Background: Orlistat (ORL) is an effective irreversible inhibitor of the lipase enzyme, and it possesses anticancer effects and limited aqueous solubility. This study was designed to improve the aqueous solubility, oral absorption, and tissue distribution of ORL via the formulation of nanocrystals (NCs). Methods: ORL-NC was prepared using the liquid antisolvent precipitation method (bottom-up technology), and it demonstrated significantly improved solubility compared with that of the blank crystals (ORL-BCs) and untreated ORL powder. The biodistribution and relative bioavailability of ORL-NC were investigated via the radiolabeling technique using Technetium-99m (^99mTc). Female Swiss albino mice were used to examine the antitumor activity of ORL-NC against solid Ehrlich carcinoma (SEC)-induced hepatic damage in mice. Results: The prepared NCs improved ORL’s solubility, bioavailability, and tissue distribution, with evidence of 258.70% relative bioavailability. In the in vivo study, the ORL-NC treatment caused a reduction in all tested liver functions (total and direct bilirubin, AST, ALT, and ALP) and improved modifications in liver sections that were marked using hematoxylin and eosin staining (H&E) and immunohistochemical staining (Ki-67 and ER-α) compared with untreated SEC mice. Conclusions: The developed ORL-NC could be considered a promising formulation approach to enhance the oral absorption tissue distribution of ORL and suppress the liver damage caused by SEC.

Cancer remains a significant global health concern, with breast cancer ranking among the leading causes of cancer-related mortality in women.

Marine bacteria are a valuable source of bioactive polysaccharides with therapeutic potential. In our previous study, we identified an exopolysaccharide produced by Kocuria sp. strain AG5 (EPSR5) isolated from the Red Sea, and demonstrated that it is a high-molecular weight, acidic heteropolysaccharide rich in sulfate (25.6%) and uronic acid (21.77%) groups. In the current study, we expanded the structural characterization and biological evaluation of EPSR5. GC–MS and HPLC analyses revealed glucose as the major monosaccharide, accompanied by xylose, arabinose, and glucuronic acid, confirming its heteropolysaccharide and polyanionic character. Thermal analysis (TGA) demonstrated stability up to 257 °C, while SEM–EDX revealed a porous, flake-like morphology enriched in oxygen, sodium, and phosphorus, suggesting phosphorylation and ionic associations. The biological activity of EPSR5 was assessed through a range of pharmacological assays. Antimicrobial testing against seven pathogenic microbes, including two fungal strains (Candida albicans, Mucor circinelloides), two Gram-positive bacteria (Enterococcus faecalis, Staphylococcus aureus), and three Gram-negative bacteria (Escherichia coli, Salmonella typhi, Helicobacter pylori), demonstrated potent inhibitory effects. EPSR5 showed notable inhibition zones up to 30 mm against E. faecalis and 27 mm against H. pylori, with MIC/MBC values as low as 7.8/15.62 μg mL⁻¹ and 15.62/15.62 μg mL⁻¹, respectively. Significant antibiofilm activity was also observed, with inhibition rates reaching up to 96.54% against E. faecalis and 97.39% against H. pylori, in a concentration-dependent manner. Antioxidant potential was confirmed via TAC and FRAP assays, showing values of 62.8 ± 0.3 and 114.9 ± 0.5 μg ascorbic acid equivalents per mg, respectively. EPSR5 exhibited antidiabetic activity by inhibiting α-glucosidase and α-amylase enzymes with IC₅₀ values of 17.06 μg mL⁻¹ and 66.35 μg mL⁻¹, respectively, comparable to Acarbose. Additionally, EPSR5 inhibited pancreatic lipase with an IC₅₀ of 41.39 μg mL⁻¹ and suppressed 90.1% of enzyme activity at 1000 μg mL⁻¹. In wound healing assays, EPSR5 promoted fibroblast migration and accelerated wound closure, reducing the wound area within 48 hours, achieving 71.85% closure compared to 66.24% in control cells. Overall, these findings suggest that EPSR5 from Kocuria sp. AG5 exhibits multifaceted bioactivities with promising therapeutic potential for antimicrobial, antioxidant, antidiabetic, and wound healing applications.

Breast cancer remains a leading cause of mortality in women, underscoring the need for multitarget therapeutic agents. A series of 2,3-disubstituted-1,3-thiazol-4-one derivatives was synthesized and characterized, and their antiproliferative activity was assessed against MDA-MB-231 and MCF-7 cells. Compound 6 was the most active analogue, showing IC₅₀ values of 2.25 ± 0.18 µM and 6.70 ± 0.63 µM, respectively, with superior selectivity and potency compared with doxorubicin. Mechanistic studies demonstrated that compound 6 induced G₀/G₁ arrest and apoptosis, supported by caspase-3/7 activation. It also inhibited key enzymes in estrogen biosynthesis, including aromatase (IC₅₀ = 38.3 ± 2.3 nM) and steroid sulfatase (IC₅₀ = 12.7 ± 0.76 µM), and selectively suppressed COX-2 (IC₅₀ = 5.38 ± 0.18 µM; SI = 10.44). Strong antioxidant activity (DPPH IC₅₀ = 16.26 ± 0.6 µM) further contributed to its pharmacological profile. In vivo, compound 6 significantly reduced tumor load in the Ehrlich ascites carcinoma model and improved liver, kidney, oxidative stress, and histopathological markers. It also lowered circulating TNF-α and VEGFR-II, indicating additional anti-inflammatory and anti-angiogenic effects. In silico toxicity profiling predicted a favorable safety profile, with no Ames mutagenicity, no hERG inhibition, no skin sensitization, low acute/chronic toxicity, and no predicted CYP450 inhibition. ProTox-III classified compound 6 as inactive toward major organ-toxicity endpoints. Computational studies supported these results: docking and 100-ns MD simulations showed stable binding to aromatase, STS, COX-2, TNF-α, and VEGFR-II. PCA and free-energy landscape analyses revealed early conformational adjustments followed by convergence into compact, low-energy states, consistent with stable ligand–protein interactions. Overall, compound 6 emerges as a promising multitarget lead integrating cytotoxic, hormone-modulatory, anti-inflammatory, antioxidant, and anti-angiogenic activities for potential breast cancer therapy.