From cup to cell: phytochemical characterization and safety profiles of some herbal teas in Türkiye

This study was carried out to investigate the antioxidant capacity, antimicrobial, cytotoxicity, and genotoxicity effects of some herbal teas (HTs) grown in Türkiye and sold in pharmacies with medical indications.

The preparations, prepared to reflect daily usage conditions, were analyzed using the CUPRAC, DPPH, FRAP, and total phenolic content (TPM) assays, the agar well diffusion method, microdilution test, MTT, micronucleus (MN), and comet assays.

FRAP values ranged between 0.956 ± 0.036 and 7.738 ± 0.427 mM FeSO₄/mg, while the CUPRAC values were 0.14 ± 0.027-5.306 ± 0.107 mM trolox equivalent/mg. Regarding the DPPH assay, the samples exhibited a range of free radical scavenging potencies. TPC values was 0.002 ± 0.00-0.398 ± 0.049 mg gallic acid equivalent/mg. The inhibition zone diameters were 0-10.07 ± 0.55 mm, and the minimum inhibitory concentration values ranged from 0.31 to 0.63 mg/mL. Cytotoxicity tests showed that the IC₅₀ values were between 99.68 ± 0.99 μg/mL and 562.45 ± 1.88 μg/mL for A549 cells, 84.02 ± 2.05 μg/mL and 640.22 ± 2.99 μg/mL for MCF7 cells, and 103.99 ± 1.11 μg/mL and 644.55 ± 2.56 μg/mL for HEK293 cells. In the comet assay, DNAT (%) ranged from 28.54 ± 4.49 to 86.88 ± 7.04 µm, while MN frequencies varied between 0% and 11.05% ± 0.13%.

Overall, the findings indicate that some herbal teas in the study, such as Melissa officinalis and Origanum vulgare, exhibit significant antioxidant capacity and anticancer potential along with relatively low genotoxic risk; however, the study also revealed that some herbal teas included in the study may show limited efficacy or potential safety concerns, and it emphasizes the necessity of accurate botanical identification, standardized preparation methods, and comprehensive scientific evaluations prior to their widespread use. Based on the study's results, it is crucial to establish more extensive public health policies concerning the sale of medicinal herbal teas, emphasizing the standardization of botanical identification and stringent safety certifications to safeguard consumers from potential hazards.