Trilobatin regulates glucose metabolism by ameliorating oxidative stress and insulin resistance in vivo and in vitro.

OBJECTIVES: Trilobatin, a glycosylated dihydrochalcone, has been reported to have anti-diabetic properties. However, the underlying mechanism remains unexplained. METHODS: In this investigation, the regulation of trilobatin on glucose metabolism of insulin resistance (IR)-HepG2 cells and streptozocin (STZ)-induced mice and its mechanism were evaluated. KEY FINDINGS: Different doses of trilobatin (5, 10 and 20 µM) increased glucose consumption, glycogen content, hexokinase (HK), and pyruvate kinase (PK) activity in IR-HepG2 cells. Among them, the HK and PK activity in IR-HepG2 cells treated with 20 µM trilobatin were 1.84 and 2.05 times than those of the IR-group. The overeating, body and tissue weight, insulin levels, liver damage, and lipid accumulation of STZ-induced mice were improved after feeding with different doses of trilobatin (10, 50, and 100 mg/kg/d) for 4 weeks. Compared with STZ-induced mice, fasting blood glucose decreased by 61.11% and fasting insulin (FINS) increased by 48.6% after feeding trilobatin (100 mg/kg/d). Meanwhile, data from quantitative real-time polymerase chain reaction (qRT-PCR) revealed trilobatin ameliorated glycogen synthesis via the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/glycogen synthase kinase-3ß (GSK-3ß) signaling pathway in IR-HepG2 cells and in STZ-induced mice. Furthermore, in vitro and in vivo experiments showed that trilobatin ameliorated oxidative stress by regulating the mRNA expression of nuclear erythroid-2 related factor 2 (Nrf2)/kelch-like ECH associated protein-1 (Keap-1) pathway as well as heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase-1 (NQO-1). CONCLUSIONS: Our research reveals a novel pharmacological activity of trilobatin: regulating glucose metabolism through PI3K/Akt/GSK-3ß and Nrf2/Keap-1 signaling pathways, improving insulin resistance and reducing oxidative stress. Trilobatin can be used as a reliable drug resource for the treatment of glucose metabolism disorders.

Inhibitory mechanism of chrysin and diosmetin to α-glucosidase: insights from kinetics, multispectroscopy and molecular docking investigations.

Inhibition of α-glucosidase activity is a promising method to prevent postprandial hyperglycemia. The inhibitory effect and interaction of chrysin and diosmetin on α-glucosidase were studied in this study. The results of inhibition kinetics showed that chrysin and diosmetin reversibly inhibited α-glucosidase activity with IC50 value of 26.445 ± 1.406 µmol L-1 and 18.380 ± 1.264 µmol L-1, respectively. Further research revealed that chrysin exhibited a mixed-type inhibitory pattern against α-glucosidase, while diosmetin was noncompetitive inhibitory with Ki value of (2.6 ± 0.04) ×10-4 mol L-1. Fluorescence spectroscopy showed that both chrysin and diosmetin could quench the intrinsic fluorescence of α-glucosidase, the maximum emission wavelength of tyrosine (Tyr) and tryptophan (Trp) were not moved by chrysin, but red shifted by diosmetin. UV-Vis, fourier transform infrared spectroscopy (FT-IR) and circular dichroism (CD) measurements showed that the secondary structure and microenvironment of α-glucosidase were changed by chrysin and diosmetin. Further analysis of molecular docking showed that chrysin and diosmetin could bind with α-glucosidase and might cause the decrease of α-glucosidase activity. The results of molecular dynamics (MD) simulation showed that the stability of chrysin (or diosmetin)-α-glucosidase complex system was changed during binding process. In conclusion, chrysin and diosmetin are good α-glucosidase inhibitors.Communicated by Ramaswamy H. Sarma.

Inhibition of α-glucosidase by trilobatin and its mechanism: kinetics, interaction mechanism and molecular docking.

