Apple pomace: antiradical activity and antiproliferative action in HeLa and HT- 29 human tumor cell lines.

PURPOSE: Apple pomace is an easily accessible source of bioactive compounds which can be used for various purposes in the food, pharmaceutical and cosmetic industry. Six types of apple pomace extracts were tested to study their health benefits, free radical scavenging and antiproliferative activities. METHODS: The radical scavenging activity was determined by electron spin resonance (ESR) spectroscopy. Antiproliferative action was measured using MTT [3-(4,5-dimethylthiazol- 2-yl)2,5-diphenyl tetrazolium bromide] colorimetric assay in cervix epithelioid carcinoma (HeLa) and colon adenocarcinoma (HT-29) human cancer cell lines. RESULTS: All extracts suppressed the formation of 2,2-diphenyl- 1-picrylhydrazyl (DPPH○) and hydroxyl-free radical in a dose-dependent manner. In the presence of 12.5 mg/ ml Pinova, Reinders and Nectar pomace extract, the ESR DPPH○ signals vanished. The ○OH was completely scavenged in the presence of 45 mg/ml or higher concentration of the investigated extracts. Pinova and Braeburn pomace extracts showed the strongest antiproliferative activity against the investigated human cancer cell lines. Also, HeLa cells were found more sensitive than HT-29 cells to all extracts. CONCLUSION: Although the relationship between radical scavenging activities and phenolic contents or flavonol glycosides (R(2)≥0.80) was high, there were no significant correlations between the total phenolic contents or individual phenolic compounds and the antiproliferative activity.

Antioxidative and antiproliferative effects of Satureja montana L. extracts.

PURPOSE: To study in vitro the antioxidative effect of 6 Satureja montana L. extracts on free radicals and their antiproliferative effect on human tumor cell lines. MATERIALS AND METHODS: The antioxidative effect of extracts on 2, 2-diphenyl-1-picryhydrazyl (DPPH) radical was investigated by electron spin resonance (ESR) spectroscopy. Cell growth effect was measured by sulforhodamine B colorimetric assay on HeLa (human cervix epidermoid carcinoma), HT-29 (human colon adenocarcinoma), and MCF-7 (human breast adenocarcinoma) cell lines. IC(50) values were calculated from the concentration response curves following 48 h exposure time. RESULTS: The antioxidative activity of extracts increased dose-dependently at mass concentrations ranging from 0.05 to 0.3 mg/ml, and decreased in the following order: n-butanol > methanol > water > ethyl acetate > petroleum ether. All extracts effected cell growth but in a different way, depending on the extract dose and cell line. Extracts exhibited antiproliferative effect on HeLa cell line with IC(50) values ranging from 0.41 to 0.84 mg/ml except petroleum ether (IC(50) >1 mg/ml). Petroleum ether and chloroform extracts stimulated proliferation of HeLa cells within a concentration range from 0.0625 to 0.125 mg/ml. No extract reduced MCF-7 cells growth by 50% even at the concentration of 1 mg/ml. Only petroleum ether and chloroform extracts induced significant growth inhibition of HT-29 cells (IC(50) was approximately 0.74 mg/ml for both extracts). Strong stimulation of HT-29 proliferation was observed within a concentration range from 0.0625 to 0.25 mg/ml for petroleum ether, n-butanol and chloroform extract, and from 0.0625 to 0.5 mg/ml for methanol and water extracts, respectively. CONCLUSION: The obtained results indicated that Satureja montana L. extracts are strong antioxidants in vitro. ESR data demonstrated that n-butanol, methanol and water Satureja montana L. extracts possess high antioxidative activity. Chloroform extract did not show any antioxidative activity. Satureja montana L. extracts selectively inhibited the growth of human tumor cells.