Chemosensitivity of MCF-7 cells to eugenol: release of cytochrome-c and lactate dehydrogenase

Abstract

Phytochemicals have been extensively researched for their potential anticancer effects. In previous study, direct exposure of rat liver mitochondria to eugenol main ingredient of clove, uncoupled mitochondria and increased F0F1ATPase activity. In the present study, we further investigated the effects of eugenol on MCF-7 cells in culture. Eugenol demonstrated: a dose-dependent decrease in viability (MTT assay), and proliferation (real time cell analysis) of MCF-7 cells, (EC50: 0.9 mM); an increase in reactive oxygen species; a decrease in ATP level and mitochondrial membrane potential (MitoPT JC-1 assay); and a release of cytochrome-c and lactate dehydrogenase (Cytotoxicity Detection Kit PLUS) into culture media at eugenol concentration >EC50. Pretreatment with the antioxidants Trolox and N-acetyl cysteine partially restored cell viability and decreased ROS, with Trolox being more potent. Expression levels of both anti- and pro-apoptotic markers (Bcl-2 and Bax, respectively) decreased with increasing eugenol concentration, with no variation in their relative ratios. Eugenol-treated MCF-7 cells overexpressing Bcl-2 exhibited results similar to those of MCF-7. Our findings indicate that eugenol toxicity is non-apoptotic Bcl-2 independent, affecting mitochondrial function and plasma membrane integrity with no effect on migration or invasion. We report here the chemo-sensitivity of MCF-7 cells to eugenol, a phytochemical with anticancer potential.

Oxidative Stress-Induced DNA Damage and Apoptosis in Clove Buds-Treated MCF-7 Cells

“…However, the results showed that SOD system reactivity is attenuated and is not able to prevent increasing oxidative stress leading to apoptosis. Moreover, this fact is also in accordance with study of Al Wafai and co-workers [57], where SOD pre-treatment was not able prevent eugenol-mediated increase of ROS levels in MCF-7 cells.…”

Characterization of the Eugenol Effects on the Bioenergetic Profile of SCC-4 Human Squamous Cell Carcinoma Cell Line

“…Our data are suggestive for an anticancer potential of EU, results which are in line with two studies which demonstrated that EU induces ROS-mediated mitochondrial permeability transition and resultant cytochrome c release in HL-60 cells [24], and an uncoupling effect induced by EU via an increase in F 0 F 1 ATPase activity on isolated rat liver mitochondria [25]. Moreover, Wafai et al, recently demonstrated that EU induced a dose-dependent decrease in viability and proliferation of MCF-7 cells, an increase in reactive oxygen species, a decrease in ATP level and mitochondrial membrane potential, and a release of cytochrome-c and lactate dehydrogenase in the culture media [26].…”

The Dual Antioxidant/Prooxidant Effect of Eugenol and Its Action in Cancer Development and Treatment

“…Controversially, some studies have indicated that eugenol has no cytotoxic activity or has cytotoxicity only when present in the mM range [ 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 ]. In studies with HSG (human submandibular gland adenocarcinoma) and HSC-2 (human oral squamous cell carcinoma) cells, eugenol caused cytotoxicity when in the mM range but no ROS induction was observed [ 58 , 59 ].…”

“…Cell viability and ROS production were restored by pretreatment with the antioxidants. On the other hand, the eugenol effect was not affected in MCF-7 cells with overexpression of Bcl-2 [ 71 ]. Human oral squamous cell carcinoma cell line HSC-2 treated with a concentration of eugenol in the mM range presented metabolic changes including reduction of ATP utilization, oxidative stress and an increase in the polyamines and glycolytic metabolites [ 72 ].…”