Chalcones and their B-aryl analogues as myeloperoxidase inhibitors: In silico, in vitro and ex vivo investigations

Determination of the Inhibitory Potential of Chalcones on Myeloperoxidase Enzyme Activity: In vitro and Molecular Docking Studies

Myeloperoxidase (MPO) is a highly abundant hemoprotein in neutrophils and monocytes. It has a crucial function in immunological surveillance and the body's defensive systems. Nevertheless, there is a strong correlation between elevated MPO activity and the development and advancement of inflammatory processes. Chalcone derivatives serve as fundamental components of pharmaceutical raw materials, which have been extensively utilized for the treatment of several ailments. In this study, it was studied the effect of some chalchones on MPO activity. Chalcones (1-6) strongly inhibited MPO with IC50s in the micromolar range of 0.05-0.828 µM. In particular, 4,4'-difluorochalcone (3) exhibited the best MPO inhibitory impact with IC50 of 0.05 µM. Additionally, molecular docking experiments were conducted to predict the binding affinities and interactions of the chalcone derivatives with the MPO active site. The docking results revealed that all tested compounds exhibited favorable binding energies, with ΔG Vina values ranging from -7.6 to -8.4 kcal/mol. Compound 3 demonstrated the strongest binding affinity (-8.4 kcal/mol), forming key hydrogen bonds with Gln91 and His95, and halogen interactions with the fluorine atoms, which may account for its enhanced inhibitory activity. These combined in vitro and in silico results suggest that chalcone derivatives hold significant potential as therapeutic candidates targeting MPO.

Therapeutic Perspectives of Aminoflavonoids-A Review

Natural compounds containing nitrogen are a source of many biologically active molecules used as drugs. Due to their multidirectional effects, they represent effective therapeutic compounds in many medical areas. Flavonoids, as well as their bioprecursors, chalcones, that occur in plants possess a number of medicinal benefits. Their synthetic amino derivatives constitute a large group of compounds that exhibit pharmacological activity. Due to the increasing level of drug resistance among patients, new therapeutic agents and options are urgently needed. Therefore, aminoflavonoids may be a promising source of new drugs. In this review, the biological activities of flavonoids, including chalcones, with complexes containing a nitrogen atom and the aminoflavones Ru and Pt are summarized. The purpose of this review is to provide an overview of the synthesis and pharmacological activity of aminoflavonoids and to show how synthetic modifications of these compounds can influence their biological activities. It covers the most recent reports on obtaining aminoflavones, aminochalcones, and their derivatives, along with information about their anticancer, antimicrobial, antimalarial, antiviral, and anti-inflammatory activities.

Unearthing novel and multifunctional peptides in peptidome of fermented chhurpi cheese of Indian Himalayan region

Fermented foods of the Indian Himalaya are unexplored functional resources with high nutritional potential. Chhurpi cheese, fermented by defined native proteolytic lactic acid bacteria of Sikkim was assessed for ACE inhibitory, HOCl reducing, and MPO inhibitory, activity across varying stages of gastrointestinal (GI) digestion. The enhanced bioactivity of Lactobacillus delbrueckii WS4 chhurpi was associated with the generation of bioactive and multifunctional peptides during fermentation and GI digestion. Qualitative and quantitative in silico tools were employed for prediction of ACE inhibitory activity of novel chhurpi peptides. Selected peptides, with highest predictive ACE inhibitory potential were synthesized and in vitro validation revealed the ACE inhibitory potential of peptides HPHPHLSFM and LKPTPEGDL. LKPTPEGDL showed the most potent ACE inhibitory activity (IC50 of 25.82 ± 0.26 µmol) which slightly decreased upon GI digestion. The peptides demonstrated a non-competitive type mixed ACE inhibition modality. Furthermore, the two peptides exerted observable HOCl reducing and MPO inhibitory activity, demonstrating their antioxidative potential. HPHPHLSFM exhibited superior HOCl reduction (EC50 of 0.29 ± 0.01 mmol), while LKPTPEGDL demonstrated higher MPO (IC50 of 0.29 ± 0.01 mmol) inhibition. Molecular docking of the two peptides with MPO revealed proline and aspartate near peptidyl C-terminus to bind with enzyme catalytic residues. This study presents the first peptidome analysis of chhurpi produced through controlled fermentation and identifies novel peptides with MPO and ACE inhibitory activity. Furthermore, it marks the first synthesis and in vitro bioactivity validation of bioactive peptides from chhurpi cheese, highlighting its multifunctional potential.

Pharmacological potential of 4-dimethylamino chalcone against acute and neuropathic pain in mice

OBJECTIVES

This work investigated the acute antinociceptive effect of a synthetic chalcone, 4-dimethylamino chalcone (DMAC), as well as its effects on vincristine-induced peripheral neuropathy (VIPN) in mice.

