Publications by authors named "Gurpreet K Grewal"

Cytochrome P450 1A1 (CYP1A1) actively catalyzes estrogen hydroxylation reactions and maintains the levels of neuroactive steroid estradiol. The widely prescribed first-line anti-epileptic drugs (AEDs) are considered to be a potent inducer of CYP1A1 and have also been observed to affect serum estradiol and calcium levels in patients with epilepsy. However, the ability of AEDs to interfere with CYP enzyme function and estrogen disposition is a relatively unexplored area.

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Despite the progress made in the development of new antiepileptic drugs (AEDs), poor response to them is a rising concern in epilepsy treatment. Of several hypotheses explaining AED treatment failure, the most promising theory is the overexpression of multidrug transporters belonging to ATP-binding cassette (ABC) transporter family at blood-brain barrier. Previous data show that AEDs themselves can induce these transporters, in turn affecting their own brain bioavailability.

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The adenosine triphosphate (ATP)-binding cassette efflux transporter G2 (ABCG2) was originally discovered in a multidrug-resistant breast cancer cell line. Studies in the past have expanded the understanding of its role in physiology, disease pathology and drug resistance. With a widely distributed expression across different cell types, ABCG2 plays a central role in ATP-dependent efflux of a vast range of endogenous and exogenous molecules, thereby maintaining cellular homeostasis and providing tissue protection against xenobiotic insults.

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ABC transporters have a significant role in drug disposition and response and various studies have implicated their involvement in epilepsy pharmacoresistance. Since genetic studies till now are inconclusive, we thought of investigating the role of xenobiotics as transcriptional modulators of ABC transporters. Here, we investigated the effect of six antiepileptic drugs (AEDs) viz.

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Purpose: Over expression of ATP-binding cassette transporters is considered one of the major reasons for non-responsiveness to antiepileptic drugs. Carbamazepine (CBZ), one of first line antiepileptic drug is known to influence ABCC2 expression but its exact molecular mechanism is unknown.

Methods: We investigated the effect of CBZ on expression of ABCC2 and pregnane X receptor (PXR) in HepG2 cell line and compared with hyperforin (agonist of PXR) and ketoconazole (antagonist of PXR) through realtime PCR and western blot assay.

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Epilepsy is a neurological disorder affecting around 1%-2% of population worldwide and its treatment includes use of antiepileptic drugs to control seizures. Failure to respond to antiepileptic drug therapy is a major clinical problem and over expression of ATP-binding cassette transporters is considered one of the major reasons for pharmacoresistance. In this review, we have summarized the regulation of ABC transporters in response to oxidative stress due to disease and antiepileptic drugs.

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Out of the 15 discrete proteins encoding the total amount of genetic information in the chromosomes of human immunodeficiency virus type 1; three perform the vital enzymatic functions i.e. a reverse transcription, an integration, and proteolysis.

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