Preclinical toxicity test results of a new antiviral–immune-modulator compound consisting of flavonoid molecules (COVID-19 clinical trial preliminary data)

Aim: Isolated specific glycone–aglycone conjugated flavonoids which are investigated for their effect of bioavailability and molecular concentrations. The specific formula is then tested via in vitro and in vivo cytotoxicity tests. Methods: Considering the higher affinity for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), quercetin, quercetin 3-sambubioside-3’-glucoside, luteolin, apigenin-7-4’alloside, kaempferol-7-O-glucoside, epicatechin-epigallocatechin-3-O-gallate, and hesperetin were selected to investigate the effects of a new combination of the formula. Specific chemical analyses, such as high-performance liquid chromatography (HPLC), liquid chromatography–mass spectrometry (LC–MS), quadrupole time of flight mass spectrometry (QTÖF–MS) analysis and ultraviolet–visible (UV–VIS) spectrophotometry, were performed for molecular qualification and quantification. Results: In silico molecular docking analyses have shown that flavonoids can bind strongly to the spike protein and main protease of the SARS-CoV-2 virus. Flavonoids also have anti-inflammatory and immune-modulating activity by inhibiting cytokines. Although flavonoids may be a treatment alternative for coronavirus disease 2019 (CÖVID-19), an effective flavonoid compound has yet to be developed. The main problem here is that the absorption rate of flavonoids is very low (2–10%) in the intestines, and these compounds are metabolized rapidly. In contrast, according to recent literature, a conjugated flavonoid mixture is better absorbed in the small intestine, and its toxic effects are relatively fewer. Conclusions: It is found that the new formula has no cytotoxic or genotoxic effects. Furthermore, oral administrations of the new compound did not produce any toxicity symptoms or any mortality in male and female rats. The pre-clinical in vitro and in vivo toxicity test results indicated that the new flavonoid formula can be safely used for clinical trials.