Natural acylated flavonoids: their chemistry and biological merits in context to molecular docking studies

Exochorda racemosa attenuates DSS-induced colitis in C57BL/6 J mice by regulating inflammatory factors, reducing oxidative stress, and modulating intestinal flora

BACKGROUND

Exochorda racemosa is a member of the genus Exochorda in the Rosaceae family. Its tender leaves and buds are favored as a unique wild vegetable by people in central China.

PURPOSE

This study systematically evaluated the pharmacological safety and anti-inflammatory efficacy of E. racemosa extracts, with concurrent identification and characterization of their primary bioactive components.

METHODS

The chemical composition of E. racemosa extract (ERE) was analyzed using HPLC and LC-MS techniques. The safety and in vivo anti-inflammatory effects of ERE were evaluated using the maximum tolerated dose (MTD) in ICR mice and a dextran sodium sulfate-induced ulcerative colitis model in C57BL/6 J mice.

RESULTS

HPLC and LC-MS analyses revealed that ERE contained abundant flavonoid active ingredients. MTD study confirmed that ERE exhibited good safety. The symptoms of persistent weight loss, DAI, and shortened colon length in UC mice were suppressed by ERE. Pathological damage in colon tissues was attenuated by ERE, with a considerable reduction in histopathological scores and a substantial increase in the number of goblet cells. The levels of IL-6, IL-1β, and TNF-α in serum were significantly decreased following ERE treatment. Moreover, nitric oxide (NO) levels and myeloperoxidase (MPO) activity in colon tissues decreased, whereas glutathione (GSH) levels and superoxide dismutase (SOD) activity in colon tissues increased after ERE treatment. Furthermore, ERE could regulate the intestinal microbial composition and maintain intestinal flora homeostasis, thereby inhibiting inflammatory responses.

CONCLUSION

ERE exhibited a favorable safety profile and alleviated UC through multiple mechanisms. It is expected to serve as a promising low-toxicity natural product for adjuvant treatment in UC.

Evaluation of the Inhibitory Potential of Apigenin and Related Flavonoids on Various Proteins Associated with Human Diseases Using AutoDock

We used molecular docking to determine the binding energy and interactions of apigenin and 16 related flavonoids, with 24 distinct proteins having diverse biological functions. We aimed to identify potential inhibitors of these proteins and understand the structural configurations of flavonoids impacting their binding energy. Our results demonstrate that apigenin exhibits high binding energies (a surrogate for binding affinity or inhibitory potential) to all tested proteins. The strongest binding energy was -8.21 kcal/mol for p38 mitogen-activated protein kinases, while the weakest was -5.34 kcal/mol for cyclin-dependent kinase 4. Apigenin and many other flavonoids showed high binding energies on xanthine oxidase (1.1-1.5 fold of febuxostat) and DNA methyltransferases (1.1-1.2 fold of azacytidine). We uncovered high binding energies of apigenin and certain flavonoids with mutated Kirsten rat sarcoma viral oncogene homolog at G12D (KRAS G12D), G12V, and G12C. Consequently, apigenin and certain flavonoids have the potential to effectively inhibit pan-KRAS oncogenic activity, not just on specific KRAS mutations. Apigenin and certain flavonoids also have high binding energies with aromatase (involved in estrogen production) and bacterial infections, i.e., DNA gyrase B and 3R-hydroxy acyl-ACP dehydratase (FABZ). Our findings are pivotal in identifying specific flavonoids that can effectively inhibit targeted proteins, paving the way for the development of innovative flavonoid-based drugs.

A combination screening strategy based on UPLC-HRMS and UPLC-MRM for the comprehensive analysis of malonyl-substituted flavonoid glycosides in Astragalus

Recently, malonylated glycosides have received increasing attention in the study of medicinal plants due to their significant physiological functions. A few malonyl-substituted flavonoid glycosides (MFGs) have been reported in Astragalus, however, the number of MFGs was limited. This study established screening strategies based on ultra-high-performance liquid chromatography - high resolution mass spectrometry (UPLC-HRMS) and ultra-high-performance liquid chromatography - multiple reaction monitoring (UPLC-MRM) to screen and quantify MFGs in Astragalus. In the UPLC-HRMS strategy, the neutral loss values of 248.0526 Da and 85.9998 Da, along with the fragmentation patterns of flavonoid aglycones, were utilized as criteria for the selection of MFGs. In the UPLC-MRM strategy, the ion pair [M+H]+/[Aglycone+H]+ was designated as the primary characteristic ion pair for candidate MFGs. Additionally, the ion pair [M+H]+/[M-Mal+H]+ was selected as a secondary ion pair to facilitate validation. A total of 48 and 133 MFGs were screened from Astragalus using the UPLC-HRMS strategy and UPLC-MRM strategy, respectively. Thus, more MFGs were screened by the UPLC-MRM strategy, which demonstrates its advantage over the UPLC-HRMS strategy. The UPLC-MRM method was applied to the screening of MFGs in different parts of Astragalus samples, and further analytical assessments revealed a significant correlation between the structures of MFGs and the expression of malonyltransferase genes in Astragalus samples. In conclusion, we provide an efficient screening strategy for the analysis of MFGs in Astragalus, laying a foundation for the study of these compounds.