α-Glucosidase is related to the increase in postprandial blood glucose in vivo. Inhibition of α-glucosidase is supposed to be an effective approach to treat type 2 diabetes mellitus (T2DM). Trilobatin, a member of the dihydrochalcone family, shows anti-oxidant, anti-inflammatory and anti-diabetic activities. In this study, the inhibitory activity and mechanism of trilobatin on α-glucosidase were investigated using multispectroscopic and molecular docking techniques. The kinetic analysis showed that trilobatin reversibly inhibited α-glucosidase in a noncompetitive-type manner and the value of IC50 was 0.24 ± 0.02 mM. The analysis of fluorescence spectra demonstrated that the formation of the trilobatin-α-glucosidase complex was driven mainly by hydrogen bonding and van der Waals forces, resulting in the conformational changes of α-glucosidase. Fourier transform infrared spectroscopy (FT-IR) and circular dichroism (CD) measurements suggested that the interaction could change the micro-environment and conformation of α-glucosidase affected by trilobatin. Molecular docking analysis determined the exact binding sites of trilobatin on α-glucosidase. These results indicated that trilobatin is a strong α-glucosidase inhibitor, thus it could be conducive to ameliorate T2DM.

Antioxidant and functional properties of cowhide collagen peptides.

In the present study, antioxidant activities and functional properties of cowhide collagen antioxidant peptides (CCAPs) with different molecular weight (MW) were investigated. The optimum preparation conditions of CCAPs were hydrolysis time of 1.53 hr, temperature of 54.9 °C, pH 7.38, and neutral enzyme to trypsin ratio of 0.048 g: 0.016 g according to single factor test and response surface methodology (RSM). Three fractions (CCAP-I, CCAP-II, and CCAP-III) were obtained by ultrafiltration and lyophilization. Antioxidant activities revealed that CCAP-III had high reducing power activity (0.323 ± 0.035) and scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals (64.30 ± 5.99%), 2,2-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) radicals (75.25 ± 3.14%), and hydroxyl radicals (68.26 ± 6.74%) compared to the other fractions. In addition, LC-MS/MS analysis showed that Ala-Gly-Glu-Arg, Gly-Ile-Ala-Gly-Glu-Arg, Gly-Pro-Ala-Gly-Pro-Ala-Gly-Pro-Arg, Gly-Val-Val-Gly-Pro-Glu-Gly-Ala-Arg and Gly-Phe-Ser-Gly-Leu-Asp-Gly-Ala-Lys were the major peptides of CCAP-III. CCAP-III showed good hygroscopicity (HYG), water holding capacity (WHC), and oil holding capacity (OHC) when compared with CCAP-I and CCAP-II. However, CCAP-II has great emulsifying properties, and CCAP-I has excellent foaming properties. Therefore, CCAPs can be used as a promising source of functional peptides with antioxidant properties. PRACTICAL APPLICATION: This study demonstrated the peptides of cowhide collagen has superior antioxidant and functional properties. This study provided a scientific basis for the preparation of antioxidant peptides from cowhide collagen.

Hyaluronic acid coating on the surface of curcumin-loaded ZIF-8 nanoparticles for improved breast cancer therapy: An in vitro and in vivo study.

Despite developments in surgery and chemotherapy, effective treatment of breast cancer is still an urgent problem owing to recurrence and metastasis. By combining the advantages of curcumin (Cur), zeolitic imidazolate framework-8 nanoparticles (ZIF-8), and hyaluronic acid (HA) in breast cancer therapy, Cur-loaded and HA-coated ZIF-8 (Cur@ZIF-8@HA) were synthesized using a method based on the pH-dependent solubility of Cur and the electrostatic interactions between zinc ions and carboxyl groups of HA. Cur@ZIF-8 were also prepared as a control group. Comprehensive comparisons of the physicochemical properties and anticancer activities of Cur@ZIF-8@HA and Cur@ZIF-8 were conducted. The results indicated that the degradation of Cur during the synthesis of Cur@ZIF-8 was negligible. The obtained Cur@ZIF-8 and Cur@ZIF-8@HA were truncated cubes with hydrodynamic diameters of 174 and 217 nm, respectively. Cur@ZIF-8@HA possessed better stability during storage in different media, a slower drug release rate under neutral and acidic conditions, and a greater inhibitory effect on breast cancer than Cur@ZIF-8. For 4T1 cells, treatment using Cur@ZIF-8@HA induced more cellular uptake and higher cytotoxicity, accompanied by higher lactate dehydrogenase release, cell cycle arrest in G2/M and S phases, production of reactive oxygen species, and apoptosis. In 4T1 tumor-bearing mice models, Cur@ZIF-8@HA showed a stronger inhibitory effect on tumor growth and pulmonary metastasis. Therefore, Cur@ZIF-8@HA might hold great potential as an agent for the effective therapy of breast cancer.

