In vivo effect of Kaempferia parviflora extract on pharmacokinetics of acetaminophen.

Kaempferia parviflora is widely used as a food supplement and a herbal medicine for vitalization. Previous study has shown that K. parviflora had CYP2E1 inducer activity. It is likely to affect the metabolism of CYP2E1 substrates such as acetaminophen which is a common household pain relief medicine. This study investigated the possible pharmacokinetic interaction between K. parviflora and acetaminophen in rats. Acetaminophen (100 mg/kg, p.o) was administered to rats for nine consecutive days. On days 4-9, K. parviflora extract (250 mg/kg, p.o) was given to the acetaminophen-treated rats. After co-administration with K. parviflora, the concentrations of acetaminophen during day 5-8 markedly decreased compared with acetaminophen-only group. At day 9, the pharmacokinetic parameters of acetaminophen in the presence of K. parviflora extract also decreased, including area under the concentration-time curve (from 1.68 ± 0.16 to 0.34 ± 0.04 mg.min/mL), the maximum concentration (from 19.10 ± 1.90 to 4.48 ± 0.56 µg/mL), and half-life (from 21.29 ± 1.36 to 10.81 ± 1.24 min). In addition, clearance and the elimination rate constant of acetaminophen were significantly increased (from 0.003 ± 0.000 to 0.006 ± 0.001 L/min and 0.03 ± 0.00 to 0.07 ± 0.01 min-1, respectively) in the presence of K. parviflora extract. These findings provide the data for in vivo herb-drug interaction between K. parviflora extract and acetaminophen. Therefore, the concomitant use of K. parviflora as a food supplement and acetaminophen should occasion therapeutic and safety concerns.

[Influence of omega-3 polyunsaturated fatty acids on oxidative stress and cytochrome P450 2E1 expression in rat liver].

Polyunsaturated fatty acids (PUFAs), omega-3 ones in particular, form phospholipid layer of biological membranes, which provides normal functioning of membrane-associated complexes of enzymes and transmembrane transport. Free omega-3 PUFAs regulate the transcription of many genes, and thereby have an effect on the level of metabolic processes, particularly control of lipid and carbohydrate metabolism in the liver. Cytochrome P450 2El (1.14.14.1) causes the transformation of lipophilic exogenous and endogenous substances, as well as involvement in homeostasis, both at the cellular and systemic levels. The aim is to study changes in expression of cytochrome P450 2E1, and to assess the antioxidant system and the level of peroxidation processes in the liver of experimental animals under the chronic action omega-3 PUFAs. During experiment more than two-fold increase in the content of cytochrome P450 2El was observed in the liver of rats which additionally received omega-3 PUFAs for 4 weeks in the standard daily diet. At the same time, such changes in the enzyme expression did not lead to an imbalance of pro- and antioxidant processes in the liver.