Toxicological Screening of Four Bioactive Citroflavonoids: In Vitro, In Vivo, and In Silico Approaches

Abstract

Many studies describe different pharmacological effects of flavonoids on experimental animals and humans. Nevertheless, few ones are confirming the safety of these compounds for therapeutic purposes. This study aimed to investigate the preclinical safety of naringenin, naringin, hesperidin, and quercetin by in vivo, in vitro, and in silico approaches. For this, an MTT-based cytotoxicity assay in VERO and MDCK cell lines was performed. In addition, acute toxicity was evaluated on Wistar rats by OECD Guidelines for the Testing of Chemicals (Test No. 423: Acute Oral Toxicity-Class Method). Furthermore, we used the ACD/Tox Suite to predict toxicological parameters such as hERG channel blockade, CYP450 inhibition, and acute toxicity in animals. The results showed that quercetin was slightly more cytotoxic on cell lines (IC₅₀ of 219.44 ± 7.22 mM and 465.41 ± 7.44 mM, respectively) than the other citroflavonoids. All flavonoids exhibited an LD₅₀ value > 2000 mg/kg, which classifies them as low-risk substances as OECD guidelines established. Similarly, predicted LD⁵⁰ was LD₅₀ > 300 to 2000 mg/kg for all flavonoids as acute toxicity assay estimated. Data suggests that all these flavonoids did not show significant toxicological effects, and they were classified as low-risk, useful substances for drug development.

Keywords: MTT-based assay; acute oral toxicity; citroflavonoids; low-risk substances; toxicity prediction.

Figure 1

Percentage viability in (a) MDCK and (b) VERO cells after exposition with citroflavonoids. Non-tumorigenic cells were incubated with different concentrations of flavonoids for 48 h. Then, the MTT assay was performed. Values are presented as mean percent of viability ± standard error. n = 3, * p < 0.05.

Figure 2

(a) Changes in body weight after treatment with control or quercetin (QRT), hesperidin (HESP), naringenin (NARGE), and naringin (NAR) at 300 mg/Kg dose, and (b) Changes in body weight after treatment with control or quercetin (QRT), hesperidin (HESP), naringenin (NARGE), and naringin (NAR) at 2000 mg/Kg dose. Results are presented as mean ± SE (n = 3), * p < 0.05.