In vitro antioxidant and antitumor activities of six selected plants used in the Traditional Arabic Palestinian herbal medicine

Abstract Context: Despite several pharmacological applications of the medicinal plants in the Traditional Arabic Palestinian Herbal Medicine in Palestine (TAPHM), studies on their antioxidant properties are still scarce. Objective: This work evaluates the antioxidant and antitumor activities of the ethanol extracts from different parts of six plants: [Arum palaestinum Boiss (Araceae), Urtica pilulifera L. (Urticaceae), Coridothymus capitatus (L.) Reichb (Lamiaceae), Majorana syriaca (L.) Rafin. (Lamiaceae), Teucrium creticum L. (Lamiaceae), and Teucrium capitatum L. (Lamiaceae)] used in the TAPHM. Materials and methods: The antioxidant activity was evaluated for the ethanol extracts by DPPH and β-carotene-linoleic acid assays together with total contents of phenols and flavonoids. For the anti-carcinogenic evaluation, the extracts were tested for the ability to inhibit the proliferation of breast cancer cells (MCF-7) using the MTT reduction assay. Results: Among the extracts, the U. pilulifera had the highest amount of total phenolics, possessing the second highest total flavonoids. It also showed a maximum cytotoxic activity (IC50 = 63 µg/ml), followed by C. capitatus, and A. palaestinum. Otherwise, the extract of T. creticum was demonstrated to be an efficient scavenger of O2 (IC50 = 83 µg/ml), followed by M. syriaca, C. capitatus, T. capitatum, A. palaestinum, and U. pilulifera. Discussion and conclusion: The results suggest that the investigated plants have shown varied antioxidant capacities which were strongly correlated with their contents of phenolics. Accordingly, this study proposes that the therapeutic benefit of these plants can be, at least in part, attributed to its potential inhibition of oxidative processes.