Synthetic Mono-Carbonyl Curcumin Analogues Attenuate Oxidative Stress in Mouse Models

Malvidin and Its Mono- and Di-Glucosides Forms: A Study of Combining Both In Vitro and Molecular Docking Studies Focused on Cholinesterase, Butyrylcholinesterase, COX-1 and COX-2 Activities

Malvidin, one of the six most prominent anthocyanins found in various fruits and vegetables, may possess a wide range of health-promoting properties. The biological activity of malvidin and its glycosides is not entirely clear and has been relatively less frequently studied compared to other anthocyanins. Therefore, this study aimed to determine the relationship between the structural derivatives of malvidin and their anti-cholinergic and anti-inflammatory activity. The study selected malvidin (Mv) and its two sugar derivatives: malvidin 3-O-glucoside (Mv 3-glc) and malvidin 3,5-O-diglucoside (Mv 3,5-diglc). The anti-inflammatory activity was assessed by inhibiting the enzymes, specifically COX-1 and COX-2. Additionally, the inhibitory effects on cholinesterase activity, particularly acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), were evaluated. Molecular modeling was also employed to examine and visualize the interactions between enzymes and anthocyanins. The results revealed that the highest inhibitory capacity at concentration 100 µM was demonstrated by Mv 3-glc in relation to AChE (26.3 ± 3.1%) and BChE (22.1 ± 3.0%), highlighting the crucial role of the glycoside substituent at the C3 position of the C ring in determining the inhibitory efficiency of these enzymes. In addition, the glycosylation of malvidin significantly reduced the anti-inflammatory activity of these derivatives compared to the aglycone form. The IC50 parameter demonstrates the following relationship for the COX-1 enzyme: Mv (12.45 ± 0.70 µM) < Mv 3-glc (74.78 ± 0.06 µM) < Mv 3,5-diglc (90.36 ± 1.92 µM). Similarly, for the COX-2 enzyme, we have: Mv (2.76 ± 0.16 µM) < Mv 3-glc (39.92 ± 3.02 µM) < Mv 3.5-diglc (66.45 ± 1.93 µM). All tested forms of malvidin exhibited higher activity towards COX-2 compared to COX-1, indicating their selectivity as inhibitors of COX-2. Theoretical calculations were capable of qualitatively replicating most of the noted patterns in the experimental data, explaining the impact of deprotonation and glycosylation on inhibitory activity. It can be suggested that anthocyanins, such as malvidins, could be valuable in the development of treatments for inflammatory conditions and Alzheimer's disease and deserve further study.

Methanol Extracts from Cirsium japonicum DC. var. australe Kitam. and Their Active Components Reduce Intracellular Oxidative Stress in Caenorhabditis elegans

Cirsium japonicum DC. var. australe Kitam. has been used as an herbal remedy and often involves using the whole plant or roots. However, the bioactivities of different parts of the plant have been far less explored. This study aimed to evaluate the antioxidative ability of methanol extracts from the flowers, leaves, stems, and roots of the Cirsium plant and their possible active components against juglone-induced oxidative stress in the nematode Caenorhabditis elegans. The results showed that the highest dry weight (12.3 g per plant) was observed in leaves, which was followed by stems (8.0 g). The methanol extract yields from the flowers, leaves, and roots were all similar (13.0-13.8%), while the yield from stems was the lowest (8.6%). The analysis of the silymarin contents in the extracts indicated that the flowers, leaves, stems, and roots contained silychristin and taxifolin; however, silydianin was only found in the leaves, stems, and roots. The flower, leaf, and stem extracts, at a concentration of 10 mg/L, significantly reduced juglone-induced oxidative stress in C. elegans, which was potentially due to the presence of silychristin and taxifolin. Overall, C. japonicum DC. var. australe Kitam. contains a significant amount of silymarin and exhibits in vivo antioxidative activity, suggesting that the prospects for the plant in terms of health supplements or as a source of silymarin are promising.

