Prevention Effects Of Gardeniae Extract On PC12 Cells Injury Induced By Aβ_1-40 And H₂O₂

The effect of gardenia extraction on neuroprotection was studied in this paper systematically, which provides a theoretical basis for the functional gardenia food development and the prevention and treatment of AD.MTT assay was tested with cell viability as an index, firstly,different concentrations of Aβ_1-40 or H₂O₂ were treated on PC12 cells four 24 hours to determine the optimal injury dose; then influence of six kinds of monomer gardenia（Gardenia glycosides, Virgin Niger ia f lat, ursolic acid, gardenia ac id, saffron-1 and 2） and four extraction methods（ultrasonic, subcritical ethanol, reflux, microwave） on PC12 cell proliferation were researched, and their protection of the two damage model was compared. To explore the mechanism of the protective effect of Gardenia extract, the changes of LDH activity 、antioxidant enzymes of T-SOD and GSH-PX vitality, and the content of MDA in the culture were tested with biochemical assay kit. The composition of four crude extractions was analyzed by HPLC.Results:1 Establishment of cell injury model.Compared with the normal cultured cells, the results show that cell viability decreased to 50% after treated PC12 with 20 μmol / L of Aβ_1-40 or 100 μmol / L of H₂O₂, there was a significant difference（P <0.01）, which was the best cell injury model.2. Protective effects of gardenia monomer and extraction method for damage modelCompared cell survival with the model group, the results of Geniposide, genipin, ursolic acid and Crocetin were significantly different（P <0.05）, and genipin and Genipos ide have very signif icant difference（P <0.01）; amoung four extraction methods which have significant differences, the methods of subcritical ethanol was very significant different（P <0.01）.3. The results of LDH, T-SOD, GSH-PX and MDACompared with the model group, the LDH, MDA content decreased after treated with Geniposide, genipin, ursolic acid,saffron pigment, and the extracts of four methods, as opposited, the vitality of the antioxidant enzymes of T-SOD and GSH-PX increased（P <0.05）; among the groups, genipin, subcritical ethanol and geniposide have best effect.4 Component analysis on neuroprotective effect of four crude extractionFour kinds of crude materials contain geniposide and genipin, saffron and endothelin 1 and 2, and the content of extraction in subcritical fraction is higher. The protective effect of the gardenia extraction was stronger than the monomer.In Aβ_1-40 and H₂O₂ injury model, Geniposide, genipin, gardenia acid, saffron pigment, and crude extractions prepared by four methods have a protective effect, amoung which Geniposide, genipin, and subcritical extraction showed the strongest effects. These protective components can inhibite anti- Aβ_1-40 and H₂O₂ damage by reducing the activity of LDH, increasing T-SOD and GSH-PX vitality, and reducing the level of MDA. And the neuroprotective effect components can be more effectively extracted with subcritic al ethanol method.