Studies on reversing MDR of K562/A02 by ramification of curcumin hydrolyzed / 中国中药杂志

<p><b>OBJECTIVE</b>To determine the reversal effects of ramification of curcumin hydrolyzed on multidrug-resistant cell line K562/A02, and explore its reversal mechanism.</p><p><b>METHOD</b>After treatment with ramification of curcumin hydrolyzed, the sensitivity of K562/A02 cells to usuall chemotherapeutic drugs were determined by MTT. The expression of P-gp in K562/A02 and K562 cells was detected by immunohistochemical method. Intracellular mean fluorescence intensity (MFI) of DNR in K562 and K562/A02 cells was detected by Flow Cytometry.</p><p><b>RESULT</b>After treatment with the ramification of curcumin, hydrolyzed (2.5 mg x L(-1)) IC50, of usuall chemotherapeutic drugs to K562/A02 decreased. The sensitivity of K562/A02 cells increased. The expression of the P-gp in K562/A02 cells decreased (P < 0.05); MFI of the DNR in K562/A02 cells more significantly increased (P < 0.05). The expression of mdrl-mRNA decreased.</p><p><b>CONCLUSION</b>The ramification of curcumin hydrolyzed have effects on the reversal multidrug-resistant of K562/A02 cells in vitro. It could enhance the sensitivity of K562/A02 cells to chemotherapeutic drugs and the mechanism might be associated with inhibiting P-gp-mediated drug efflux and increasing of intracellular concentration of chemotherapeutic drugs.</p>

Effects of poly- N -acetylglucosamine on metabolism of low density lipoprotein and lipoprotein(a) / 中国药理学通报

AIM To study the effects of poly- N -acetylglucosamine on the metabolism of low density lipoprotein and lipoprotein (a). METHODS Poly- N -acetylglucosamine was injected into the body of hedgehogs viathe armpit vein 2 minutes before the 125 I low density lipoprotein ( 125 I-LDL), 125 I lipoprotein(a) 〔 125 I-Lp(a)〕, 125 I desialylated low density lipoprotein ( 125 I-ds-LDL) or 125 I desialylated lipoprotein(a) 〔 125 I-ds-Lp(a)〕 were injected separatively . The animals were put to death in one hour. The radioactivity in the blood, liver, kidney, spleen, gall and adrenal were measured. RESULTS Absorption of ds-LDL and ds-Lp(a) increased in the liver. Later ds-LDL was reutilized and released into blood, but the majority of ds-Lp(a) was excreted out of the body from liver. It was not eliminated that ds-LDL was metabolized via the LDL receptor for the uptake of ds-LDL also increased in the kidney and the adrenal. It is possible that ds-Lp(a) and the part of ds-LDL may be catabolized via the desialylated lipoprotein-related receptor. Poly- N -acetylglucosamine could increase the absorption of LDL in the liver and the adrenal, meanwhile the concentration of LDL decreased in the blood and the absorption of LDL decreased in the spleen. CONCLUSION Poly- N -acetylglucosamine has the effects of lowering lipids through activating LDL receptor.