Inhibitory activity and mechanism of trilobatin on tyrosinase: kinetics, interaction mechanism and molecular docking.

Tyrosinase is the rate-limiting enzyme controlling the production of melanin, and tyrosinase inhibitors can regulate the overproduction of melanin by inhibiting tyrosinase activity, which is an effective method to treat pigmentation disorders. In this study, kinetic analysis, multispectroscopic methods and molecular simulation were used to investigate the inhibitory activity and mechanism of trilobatin on tyrosinase. The kinetic analysis showed that trilobatin had significant inhibitory activity on tyrosinase in a reversible and mixed-type manner with IC50 values of (2.24 ± 0.35) × 10-5 mol L-1. The intrinsic fluorescence of tyrosinase was quenched by trilobatin through a static quenching mechanism. Different spectroscopic measurements demonstrated that trilobatin could change the microenvironments and conformation of tyrosinase and molecular docking determined the binding site of quercetin on tyrosinase.

In Vitro Anticancer Potential of Berberis lycium Royle Extracts against Human Hepatocarcinoma (HepG2) Cells.

Human liver cancer has emerged as a serious health concern in the world, associated with poorly available therapies. The Berberis genus contains vital medicinal plants with miraculous healing properties and a wide range of bioactivities. In this study, different crude extracts of B. lycium Royle were prepared and screened against Human Hepatocarcinoma (HepG2) cell lines. The water/ethanolic extract of B. lycium Royle (BLE) exhibited significant antiproliferative activity against the HepG2 cancer cell line with an IC50 value of 47 µg/mL. The extract decreased the clonogenic potential of HepG2 cells in a dose-dependent manner. It induced apoptotic cell death in HepG2 cells that were confirmed by cytometric analysis and microscopic examination of cellular morphology through DAPI-stained cells. Biochemical evidence of apoptosis came from elevating the intracellular ROS level that was accompanied by the loss of mitochondrial membrane potential. The mechanism of apoptosis was further confirmed by gene expression analysis using RT-qPCR that revealed the decline in Bcl-2 independent of p53 mRNA and a rise in CDK1 while downregulating CDK5, CDK9, and CDK10 mRNA levels at 48 h of BLE treatment. The most active fraction was subjected to HPLC which indicated the presence of berberine (48 µg/mL) and benzoic acid (15.8 µg/mL) as major compounds in BLE and a trace amount of luteolin, rutin, and gallic acid. Our study highlighted the importance of the most active BLE extract as an excellent source of nutraceuticals against Human Hepatocarcinoma that can serve as an herbal natural cure against liver cancer.

Suppressive effects of Momordin Ic on HepG2 cell migration and invasion by regulating MMP-9 and adhesion molecules: Involvement of p38 and JNK pathways.

Momordin Ic was previously found to induce liver cancer cell apoptosis and autophagy. To further elucidate the anti-cancer activity of Momordin Ic, we analyzed the suppressive effects of Momordin Ic on cell migration and invasion. We also investigated the mechanisms associated with MMP-9, adhesion molecules and signaling transductions. The results demonstrated that Momordin Ic effectively prevented cell attachment, migration and invasion. E-cadherin, mediation of homotypic adhesion was induced while VCAM-1 and ICAM-1 and MMP-9 were inhibited. Momordin Ic influenced phosphorylations of p38, JNK and Erk with VEGF. p38 effectively regulated expressions of E-cadherin, VCAM-1 and ICAM-1. JNK greatly contributed to E-cadherin alteration. Erk hardly modified E-cadherin, VCAM-1, ICAM-1 and MMP-9 although Erk phosphorylation decreased by Momordin Ic. These results revealed Momordin Ic prevent cell invasion by inhibiting VCAM-1, ICAM-1, MMP-9 but inducing E-cadherin expression via p38 and JNK pathways. Thus momordin Ic may be a promising candidate with anti-cancer bioactivity.

Curative versus palliative treatments for colorectal cancer with peritoneal carcinomatosis: a systematic review and meta-analysis.

