The objective of our research was to examine the antioxidant and membrane-protective characteristics of a few medicinal plant extracts belonging to the Asteracea family, along with their flavonoid and polyphenolic content, in order to identify strategies for enhancing beverage composition and boosting the antioxidant capacity of green and black tea. The activity of aqueous-ethanolic extracts from the dried parts of plants, such as Arictum tomentosum Mill., Ghnapilum kasachstanicum Kirp. & Kuprian. ex Kirp., Artemisia schrenkiana Ledeb., A. rutifolia Steph. ex Spreng., A. cina O.Berg, and A. vulgaris L., were examined using a model of Wistar rats. Thiobarbituric acid-reacting substances (TBARS), a marker of malondialdehyde concentration, were used to measure the amount of lipid peroxidation (LPO) in liver microsomes. Considering the outcomes, the extracts from A. tomentosum, G. kasachstanicum, and A. vulgaris exhibit the strongest membrane-stabilizing action among those examined. At a concentration of 5 g/mL, the extracts of these plants demonstrated a significant anti-hemolitic impact, whereas the remaining extracts displayed a similar effect at doses above 10 g/mL. Accordingly, among the extracts studied, the A. tomentosum, G. kasachstanicum, A. schrenkiana, A. rutifolia, A. cina, and A. vulgaris extracts have significant antioxidant properties. The integrated antioxidant and antihemolytic qualities of A. tomentosum and green tea extracts were comparable to those of the individual plant extracts. When the extracts of A. schrenkiana and green tea were combined, similar outcomes were seen, suggesting that there was no appreciable synergistic interaction.

The Escherichia coli adenine-DNA glycosylase (MutY) and its human homologue, MUTYH, protect cells against oxygen-free radical-induced mutagenesis by excising regular adenine impaired with 8-oxo-7,8-dihydro-guanine (8oxoG) in the base excision repair (BER) pathway. However, removal of adenine by MutY and MUTYH from an A·8oxoG pair generated via misincorporation of an oxidized nucleotide during DNA synthesis might induce A·T→C·G transversions. Here, to examine MutY and MUTYH in vitro activities, we used short synthetic DNA duplexes in which the target adenine residue was positioned opposite a variety of DNA base modifications. MUTYH does not excise mismatched adenine in non-canonical DNA substrates, whereas MutY excises adenine mispaired with 1,3-d(GpNpG) cisplatin intra-strand crosslink. In addition, we characterized four MUTYH variants associated with cancer risk, which exhibit the following order of DNA glycosylase deficiency: WT ≥ G169D > G202E ≈ Y165C >> D222N. Human adenine-DNA glycosylase MUTYH and its mutant variants, contrary to bacterial MutY, are not prone to aberrant removal of regular adenine residues opposite modified residues in DNA duplexes. We hypothesize that E. coli MutY is prone to aberrant repair under certain conditions and that this may prevent incorporation of adenine opposite blocking lesions in the template strand.