Rethinking therapeutic strategies of dual-target drugs: An update on pharmacological small-molecule compounds in cancer.

Oncogenes and tumor suppressors are well-known to orchestrate several signaling cascades, regulate extracellular and intracellular stimuli, and ultimately control the fate of cancer cells. Accumulating evidence has recently revealed that perturbation of these key modulators by mutations or abnormal protein expressions are closely associated with drug resistance in cancer therapy; however, the inherent drug resistance or compensatory mechanism remains to be clarified for targeted drug discovery. Thus, dual-target drug development has been widely reported to be a promising therapeutic strategy for improving drug efficiency or overcoming resistance mechanisms. In this review, we provide an overview of the therapeutic strategies of dual-target drugs, especially focusing on pharmacological small-molecule compounds in cancer, including small molecules targeting mutation resistance, compensatory mechanisms, synthetic lethality, synergistic effects, and other new emerging strategies. Together, these therapeutic strategies of dual-target drugs would shed light on discovering more novel candidate small-molecule drugs for the future cancer treatment.

Photosynthetic mechanism of maize yield under fluctuating light environments in the field.

The photosynthetic mechanism of crop yields in fluctuating light environments in the field remains controversial. To further elucidate this mechanism, we conducted field and simulation experiments using maize (Zea mays) plants. Increased planting density enhanced the light fluctuation frequency and reduced the duration of daily high light, as well as the light-saturated photosynthetic rate, biomass, and yield per plant. Further analysis confirmed a highly significant positive correlation between biomass and yield per plant and the duration of photosynthesis related to daily high light. The simulation experiment indicated that the light-saturated photosynthetic rate of maize leaves decreased gradually and considerably when shortening the daily duration of high light. Under an identical duration of high light exposure, increasing the fluctuation frequency decreased the light-saturated photosynthetic rate slightly. Proteomic data also demonstrated that photosynthesis was mainly affected by the duration of high light and not by the light fluctuation frequency. Consequently, the current study proposes that an appropriate duration of daily high light under fluctuating light environments is the key factor for greatly improving photosynthesis. This is a promising mechanism by which the photosynthetic productivity and yield of maize can be enhanced under complex light environments in the field.

Discovery of potential components characteristic by conjugated enone from the branches and leaves of Croton lauioides with anti-neuroinflammatory activity via regulating the NF-κB pathway.

In this study, the chemical composition and pharmacological activity of Croton lauioides were investigated for the first time. The bioactive and HPLC-UV guided isolation led to the discovery of twenty-three conjugated enone-type components (1-23), including nine previously unknown sesquiterpenoid derivatives (1-4, 9-10, 12-14). Notably, compounds 1 and 12 are epoxides containing an endoperoxide bridge (1) or a unique dioxaspiro core (12), respectively. Compounds 2-7 are non-benzenoid aromatics featuring a tropone function, while 9-11 possess a rare rearranged scaffold with tropone shift into benzene. Extensive characterization was performed using NMR spectra, HRESIMS data, and electronic circular dichroism (ECD) calculations. Furthermore, we evaluated the bioactivities of all isolated compounds against neuroinflammation in LPS-stimulated BV-2 microglial cells. Remarkably, most sesquiterpenoid derivatives exhibited significant NO inhibit activities, and compound 5 showed the most potent effect with an IC50 value of 0.14 ± 0.04 µM. Structure-activity relationship (SAR) analysis revealed that sesquiterpenoids modified with endocyclic enone conjugation may serve as a key pharmacophore for NO inhibition, particularly involving aromatic tropone moiety. The qPCR and Western blot results demonstrated that 5 exerted an inhibitory effect on the mRNA levels of iNOS, TNF-α and COX-2 in a time-dependent manner, as well as suppressed the protein expression of iNOS, TNF-α, COX-2. In mechanism, 5 could prevented activation of NF-κB pathway by suppressing phosphorylation of p65 and IκB-α. These findings revealed C. lauioides might be a promising resource for drug candidate development targeting neuroinflammation.

Ethanol Extract of Limonium bicolor Improves Dextran Sulfate Sodium-Induced Ulcerative Colitis by Alleviating Inflammation and Restoring Gut Microbiota Dysbiosis in Mice.