The objective of this study was to provide an up-to-date summary of the current evidence that may be useful for updating guidelines. We comprehensively searched the published literatures and conferences for studies that compared curative with palliative treatments in colorectal cancer patients with peritoneal metastasis. The primary outcomes considered in this study were three- and five-year overall survival rates. We pooled data across studies and estimated summary effect sizes. Overall, patients who received curative treatments had improved three-year survival (hazard ratio (HR), 2.19 [95% CI, 1.83 to 2.62]) and five-year survival (HR, 2.22 [95% CI, 1.83 to 2.69]) compared with those who received palliative treatments. Patients who received curative treatments had an increased risk of treatment-related morbidity (odds ratio (OR), 2.90 [95% CI, 2.02 to 4.17]), but there was no significant difference in treatment-related mortality between patients who received curative treatments and those who received palliative treatments (OR, 1.46 [CI, 0.62 to 3.47]). Curative treatments improved overall survival in colorectal cancer patients with peritoneal metastasis and did not increase the risk of treatment-related mortality. Curative treatments were associated with a higher risk of treatment-related morbidity. These data highlight the importance for further investigation aimed at prevention of treatment-associated morbidity.

A novel mechanism for momordin Ic-induced HepG2 apoptosis: involvement of PI3K- and MAPK-dependent PPARγ activation.

Momordin Ic is a natural triterpenoid saponin found in various Chinese and Japanese natural medicines such as the fruit of Kochia scoparia (L.) Schrad. Momordin Ic has been previously demonstrated to induce HepG2 cell apoptosis in a ROS-mediated PI3K and MAPK pathway-dependent manner. In the present study, the underlying mechanisms of PI3K and MAPK pathway-mediated PPARγ, and PGC-1α co-regulator activation, as well as the effects of downstream proteins, COX-2 and FoxO4, on cell apoptosis were investigated. The results demonstrated that momordin Ic activated PPARγ and inhibited COX-2. PGC-1α and FoxO4 expressions were increased by the PI3K or MAPK pathways. Furthermore, PPARγ inhibition decreased p-p38 and FoxO4 expression, and restored COX-2 expression. ROS inhibition exerted little effect on PPARγ, COX-2 and FoxO4 expression but affected PGC-1α expression. These results revealed the involvement of PI3K and MAPK-dependent PPARγ activation in momordin Ic-induced apoptosis, providing more detailed information underlying the pro-apoptotic mechanism of momordin Ic in HepG2 cell apoptosis.

Additive effect of zinc oxide nanoparticles and isoorientin on apoptosis in human hepatoma cell line.

Metal nanomaterial could effectively decrease tumour resistance to anti-cancer drugs. In this paper, we have explored the synergistic effect and mechanisms of zinc oxide nanoparticles (ZnO Nps) and isoorientin (ISO) on cytotoxicity in human hepatoma (HepG2) cells. The results showed that ZnO Nps could exert dose- and time-dependent cytotoxicity in HepG2 cells, and the combining treatment resulted in a greater cytotoxicity than single treatment. ZnO Nps could synergistically potentiate ISO to induce apoptosis through resulting in mitochondrial dysfunction, inhibiting the phosphorylation of Akt and ERK1/2, and enhancing the phosphorylation of JNK and P38. Additionally, ZnO Nps were uptaked by cells through endocytic pathway and it enhanced the cellular uptake of ISO, while no significant injury was found in normal liver cells after the combined treatment. These results suggest that the combination of metal nanoparticle with anti-cancer drugs may provide a promising alternative for novel cancer treatments.

Chicoric acid induces apoptosis in 3T3-L1 preadipocytes through ROS-mediated PI3K/Akt and MAPK signaling pathways.

Chicoric acid has been reported to possess various bioactivities. However, the antiobesity effects of chicoric acid remain poorly understood. In this study, we investigated the effects of chicoric acid on 3T3-L1 preadipocytes and its molecular mechanisms of apoptosis. Chicoric acid inhibited cell viability and induced apoptosis in 3T3-L1 preadipocytes which was characterized by chromatin condensation and poly ADP-ribose-polymerase (PARP) cleavage. Mitochondrial membrane potential (MMP) loss, Bax/Bcl-2 dysregulation, cytochrome c release, and caspase-3 activation were observed, indicating mitochondria-dependent apoptosis induced by chicoric acid. Furthermore, PI3K/Akt and MAPK (p38 MAPK, JNK, and ERK1/2) signaling pathways were involved in chicoric acid-induced apoptosis. The employment of protein kinase inhibitors LY294002, SB203580, SP600125, and U0126 revealed that PI3K/Akt signaling pathway interplayed with MAPK signaling pathways. Moreover, chicoric acid induced reactive oxygen species (ROS) generation. Pretreatment with the antioxidant N-acetylcysteine (NAC) significantly blocked cell death and changes of Akt and MAPK signalings induced by chicoric acid. In addition, chicoric acid down regulated HO-1 and COX-2 via the PI3K/Akt pathway.

