Effect Of Polyphenol In Lingonberry On Damage Induced By Oxidation And Antiproliferative Activities Of Cancer Cell

The medical research on free radicals has proved that the oxidation damageinduced by free radical is closely related to nearly100kinds of human diseases. Inrecent20years, the studies on reactive oxygen species and free radicals have becomethe hotspots in modern life science. Evaluation and selection of natural resources withstrong antioxidant activity has become a new tendency in biology, medicine and foodscience. In this study, we prepared high-activity polyphenol in Lingonberry (LBP) bybioactivity-guided isolation, and analyzed its main components. We systematicallyanalyzed antioxidant activities of LBP in vitro, its protective effects on radiation-induced oxidation damage, inhibition on tumor cell proliferation. The results showedthat LBP had stronger antioxidant and antiproliferative activities, with a goodcorrelation, indicating that the combined effects of natural plant compounds play crucialroles in antioxidant and cancer prevention.Wild lingonberry was isolated and purified by active tracking method. Free phenolsand flavonoid in fresh fruits were extracted with chilled80%acetone (1:2, w/v) using achilled JJ-2Tissue disintegrator. The homogenates were filtered and evaporated.Residue was diluted in distilled water. After separating the precipitate by filtration, theremaining solution was further separated on an adsorptive resin X-5column. Theeffective constituents were determined by ethanol gradient elution using contents ofpolyphenol and ABTS as an index, named LB-1, LB-2, LB-3, LB-4; the total elutioncomponents were named as LB-MIX (LBP). The antiproliferative activities of the abovefive effective constituents on HT29, Hela, A549and HepG-2cells were measured byMTT assay. The results showed that LBP had good antiproliferative activities on cancercell. Under the condition, the cisplatin was chosen as positive control for its highanticancer activity. The constituent of LBP was determined by UPLC-ESI-MS. Theresults showed that main constituent of LBP consisted of nine kinds of anthocyanins,four kinds of proanthocyanidins and five kinds of phenolic acids.Antioxidant activities of LBP were studied in vitro, such as removal ofphysiological free radicals and non-physiological free radicals, reduction, chelation,antilipidperoxidation and protective effect on radiation-induced damages. The resultsshowed that LBP had high antioxidant activities, which were slightly lower thanascorbic acid or equivalent, with good doseresponse relationships. LBP also had higheffect of reduction, chelation and protective effect on radiation-induced damages. The11kinds of fruits including lingonberry in China were evaluated for total contents ofphenolics, flavonoids and anthocyanins. We constructed a model of radiation-induced oxidative damage. All the LBP dosessignificantly increased the proliferation of hematopoietic cell and immunological cell;enhanced the activities of superoxide dismutase (SOD), catlase (CAT), lactatedehydrogenase (LDH) and increased the content of glutathione (GSH); lowered theactivities of myeloperoxidase (POM) and the content of malonyldiadehyde (MDA).Moreover, LBP plays functions in the activation of antioxidant enzyme system,inhibition of oxidase system, the decrease of lipid peroxidation, protection of cellmembrane, and generation inhibition on production of radiation-induced micronuclei.Analysis on cell cycle distribution and model groups showed significant differencesbetween different LBP dosage groups (p<0.01). The LBP medicine group had less cellsin the G0/G1stages and more cells in G2/M stages. This result implies that thetreatment play a role in the recovery of cell proliferation.LBP has significantly inhibitory effect on cancer cell proliferation. Among the11fruits, the inhibitory effect of lingonberry extracts on both HT-29and HepG2cancercells was the highest, blue honeysuckle the lowest. There was no correlation betweenthe antiproliferative activity and the total phenolic contents in fruit extracts. Agarose gelelectrophoresis analysis demonstrated that LBP resulted in the damage of cancermembrane as indicated by the generation of DNA-Ladder fragment. The effects of LBPand cisplatin treatment on cancer cell cycles were measured by using flow cytometer.Single cell gel electrophoresis was used to detect the DNA molecular damage. Theresults indicated that LBP can induce the cell apoptosis in different pathways. Thepresent study showed a close correlation between LBP activity and anti-proliferation ofcancer cell. This result demonstrated that lingonberry has effective functional activity.The study has importantly theoretical and practical significance to reveal mechanism ofpreventing various damages induced by free radical and develop new anticancer drugs.