Low Dose of Emodin Inhibits Hypercholesterolemia in a Rat Model of High Cholesterol.

BACKGROUND Emodin has been widely used in traditional Chinese medicine, but few studies have tried to understand the mechanism of its anti-hypercholesterolemic effect. MATERIAL AND METHODS To delineate the underlying pathways, high-cholesterol diet (HCD)-fed Sprague-Dawley rats were orally administrated emodin or the lipid-lowering medicine simvastatin. Emodin was administered at 10, 30, or 100 mg/kg, while simvastatin was administered at 10 mg/kg. Parameters measured included lipid profiles (serum total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, aorta endothelium-dependent vasorelaxation in response to acetylcholine, and nitric oxide (NO) production. RT-qPCR and western blotting were performed to evaluate aortic endothelial nitric oxide synthase (eNOS), phosphorylated eNOS (p-eNOS), and hepatic LDL receptor (LDLR). Indices of liver and serum oxidation were also measured. RESULTS The atherogenic index was increased by the HCD but significantly reduced in all treatment groups. The HCD-fed experimental group treated with emodin at 10 mg/kg had significantly lower serum total-C and LDL-C and improved aorta vasorelaxation and enhanced NO production. Also, emodin significantly attenuated the lipid profiles and restored endothelial function, as reflected by upregulated expression of hepatic LDLR and p-eNOS, respectively. Furthermore, emodin at 10 mg/kg significantly enhanced superoxide dismutase activity, lowered the malondialdehyde level in both liver and serum, and enhanced catalase activity in serum. CONCLUSIONS The ability of emodin to inhibit hypercholesterolemia in HCD-fed rats was associated with lower serum total-C and LDL-C, restoration of aortic endothelial function, and improved antioxidant capacity. Low-dose emodin showed better protection of aortic endothelium and better antioxidant activity than did higher doses.

[Proliferation apoptotic influence of crocin on human bladder cancer T24 cell line].

OBJECTIVE: To investigate the proliferation, apoptosis and mechanisms on T24 cell of transitional cell carcinoma of bladder (TCCB) by crocin. METHOD: MTT assay was used to evaluate the proliferation of T24 cells. The changes of cell cycle and cell apoptotic percentage were measured by flow cytometry. T24 cells were inoculated into BALB/c nude mice to establish model of carcinoma of bladder. The mice were randomly divided into control group and experimental group. After treatment with 50 mmol x L(-1) crocin, the inhibited growth of tumor was observed. Electronic microscope was used to observe the morphological changes. The expressions of Bcl-2, Bax, Survivin and Cyclin D1 were detected by immunohistochemistry. RESULT: The growth of T24 cells was remarkably inhibited after treatment of crocin. Flow cytometric profiles revealed that crocin led to the increase of the cells in G0/G1 phase, the percentage of cell apoptosis was also increased. Crocin could inhibit the growth of BALB/c xenograft tumor. The morphology changes of cell apoptosis were observed. Bcl-2, Cyclin D1 and survivin expressions determined by immunohistochemical staining were down-regulated after treatment with Bax expression up-regulated. CONCLUSION: Crocin exerts both in vitro and in vivo anti-cancer effect on TCCB T24 cell line. The mechanisms may change tumour cell cycle and induce tumour cell apoptosis by down-regulating the expression of Bcl-2, Survivin, Cyclin D1 and up-regulating the expression of Bax.

[Influence of crocin on gene expression profile of human bladder cancer cell lines T24].

OBJECTIVE: To investigate the changes of gene expression profile in transitional cell carcinoma of bladder T24 cell after crocin treatment, in order to find the possible crocin targets. METHOD: The bladder cancer T24 cell line was treated with crocin. MTT assay was adopted to determine the inhibition rate for selecting the best effect time and concentration of crocin. Differentially expressed genes on groups with or without treatment of crocin were screened with high throughout cDNA microarray. One up-regulated gene p21(WAF1) and one down-regulated gene cyclinD1 were selected to undergo analysis by the reverse transcription polymerase chain reaction (RT-PCR). Moreover, immunocytochemical method was used to evaluate p21(WAF1) and cyclinD1 protein expression. RESULT: The growth of T24 cells was inhibited remarkably following a marked positive correlation between crocin concentration, time and inhibitor rate. When 3 mmol x L(-1) crocin treated T24 cells for 48h, the difference was significant compared with the control group (P < 0.05). Crocin induced wide changes of the gene expression profile of T24 cells. A total of 836 genes were up-regulated or down-regulated by more than 2 times, which were involved cell cycle controlling, DNA cell apoptosis, replication factor, and so on. The mRNA expression of p21(WAF1) and cyclinD1 detected by RT-PCR were in accordance with cDNA microarray data. The results of immunocytochemical method showed that p21(WAF1) and cyclinD1 protein expression were consistent with those mRNA expression. CONCLUSION: Crocin can induce the significant alteration of gene expression profile of T24 cell. It is suggested that the widly konwn anti-tumor effects of crocin are medicated at least in part by regulating the cell cycle controlling gene expression.