Effect of piperine, a major component of black pepper, on the intestinal absorption of fexofenadine and its implication on food-drug interaction

White pepper and piperine have different effects on pharmacokinetics of puerarin in rats

This study attempted to explore the effects of white pepper and its major component piperine on puerarin administered to rats. Pharmacokinetic parameters of puerarin in rats were determined by oral administration (400 mg/kg) or intravenous injection (40 mg/kg) of puerarin, pretreated with or without white pepper and piperine given orally. Compared to the control group given oral puerarin only, the combined use of piperine (10 or 20 mg/kg) increased the C_max of puerarin by 1.30-fold or 1.64-fold and the AUC_0–∞ by 133% or 157%, respectively. In contrast, coadministration of white pepper (125 or 250 mg/kg) decreased oral absorption of puerarin to 83% or 74%, respectively. On the other hand, pretreatment with piperine orally did not alter the intravenous pharmacokinetics of puerarin, while the AUC of puerarin after intravenous administration was increased by pretreatment with white pepper. The results indicate that pretreatment with piperine or pepper exerts different effects on pharmacokinetics of puerarin administrated via intragastric and intravenous routes. Therefore, it is suggested that the combined application of piperine or white pepper with puerarin should be carefully monitored for potential diet-drug interactions.

Effects of piperine on the intestinal permeability and pharmacokinetics of linarin in rats

Although linarin possesses diverse pharmacological activities, its poor oral bioavailability has been a concern for further development. The present study aimed to demonstrate the feasibility of improving the oral absorption of linarin in rats with a bioenhancer‒piperine. First, the intestinal permeability of linarin in the presence and absence of verapamil or piperine was investigated using an in situ single-pass rat intestinal perfusion method. A significant increase in the Peff when co-perfused with verapamil or piperine indicated that piperine effectively inhibited P-glycoprotein mediated efflux of linarin. Then, the pharmacokinetic profiles of linarin in rats after oral administration of linarin (50 mg/kg) alone and in combination with piperine (20 mg/kg) were determined using a validated LC-MS/MS method. The results showed that piperine increased the plasma exposure (AUC) of linarin by 381% along with an increase in the Cmax by 346% and the Tmax from 0.05 h to 0.2 h. The present study revealed that piperine significantly enhanced the oral absorption of linarin in rats by inhibiting P-glycoprotein mediated cellular efflux during the intestinal absorption and likely simultaneously by inhibiting the metabolism of linarin.

Adipogenic effects of piperlonguminine in 3T3-L1 cells and plasma concentrations of several amide constituents from Piper chaba extracts after treatment of mice

In our previous study, piperlonguminine from the fruit of Piper chaba was reported to promote adipogenesis in 3T3-L1 cells like the peroxisome proliferator-activated receptor-γ (PPARγ) agonist, troglitazone. In the present study, the mode of action of piperlonguminine in cells was examined. Piperlonguminine increased mRNA levels of adiponectin, glucose transporter 4, and fatty acid-binding protein (aP2). It also increased mRNA levels of PPARγ2 but, unlike troglitazone, piperlonguminine did not activate PPARγ directly in a nuclear receptor cofactor assay. Analyses of plasma from mice treated with piperlonguminine, piperine, and retrofractamide A, and an extract of the fruit, showed that concentrations of piperlonguminine were higher than those of piperine and retrofractamide A, and that the "area-under-the-curve" of piperine increased following in vivo administration of the extract.

Excipient foods: designing food matrices that improve the oral bioavailability of pharmaceuticals and nutraceuticals

The oral bioavailability of many lipophilic bioactive agents (pharmaceuticals and nutraceuticals) is limited due to various physicochemical and physiological processes. Excipient foods can be designed to improve the oral bioavailability of these bioactive agents.

Repeated dosing of piperine induced gene expression of P-glycoprotein via stimulated pregnane-X-receptor activity and altered pharmacokinetics of diltiazem in rats

This study investigated the effect of piperine on the gene expression of P-glycoprotein (P-gp) as well as pregnane-X-receptor (PXR) activity and also its implication on the bioavailability of diltiazem, a P-gp substrate. The effect of piperine on the systemic exposure of diltiazem was examined in rats after the intravenous and oral administration of diltiazem with/without 2 week pretreatment with piperine. Compared with the control group given diltiazem (20 mg/kg) alone, the pretreatment with piperine (10 or 20 mg/kg, once daily for 2 weeks) decreased the oral exposure of diltiazem by 36-48% in rats. Consequently, the bioavailability of oral diltiazem was significantly lower (p < 0.05) after the 2 week pretreatment with piperine. The pretreatment with piperine for 2 weeks also reduced the systemic exposure of desacetyldiltiazem, a major active metabolite of diltiazem by approximately 73%, accompanied by a significant decrease in the metabolite-parent ratio. In contrast to the oral pharmacokinetics, piperine did not affect the intravenous pharmacokinetics of diltiazem in rats. Immunoblot analysis indicated that the protein expression level of intestinal P-gp was significantly enhanced after the 2 week pretreatment with piperine in rats. In addition, piperine increased the PXR reporter activity in human hepatoma cells. Taken together, the 2 week pretreatment with piperine significantly induced intestinal P-gp expression in conjunction with stimulated PXR activity and decreased the oral exposure of diltiazem and desacetyldiltiazem in rats.

A comprehensive review on pharmacotherapeutics of herbal bioenhancers

In India, Ayurveda has made a major contribution to the drug discovery process with new means of identifying active compounds. Recent advancement in bioavailability enhancement of drugs by compounds of herbal origin has produced a revolutionary shift in the way of therapeutics. Thus, bibliographic investigation was carried out by analyzing classical text books and peer-reviewed papers, consulting worldwide-accepted scientific databases from last 30 years. Herbal bioenhancers have been shown to enhance bioavailability and bioefficacy of different classes of drugs, such as antibiotics, antituberculosis, antiviral, antifungal, and anticancerous drugs at low doses. They have also improved oral absorption of nutraceuticals like vitamins, minerals, amino acids, and certain herbal compounds. Their mechanism of action is mainly through absorption process, drug metabolism, and action on drug target. This paper clearly indicates that scientific researchers and pharmaceutical industries have to give emphasis on experimental studies to find out novel active principles from such a vast array of unexploited plants having a role as a bioavailability and bioefficacy enhancer. Also, the mechanisms of action by which bioenhancer compounds exert bioenhancing effects remain to be explored.

Curcumin bioavailability from enriched bread: the effect of microencapsulated ingredients

Human bioavailability of curcumin from breads enriched with 1 g/portion of free curcumin (FCB), encapsulated curcumin (ECB), or encapsulated curcumin plus other polyphenols (ECBB) was evaluated. Parental and metabolized curcuminoids and phenolic acids were quantified by HPLC/MS/MS in blood, urine, and feces collected over 24 h. The concentrations of serum curcuminoids were always below 4 nmol/L and those of glucuronides 10-fold less. Encapsulation delayed and increased curcuminoid absorption as compared to the free ingredient. Serum and urinary concentrations of ferulic and vanillic acid were between 2- and 1000-fold higher than those of curcuminoids, with ECBB eliciting the highest amounts. Fecal curcuminoids were 6-fold more abundant after ECB than FCB, while phenolic acids after ECBB quadruplicated those after ECB. Curcuminoid encapsulation increased their bioavailability from enriched bread, probably preventing their biotransformation, with combined compounds slightly reducing this effect. Phenolic acids are the major metabolites of curcuminoids and may contribute to their biological properties.