Ulcerative colitis (UC) is a kind of inflammatory bowel condition characterized by inflammation within the mucous membrane, rectal bleeding, diarrhea, and pain experienced in the abdominal region. Existing medications for UC have limited treatment efficacy and primarily focus on symptom relief. Limonium bicolor (LB), an aquatic traditional Chinese medicine (TCM), exerts multi-targeted therapeutic effects with few side effects and is used to treat anemia and hemostasis. Nevertheless, the impact of LB on UC and its mechanism of action remain unclear. Therefore, the objective of this study was to investigate the anti-inflammatory effects and mechanism of action of ethanol extract of LB (LBE) in lipopolysaccharide-induced RAW 264.7 macrophages and dextran sulfate sodium (DSS)-induced UC. The results showed that LBE suppressed the secretion of cytokines in LPS-stimulated RAW 264.7 cells in a dose-dependent manner. LBE had protective effects against DSS-induced colitis in mice, decreased the disease activity index (DAI) score, alleviated symptoms, increased colon length, and improved histological characteristics, thus having protective effects against DSS-induced colitis in mice. In addition, it reversed disturbances in the abundance of proteobacteria and probiotics such as Lactobacillus and Blautia in mice with DSS-induced UC. Based on the results of network pharmacology analysis, we identified four main compounds in LBE that are associated with five inflammatory genes (Ptgs2, Plg, Ppar-γ, F2, and Gpr35). These results improve comprehension of the biological activity and functionality of LB and may facilitate the development of LB-based compounds for the treatment of UC.

Pathogenic fungi synergistically cooperate with Serratia marcescens to increase cockroach mortality.

The abuse of chemical insecticides has led to strong resistance in cockroaches, and biopesticides with active ingredients based on insect pathogens have good development prospects; however, their slow effect has limited their practical application, and improving their effectiveness has become an urgent problem. In this study, the interaction between Serratia marcescens and Metarhizium anisopliae enhanced their virulence against Blattella germanica and exhibited a synergistic effect. The combination of S. marcescens and M. anisopliae caused more severe tissue damage and accelerated the proliferation of the insect pathogen. The results of high-throughput sequencing demonstrated that the gut microbiota was dysbiotic, the abundance of the opportunistic pathogen Weissella cibaria increased, and entry into the hemocoel accelerated the death of the German cockroaches. In addition, the combination of these two agents strongly downregulated the expression of Imd and Akirin in the IMD pathway and ultimately inhibited the expression of antimicrobial peptides (AMPs). S. marcescens released prodigiosin to disrupted the gut homeostasis and structure, M. anisopliae released destruxin to damaged crucial organs, opportunistic pathogen Weissella cibaria overproliferated, broke the gut epithelium and entered the hemocoel, leading to the death of pests. These findings will allow us to optimize the use of insect pathogens for the management of pests and produce more effective biopesticides.

Discovery of new triterpenoids from Leptopus clarkei and their antiproliferative activity on cancer cells.

Two new triterpenoids (1-2), along with six known analogues (3-8) were obtained from the dried whole plant of Leptopus clarkei. Compound 1 is a 3,4-seco-lupane-type triterpenoid, and compound 2 is a phenylpropanoid-conjugated pentacyclic triterpenoid possessing trans-p-coumaroyl unit attached to oleanane-type skeleton. This is the first report on chemical investigation of the L. clarkei, and the triterpenoid derivatives were found in this plant for the first time. The structures of the new compounds were unequivocally elucidated by HRESIMS and 1D/2D NMR data. Additionally, the isolated compounds were evaluated for theircytotoxicities against four cancer cell lines including HepG2, MCF-7, A549 and HeLa. Notably, compound 2 exhibited the most significant antiproliferative activity with IC50 less than 20 µM for four cancer lines.

Two new cassane diterpenoids from the seed kernels of Caesalpinia sinensis.

Two new cassane diterpenoids, sucupiranin MN (1) and sucupiranin ML (2), together with two known compounds sucutinirane C (3) and deacetylsucutinirane C (4) were isolated from the seed kernels of Caesalpinia sinensis. Their structures were elucidated by means of analysis of comprehensive spectroscopic data, especially HRESIMS and 1D/2D NMR spectroscopy. Compounds 1-4 are typical furan-type cassane derivatives with an aromatized C ring. Biological evaluation revealed that compounds 1-4 at the concentration of 10 µM could inhibit the overproduction of NO in LPS-stimulated RAW 264.7 macrophages.

A new cassane diterpenoid from the seed of Caesalpinia sappan.

In this study, a previously undescribed cassane diterpenoid, named caesalpinin JF (1), along with two known cassane diterpenoids caesanine C (2) and tomocinol B (3), was isolated from 95% EtOH extract of the seeds of Caesalpinia sappan Linn. Additionally, three known compounds including pulcherrin R (4), syringaresinol-4'-O-ß-D-glucopyranoside (5) and kaempferol (6) were also identified. The structures of the isolated compounds were elucidated by comprehensive 1D and 2D NMR spectroscopic analyses. Additionally, electronic circular dichroism (ECD) calculation was used to identify the absolute structure of compound 1. Among the isolated compounds, compound 1 displayed a potent anti-neuroinflammation with an IC50 value of 9.87 ± 1.71 µM.