Non-small cell lung cancer sensitisation to platinum chemotherapy via new thiazole-triazole hybrids acting as dual T-type CCB/MMP-9 inhibitors

Cisplatin remains the unchallenged standard therapy for NSCLC. However, it is not completely curative due to drug resistance and oxidative stress-induced toxicity. Drug resistance is linked to overexpression of matrix metalloproteinases (MMPs) and aberrant calcium signalling. We report synthesis of novel thiazole-triazole hybrids as MMP-9 inhibitors with T-type calcium channel blocking and antioxidant effects to sensitise NSCLC to cisplatin and ameliorate its toxicity. MTT and whole cell patch clamp assays revealed that 6d has a balanced profile of cytotoxicity (IC50 = 21 ± 1 nM, SI = 12.14) and T-type calcium channel blocking activity (⁓60% at 10 μM). It exhibited moderate ROS scavenging activity and nanomolar MMP-9 inhibition (IC50 = 90 ± 7 nM) surpassing NNGH with MMP-9 over -2 and MMP-10 over -13 selectivity. Docking and MDs simulated its receptor binding mode. Combination studies confirmed that 6d synergized with cisplatin (CI = 0.69 ± 0.05) lowering its IC50 by 6.89 folds. Overall, the study introduces potential lead adjuvants for NSCLC platinum-based therapy.

Depiction of new flavonoids from Nyctanthus arbor-tristis, their antimicrobial activity and drug-likeness prediction

Bioactive compounds derived from medicinal plants, such as alkaloids, tannins and flavonoids, possess significant medicinal properties. These compounds have a broad and versatile impact on human nutrition and physiology, contributing to the treatment and management of various diseases. The isolation, structure elucidation and inhibition studies of two novel flavonoids against specific microorganisms, from the leaves of Nyctanthus arbor-tristis are reported in this study. It has been observed for the first time that the presence of an acyl aliphatic moiety, along with the O- glycoside unit at C-7, and the hydroxyl group at C-5, C-4' position in apigenin significantly enhanced antimicrobial activity. Moreover, bioactivity was also investigated through 'Molinspiration' on various parameters followed by the 'rule of five'. This study can be used to highlight the need for the potential development of natural therapeutic products with fewer side effects.

LC-MS/MS profiling of Tipuana tipu flower, HPLC-DAD quantification of its bioactive components, and interrelationships with antioxidant, and anti-inflammatory activity: in vitro and in silico approaches

BACKGROUND

Fabaceae plays a crucial role in African traditional medicine as a source of large number of important folk medication, agriculture and food plants. In a search of potential antioxidant and anti-inflammatory candidates derived from locally cultivated plants, the flowers of Tipuana tipu (Benth.) Lillo growing in Egypt were subjected to extensive biological and phytochemical studies. The impact of the extraction technique on the estimated biological activities was investigated.

METHODS

The flowers were extracted using different solvents (aqueous, methanol, water/methanol (1:1), methanol/methylene chloride (1:1), and methylene chloride). The different extracts were subjected to antioxidant (DPPH, ABTS, and FRAP) and anti-inflammatory (COX-2 and 5-LOX) assays. The methanol extract was assessed for its inhibitory activity against iNOS, NO production, and pro-inflammatory cytokines (NF-KB, TNF-R2, TNF-α, IL-1β, and IL-6) in LPS-activated RAW 264.7 macrophages. The composition-activity relationship of the active methanol extract was further investigated using a comprehensive LC-QTOF-MS/MS analysis. The major identified phenolic compounds were further quantified using HPLC-DAD technique. The affinity of representative compounds to iNOS, COX-2, and 5-LOX target active sites was investigated using molecular docking and molecular dynamics simulations.

