Quantitative structure–activity relationships for estimating the aryl hydrocarbon receptor binding affinities of resveratrol derivatives and the antioxidant activities of hydroxystilbenes

Computational prediction of cytochrome P450 inhibition and induction

Cytochrome P450 (CYP) enzymes play an important role in the phase I metabolism of many xenobiotics. Most drug-drug interactions (DDIs) associated with CYP are caused by either CYP inhibition or induction. The early detection of potential DDIs is highly desirable in the pharmaceutical industry because DDIs can cause serious adverse events, which can lead to poor patient health and drug development failures. Recently, many computational studies predicting CYP inhibition and induction have been reported. The current computational modeling approaches for CYP metabolism are classified as ligand- and structure-based; various techniques, such as quantitative structure-activity relationships, machine learning, docking, and molecular dynamic simulation, are involved in both the approaches. Recently, combining these two approaches have resulted in improvements in the prediction accuracy of DDIs. In this review, we present important, recent developments in the computational prediction of the inhibition of four clinically crucial CYP isoforms (CYP1A2, 2C9, 2D6, and 3A4) and three nuclear receptors (aryl hydrocarbon receptor, constitutive androstane receptor, and pregnane X receptor) involved in the induction of CYP1A2, 2B6, and 3A4, respectively.

Pharmacometrics of 3-methoxypterostilbene: a component of traditional chinese medicinal plants

3-Methoxypterostilbene is a naturally occurring stilbene with potential in the treatment of diabetes. The preclinical pharmacokinetics and pharmacodynamics of 3-methoxypterostilbene were evaluated in the present study. The right jugular veins of male Sprague-Dawley rats were cannulated. The rats were dosed 10 mg/kg or 100 mg/kg of 3-methoxypterostilbene intravenously (IV) or orally (PO), respectively. Serum and urine samples were analyzed using a previously validated reversed-phase HPLC method. Serum AUC, serum t 1/2, urine t 1/2, Cltotal, and Vd for IV dosing were 48.1 ± 23.8  μ g/h/mL, 18.9 ± 10.9 h, 9.54 ± 1.51 h, 47.8 ± 23.7 L/h/kg, and 5.11 ± 0.38 L/kg, respectively (mean ± SEM, n = 4) . Serum AUC, serum t 1/2, urine t 1/2, Cltotal, and Vd for PO dosing were 229 ± 44.6  μ g/h/mL, 73.3 ± 8.91 h, 20.6 ± 3.01 h, 0.48 ± 0.008 L/h/kg, and 52.0 ± 10.5 L/kg, respectively (mean ± SEM, n = 4). Bioavailability of the stilbene was determined to be 50.6%  ± 10.0%. A 3-methoxypterostilbene glucuronidated metabolite was detected in both serum and urine. 3-Methoxypterostilbene exhibited antidiabetic activity including α-glucosidase and α-amylase inhibition as well as concentration-dependent antioxidant capacity similar to resveratrol. 3-Methoxypterostilbene also exhibited anti-inflammatory activity. 3-Methoxypterostilbene appears to be a bioactive compound and may be useful in reducing postprandial hyperglycemia.

Azastilbene analogs as tyrosinase inhibitors: new molecules with depigmenting potential

This research has been an effort to develop synthetic resveratrol analogs in order to improve the depigmenting potential of natural resveratrol. Six resveratrol analogs were synthesized and tested for tyrosinase inhibitory activity in vitro, by qualitative and quantitative steps. The results showed the analog C as being the most powerful tyrosinase inhibitor (IA50=65.67±0.60 μg/mL), followed by the analogs B, E, F, A, and D, respectively. The analog C presented a tyrosinase inhibition potential better than natural resveratrol (P<0.001). The best depigmenting activity was provided by the presence of hydroxyl in the orthoposition on the second phenolic ring.

Inhibitory effects of resveratrol analogs on mushroom tyrosinase activity

Skin pigmentation disorders typically involve an overproduction or uneven distribution of melanin, which results in skin spots. Resveratrol can inhibit tyrosinase, the active enzyme in the synthesis of melanin, but it does not inhibit the synthesis of melanin to an extent that enables its use alone as a skin whitening agent in pharmaceutical formulations, so its use as a coadjuvant in treatment of hyperpigmentation is suggested. Six resveratrol analogs were tested for tyrosinase inhibitory activity in vitro. Among the analogs tested, compound D was the most powerful tyrosinase inhibitor (IC(50) = 28.66 µg/mL), two times more active than resveratrol (IC(50) = 57.05 µg/mL), followed by the analogs A, E, B, F and C, respectively. This demonstrated that the hydroxylation at C4' on the phenolic ring was the molecular modification with most importance for the observed activity.