Transcriptome analysis revealed that short-term stress in Blattella germanica to ß-cypermethrin can reshape the phenotype of resistance adaptation.

Previous studies on insect resistance have primarily focused on resistance monitoring and the molecular mechanisms involved, while overlooking the process of phenotype formation induced by insecticide stress. In this study, we compared the expression profiles of a beta-cypermethrin (ß-CYP) resistant strain (R) and a susceptible strain (S) of Blattella germanica after ß-CYP induction using transcriptome sequencing. In the short-term stress experiment, we identified a total of 792 and 622 differentially expressed genes (DEGs) in the S and R strains. Additionally, 893 DEGs were identified in the long-term adaptation experiment. To validate the RNA-Seq data, we performed qRT-PCR on eleven selected DEGs, and the results were consistent with the transcriptome sequencing data. These DEGs exhibited down-regulation in the short-term stress group and up-regulation in the long-term adaptation group. Among the validated DEGs, CUO8 and Cyp4g19 were identified and subjected to knockdown using RNA interference. Subsequent insecticide bioassays revealed that the mortality rate of cockroaches treated with ß-CYP increased by 69.3% and 66.7% after silencing the CUO8 and Cyp4g19 genes (P<0.05). Furthermore, the silencing of CUO8 resulted in a significant thinning of the cuticle by 59.3% and 53.4% (P<0.05), as observed through transmission electron microscopy and eosin staining, in the S and R strains, respectively. Overall, our findings demonstrate that the phenotypic plasticity in response to short-term stress can reshape the adaptive mechanisms of genetic variation during prolonged exposure to insecticides. And the identified resistance-related genes, CUO8 and Cyp4g19, could serve as potential targets for controlling these pest populations.

Guided Isolation of New Cytotoxic Cassane Diterpenoids from Caesalpinia sappan.

Guided by an MS/MS-based molecular networking, six undescribed cassane diterpenoids and three known ones were isolated and identified from the seeds of Caesalpinia sappan. Their structures were unequivocally elucidated by extensive spectroscopic analyses and electronic circular dichroism (ECD) calculations. Cytotoxic evaluation showed that phanginin JA exhibited significant antiproliferative activities against human non-small cell lung cancer (A549) cells with IC50 values of 16.79±0.83 µM. Further flow cytometry analysis revealed that phanginin JA could exert apoptotic effect of A549 cells by arresting cell cycle in G0/G1 phase.

Room-temperature synthesis of imine-linked magnetic covalent organic polymers in deep eutectic solvents for the extraction of flavonoids and their determination with HPLC-MS/MS.

A novel imine-linked magnetic covalent organic polymer, Fe3O4@TAB-TFPT, was synthesized using environmentally friendly deep eutectic solvents as the reaction medium instead of conventional organic solvents. The materials were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), FT-IR, N2 adsorption-desorption isotherms, energy dispersive spectrometer (EDS), X-ray photoelectron spectra (XPS), and thermo gravimetric analysis (TGA). Subsequently, the materials were employed as an adsorbent for magnetic solid-phase extraction (MSPE) of flavonoids, including Kurarinone, Norkurarinone, Xanthohumol, and Isoxanthohumol, prior to their determination by HPLC-MS/MS. The validation results demonstrate good linearity within the concentration range 0.1-1000 ng∙mL-1 (R2 ≥ 0.9963), high enrichment factors ranging from 18.9 to 30.7, and low LODs (0.01-0.05 ng∙mL-1) and LOQs (0.05-0.1 ng∙mL-1). Furthermore, recoveries between 80.60% and 108.40% with relative standard deviations ≤ 8.49% were achieved. The proposed MSPE-HPLC-MS/MS method was successfully applied to the determination of flavonoids in Sophora flavescens Aition sample.

An efficient method for identifying natural common homoisoflavonoid by 1H-NMR.

Homoisoflavone contains 16 carbon atoms in the skeleton. The homoisoflavonoid skeleton from natural products can be roughly divided into 13 kinds, among which 5 kinds of common skeletons contain a large amount of compounds and 8 kinds of abnormal skeletons comprise a small amount of compounds. In this article, the structure identification experience of homoisoflavonoids found in Caesalpinia mimosoides was used as references and an efficient 1H NMR spectroscopic method for identifying homoisoflavonoid structure has been established. Using the chemical shift differences of H-2, 3, 4 and 9, the common natural homoisoflavonoids can be quickly and conveniently determined.

