Carrot （Daucus carom） is a valuable source of health promoting ingredients such as anthocyanin, carotenes, phenolic compounds etc. These substances are important to man as a source of pharmaceuticals, fragrance, agr...Carrot （Daucus carom） is a valuable source of health promoting ingredients such as anthocyanin, carotenes, phenolic compounds etc. These substances are important to man as a source of pharmaceuticals, fragrance, agrochemicals as well as food additives and used for prevention of many chronic diseases. Since these activities may be correlated with the presence of antioxidant compounds, extract of carrot and carrot callus were evaluated for their anthocyanin, flavonoids and total phenolic content as well as total antioxidant activity. Anthocyanin content was measured by spectrophotometric method. Total phenols and flavonoids were analyzed according to the Folin-Ciocalteu method and total antioxidant activity was assessed by ferric reducing/antioxidant power （FRAP） assay. Anthocyanin, flavonoids and total phenolic content were estimated to be 9.36 mg%, 46.96 mg% and 57.01 mg% for callus and 6.82 mg%, 32.96 mg% and 42.69 mg% for carrot, respectively, on fresh weight basis. The total antioxidant activity for the callus and carrot was found to be 51.13 mg, 118.77 mg, 91.08 mg and 140.08 mg equivalent and 79.40 mg, 184.44 mg, 141.43 mg and 217.52 mg equivalent to gallic acid, vitamin C, butylated hydroxyanisole （BHA） and trolox, respectively, when expressed per 100 g on fresh weight basis. The antioxidant activity of fresh carrot was found to be higher compared to its callus.展开更多
Multidrug resistance （MDR） in tumor cells can reduce the efficacy of chemotherapy. Overexpression of transporters is an important mechanism for MDR. P-glycoprotein （P-gp） is an ATP-binding cassette transporter fre...Multidrug resistance （MDR） in tumor cells can reduce the efficacy of chemotherapy. Overexpression of transporters is an important mechanism for MDR. P-glycoprotein （P-gp） is an ATP-binding cassette transporter frequently expressed in multidrug resistant tumor cells, inducing MDR. To reverse P-gp dependent MDR, anticancer drugs can be administered with P-gp inhibitors. Piperine and （R）-（＋）-citronellal both are P-gp inhibitors from dietary sources. In the present study, we aimed to evaluate the MDR reversal effects of piperine and （R）-（＋）-citronellal in multidrug resistant MCF-7/DOX cells. The results of cytotoxicity studies indicated that piperine and （R）-（＋）-citronellal both could abate the resistance of MCF-7/DOX after 72-h incubation. After 72-h incubation, piperine could dose-dependently down-regulate the MDR1 expression at the mRNA level, while （R）-（＋）-citronellal had no effect on the MDR1 expression. Therefore, piperine and （R）-（＋）-citronellal both could reverse MDR in MCF-7/DOX cells, and the reversal effect ofpiperine was related to dose-dependent down-regulation of the MDR1 expression at the mRNA level.展开更多
文摘Carrot （Daucus carom） is a valuable source of health promoting ingredients such as anthocyanin, carotenes, phenolic compounds etc. These substances are important to man as a source of pharmaceuticals, fragrance, agrochemicals as well as food additives and used for prevention of many chronic diseases. Since these activities may be correlated with the presence of antioxidant compounds, extract of carrot and carrot callus were evaluated for their anthocyanin, flavonoids and total phenolic content as well as total antioxidant activity. Anthocyanin content was measured by spectrophotometric method. Total phenols and flavonoids were analyzed according to the Folin-Ciocalteu method and total antioxidant activity was assessed by ferric reducing/antioxidant power （FRAP） assay. Anthocyanin, flavonoids and total phenolic content were estimated to be 9.36 mg%, 46.96 mg% and 57.01 mg% for callus and 6.82 mg%, 32.96 mg% and 42.69 mg% for carrot, respectively, on fresh weight basis. The total antioxidant activity for the callus and carrot was found to be 51.13 mg, 118.77 mg, 91.08 mg and 140.08 mg equivalent and 79.40 mg, 184.44 mg, 141.43 mg and 217.52 mg equivalent to gallic acid, vitamin C, butylated hydroxyanisole （BHA） and trolox, respectively, when expressed per 100 g on fresh weight basis. The antioxidant activity of fresh carrot was found to be higher compared to its callus.
文摘Multidrug resistance （MDR） in tumor cells can reduce the efficacy of chemotherapy. Overexpression of transporters is an important mechanism for MDR. P-glycoprotein （P-gp） is an ATP-binding cassette transporter frequently expressed in multidrug resistant tumor cells, inducing MDR. To reverse P-gp dependent MDR, anticancer drugs can be administered with P-gp inhibitors. Piperine and （R）-（＋）-citronellal both are P-gp inhibitors from dietary sources. In the present study, we aimed to evaluate the MDR reversal effects of piperine and （R）-（＋）-citronellal in multidrug resistant MCF-7/DOX cells. The results of cytotoxicity studies indicated that piperine and （R）-（＋）-citronellal both could abate the resistance of MCF-7/DOX after 72-h incubation. After 72-h incubation, piperine could dose-dependently down-regulate the MDR1 expression at the mRNA level, while （R）-（＋）-citronellal had no effect on the MDR1 expression. Therefore, piperine and （R）-（＋）-citronellal both could reverse MDR in MCF-7/DOX cells, and the reversal effect ofpiperine was related to dose-dependent down-regulation of the MDR1 expression at the mRNA level.
