Inhibition of human drug metabolizing cytochrome P450 enzymes by plant isoquinoline alkaloids

Natural Products Modulate the Multifactorial Multidrug Resistance of Cancer

“…Overall, there were clear differences in the ability of these alkaloids to inhibit individual CYP forms [172] [173].…”

Protective effects of crude and alkaloidal extracts of Tamarindus indica against acute inflammation and nociception in rats

“…Among them, alkaloids are one of the largest groups, also with a great chemical diversity. In fact, plants are estimated to produce approximately 12 000 different alkaloids with wide range of pharmacological properties, including anti-inflamatory and antinociceptive [5,6].…”

Time-Dependent Inhibition of CYP2C19 by Isoquinoline Alkaloids: In Vitro and In Silico Analysis

“…The isoquinoline alkaloids 1-8, 10-17, and 20-39 have been described in our previous studies (Meyer and Imming, 2011;Salminen et al, 2011b); alkaloids 40 and 42 are synthetic, and 9 and 41 are semisynthetic derivatives of 23 (tetrahydropalmatine) (unpublished data). Alkaloids 18-19 and 43-49 were purchased from Sigma-Aldrich (St. Louis, MO) and were of the highest purity available.…”

“…In the standard preincubation assay, a mixture containing the inhibitor, enzyme (1.5 pmol), and an NADPH-regenerating system was first preincubated for 30 minutes at 37°C, after which the reactions were initiated by the addition of the substrate at a concentration corresponding to its apparent K m (1 mM DBF). The IC 50 values were compared with those obtained in similar experimental conditions without preincubation (Salminen et al, 2011b). All IC 50 values are reported as means from duplicate determinations.…”

“…Natural herbal products, including traditional Chinese medicine (TCM) preparations, are becoming increasingly popular even in Western countries (Gotti, 2011;Salminen et al, 2011b;Pelkonen et al, 2014). It is often claimed that herbal medicines are harmless because of their natural origin and long-term use.…”