It was found to increase the bioavailability of various drugs from 30% to 200%.[25] PIPERINE AS BIOENHANCER Piperine, obtained from the oleoresin in the peppercorns is by far the most studied and researched bioenhancer. It improves the bioavailability of other nutritive substances, including ��-carotene, curcumin, selenium, pyroxidine, glucose, and selleckchem Navitoclax amino acids[9] and coenzyme Q10, and gallic acid. Piperine increases area under the curve (AUC) of phenytoin, propranolol, and theophylline in healthy volunteers and plasma concentrations of rifamipicin in patients with pulmonary tuberculosis.[10] A lot of research is being carried out on piperine and its bioenhancing effect on various modern medicines [Table 1].
Table 1 Published research on bioenhancer effect of piperine with various medicines Piperine and antitubercular treatment Risorine is a formulation developed by Indian Institute of Integrative Medicine, Jammu, and marketed in India in November 2009 in public�Cprivate partnership with Cadila Pharmaceutical Ltd, Ahmedabad. Risorine has been approved for marketing by Drug Controller General of India, after successful completion of all the phased clinical trials. It contains rifampicin (200 mg), isoniazid (300 mg), and piperine (10 mg). It has been found to be bioequivalent with commercially available rifampicin preparations. This is due to enhanced uptake of the drug by body cells, and also because the drug remains available in blood for longer durations. Combining piperine with rifampicin decreases the dose of rifampicin from 450 to 200 mg.
[25] Interestingly, in a multicentric clinical trial conducted across India in patients with radiologically confirmed diagnosis of pulmonary tuberculosis, more than 90% of the patients treated with Risorine were cured of tuberculosis with lesser side effects.[25] A formulation, containing rifampicin, isoniazid, pyrazinamide, and piperine have been tested in human volunteers (Indian Patent No.1232/DEL/89). In the majority of cases, the comparative levels and peak concentration of the drugs in the presence of piperine were higher.[26] A 24:1 (w/w) mixture of rifampicin and piperine showed remarkable growth inhibition, which was higher than that of rifampicin alone. This combination acted by completely abolishing the transcriptional activity of rifampicin-resistant RNA polymerase. Interestingly, piperine alone, even at higher concentration, did not inhibit the growth of mycobacteria.[11] This combination Anacetrapib may also reduce the emergence of multiple drug��resistant strains of mycobacterium. In a conflicting report, rabbits treated with a single dose of trikatu (500 mg/kg �� 7 days, p.o.) showed a significant decrease in the peak plasma concentration (Cmax) of rifampicin (24 mg/kg, p.o.) (P < 0.05).