Current Topics in Medicinal Chemistry - Volume 24, Issue 24, 2024

Self-emulsifying nano-phase of traditional Chinese medicine are a research hotspot. Xiao-Chai-Hu decoction is a commonly used compound decoction in clinical practice, which is of great research significance. The aim of this study was to isolate and characterize the self-emulsifying nano-phase and other phases of Xiao-Chai-Hu decoction, and to study the effects of each phase on acute liver injury.

The liquid medicine was prepared employing centrifugation followed by dialysis. Single-factor investigation methodology was utilized to optimize the preparation parameters for both phases. Characterization of the formulated phase involved analyses such as surface morphology assessment, measurement of nanoparticle size and Zeta potential using an analyzer, observation of the Tyndall effect, conducting diffusion and dilution tests, examination under a microscope, and structural visualization via transmission electron microscopy (TEM). Furthermore, an acute liver injury model was established in rats through intraperitoneal injection of D-Galactosamine (D-GalN). To assess hepatic function and oxidative stress status, serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), superoxide dismutase (SOD) activity, and malondialdehyde (MDA) content in liver tissue were quantified. The liver coefficients for each group were calculated as an additional parameter. For histopathological evaluation, liver tissue sections from the experimental group were stained with Hematoxylin and Eosin (H&E) and examined microscopically under light conditions. These revisions aim to enhance clarity, correct minor grammatical errors (such as capitalization of “HE” to “H&E”), and ensure a smoother flow of information without altering the scientific content of your original text.

Successful establishment and separation of four distinct phases were achieved, including the self-emulsifying nano-phase, precipitation phase, suspension phase, and true solution phase. The self-emulsifying nano-phase was characterized as spherical particles with an average diameter of approximately 100 nm. Pharmacodynamic assessments revealed that both Xiao-Chai-Hu decoction and its self-emulsifying nano-phase significantly reduced liver coefficients and alanine aminotransferase (ALT) levels compared to controls (P<0.05). However, no statistically significant differences were observed in regards to aspartate aminotransferase (AST) concentrations, malondialdehyde (MDA) content, or superoxide dismutase (SOD) activity between the treatment groups and control (P>0.05). These findings indicate that both Xiao-Chai-Hu decoction and its self-emulsifying nano-formulation ameliorated D-GalN-induced acute liver injury, albeit without statistically distinguishable efficacy between them (P>0.05).

The presence of a self-emulsifying nano-phase within Xiao-Chai-Hu decoction is confirmed, and this nano-phase emerges as a therapeutically efficacious component in mitigating acute liver injury.

This study explores the potential of the endophytic fungus Aureobasidium pullulans AKW for melanin production and its anticancer activity.

We report a significant achievement: A. pullulans AKW synthesized 4.89 g/l of melanin in a simple fermentation medium devoid of tyrosine, a precursor typically required for melanin biosynthesis. This suggests a potentially novel pathway for melanin production compared to previous studies relying on complex media and tyrosine. Furthermore, the isolated and characterized melanin exhibited promising selectivity as an anti-cancer agent. It triggered apoptosis in A431 cancer cells, demonstrating some selectivity compared to normal cells. This selectivity was confirmed by IC50 values and further supported by gene expression changes in A431 cells. Melanin treatment downregulated the anti-apoptotic Bcl2 gene while upregulating pro-apoptotic Bax and p53 genes, indicating its ability to induce programmed cell death in cancer cells.

Our results demonstrate that A. pullulans AKW-derived melanin exhibits cytotoxic effects against A431, HEPG2, and MCF7 cell lines. Interestingly, the present fungal strain synthesized melanin in a simple medium without requiring precursors.

The selective activity of the current melanin towards cancer cells, its ability to induce apoptosis, and its relatively low toxicity towards normal cells warrant further investigation for its development as a novel therapeutic option.

This study investigates the potential of eleven 1H-1,2,3-triazol-1,4-naphthoquinone conjugates as virulence factor inhibitors (like Pyocyanin) and their affinity for PhzM, a crucial enzyme for Pyocyanin biosynthesis in Pseudomonas aeruginosa infections.

A straightforward synthetic pathway enabled the production of these compounds, which were characterized and structurally confirmed through spectroscopic analyses. Evaluation of their impact on PhzM thermal stability identified promising candidates for PhzM binders.

Concentration-response behavior elucidated their binding affinity, revealing them as the first reported micromolar affinity ligands for PhzM. Structure-activity relationship analysis emphasized the role of specific molecular moieties in binding affinity modulation, paving the way for future advanced inhibitors’ development.

These findings highlight the potential of naphthoquinone-triazole derivatives as leads for novel therapeutics against P. aeruginosa infections.