METHODS

The inhibitory activity of myeloperoxidase was assessed by measuring HOCl formation. Formalin and hot plate tests were used to study the acute antinociceptive effect of DMAC. VIPN was induced through the administration of vincristine sulphate (0.1 mg/kg, i.p., 14 days). Then, DMSO, DMAC (10 or 30 mg/kg; i.p.), or pregabalin (10 mg/kg, i.p.) were administered for 14 consecutive days. Thermal hyperalgesia and mechanical allodynia were evaluated before and after VIPN induction and on days 1, 3, 7, and 14 of treatment. Neurodegeneration and neuroinflammation were assessed through immunohistochemistry for NF200, iNOS, and arginase-1 within the sciatic nerve.

KEY FINDINGS

DMAC inhibited myeloperoxidase activity in vitro and presented an acute antinociceptive effect in both formalin and hot plate tests, with the involvement of muscarinic and opioid receptors. Treatment with 30 mg/kg of DMAC significantly attenuated thermal hyperalgesia and mechanical allodynia and prevented macrophage proinflammatory polarisation in VIPN mice.

CONCLUSIONS

Our results show that DMAC, acting through different mechanisms, effectively attenuates VIPN.

Exploring peptidomes of by-products generated during chhurpi production using Lactobacillus delbrueckii WS4 for identification of novel bioactive peptides

The considerable value of whey is evident from its significant potential applications and contributions to the functional food and nutraceutical market. The by-products were individually obtained during functional chhurpi and novel soy chhurpi cheese production using defined lactic acid bacterial strains of Sikkim Himalaya's traditional chhurpi. Hydrolysis of substrate proteins by starter proteinases resulted in a comparable peptide content in whey and soy whey which was associated with antioxidant and ACE inhibition potential. Peptidome analysis of Lactobacillus delbrueckii WS4 whey and soy whey revealed the presence of several bioactive peptides including the multifunctional peptides PVVVPPFLQPE and YQEPVLGPVRGPFPIIV. In silico analyses predicted the antihypertensive potential of whey and soy whey peptides with strong binding affinity for ACE active sites. QSAR models predicted the highest ACE inhibition potential (IC50) for the β-casein-derived decapeptide PVRGPFPIIV (0.95 μM) and the Kunitz trypsin inhibitor protein-derived nonapeptide KNKPLVVQF (16.64 μM). Chhurpi whey and soy whey can be explored as a valuable source of diverse and novel bioactive peptides for applications in designer functional foods development.

Hydroxy Chalcones and Analogs with Chemopreventive Properties

The aim of this review is to highlight the chemopreventive properties of hydroxy-substituted natural and synthetic chalcones along with a number of their analogs. These products display various biological activities, and have many applications against various diseases. Antioxidant and anti-inflammatory properties of chalcones bearing hydroxy substituents are underlined. The influence of hydroxy substituents located on ring A, B, or both are systematized according to the exhibited biological properties.

Potential effect of novel thiadiazole derivatives against radiation induced inflammation with low cardiovascular risk in rats

The aim of the present study is to explore new selective anti-inflammatory compounds with low cardiovascular risk. Twelve thiadiazole derivatives incorporating different amino acid moieties were newly synthesized (4–15) as potential anti-inflammatory agents with low cardiovascular risks through dual COX-2/MPO inhibition. Compounds were initially screened for their anti-inflammatory effect by assay of COX-2, the most potent (4–6, 8) were further tested for COX-1 inhibition, myeloperoxidase MPO activity as well as total nitric oxide content NO in heart of irradiated rats. Cardiac toxicity potential was evaluated by assay of creatine kinase-MB (CK-MB), troponin-I (Tn-I) and lactate dehydrogenase (LDH). Celcoxcib was used as reference drug. S-(5-((4-Methoxybenzylidene)amino)-2,3-dihydro-1,3,4-thiadiazol-2-yl)2-amino propanethioate (5) was the most potent anti-inflammatory with the least cardiotoxicity effect. It exhibited IC50 0.09 µM on COX-2 inhibition with very low activity on COX-1. Troponin I was elevated by 11% using compound 5 in non-irradiated rats. Moreover, compound (5) showed 73% reduction in MPO level. Results were supported by molecular docking into the active sites of COX-2 and MPO enzymes to have more insights about the possible dual inhibition of compound 5 of both enzymes.

Identification of a Prenyl Chalcone as a Competitive Lipoxygenase Inhibitor: Screening, Biochemical Evaluation and Molecular Modeling Studies

Cyclooxygenase (COX) and lipoxygenase (LOX) are key targets for the development of new anti-inflammatory agents. LOX, which is involved in the biosynthesis of mediators in inflammation and allergic reactions, was selected for a biochemical screening campaign to identify LOX inhibitors by employing the main natural product library of Brazilian biodiversity. Two prenyl chalcones were identified as potent inhibitors of LOX-1 in the screening. The most active compound, (E)-2-O-farnesyl chalcone, decreased the rate of oxygen consumption to an extent similar to that of the positive control, nordihydroguaiaretic acid. Additionally, studies on the mechanism of the action indicated that (E)-2-O-farnesyl chalcone is a competitive LOX-1 inhibitor. Molecular modeling studies indicated the importance of the prenyl moieties for the binding of the inhibitors to the LOX binding site, which is related to their pharmacological properties.