Pharmazie
-
Comparative Study
Drug interaction potentials among different brands of grapefruit juice.
The discrepancy of drug-interaction potential among different brands of grapefruit juice was estimated based on inhibition of CYP3A activity caused by furanocoumarin derivatives in the grapefruit juice. Heat treatment of the grapefruit juice at 95 degrees C for 1 h was utilized to degrade the furanocoumarins. ⋯ Changes in the velocities of the reaction mixture were observed when 10% of each brand of untreated grapefruit juice or heat-treated grapefruit juice was added. The differences in the velocities between untreated and heat-treated grapefruit juice were defined as the potentials of furanocoumarin-caused CYP3A-inhibitions.
-
Microdialysis (MD) has become one of the major tools to sample endogenous and exogenous substances in extracellular spaces. It is more suitable for pharmacokinetic-pharmacodynamic (PK-PD) studies than other techniques. ⋯ It can be concluded that MD offers an unique opportunity, to study simultaneously pharmacokinetic (PK) behavior of a drug and its effect on the extracellular levels of endogenous compounds, which may facilitate proof-of-concept demonstrations for target modulation, enhance the rational selection of an optimal drug dose and schedule. In addition, MD/PK-PD can also minimize uncertainties associated with predicting drug safety and efficacy, reduce the high levels of drug attrition during development, accelerate drug approval, and decrease the overall costs of drug development.
-
Comparative Study
Comparison of antioxidant activities and total polyphenolic and methylxanthine contents between the unripe fruit and leaves of Ilex paraguariensis A. St. Hil.
Ilex paraguariensis is used in Brazil as a stimulating beverage called "mate". Leaves and immature fruit extracts of Ilex paraguariensis were evaluated for their radical scavenging capacity, total methylxanthine and polyphenol contents. Antimicrobial activity of two enriched saponin fractions obtained from the fruits were also evaluated. ⋯ Total polyphenol content varied from 86.82 +/- 3 x 10(-4) to 199.91 +/- 3 x 10(-3) mg/g in leaf fractions and from 54.25 +/- 1 x 10(-3) to 110.36 +/- 4 x 10(-4) mg/g in fruit fractions. Enriched saponin fractions from the fruits showed no antimicrobial activity. To our knowledge, this are the first data available on the antioxidant/antimicrobial activities and polyphenol/methylxanthine contents of Ilex paraguariensis fruits.
-
Aqueous extracts from whole dried mistletoe (Viscum album L., Iscucin) are often used in anti-cancer treatment. We studied the effect of extracts obtained from mistletoe bushes that grew on different host trees on bladder cancer cells by means of MTT-colorimetric cell proliferation/survival assays. ⋯ A 2-hours treatment of bladder cancer cells triggered a later, strong cytotoxic effect. This prolonged effect suggests that instillation with Iscucin has therapeutic potential for bladder cancer patients.
-
Curcumin (Cur), a promising anticancer drug, kills tumor cells through either diminishing or promoting reactive oxygen species (ROS) generation. In this study, it was investigated whether trichostatin A (TSA), a specific histone deacetylase (HDAC) inhibitor and a new anticancer drug, could improve the anticancer activity of low concentrations of Cur in human leukemia cells (HL-60). HL-60 cells were treated with Cur, TSA or their combinations; cell proliferation arrest, lactate dehydrogenase (LDH) release and cell viability were measured as indicators of cell damage. ⋯ When their effects on histone acetylation were determined, low Cur showed no effect, while TSA significantly increased that. As expected, combinations of low Cur and TSA could not only diminish ROS generation, but also increase histone acetylation, and hence showed a more significant cytotoxicity in HL-60 cells. Since the extra ROS generation may also harm normal cells, instead of using high Cur, combining low Cur with TSA is obviously a better strategy to improve the anticancer activity of Cur.