Pinocembrin, a bioflavonoid, is extensively used in complementary/alternative medicine. It turns out as a promising candidate against neurodegenerative diseases because of its multifaceted pharmacological action toward neuroprotection. However, literature evidence is still lacking for its inhibitory action on CYP1A2, which is responsible for xenobiotic metabolism leading to the generation of toxic metabolites and bioactivation of procarcinogens. In the present study, our aim was to evaluate the CYP1A2 inhibitory potential of pinocembrin via in silico, in vitro, and in vivo investigations. From the results of in vitro studies, pinocembrin is found to be a potent and competitive inhibitor of CYP1A2. In vitro-in vivo extrapolation results indicate the potential of pinocembrin to interact with CYP1A2 substrate drugs clinically. Molecular docking-based in silico studies demonstrate the strong interaction of pinocembrin with human CYP1A2. In in vivo investigations using a rat model, pinocembrin displayed a marked alteration in the plasma exposure of CYP1A2 substrate drugs, namely, caffeine and tacrine. In conclusion, pinocembrin has a potent CYP1A2 inhibitory action to cause drug interactions, and further confirmatory study is warranted at the clinical level.

Hydroxyurea (HU) is the first-ever approved drug by USFDA for sickle cell anemia (SCA). However, its treatment is associated with severe side effects like myelosuppression. Current studies are focused on the supplementation therapy for symptomatic management of SCA. In the present study, we aimed to explore rutin's and gallic acid's potential individually, for concomitant therapy with HU using pharmacokinetic and pharmacodynamic approaches since there is no such precedent till date. In vivo pharmacokinetic studies of HU in rats showed that rutin could be safely co-administered with HU, while gallic acid significantly raised the plasma concentration of HU. Both the phytochemicals did not have any marked inhibitory effect on urease but have considerable effects on horseradish peroxidase enzyme. The experimental phytoconstituents displayed a very low propensity to cause in vitro hemolysis. Gallic acid markedly enhanced the HU-induced decrease in lymphocyte proliferation. A substantial improvement by rutin or gallic acid was observed in HU-induced reduction of the main hematological parameters in rats. Combined treatment of HU with rutin and gallic acid reduced serum levels of both IL-6 and IL-17A. Overall, both rutin and gallic acid are found to have promising phytotherapy potential with HU. Further exploration needs to be done on both candidates for use as phytotherapeutics for SCA.