Characterization Of Antioxidant And Anti-tumor Of Actinidia Kolomikta Polyphenol

It is widely recognized by modern medicine that free radicals possess strongoxidability and thus could attack biomacromolecules, causing damages to tissues andcells and resulting in cancer, inflammation, cardiopathy, cardiovascular diseases anddiabetes, etc. Therefore, evaluation and searching of antioxidant materials from naturalproducts are one of the hot issues in modern life science. This paper takes polyphenolsof kiwi fruit as research object, using active tracking method to obtain the most activeactinidia kolomikta polyphenol （AKP） and analyzing its composition. We analyze theactivity of antioxidant activity in vitro, and anti-tumor proliferation of AKP and thecorrelation of protection of oxidative damage and anti-tumor effect in vivo.The antioxidant and anti-tumor proliferation capacities were systematicallyanalyzed. By the analysis of total reducing power, scavenging of physiologic freeradicals（Hydroxyl radical, superoxide free radicals）, non-physiological free radicals（ABTS, DPPH）, and anti-lipid peroxidation, actinidiakolomikta was found to possessthe lowest IC50value and the strongest antioxidant capacity, followed by actinidiaargutaand actinidiachinensis. Additionally, its antioxidant capacity had a strong correlationwith its total polyphenol content, with a correlation coefficient of more than0.7.Furthermore, all the three species were found to be desirably efficient in inhibiting theproliferation of HepG2, HT-29, HeLa and A549.AKP was extracted and purified based on activity tracking. Polyphenols of threespecies were firstly extracted by60%ethanol with the assistance of ultrasonic. Sampleswere concentrated by rotary evaporator and the polyphenols content was measured byFolin-phenol reagent method. The result showed that actinidiakolomikta was found tohave the highest content of polyphenol, namely,430.03±21.85mg GAE per100g freshfruit. Multichannel two-dimensional chromatography was applied to separate AKP. Theexperiment condition was optimized by response surface methods, namely, loadingvolume of57.27mL, elution concentration of71.71%and elution volume2.85. Theprediction yield of polyphenol of RSM was11.99mg/mL, which had no significantdifference with the actual value.Purified AKP was analyzed by HPLC-ESI-MS. Results showed that it containedcoumaric acid, vanillic acid, chlorogenic acid, kaempferol, catechins, resveratrol,isorhamnetin3-O-glycoside, quercetin3-O-hexyl glycoside, quercetin3-O-rhamnoside,etc.Animal model for oxidative damage was constructed by⁶⁰Co γ-ray irradiated mice.Results showed that AKP can enhance the function of immune system throughpromoting hematopoiesis, the proliferation of splenocytes and the generation of interleukin IL-2, IL-4, IL-10and IFN-γ. It could also induce the expression ofendogenous antioxidases like SOD, CAT and GSH-Px, inhibit lipid peroxidation, reducethe content of MDA and increase the content of GSH of non-enzymatic systemantioxidant substance. It also protected body from the damage of excessive free radicalsinduced by irradiation. AKP could inhibit the activities of oxidases as well as promotethe activities of antioxidases and reduce lipid peroxidation. It could also decrease thefrequency of micronucleus and chromosomal aberration in bone marrow cells, whichhad further demonstrated its protective effect of oxidative damage induced by radiation.Malignant tumor model was constructed by S180loaded mice. Results showed thatAKP could significantly prolong the survival time of tumor mice. Low, moderate andhigh dose of AKP could inhibit S180tumor by20.91%,38.17%and44.27%,respectively. Polyphenol treatment could also enhance immune system by promoting theproliferation of splenic lymphocytes and improving spleen index and thymus index. Theimmune system could rapidly detect and response to the generation of tumor cells forachieving the goal of antitumor.DNA Ladder experiment and flow cytometer were used to analyze the cell cycle ofcancer cells. Results showed that AKP could efficiently induce HepG2and HeLa cellsto produce a lot of gradient stripe. More specifically, AKP could block HepG2at thestage of G2/M and block HeLa at the stage of G0/G1. This indicated that AKP couldinduce apoptosis in different paths to achieve the goal of proliferation of cancer cell.Results also showed that the antioxidant activities of AKP were closely correlated withits antiproliferation activity, and revealed the closely relationship between antioxidantactivity of polyphenol compounds and the removal of reactive oxygen free radicals andfunction of tumor suppressor.