RESULTS

The methanol extract exhibited the highest radical scavenging capacity and enzyme inhibitory activities against COX-2 and 5-LOX enzymes with IC50 values of 10.6 ± 0.4 and 14.4 ± 1.0 µg/mL, respectively. It also inhibited iNOS enzyme activity, suppressed NO production, and decreased the secretion of pro-inflammatory cytokines. In total, 62 compounds were identified in the extract including flavonoids, coumarins, organic, phenolic, and fatty acids. Among them 18 phenolic compounds were quantified by HPLC-DAD. The highest docking scores were achieved by kaempferol-3-glucoside and orientin. Additionally, molecular dynamics simulations supported the docking findings.

CONCLUSION

The flower could be considered a potentially valuable component in herbal medicines owing to its unique composition and promising bioactivities. These findings encourage increased propagation of T. tipu or even tissue culturing of its flowers for bioprospecting of novel anti-inflammatory drugs. Such applications could be adopted as future approaches that benefit the biomedical field.

Prosopis africana exerts neuroprotective activity against quaternary metal mixture-induced memory impairment mediated by oxido-inflammatory response via Nrf2 pathway

The beneficial effects of Prosopis africana (PA) on human health have been demonstrated; however, its protective effects against heavy metals (HM) are not yet understood. This study evaluated the potential neuroprotective effects of PA in the cerebral cortex and cerebellum. To accomplish this, we divided 35 albino Sprague Dawley rats into five groups. Group I did not receive either heavy metal mixture (HMM) or PA. Group II received a HMM of PbCl2 (20 mg/kg), CdCl2 (1.61 mg/kg), HgCl2 (0.40 mg/kg), and NaAsO3 (10 mg/kg) orally for a period of two months. Groups III, IV, and V received HMM along with PA at doses of 500, 1000, and 1500 mg/kg, respectively. PA caused decreased levels of HM accumulation in the cerebral cortex and cerebellum and improved performance in the Barnes maze and rotarod tests. PA significantly reduced levels of IL-6 and TNF-α. PA increased concentrations of SOD, CAT, GSH, and Hmox-1 and decreased the activities of AChE and Nrf2. In addition, levels of MDA and NO decreased in groups III, IV, and V, along with an increase in the number of live neurons. In conclusion, PA demonstrates a complex neuroprotective effect with the potential to alleviate various aspects of HM-induced neurotoxicity.

How Does Lagenaria siceraria (Bottle Gourd) Metabolome Compare to Cucumis sativus (Cucumber) F. Cucurbitaceae? A Multiplex Approach of HR-UPLC/MS/MS and GC/MS Using Molecular Networking and Chemometrics

Cucurbitaceae comprises 800 species, the majority of which are known for their nutritive, economic, and health-promoting effects. This study aims at the metabolome profiling of cucumber (Cucumis sativus) and bottle gourd (Lagenaria siceraria) fruits in a comparative manner for the first time, considering that both species are reported to exhibit several in-common phytochemical classes and bioactivities. Nevertheless, bottle gourd is far less known and/or consumed than cucumber, which is famous worldwide. A multiplex approach, including HR-UPLC/MS/MS, GNPS networking, SPME, and GC/MS, was employed to profile primary and secondary metabolites in both species that could mediate for new health and nutritive aspects, in addition to their aroma profiling, which affects the consumers' preferences. Spectroscopic datasets were analyzed using multivariate data analyses (PCA and OPLS) for assigning biomarkers that distinguish each fruit. Herein, 107 metabolites were annotated in cucumber and bottle gourd fruits via HR-UPLC/MS/MS analysis in both modes, aided by GNPS networking. Metabolites belong to amino acids, organic acids, cinnamates, alkaloids, flavonoids, pterocarpans, alkyl glycosides, sesquiterpenes, saponins, lignans, fatty acids/amides, and lysophospholipids, including several first-time reported metabolites and classes in Cucurbitaceae. Aroma profiling detected 93 volatiles presented at comparable levels in both species, from which it can be inferred that bottle gourds possess a consumer-pleasant aroma, although data analyses detected further enrichment of bottle gourd with ketones and esters versus aldehydes in cucumber. GC/MS analysis of silylated compounds detected 49 peaks in both species, including alcohols, amino acids, fatty acids/esters, nitrogenous compounds, organic acids, phenolic acids, steroids, and sugars, from which data analyses recognized that the bottle gourd was further enriched with fatty acids in contrast to higher sugar levels in cucumber. This study provides new possible attributes for both species in nutrition and health-care fields based on the newly detected metabolites, and further highlights the potential of the less famous fruit "bottle gourd", recommending its propagation.