Development of Inactivated FAKHRAVAC® Vaccine against SARS-CoV-2 Virus: Preclinical Study in Animal Models.

The recent viral infection disease pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in a global public health crisis. Iran, as one of the countries that reported over five million infected cases by September 2021, has been concerned with the urgent development of effective vaccines against SARS-CoV-2. In this paper, we report the results of a study on potency and safety of an inactivated SARS-CoV-2 vaccine candidate (FAKHRAVAC) in a preclinical study so as to confirm its potential for further clinical evaluation. Here, we developed a pilot-scale production of FAKHRAVAC, a purified inactivated SARS-CoV-2 virus vaccine candidate that induces neutralizing antibodies in Balb/c mice, guinea pigs, rabbits, and non-human primates (Rhesus macaques-RM). After obtaining ethical code of IR.IUMS.REC.1399.566, immunizations of animals were conducted by using either of three different vaccine dilutions; High (H): 10 µg/dose, Medium (M): 5 µg/dose, and Low (L): 1 µg/dose, respectively. In the process of screening for viral seeds, viral strains that resulted in the most severe clinical manifestation in patients have been isolated for vaccine development. The viral seed produced the optimal immunity against SARS-CoV-2 virus, which suggests a possible broader neutralizing ability against SARS-CoV-2 strains. The seroconversion rate at the H-, M-, and L-dose groups of all tested animals reached 100% by 28 days after immunization. These data support the eligibility of FAKHRAVAC vaccine candidate for further evaluation in a clinical trial.

Development of a combined solution formulation of atropine sulfate and obidoxime chloride for autoinjector and evaluation of its stability.

Atropine (AT) and oximes, alone or in combination, have been proven greatly valuable therapeutics in the treatment of organophosphates intoxications. An injectable mixture of AT and obidoxime (OB) was formulated for the administration by automatic self-injector. The aqueous single dose solution contained 275 mg obidoxime chloride and 2.5 mg atropine sulfate per 1 mL (220 mg and 2 mg per 0.8 effective dose, respectively). The final solution was sterilized by filtration through a 0.22 µm pore size filter. This more concentrated solution allowed to use a smaller size and lighter weight cartridge. Quality control tests, including assay of the two major compounds were performed separately, using reversed-phase HPLC methods. Besides, the stability test was carried out according to ICH guideline for the accelerated test. The obtained results showed that the proposed formulation is stable over a period of 2 years after preparation.

Protective effects of fungal ß-(1→3)-D-glucan against oxidative stress cytotoxicity induced by depleted uranium in isolated rat hepatocytes.

Previous reports suggested that certain carbohydrate polymers, such as ß-(1→3)-D-glucan, may possess free radical scavenging activity. The present study examined the free radical scavenging activity of a carbohydrate polymer, ß-(1→3)-D-glucan against oxidative stress induced by depleted uranium in isolated rat hepatocytes. Addition of U (VI) (uranyl acetate) to isolated rat hepatocytes results in reactive oxygen species (ROS) formation, rapid glutathione depletion, mitochondrial membrane potential collapse and lysosomal membrane rupture before hepatocyte lysis occurred. Our results showed that quite similar to silymarin, which is a known antioxidant and radical scavenger, tiny concentration of ß-glucan (138 nM) very successfully protected the hepatocytes against cell lysis and all oxidative stress cytotoxicity endpoints caused by depleted uranium including ROS formation, glutathione depletion, decreased mitochondrial membrane potential, lysosomal membrane rupture and caspase 3 activity increase. In conclusion, our results confirmed the antioxidant and radical scavenging activity of ß-(1→3)-D-glucan and suggested this compound and silymarin as possible drug candidates for prophylaxis and treatment against depleted uranium toxic effects.

A search for cellular and molecular mechanisms involved in depleted uranium (DU) toxicity.

Addition of U(VI) (uranyl acetate) to isolated rat hepatocytes results in rapid glutathione oxidation, reactive oxygen species (ROS) formation, lipid peroxidation, decreased mitochondrial membrane potential, and lysosomal membrane rupture before hepatocyte lysis occurred. Cytotoxicity was prevented by ROS scavengers, antioxidants, and glutamine (ATP generator). Hepatocyte dichlorofluorescein oxidation was inhibited by mannitol (a hydroxyl radical scavenger) or butylated hydroxyanisole and butylated hydroxytoluene (antioxidants). Glutathione depleted hepatocytes were resistant to U(VI) toxicity and much less dichlorofluorescein oxidation occurred. Reduction of U(VI) by glutathione or cysteine in vitro was also accompanied by oxygen uptake and was inhibited by Ca(II) (a U(IV) or U(VI) reduction inhibitor). U(VI)-induced cytotoxicity and ROS formation was also inhibited by Ca(II), which suggests that U(IV) and U(IV) GSH mediate ROS formation in isolated hepatocytes. The U(VI) reductive mechanism required for toxicity has not been investigated. Cytotoxicity was also prevented by cytochrome P450 inhibitors, particularly CYP 2E1 inhibitors, but not inhibitors of DT diaphorase or glutathione reductase. This suggests that P450 reductase and reduced cytochrome P450 contributes to U(VI) reduction to U(IV). In conclusion, U(VI) cytotoxicity is associated with mitochondrial/lysosomal toxicity by the reduced biological metabolites and ROS.