Momordin Ic induces HepG2 cell apoptosis through MAPK and PI3K/Akt-mediated mitochondrial pathways.

Momordin Ic is a natural triterpenoid saponin enriched in various Chinese and Japanese natural medicines such as the fruit of Kochia scoparia (L.) Schrad. So far, there is little scientific evidence for momordin Ic with regard to the anti-tumor activities. The aim of this work was to elucidate the anti-tumor effect of momordin Ic and the signal transduction pathways involved. We found that momordin Ic induced apoptosis in human hepatocellular carcinoma HepG2 cells, which were supported by DNA fragmentation, caspase-3 activation and PARP cleavage. Meanwhile, momordin Ic triggered reactive oxygen species (ROS) production together with collapse of mitochondrial membrane potential, cytochrome c release, down-regulation of Bcl-2 and up-regulation of Bax expression. The activation of p38 and JNK, inactivation of Erk1/2 and Akt were also demonstrated. Although ROS production rather than NO was stimulated, the expression of iNOS and HO-1 were altered after momordin Ic treatment for 4 h. Furthermore, the cytochrome c release, caspase-3 activation, Bax/Bcl-2 expression and PARP cleavage were promoted with LY294002 and U0126 intervention but were blocked by SB203580, SP600125, PI3K activator, NAC and 1,400 W pretreatment, demonstrating the mitochondrial disruption. Furthermore, momordin Ic combination with NAC influenced MAPK, PI3K/Akt and HO-1, iNOS pathways, MAPK and PI3K/Akt pathways also regulated the expression of HO-1 and iNOS. These results indicated that momordin Ic induced apoptosis through oxidative stress-regulated mitochondrial dysfunction involving the MAPK and PI3K-mediated iNOS and HO-1 pathways. Thus, momordin Ic might represent a potential source of anticancer candidate.

Carnosic acid attenuates lipopolysaccharide-induced liver injury in rats via fortifying cellular antioxidant defense system.

The study investigated the protective effects of carnosic acid (CA), the principal constituent of rosemary, on lipopolysaccharide (LPS)-induced oxidative/nitrosative stress and hepatotoxicity in rats. CA was administered orally to rats at doses of 15, 30 and 60 mg/kg body weight before LPS challenge (single intraperitoneal injection, 1 mg/kg body weight). The results revealed that CA inhibited LPS-induced liver damage and disorder of lipid metabolism, which were mainly evidenced by decreased serum levels of alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase. CA also inhibited LPS-induced oxidative/nitrosative stress by decreasing lipid peroxidation, protein carbonylation, and serum levels of nitric oxide. Histopathological examination demonstrated that CA could improve pathological abnormalities and reduce the immigration of inflammatory cells in liver tissues with LPS challenge. Concurrently, CA potently inhibited the LPS-induced rise in serum levels of the pro-inflammatory cytokines tumor necrosis factor-α and interleukin-6. CA supplementation markedly enhanced the body's cellular antioxidant defense system by restoring the levels of superoxide dismutase, glutathione peroxidase, and glutathione in serum and liver after the LPS challenge. In conclusion, the present study suggests that CA successfully and dose dependently attenuates LPS-induced hepatotoxicity possibly by preventing cytotoxic effects of oxygen free radicals, NO and cytokines.

MAPK signaling pathways regulate mitochondrial-mediated apoptosis induced by isoorientin in human hepatoblastoma cancer cells.

