New histone deacetylase inhibitors and anticancer agents from Curcuma longa

HDAC Inhibitory and Anti-Cancer Activities of Curcumin and Curcumin Derivative CU17 against Human Lung Cancer A549 Cells

Previous research reported that the curcumin derivative (CU17) inhibited several cancer cell growths in vitro. However, its anticancer potential against human lung cancer cells (A549 cell lines) has not yet been evaluated. The purpose of this research was to examine the HDAC inhibitory and anti-cancer activities of CU17 compared to curcumin (CU) in A549 cells. An in vitro study showed that CU17 had greater HDAC inhibitory activity than CU. CU17 inhibited HDAC activity in a dose dependent manner with the half-maximal inhibitory concentration (IC50) value of 0.30 ± 0.086 µg/mL against HDAC enzymes from HeLa nuclear extract. In addition, CU17 could bind at the active pockets of both human class I HDACs (HDAC1, 2, 3, and 8) and class II HDACs (HDAC4, 6, and 7) demonstrated by molecular docking studies, and caused hyperacetylation of histone H3 (Ac-H3) in A549 cells shown by Western blot analysis. MTT assay indicated that both CU and CU17 suppressed A549 cell growth in a dose- and time-dependent manner. Besides, CU and CU17 induced G2/M phase cell cycle arrest and p53-independent apoptosis in A549 cells. Both CU and CU17 down-regulated the expression of p53, p21, Bcl-2, and pERK1/2, but up-regulated Bax expression in this cell line. Although CU17 inhibited the growth of lung cancer cells less effectively than CU, it showed less toxicity than CU for non-cancer cells. Accordingly, CU17 is a promising agent for lung cancer treatment. Additionally, CU17 synergized the antiproliferative activity of Gem in A549 cells, indicating the possibility of employing CU17 as an adjuvant treatment to enhance the chemotherapeutic effect of Gem in lung cancer.

Cyclization of arylhydrazones of cross-conjugated enynones: synthesis of luminescent styryl-1H-pyrazoles and propenyl-1H-pyrazoles

On the basis of available ethynyl vinyl ketones and arylhydrazines, the authors have developed the two-stage synthesis method for styrylpyrazoles possessing fluorescent abilities, as well as the gram-scale synthesis method for fluorescent probes.

Synthesis and Biological Evaluation of Hydroxylated Monocarbonyl Curcumin Derivatives as Potential Inducers of Neprilysin Activity

BACKGROUND

Alzheimer's disease (AD) involves impairment of Aβ clearance. Neprilysin (NEP) is the most efficient Aβ peptidase. Enhancement of the activity or expression of NEP may provide a prominent therapeutic strategy against AD.

AIMS

Ten hydroxylated monocarbonyl curcumin derivatives were designed, synthesized and evaluated for their NEP upregulating potential using sensitive fluorescence-based Aβ digestion and inhibition assays.

RESULTS

Compound 4 was the most active one, resulting in a 50% increase in Aβ cleavage activity. Cyclohexanone-bearing derivatives exhibited higher activity enhancement compared to their acetone counterparts. Inhibition experiments with the NEP-specific inhibitor thiorphan resulted in dramatic cleavage reduction. Conclusion: The increased Aβ cleavage activity and the ease of synthesis of 4 renders it an extremely attractive lead compound.

Influence of side-chain changes on histone deacetylase inhibitory and cytotoxicity activities of curcuminoid derivatives

Using curcuminoids as lead compounds, fifty-nine curcuminoid derivatives with different side chains at the phenolic moiety were synthesized. All compounds were investigated for their histone deacetylase (HDAC) inhibitory activities. The potent pan-HDAC inhibitors were further tested against three human cancer cell lines including Hela, HCT116 and MCF-7 with MTT-based assay. The bisethylamide 4z and the mono-sec-butyl derivative 5j manifested good antiproliferative activities against HCT116 cancer cells with the IC₅₀ values as 14.60 ± 1.19 μg/mL and 7.33 ± 0.98 μg/mL, respectively. Molecular docking study of both compounds with Class I HDACs revealed that the compounds might bind tightly to the binding pocket of HDAC2. These findings suggested that these compounds can be putative candidates for the development of anticancer drugs via inhibiting HDACs.