Identification of Daphne genkwa and Its Vinegar-Processed Products by Ultraperformance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry and Chemometrics.

Crude herbs of Daphne genkwa (CHDG) are often used in traditional Chinese medicine to treat scabies baldness, carbuncles, and chilblain owing to their significant purgation and curative effects. The most common technique for processing DG involves the use of vinegar to reduce the toxicity of CHDG and enhance its clinical efficacy. Vinegar-processed DG (VPDG) is used as an internal medicine to treat chest and abdominal water accumulation, phlegm accumulation, asthma, and constipation, among other diseases. In this study, the changes in the chemical composition of CHDG after vinegar processing and the inner components of the changed curative effects were elucidated using optimized ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Untargeted metabolomics, based on multivariate statistical analyses, was also used to profile differences between CHDG and VPDG. Eight marker compounds were identified using orthogonal partial least-squares discrimination analysis, which indicated significant differences between CHDG and VPDG. The concentrations of apigenin-7-O-ß-d-methylglucuronate and hydroxygenkwanin were considerably higher in VPDG than those in CHDG, whereas the amounts of caffeic acid, quercetin, tiliroside, naringenin, genkwanines O, and orthobenzoate 2 were significantly lower. The obtained results can indicate the transformation mechanisms of certain changed compounds. To the best of our knowledge, this study is the first to employ mass spectrometry to detect the marker components of CHDG and VPDG.

Has breeding altered the light environment, photosynthetic apparatus, and photosynthetic capacity of wheat leaves?

Whether photosynthesis has improved with increasing yield in major crops remains controversial. Research in this area has often neglected to account for differences in light intensity experienced by cultivars released in different years. Light intensity is expected to be positively associated with photosynthetic capacity and the resistance of the photosynthetic apparatus to high light but negatively associated with light-utilization efficiency under low light. Here, we analyzed the light environment, photosynthetic activity, and protein components of leaves of 26 winter wheat cultivars released during the past 60 years in China. Over time, light levels on flag leaves significantly decreased due to architectural changes, but photosynthetic rates under high or low light and the resistance of the photosynthetic apparatus to high light remained steady, contrary to expectations. We propose that the difference between the actual and expected trends is due to breeding. Specifically, breeding has optimized photosynthetic performance under high light rather than low light. Moreover, breeding selectivity altered the stoichiometry of several proteins related to dynamic photosynthesis, canopy light distribution, and photoprotection. These results indicate that breeding has significantly altered the photosynthetic mechanism in wheat and its response to the light environment. These changes likely have helped increase wheat yields.

New polyphenolic glycosides from the stems of Caesalpinia cucullata and their inhibitory effect on methicillin-resistant Staphylococcus aureus with different ways.

Anti-virulence strategy represents an emerging alternative strategy in the war against increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) due to its milder selection pressure on bacterial resistance. Sortase A (SrtA), as an important virulence factor, is a membrane-localized cysteine transpeptidase which anchors cell surface proteins to the cell wall. Natural products in medicinal plants are the source of targeting bacterial virulence factors. Here, we found polyphenolic glycosides (1-15), including thirteen new derivatives isolated from the stems of Caesalpinia cucullata, exhibited weak to moderate SrtA inhibitory activity without affecting the growth of MRSA, and compound 7 (53.7 % inhibition at 100 µM) was superior to the positive control curcumin. Meanwhile, compounds 2, 4 and 8 could effectively reduce the dose of ceftiofur in combination in vitro with fractional inhibitory concentration index (FICI) ranging from 0.188 to 0.375, which meant polyphenolic glycosides have got antibacterial activity with different ways. Here, we reported all new compounds structures determined by spectroscopy methods and their antibacterial activities, together, the relationship between structures with the inhibitory efficiency. The results indicated that polyphenolic glycosides could be used as promising therapeutic agents to prevent resistance development for S. aureus infections.

Isolation and structure elucidation of two new cassane derivatives from the seed kernels of Caesalpinia sinensis.

Two new cassane-type derivatives (1-2), together with three known compounds (3-5), were isolated from the seed kernels of Caesalpinia sinensis. Their structures were elucidated on the basis of interpretation of comprehensive spectroscopic data, including HRESIMS and 1D/2D NMR spectroscopy, and the absolute configuration were established by means of ECD calculation. Compound 2, possessing a 16-degradative cassane skeleton, was rarely encountered in cassane diterpenoids isolated from the genus Caesalpinia. All compounds were evaluated for their anti-inflammatory activities against the overproduction of NO in LPS-stimulated RAW 264.7 macrophages, and compounds 1-5 could inhibit production of NO at the concentration of 50 µM.

