catalase (CAT), and glutathione (GSH) were increased in all the experiments, whereas the effect on melanoaldehyde Malondialdehyde (MDA) levels was variable. Histopathology further corroborated these results with no change in the architectures of selected organs. Consequently, a 2000 mg/kg dose of SF1 tends to induce minor liver dysfunction along with immunomodulation, and it is well below its LD50. Moreover, it can be safely used in pregnancy owing to its no detectable teratogenicity.

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and 579,366 associated deaths had been reported in the United States (https://covid.cdc. gov/covid -data-track er/#cases_cases per10 0klas t7days). It is caused by the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (Alamri et al., 2020a; Alamri et al., 2020b;. The elderly, and those afflicted with chronic illness or possessing a compromised immune system are more likely to be severely affected (Shah et al., 2020). Virions are readily transmitted through aerosols or droplets adsorbing via the mucous membranes of the eyes, mouth, lungs, and nose (Karia et al., 2020). At this point, the zoological origin of the disease remains uncertain, with competing hypotheses suggesting it might have been

Toxicity studies are necessary for the development of a new drug. Naphthalene is a bicyclic molecule and is easy to derivatize. In our previous study, a derivative of naphthalene (4-phenyl,3,4-dihydrobenzoquinoline-2( H )one) was synthesized and reported its in vitro activity on different enzymes. This study was a probe to investigate the toxicity potential of that compound (SF3). Acute oral (425), subacute (407), and teratogenicity (414) studies were planned according to their respective guidelines given by organization of economic cooperation and development (OECD). Acute oral, subacute, and teratogenicity studies were carried out on 2000, 5–40, and 40 mg/kg doses. Blood samples were collected for hematological and biochemical analyses. Vital organs were excised for oxidative stress (superoxide dismutase, catalase, glutathione, and malondialdehyde) and histopathological analysis. LD 50 of SF3 was higher than 2000 mg/kg. In acute and subacute studies, levels of alkaline phosphates and aspartate transaminase were increased. Teratogenicity showed no resorptions, no skeletal or soft tissue abnormalities, and no cleft pallet. Oxidative stress biomarkers were close to the normal, and no increase in the malondialdehyde level was seen. Histopathological studies revealed normal tissue architecture of the selected organs, except kidney, in acute oral and subacute toxicity studies at 40 mg/kg. The study concluded that SF3 is safer if used as a drug.