Research progress on antioxidants and protein aggregation inhibitors in cataract prevention and therapy (Review)

Structure activity relationship of Aristolochic acid analogues: Inhibitory effect on human and rat gonadal 3β-Hydroxysteroid dehydrogenases

Aristolochia species have been used in traditional Chinese medicine for over 1500 years to treat gynecological disorders. Recent pharmacological efforts focus on developing safer aristolochic acid derivatives (AAs) to retain therapeutic efficacy while minimizing toxicity. Human 3β-hydroxysteroid dehydrogenase 2 (h3β-HSD2) catalyzes the formation of precursors for sex hormones and corticosteroids, which play critical role in endocrine disorders such as polycystic ovary syndrome (PCOS) and Cushing's syndrome. This study aimed to evaluate AAs for their inhibitory effects on h3β-HSD2 and compared it with rat testicular 3β-HSD1. The inhibitory strength on h3β-HSD2 was AAB (IC50, 18.31 μM) > aristololactam I (28.52 μM) > AAC (39.73 μM) > AAD (164.76 μM). The inhibitory strength on rat 3β-HSD1 was AAB (IC50, 17.52 μM) > AAI (31.37 μM) > AAC (37.32 μM) > aristolone (89.66 μM). Docking showed that all chemicals bind to NAD+-binding site with the mix mode. AAs dose-dependently inhibited P4 synthesis in KGN cells, and ALI showed no cytotoxicity even at 100 μM. Overall, this study identifies AAs as potent inhibitors of h3β-HSD2 and r3β-HSD1, enzymes implicated in the pathophysiology of PCOS and Cushing's syndrome. Safe AAs-based therapeutics for endocrine disorders may be achievable.

Development of a Liposome Nanoformulation for the Delivery of Lipoic Acid as a Potential Neuroprotective Therapy in Glaucoma

Background/Objectives: Glaucoma is the leading cause of irreversible blindness worldwide and oxidative stress is considered to play a key role in its development. While antioxidants offer a promising approach to mitigating oxidative stress, their clinical application is often hindered by bioavailability and absorption challenges. Entrapment antioxidants within liposomes may overcome these issues, enhancing their stability and delivery. The aim of this study was to develop a novel composite liposomal formulation for glaucoma treatment, designed to enhance lipoic acid bioavailability and administration through its incorporation into the lipid bilayer. Methods: Liposomes were prepared via lipid film hydration and extrusion. To characterize them, the following analyses were performed: FTIR spectroscopy, liposomal bilayer melting temperature (Tm), TEM, DLS, Z-potential, antioxidant activity, and cytotoxicity assays. Results: The efficient incorporation of lipoic acid into the liposomes' lipid bilayer was confirmed by FTIR. This incorporation resulted in an increase in the Tm, from 37.0 °C for liposomes to 40.0 °C for liposomes with lipoic acid (L-LA). TEM images confirmed that the spherical morphology of the lipid vesicles remained unchanged following LA incorporation. Dynamic Light Scattering analysis revealed effective diameters of 423 ± 36 nm for L liposomes and 404 ± 62 nm for L-LA liposomes. Notably, the Z-potential shifted from +4.7 ± 0.4 mV (L) to -0.4 ± 0.3 mV (L-LA). Furthermore, L-LA exhibited significant antioxidant activity (31.6 ± 0.4%) compared with L (5.3 ± 0.3%) and biocompatibility, suggesting its potential for therapeutic applications. Conclusions: In summary, biocompatible composite liposomes with antioxidant capacity were successfully developed, resulting in promising candidates for neuroprotective glaucoma therapy.

Fe3O4@SiO2-SnCl4-promoted synthesis, cytotoxic evaluation, molecular docking, and MD simulation of some indenopyrido[2,3-d]pyrimidine derivatives

In this study, an efficient and environmentally friendly method for the one-pot synthesis of indenopyrido[2,3-d]pyrimidine derivatives was developed using Fe3O4@SiO2-SnCl4 nanoparticles as a catalyst. Indenopyrido[2,3-d]pyrimidines (4a-4j) were synthesized via three-component couplings of 6-amino-2-(methylthio)pyrimidin-4(3H)-one, 1,3-indanedione, and aldehydes in water as the solvent. In this reaction, Fe3O4@SiO2-SnCl4 demonstrated a highly catalytic nature, an easy handling procedure, short reaction times, recyclability exploitation, and excellent yields. The cytotoxic activities of the synthesized indenopyrido[2,3-d] pyrimidines analogues were evaluated against three cancer cell lines; MCF-7 (breast carcinoma), A549 (lung non-small cell carcinoma), and SKOV3 (ovarian carcinoma) using MTT assay. Additionally, molecular docking studies and molecular dynamics (MD) simulation of the investigated compounds was performed to verify their binding modes toward EGFR kinase receptor as the possible targets. This analysis aimed to predict the antitumor mechanisms of the synthesized compounds. The binding free energy values of the compounds showed a satisfactory correlation with their cytotoxic activities.