Isoorientin (ISO) (CAS RN: 4261-42-1) is a flavonoid compound that can be extracted from several plant species, such as Phyllostachys pubescens, Patrinia, and Drosophyllum lusitanicum. ISO is able to induce apoptosis through mitochondrial dysfunction and inhibition of PI3K/Akt signaling pathway in HepG2 cells, however, the effects of ISO on MAPK signaling pathways remain unknown. The present study investigated the effects of ISO on this pathway, and the roles of MAPK kinases on mitochondrial-mediated apoptosis in HepG2 cells. The results showed that ISO induced cell death in a dose- and time-dependent manner, and induction apoptosis is main cause for ISO-induced cytotoxicity in HepG2 cells. ISO significantly inhibited the levels of ERK1/2 kinase and increased the expression of JNK and p38 kinases. Furthermore, U0126 (an ERK1/2 inhibitor) significantly enhanced the ISO-induced the Bax/Bcl-2 ratio, the release of cytochrome c to the cytosol fraction, and the levels of cleaved caspase-3. While SP600125 (a JNK inhibitor) and SB203580 (a p38 inhibitor) markedly prevented the expression of these proteins induced by ISO. Furthermore, the ROS inhibitor (NAC) notably promoted the inhibited effect of ISO on the ERK1/2 kinase. NAC also suppressed the p-JNK and p-p38, but failed to reverse the effects of ISO. These results demonstrated for the first time that ISO induces apoptosis in HepG2 cells through inactivating ERK1/2 kinase and activating JNK and p38 kinases, and ROS stimulated by ISO is able to activate the MAPK singaling pathway as the upstream signaling molecules. Initiating event of the mitochondrial-mediated apoptosis induced by ISO is MAPK signals.

Isoorientin induces apoptosis through mitochondrial dysfunction and inhibition of PI3K/Akt signaling pathway in HepG2 cancer cells.

Isoorientin (ISO) is a flavonoid compound that can be extracted from several plant species, such as Phyllostachys pubescens, Patrinia, and Drosophyllum lusitanicum; however, its biological activity remains poorly understood. The present study investigated the effects and putative mechanism of apoptosis induced by ISO in human hepatoblastoma cancer (HepG2) cells. The results showed that ISO induced cell death in a dose-dependent manner in HepG2 cells, but no toxicity in human liver cells (HL-7702) and buffalo rat liver cells (BRL-3A) treated with ISO at the indicated concentrations. ISO-induced cell death included apoptosis which characterized by the appearance of nuclear shrinkage, the cleavage of poly (ADP-ribose) polymerase (PARP) and DNA fragmentation. ISO significantly (p<0.01) increased the Bax/Bcl-2 ratio, disrupted the mitochondrial membrane potential (MMP), increased the release of cytochrome c, activated caspase-3, and enhanced intracellular levels of reactive oxygen species (ROS) and nitric oxide (NO). In addition, ISO effectively inhibited the phosphorylation of Akt and increased FoxO4 expression. The PI3K/Akt inhibitor LY294002 enhanced the apoptosis-inducing effect of ISO. However, LY294002 markedly quenched ROS and NO generation and diminished the protein expression of heme peroxidase enzyme (HO-1) and inducible nitric oxide synthase (iNOS). Furthermore, the addition of a ROS inhibitor (N-acetyl cysteine, NAC) or iNOS inhibitor (N-[3-(aminomethyl) benzyl] acetamidine, dihydrochloride, 1400W) significantly diminished the apoptosis induced by ISO and also blocked the phosphorylation of Akt. These results demonstrated for the first time that ISO induces apoptosis in HepG2 cells and indicate that this apoptosis might be mediated through mitochondrial dysfunction and PI3K/Akt signaling pathway, and has no toxicity in normal liver cells, suggesting that ISO may have good potential as a therapeutic and chemopreventive agent for liver cancer.

Novel physiological properties of ethanol extracts from Eremurus chinensis Fedtsch. roots: in vitro antioxidant and anticancer activities.

Eremurus chinensis Fedtch. (ECF) with nutritious roots, belonging to the genus of Eremurus, is a special species grown in China. However, the functional properties of ECF roots have not been intensely investigated. The antioxidant and anticancer effects of ethanol extracts from E. chinensis Fedtch. roots (ECFE) were evaluated in the present study. ECFE exhibited high radical-scavenging activities on DPPH and ABTS radicals, strong reducing power and Fe(2+)-chelating activity. ECFE also effectively protected biological macromolecules including proteins, lipids and DNA against oxidative damage induced by Cu(2+)/H(2)O(2) and AAPH systems. Moreover, the MTT assay revealed that ECFE inhibited proliferation of HepG2 cells in a dose- and time-dependent manner. Western blot analysis demonstrated that treatment with ECFE led to cell apoptosis hallmarked by PARP cleavage. Additionally, caspase-3 activation, cytochrome C (Cyt-C) release and increase of Bax/Bcl-2 ratio suggested that mitochondria-mediated signaling pathway might be involved in ECFE-induced apoptosis in HepG2 cells. These results demonstrate the remarkable potentiality of ECFE as a valuable source of antioxidants which possess original anticancer abilities.