Curcumin [1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadien-3,5-dione], a component of Curcuma longa L. rhizomes, displays various biological and pharmacological activities. However, it is poorly bioavailable and unstable in physiological pH, which has led more stable and effective curcumin analogs (e.g., monoketone curcuminoids, or MKCs) to be synthesized, and their biological activities to be described. In this review, we cover papers published between 2019 and 2023 on the antimicrobial, anticancer, antioxidant, and antiparasitic actions as well as other less common MKC biological and pharmacological activities. We also address the Claisen-Schmidt condensation as a standard procedure to synthesize MKCs.

Curcumin, a polyphenol with a rich history spanning two centuries, has emerged as a promising therapeutic agent targeting multiple signaling pathways and exhibiting cellular-level activities that contribute to its diverse health benefits. Extensive preclinical and clinical studies have demonstrated its ability to enhance the therapeutic potential of various bioactive compounds. While its reported therapeutic advantages are manifold, predominantly attributed to its antioxidant and anti-inflammatory properties, its efficacy is hindered by poor bioavailability stemming from inadequate absorption, rapid metabolism, and elimination. To address this challenge, nano-delivery systems have emerged as a promising approach, offering enhanced solubility, biocompatibility, and therapeutic effects for curcumin. We have analyzed the knowledge on curcumin nano-encapsulation and its synergistic effects with other compounds, extracted from electronic databases. We discuss the pharmacokinetic profile of curcumin, current advancements in nano-encapsulation techniques, and the combined effects of curcumin with other agents across various disorders. By unifying existing knowledge, this analysis intends to provide insights into the potential of nano-encapsulation technologies to overcome constraints associated with curcumin treatments, emphasizing the importance of combinatorial approaches in improving therapeutic efficacy. Finally, this compilation of study data aims to inform and inspire future research into encapsulating drugs with poor pharmacokinetic characteristics and investigating innovative drug combinations to improve bioavailability and therapeutic outcomes.

The number of published studies on curcuminoids in cancer research, including its lead molecule curcumin and synthetic analogs, has been increasing substantially during the past two decades. Insights on the diversity of inhibitory effects they produced on a multitude of pathways involved in carcinogenesis and tumor progression were provided. As this wealth of data was obtained in a setting of various experimental and clinical data, this review first aimed at presenting a chronology of discoveries and an update on their complex in vivo effects. Secondly, there are many interesting questions linked to their pleiotropic effects. One of them, which is a growing research topic, relates to their ability to modulate metabolic reprogramming. This review will also cover the use of curcuminoids as chemosensitizing molecules, that can be combined with several anticancer drugs for reversing the phenomenon of multidrug resistance. Finally, current investigations in these three complementary research fields raise several important questions that will be put in the prospects for the future research related to the importance of these molecules in cancer research.

Juvenile hormones (JH) play crucial roles in insect development, reproduction, and other physi-ological functions. Because JH is specific to arthropods, including insects, it has long been stud-ied for use in pest control. Accordingly, this study aimed to identify the substances that act as JH disruptors from edible plants. Curcuminoids generally exhibit a wide range of biological ac-tivities, such as antioxidant, anti-inflammatory, antibacterial, and insecticidal properties, and they exhibit insect growth inhibitory effects. Demethoxycurcumin and bisdemethoxycurcumin, two curcuminoids from the turmeric plant Curcuma longa L. inhibit the formation of a metho-prene-tolerant (Met)–Taiman (Tai) heterodimer complex as shown through in vitro yeast two-hybrid assays. An artificial diet containing 1% (w/v) demethoxycurcumin or bisdemethox-ycurcumin reduced the number of larvae, leading to no pupal development. Building on our re-sults regarding curcuminoids, researchers can use our study as a reference to develop eco-friendly pesticides.

Abstract: Breast cancer is one of the leading causes of death in the female population due to the re-sistance of cancer cells to many anticancer drugs used. Curcumin has cytotoxic activities against breast cancer cells, although it has limited use due to its poor bioavailability and rapid metabolic elimination. The synthesis of metal complexes of curcumin and curcuminoids is a relevant topic in the search for more active and selective derivatives of these molecular scaffolds. However, solubil-ity and bioavailability are concomitant disadvantages of these types of molecules. To overcome such drawbacks, the preparation of inclusion complexes offers a chemical and pharmacologically safe option for improving the aqueous solubility of organic molecules. Herein, we describe the preparation of the inclusion complex of dimethoxy curcumin magnesium complex with cyclodex-trin (DiMeOC-Mg-BCD, 5) in the stoichiometric relationship 1:1. This new inclusion complex's solubility in aqueous media (PBS) was improved by a factor of 6x over the free metal complex (DiMeOC-Mg). Furthermore, 5 affects cell metabolic rate, cell morphology, cell migration, induced apoptosis, and downregulation of the MMP-2 and MMP-9, IL-6, and STAT3 expression levels on MDA MB 231 cell lines. Results of an antitumor assay in an in-ovo model showed up to 30% inhi-bition of tumour growth for breast cancer (MDA-MB-231) when using 5 (0.650 mg/Kg dose), and 17.29 % inhibition with the free homoleptic metal complex (1.5 mg/Kg dose, DiMeOC-Mg). While the formulation of inclusion complexes from metal complexes of curcuminoids demonstrates its usefulness in improving the solubility and bioavailability of these metallodrugs, the new DiMeOC-Mg-BCD exhibits excellent potential for use as a therapeutic agent in the battle against breast cancer.

Inflammation mediators enhance the activity of connexin (Cx) hemichannels especially in the epithelial and endothelial tissues. As potential release route for injury signals like (oligo)nucleotides, Cx hemichannels may contribute to long lasting inflammation. Specific inhibition of Cx hemichannels may therefore be a mode of prevention and treatment of long lasting, chronic sterile inflammation. The activity of Cx hemichannels was analysed in N2A and HeLa cells transfected with human Cx26 and Cx46 as well as in Calu-3 cells using the dye uptake as functional assay. Moreover, possible impact of the bioactive phenolic agents CVB2-61 and CVB4-57 on the barrier function of epithelial cells was analysed using Calu-3 cells. Both agents inhibited the dye uptake in N2A cells expressing Cx26 (> 5 µM) and Cx46 (> 20 µM). In Calu-3 cells, CVB2-61 and CVB4-57 reversible inhibited the dye uptake at concentrations as low as 5 µM, without affecting the gap junction communication and barrier function, even at concentrations of 20 µM. While CVB2-61 or CVB4-57 maintained a reduced dye uptake in Calu-3 cells, an enhancement of the dye uptake in response to stimulation of adenosine signaling was still observed after removal of the agents. The report shows that CVB2-61 and CVB4-57 reversible block Cx hemichannels. Deciphering the interaction mechanisms with Cx hemichannels could allow further development of phenolic compounds to target Cx hemichannels for a better and safer use in treatment of pathologies that involve Cx hemichannels.