Cepharanthine Exerts Antioxidant and Anti-Inflammatory Effects in Lipopolysaccharide (LPS)-Induced Macrophages and DSS-Induced Colitis Mice

Cepharanthine (CEP), a biscoclaurine alkaloid extracted from Stephania cepharantha Hayata, has been widely used for the treatment of various acute and chronic diseases, including leukopenia, and snake bites. Here, our objective was to investigate the anti-oxidative stress and anti-inflammatory response effects of CEP in lipopolysaccharide (LPS)-induced macrophages as well as dextran sulfate sodium (DSS)-induced colitis mice. Our findings demonstrated that supplementation with CEP effectively mitigates body weight loss and elevation of disease activity index (DAI), reduces the malondialdehyde (MDA) content to 2.45 nM/mL while increasing the reduced glutathione (GSH) content to 35.53 μg/mL, inhibits inflammatory response, and maintains proper intestinal epithelium tight junctions in DSS-induced wild type (WT) mice. However, it failed to provide protective effects in DSS-induced transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) knockout (NRF2-/-) mice. GSH content decreased to 10.85 μg/106 cells following LPS treatment, whereas supplementation with CEP increased the GSH content to 12.26 μg/106 cells. Moreover, CEP effectively attenuated ROS production in LPS-induced macrophages. Additionally, CEP exhibited inhibitory effects on pro-inflammatory cytokines and mediators in LPS-induced macrophages. Furthermore, we observed that supplementation with CEP promoted the expression of NRF2/heme oxygenase 1 (HO-1)/NADPH quinone oxidoreductase-1 (NQO-1) as well as the phosphorylation of the adenosine monophosphate-activated protein kinase alpha 1 (AMPK-α1)/protein kinase B (AKT)/glycogen synthase kinase-3 beta (GSK-3β) signaling pathway in macrophages while inhibiting the phosphorylation of the extracellular signal-regulated kinase (ERK)/c-Jun N-terminal kinase (JNK), and nuclear factor-kappa B p65 (NF-κB p65) signaling pathway in LPS-induced macrophages. Although CEP did not demonstrate inhibitory effects on oxidative stress or promote the expression of HO-1/NQO-1, it effectively activated the phosphorylation of the AMPK-α1/AKT/GSK-3β signaling pathway which is an upstream regulator of NRF2 in LPS-induced primary peritoneal macrophages from NRF2-/- mice. In summary, our findings suggest that CEP exerts protective effects against oxidative stress and inflammatory response by activating the AMPK-α1/AKT/GSK-3β/NRF2 signaling pathway while concurrently inhibiting the activation of mitogen activated protein kinases (MAPKs) and the NF-κB p65 signaling pathway. These results not only elucidate the mechanisms underlying CEP's protective effects on colon oxidative stress and inflammation but also provide evidence supporting NRF2 as a potential therapeutic target for IBD treatment.

The Homoleptic Curcumin-Copper Single Crystal (ML2): A Long Awaited Breakthrough in the Field of Curcumin Metal Complexes

The first single crystal structure of the homoleptic copper (II) ML2 complex (M=Cu (II), L = curcumin) was obtained and its structure was elucidated by X-ray diffraction showing a square planar geometry, also confirmed by EPR. The supramolecular arrangement is supported by C-H···O interactions and the solvent (MeOH) plays an important role in stabilizing the crystal packing Crystallinity was additionally assessed by XRD patterns. The log P value of the complex (2.3 ± 0.15) was determined showing the improvement in water solubility. The cytotoxic activity of the complex against six cancer cell lines substantially surpasses that of curcumin itself, and it is particularly selective against leukemia (K562) and human glioblastoma (U251) cell lines, with similar antioxidant activity to BHT. This constitutes the first crystal structure of pristine curcumin complexed with a metal ion.

High Yield Synthesis of Curcumin and Symmetric Curcuminoids: A "Click" and "Unclick" Chemistry Approach

The worldwide known and employed spice of Asian origin, turmeric, receives significant attention due to its numerous purported medicinal properties. Herein, we report an optimized synthesis of curcumin and symmetric curcuminoids of aromatic (bisdemethoxycurcumin) and heterocyclic type, with yields going from good to excellent using the cyclic difluoro-boronate derivative of acetylacetone prepared by reaction of 2,4-pentanedione with boron trifluoride in THF (ca. 95%). The subsequent cleavage of the BF₂ group is of significant importance for achieving a high overall yield in this two-step procedure. Such cleavage occurs by treatment with hydrated alumina (Al₂O₃) or silica (SiO₂) oxides, thus allowing the target heptanoids obtained in high yields as an amorphous powder to be filtered off directly from the reaction media. Furthermore, crystallization instead of chromatographic procedures provides a straightforward purification step. The ease and efficiency with which the present methodology can be applied to synthesizing the title compounds earns the terms "click" and "unclick" applied to describe particularly straightforward, efficient reactions. Furthermore, the methodology offers a simple, versatile, fast, and economical synthetic alternative for the obtention of curcumin (85% yield), bis-demethoxycurcumin (78% yield), and the symmetrical heterocyclic curcuminoids (80-92% yield), in pure form and excellent yields.