New polymethoxyflavones from Hottonia palustris and their effects in an oral squamous carcinoma (SCC-25) cell line

More than 90% of types of oral cancers originate from the squamous cells that are inside of the oral cavity. It is estimated that in 2020, nearly 10 million deaths from cancer occurred worldwide, including approximately 180,000 deaths from oral cancer [1]. Our study involved the isolation and identification of flavonoid compounds from the aerial parts of Hottonia palustris L. (Primulaceae) and their cytotoxic effects on human tongue squamous cell carcinoma line SCC-25 and human oral keratinocyte. In particular, the current study documented the presence of previously isolated dibenzoylmethane (1) [2] and two flavones, 5,6′-dihydroxy-2′-methoxyflavone (2) and 5,6′-dihydroxy-2′,3′-dimethoxyflavone (3). Their structures were determined by spectral (NMR, MS) analyses. To our knowledge, metabolites 2 and 3 are new natural products to be reported in the plant kingdom. Compounds (1 – 3), zapotin (4) [3] and selected extracts (methanol – HP1, petroleum ether – HP8) were evaluated for cytotoxic activity by MTT assays [4]. The highest cytotoxic activity (IC₅₀ after 48 h) was found for HP8 – 14.90 ± 0.74 µg/mL and for compounds (4) 20.33 ± 1.02, (2) 24.20 ± 1.21, and (1) 29.10 ± 1.45 µM/mL. Our data suggest that H. palustris is a source of polyphenols with chemopreventive and chemotherapeutic activities and potential to be developed as candidates for oral cancer treatment.

• References

• 1 Sung H, Ferlay J, Siegel RL. et al. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. CA Cancer J Clin 2021; 71: 209-249
• 2 Wojtulewski S, Strawa JW, Tomczyk M. et al. A new look at two polymorphic crystal structures of dibenzoylmethane: relationship between the crystal packing and the hydrogen atom position revealed by quantum chemistry and quantum crystallography methods. Acta Crystallogr Sect B Struct Sci Cryst Eng Mater 2020; 76: 957-966
• 3 Strawa JW, Jakimiuk K, Tomczyk M. Zapotin, a polymethoxyflavone, with potential therapeutic attributes. Int J Mol Sci 2021; 22
• 4 Szoka L, Nazaruk J, Stocki M. et al. Santin and cirsimaritin from Betula pubescens and Betula pendula buds induce apoptosis in human digestive system cancer cells. J Cell Mol Med 2021; 25: 11085-11096

Publikationsverlauf

Artikel online veröffentlicht:
12. Dezember 2022