Photoprotection by mitochondrial alternative pathway is enhanced at heat but disabled at chilling.

The mitochondrial alternative pathway (AP) represents an important photoprotective mechanism for the chloroplast, but the temperature sensitivity of its photoprotective role is unknown. In this study, using the aox1a Arabidopsis mutant, the photoprotective role of the AP was verified under various temperatures, and the mechanism underlying the temperature sensitivity of the AP's photoprotective role was clarified. It was observed that the photoprotective role of the AP increased with rising temperature but was absent at low temperature. The photoprotective role of the AP was severely reduced under non-photorespiratory conditions. Disturbance of the AP inhibited the conversion of glycine to serine in mitochondria, which may restrain upstream photorespiratory metabolism and aggravate photoinhibition. With rising temperatures, photorespiration accelerated and the restraint of photorespiration caused by disturbance of the AP also increased, determining the temperature sensitivity of the AP's photoprotective role. We also verified that not only the AP but also the cytochrome pathway in mitochondria contributes to photoprotection by maintaining photorespiration.

Anti-inflammatory Cassane-Type Diterpenoids from the Seed Kernels of Caesalpinia sinensis.

Eighteen cassane diterpenoids, including five new lactam-type (4-8), 12 new lactone-type (1-3 and 9-17), and one known compound (18), were isolated from Caesalpinia sinensis. To our knowledge, this is the first study on the seed kernels of C. sinensis, and cassane derivatives were discovered in this plant for the first time. Their structures including absolute configurations were established by extensive spectroscopic methods complemented with single-crystal X-ray diffraction analyses and ECD calculations. Compounds 4-8 were identified as a group of rare cassane diterpenoids possessing a lactam D-ring instead of a typical lactone moiety. Biological evaluation revealed that compounds 4-6 exhibited effective inhibitory effects on NO production in the LPS-induced RAW 264.7 macrophages, with IC50 values in the range 8.2-11.2 µM. Compound 4 suppressed the excessive production of NO by down-regulating the expression of inducible nitric oxide synthase enzymes (iNOS) and reducing the enzymatic activity of iNOS. Moreover, the intermolecular interaction and binding mode between compound 4 and iNOS were elaborated by conducting a molecular docking study.

New phenylpropanoid-conjugated pentacyclic triterpenoids from the whole plants of Leptopus lolonum with their antiproliferative activities on cancer cells.

Most of Euphorbiaceae plants are considered as folk medicinal plants because of their various pharmacological effects. However, there are eight Leptopus genus plants which belong to Euphorbiaceae have never be investigated. Thus, four Leptopus genus plants were collected to study their chemical constituents and pharmacological activities. In the present work, the cytotoxicities of the extracts of four Leptopus genus plants were evaluated before phytochemical experiments. And nine new phenylpropanoid-conjugated pentacyclic triterpenoids, along with twenty-two known compounds were isolated from the whole plants of Leptopus lolonum. The structures of these new compounds were unequivocally elucidated by HRESIMS and 1D/2D NMR data. All triterpenoids were screened for their cytotoxicities against four cancer cell lines including HepG2, MCF-7, A549 and HeLa. Among these isolates, the triterpenoid with a phenylpropanoid unit showed increasing cytotoxicity on cancer cells, which suggested the importance of the phenylpropanoid moiety.

Phenylpropanoid-conjugated pentacyclic triterpenoids from the whole plants of Leptopus lolonum induced cell apoptosis via MAPK and Akt pathways in human hepatocellular carcinoma cells.

Our present and previous phytochemical investigations on Leptopus lolonum have resulted in the isolation of almost 30 phenylpropanoid-conjugated pentacyclic triterpenoids (PCPTs). During the continuous study on PCPTs, this kind of triterpenoid ester is considered as a natural product with low toxicity because of it's widely distribution in natural plants and edible fruits including kiwi fruit, durian, jujube, pawpaw, apple and pear. In the present work, we report the isolation, structural elucidation and cytotoxic evaluation of four new PCPTs (1-4) which obtained from L. lolonum. In addition, the possible biosynthesis pathway for 28-norlupane triterpenoid and potent effect of phenylpropanoid moiety for increasing the cytotxic effect of triterpenoids were also discussed. Among these compounds, compound 1 exhibited the highest cytotoxic effect on HepG2 cells with IC50 value of 11.87 µM. Further flow cytometry and western blot analysis demonstrated that 1 caused G1 cell cycle arrest by up-regulated the expression of phosphorylated p53 protein in HepG2 cells and induced cell apoptosis via MAPK and Akt pathways. These results emphasized the potential of PCPTs as lead compounds for developing anti-cancer drugs.