Evaluation of Synergistic Interactions on Antioxidant and Anticancer Efficacy of Methanol Extracts of some Egyptian Spices in Combination

Objective: The aim of this study was to evaluate the synergistic effect and the antioxidant activity of 6 methanolic extracts from different Egyptian spices as well as the cytotoxic effect of different blends on liver cancer cell line Hep-G2 using MTT assay.The identification of phenolics/flavonoids constituents of different blends from these extracts using direct analysis in real time DART mass spectrometry for the first time was another major interested goal for this study.Methodology: Based on DPPH, ABTS and FRAP assays, the antioxidant activity for methanol extracts of 6 Egyptian spices (clove, cinnamon, thyme, basil, fennel and juniper) was evaluated.Additionally, total phenolic content and total flavonoids of the extracts were measured using Folin-Ciocalteu method and rutin.The identification of phenolics/flavonoids constituents of two different blends of these extracts was performed using direct analysis in real time DART mass spectrometry for the first time.The in vitro cytotoxicity was assessed against liver human cancer cell line (Hep G-2) using MTT assay for two blends compared with reference drug, 5-flurouracil.Results: Clove, cinnamon and thyme methanol extracts were showed potential antioxidant activity as well as the highest phenolic and flavonoid contents among the tested extracts, hence used in order to evaluate the possible synergistic interactions on anticancer and antioxidant efficacy of these extracts in combination.Clove/cinnamon combination showed synergistic interaction in both anticancer (IC 50 72.6 µg mLG 1 ) and antioxidant (CI 0.87) activities, while clove/cinnamon/thyme had antagonistic effect.Identification of the bioactive compounds of the examined extracts combination was performed using DART-MS.Phenolic constituents e.g., catechol, pyrogallol, eugenol, linalool, caffeic and ferulic acids were identified in both combination, however, flavonoids e.g., galangin, quercetin and apeginin were detected only in clove/cinnamon combination which may correlated to its synergistic effect as well as the nature of the phenolic constituents therein.Conclusion: The combining methanol extracts of clove/cinnamon (blend 1) displayed stronger cytotoxic effect on liver cancer cell line Hep-G2 and a synergistic antioxidant effect in comparison to clove/cinnamon/thyme (blend 2) and may represent a novel therapeutic blend for cancer treatment.