Design, synthesis, biological assessments and computational studies of 3-substituted phenyl quinazolinone derivatives as promising anti-cancer agents

A new series of 3-substituted phenyl quinazolinone derivatives were designed and synthesized as anti-cancer agents. The most potent derivative with IC50 values of 12.84 ± 0.84 and 10.90 ± 0.84 µM against MCF-7 and SW480 cell lines was comparable to Cisplatin and Erlotinib as positive controls. Cell cycle analysis showed that the most active compound could arrest at S phase in MCF-7 breast cancer cells. The apoptosis assay demonstrated the induction of apoptosis in the MCF-7 cell line, too. Molecular docking results showed better accommodation of the most active compound through hydrogen bonding interaction in the binding site of EGFR enzyme. Molecular dynamics simulations for the potent analogue demonstrated well binding stability compared to the less active analogue, with a lower RMSD, Rg and more interactions with the original active site residues. DFT calculations were performed on the active and inactive compounds, using Gaussian 09 at the M06-2X/6-31 + G(d) theoretical level. ADME (Absorption, Distribution, Metabolism, and Excretion) properties showed that most of the compounds are in acceptable range of Lipiniski rule. These findings underscore the potential of the synthesized compounds as potent cytotoxic inhibitors and provide insights for developing effective treatments for cancer therapy.

Development of new anticancer thiadiazole-sulfonamides as dual EGFR/carbonic anhydrase inhibitors

BACKGROUND

Thiadiazole-sulfonamide derivatives were synthesized as dual inhibitors of epidermal growth factor receptor (EGFR) and carbonic anhydrase IX (CA-IX) to develop selective anticancer agents.

METHODS

Cytotoxicity was evaluated against MDA-MB-231 and MCF-7 breast cancer cells, with selectivity tested on Vero cells. Enzymatic inhibition studies were conducted against EGFR and CA-IX, using erlotinib and acetazolamide as reference drugs. Apoptosis was assessed through gene expression analysis of BAX/Bcl-2, caspase-8, and caspase-9, alongside flow cytometry for apoptosis and cell cycle analysis. Molecular docking and 200 ns molecular dynamics (MD) simulations evaluated binding interactions. Density Functional Theory (DFT) calculations and in silico ADMET predictions assessed stability, electronic properties, and safety.

RESULTS

Compound 14 exhibited potent cytotoxicity (IC₅₀ = 5.78 μM, MDA-MB-231; 8.05 μM, MCF-7) and high selectivity (IC₅₀ = 313.08 μM, Vero). It inhibited EGFR (IC₅₀ = 5.92 nM) and CA-IX (IC₅₀ = 63 nM), surpassing reference drugs. Apoptosis induction was confirmed by a 13.97-fold increase in BAX/Bcl-2, caspase upregulation, and G1-phase arrest. Computational analyses confirmed stable binding and favorable safety.

CONCLUSIONS

Compound 14 represents a promising dual EGFR/CA-IX inhibitor with selective anticancer activity. Further in vivo studies are warranted.

Therapeutic Effects of GLP-1 Receptor Agonists and DPP-4 Inhibitors in Neuropathic Pain: Mechanisms and Clinical Implications

Glucagon-like peptide-1 (GLP-1) is a peptide hormone secreted by the small intestine upon food intake. GLP-1 enhances insulin secretion, suppresses glucagon release, and promotes satiety, resulting in reduced food consumption and subsequent weight loss. Endogenous GLP-1 has a very short half-life and is rapidly degraded by the enzyme dipeptidyl-peptidase-IV (DPP-4). To address this limitation, GLP-1 receptor agonists (GLP-1RAs) and DPP-4 inhibitors (DPP-4is) were developed and have demonstrated potency in clinical practice. In recent years, GLP-1RA and DPP4-i therapies are known to have pleiotropic effects, such as a reduction in oxidative stress, autophagy regulation, metabolic reprogramming, enhancement of anti-inflammatory signaling, regulation of gene expression, and being neuroprotective. These effects imply a therapeutic perspective for GLP-1RA and DPP-4i therapies in neuropathic pain treatment. Preclinical and clinical studies increasingly support the hypothesis that these therapies may alleviate neuropathic pain by targeting multiple mechanisms that induce neuropathic pain, such as inflammation, oxidative stress, and mitochondrial dysfunction. This review explores the mechanisms by which GLP-1RAs and DPP-4is alleviate neuropathic pain. It also highlights current advancements in incretin research, focusing on the therapeutic effects of GLP-1RAs and DPP-4-is for neuropathic pain.