In vitro assessment of genotoxic and cytotoxic effects of Artemisia annua L. tincture

The genus Artemisia (fam. Asteraceae) is one of the largest and widely distributed with around 500 species, majority used as aromatic and medicinal plants. Artemisia annua L. is widely used as a dietary spice, herbal tea, as a supplement, and in a non-pharmaceutical form for treatment of malaria and fever. It is orally consumed as capsules, extracts and tinctures and topically applied as an essential oil diluted in lotions and ointments. Artemisinin is the main constituent of Artemisia annua L. extracts. Since the discovery that the artemisinin is efficient in malaria treatment, there is also a growth in consumption of A. annua extracts for antitumour and even recently for antiviral treatments against SARS-CoV-2 infections. This study aimed to investigate genotoxic effect in peripheral blood culture and cytotoxic effects in cancer and normal cell lines, of commercially available A. annua L. tincture in series of dilutions. Both comet and neutral red uptake assays revealed dose-dependent genotoxicity and cytotoxicity of A. annua tincture dilutions. Comet assay revealed significantly increased DNA damage in peripheral blood cells while neutral-red assays showed increase in cytotoxicity (p<0.001) in both normal and cancer cell cultures treated with the lowest extract dilution compared to the highest one applied. Obtained results indicate caution needed in A. annua L. tincture use, especially when poorly diluted.