Tradescantia zebrina Bosse: study of the phenolic composition and bioactive properties of a potential natural coloring ingredient

Abstract

Tradescantia zebrina Bosse is a succulent pantropical herb, native to Central America with a high capacity to grow in various conditions [1]. This plant is popularly used in cooking and traditional medicine [2]. Some species of the Transdecantia genus are described as possessing exceptionally stable anthocyanic compounds in plant organs, a condition of extreme importance for application in the food industry that is currently looking for potential natural coloring ingredients [3]. In this sense, the present work aimed to explore the phenolic composition and bioactive properties of the aerial parts T. zebrina extract. The phenolic composition of the extract was defined by High Performance Liquid Cromatography (HPLC-DAD-ESI/MS) and allowed the identification of 11 anthocyanins glycoside derivatives. Regarding the bioactive properties, i) the antioxidant activity was tested using an oxidative hemolysis assays (OxHLIA), reducing power, and free radical scavenging assay (DPPH); ii) cytotoxicity was evaluated in human tumor cells (MCF-7, breast carcinoma; NCI-H460, lung cancer; AGS, gastric carcinoma; and CaCo, colorectal adenocarcinoma) and hepatotoxicity in non-tumor cells (PLP2, pig liver; and Vero, monkey kidney cell) by the sulphorodamine B method; iii) the antimicrobial activity was evaluated against a panel of twelve food pathogens (S. aureus, B. cereus, L. monocytogenes, E. coli, S. Typhimurium, E. cloacae, A. fumigatus, A. niger, A. versicolor, P. funiculosum, P. verrucosum var. ciclopium and T. viride) using the microdilution method. The analyzed extract presented promising antioxidant activity, with promising EC50 values for all the testes assays, ranging from of 0.190 ± 0.001 mg/mL (DPPH), 0.061 ± 0.002 mg/mL (reducing power), and 0.057 ± 0.001 mg/mL (OxHILIA). Furthermore, the extract did not demonstrate toxicity at the maximum tested concentration (>400 μg/mL), but a remarkable activity against gastric carcinoma (AGS) was detected. Additionally, the extract showed excellent results in antibacterial and antifungal performance against all strains tested. In conclusion, it can be observed that the extract obtained from the aerial parts of T. zebrina represents themselves a natural antioxidants of great value for the industry, which, in addition to conferring colour to food products due to the quantity of anthocyanins, can contribute to the preservation of food products.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020), for E.O. PIRES JR. grant (2021.05425.BD), and for the contracts of C. Pereira, M.I. Dias, R.C. Calhelha, and L. Barros through the institutional scientific employment program-contract. To the project Healthy-PETFOOD for the contract of C. Caleja (Project Healthy-PETFOOD (POCI-01-0247-FEDER-047073) and to the Valor Natural project for the contract of E. Pereira (Mobilized Project Norte-01-0247-FEDER-024479). This work is funded by the European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project GreenHealth - Digital strategies in biological assets to improve well-being and promote green health, Norte-01- 0145FEDER-000042 and by FEDER-Interreg España-Portugal programme for financial support through the project TRANSCoLAB 0612_TRANS_CO_LAB_2_P. This work has been supported by the Ministry of Education, Science and Technological Development of Republic of Serbia (451-03-68/2020-14/200007).info:eu-repo/semantics/publishedVersio