Tetrahydrocurcumin, the most abundant curcumin transformation product in biological systems, can potentially be a new alternative therapeutic agent with improved anti-inflammatory activity and higher bioavailability than curcumin. In this article, we describe the synthesis and evaluation of the anti-inflammatory activities of tetrahydrocurcumin derivatives. Eleven tetrahydrocurcumin derivatives were synthesized via Steglich esterification on both sides of the phenolic rings of tetrahydrocurcumin with the aim of improving the anti-inflammatory activity of this compound. We showed that tetrahydrocurcumin (2) inhibited TNF-α and IL-6 production but not PGE₂ production. Three tetrahydrocurcumin derivatives inhibited TNF-α production, five inhibited IL-6 production, and three inhibited PGE₂ production_. The structure–activity relationship analysis suggested that two factors could contribute to the biological activities of these compounds: the presence or absence of planarity and their structural differences. Among the tetrahydrocurcumin derivatives, cyclic compound 13 was the most active in terms of TNF-α production, showing even better activity than tetrahydrocurcumin. Acyclic compound 11 was the most effective in terms of IL-6 production and retained the same effect as tetrahydrocurcumin. Moreover, acyclic compound 12 was the most active in terms of PGE₂ production, displaying better inhibition than tetrahydrocurcumin. A 3D-QSAR analysis suggested that the anti-inflammatory activities of tetrahydrocurcumin derivatives could be increased by adding bulky groups at the ends of compounds 2, 11, and 12.

Click on the article title to read more.

A simple and reliable high performance liquid chromatography method was developed and validated for the rapid determination of cyclosporine A in new pharmaceutical dosage forms based on the use of poly (methylvinylether-co-maleic anhydride) nanoparticles. The chromatographic separation was achieved using Ultrabase C18 column (250×4.6 mm, 5 μm), which was kept at 75°. The gradient mobile phase consisted of acetonitrile and water with a flow rate of 1 ml/min. The effluent was monitored at 205 nm using diode array detector. The method exhibited linearity over the assayed concentration range (22-250 μg/ml) and demonstrated good intraday and interday precision and accuracy (relative standard deviations were less than 6.5% and the deviation from theoretical values is below 5.5%). The detection limit was 1.36 μg/ml. This method was also applied for quantitative analysis of cyclosporine A released from poly (methylvinylether-co-maleic anhydride) nanoparticles.

α-synuclein (α-syn) deposition in the mid-brain region is one of the hallmark pathologies of Parkinson's disease (PD). The key steps involve the transformation of α-synuclein into a toxic oligomer and insoluble fibrillar aggregates. To understand the role of curcumin-glucoside in the prevention of α-syn aggregation, a mechanistic approach. In the present study, we synthesized a novel molecule, curcumin-glucoside (Curc-gluc), to improve the water solubility and partition coefficient, making the molecule with high bioavailability. The present study is focused on understanding the α-syn aggregation kinetics in the presence and absence of Curc-gluc, curcumin (Cur), copper (Cu), and iron (Fe) through Thioflavin T analysis, circular dichroism (CD), mathematical approach by self-association kinetics, and molecular docking models. The results indicated that Curc-gluc potentially prevented synuclein aggregation compared to Curc alone and inhibited Cu and Fe-induced synuclein aggregation. CD studies indicated that Curc-gluc favored α-helix formation. The docking studies indicated that Curc-gluc derivatives interacted with various chains of α-syn fibrils, namely G-chain, A-chain, I-Chain, and E-chain and the Pi-Pi interaction indicate that, Curc-gluc shows the most favorable binding affinity with the α-syn fibrils with 60.7222 kcal/mol of -CDOCKER_ ENERGY and 89.6516 kcal/mol of -CDOCKER INTERACTION_ ENERGY. The Absorption, Distribution, Metabolism, Excretion (ADME) analysis indicated that Curc-mono and di-gluc have the highest solubility, bioavailability, and tissue distribution compared to Curc alone. The studies indicated that Curc-gluc prevented α-syn aggregation by favoring α-helix, binding to α-syn, and preventing aggregation, and had high bioavailability.