Vicenin-2 acts as a radiosensitizer of the non-small cell lung cancer by lowering Akt expression

Significance of flavonoids targeting PI3K/Akt/HIF-1α signaling pathway in therapy-resistant cancer cells - A potential contribution to the predictive, preventive, and personalized medicine

BACKGROUND

Cancer management faces multiple obstacles, including resistance to current therapeutic approaches. In the face of challenging microenvironments, cancer cells adapt metabolically to maintain their supply of energy and precursor molecules for biosynthesis and thus sustain rapid proliferation and tumor growth. Among the various metabolic adaptations observed in cancer cells, the altered glucose metabolism is the most widely studied. The aberrant glycolytic modification in cancer cells has been associated with rapid cell division, tumor growth, cancer progression, and drug resistance. The higher rates of glycolysis in cancer cells, as a hallmark of cancer progression, is modulated by the transcription factor hypoxia inducible factor 1 alpha (HIF-1α), a downstream target of the PI3K/Akt signaling, the most deregulated pathway in cancer.

AIM OF REVIEW

We provide a detailed overview of current, primarily experimental, evidence on the potential effectiveness of flavonoids to combat aberrant glycolysis-induced resistance of cancer cells to conventional and targeted therapies. The manuscript focuses primarily on flavonoids reducing cancer resistance via affecting PI3K/Akt, HIF-1α (as the transcription factor critical for glucose metabolism of cancer cells that is regulated by PI3K/Akt pathway), and key glycolytic mediators downstream of PI3K/Akt/HIF-1α signaling (glucose transporters and key glycolytic enzymes).

KEY SCIENTIFIC CONCEPTS OF REVIEW

The working hypothesis of the manuscript proposes HIF-1α - the transcription factor critical for glucose metabolism of cancer cells regulated by PI3K/Akt pathway as an attractive target for application of flavonoids to mitigate cancer resistance. Phytochemicals represent a source of promising substances for cancer management applicable to primary, secondary, and tertiary care. However, accurate patient stratification and individualized patient profiling represent crucial steps in the paradigm shift from reactive to predictive, preventive, and personalized medicine (PPPM / 3PM). The article is focused on targeting molecular patterns by natural substances and provides evidence-based recommendations for the 3PM relevant implementation.

Antinociceptive Effect of Dendrobii caulis in Paclitaxel-Induced Neuropathic Pain in Mice

Paclitaxel-induced neuropathic pain (PINP) is a serious adverse effect of chemotherapy. Dendrobii caulis (D. caulis) is a new food source used as herbal medicine in east Asia. We examined the antinociceptive effects of D. caulis extract on PINP and clarified the mechanism of action of transient receptor potential vanilloid 1 receptor (TRPV1) in the spinal cord. PINP was induced in male mice using multiple intraperitoneal injections of paclitaxel (total dose, 8 mg/kg). PINP was maintained from D10 to D21 when assessed for cold and mechanical allodynia. Oral administration of 300 and 500 mg/kg D. caulis relieved cold and mechanical allodynia. In addition, TRPV1 in the paclitaxel group showed increased gene and protein expression, whereas the D. caulis 300 and 500 mg/kg groups showed a significant decrease. Among various substances in D. caulis, vicenin-2 was quantified by high-performance liquid chromatography, and its administration (10 mg/kg, i.p.) showed antinociceptive effects similar to those of D. caulis 500 mg/kg. Administration of the TRPV1 antagonist capsazepine also showed antinociceptive effects similar to those of D. caulis, and D. caulis is thought to exhibit antinociceptive effects on PINP by modulating the spinal TRPV1.

Different RONS Generation in MTC-SK and NSCL Cells Lead to Varying Antitumoral Effects of Alpha-Ketoglutarate + 5-HMF

BACKGROUND

Carbonylated proteins (CPs) serve as specific indicators of increased reactive oxygen and nitrogen species (RONS) production in cancer cells, attributed to the dysregulated mitochondrial energy metabolism known as the Warburg effect. The aim of this study was to investigate the potential of alpha-ketoglutarate (aKG), 5-hydroxymethylfurfural (5-HMF), and their combination as mitochondrial-targeting antioxidants in MTC-SK or NCI-H23 cancer cells.

METHODS

MTC-SK and NCI-H23 cells were cultured in the absence or presence of varying concentrations (0-500 µg/mL) of aKG, 5-HMF, and the combined aKG + 5-HMF solutions. After 0, 24, 48, and 72 h, mitochondrial activity, cancer cell membrane CP levels, cell growth, and caspase-3 activity were assessed in aliquots of MTC-SK and NCI-H23 cells.

RESULTS

The mitochondrial activity of MTC-SK cells exhibited a concentration- and time-dependent reduction upon treatment with aKG, 5-HMF, or the combined aKG + 5-HMF. The half-maximal inhibitory concentration (IC50%) for mitochondrial activity was achieved at 500 µg/mL aKG, 200 µg/mL 5-HMF, and 200 µg/mL aKG + 66.7 µg/mL 5-HMF after 72 h. In contrast, NCI-H23 cells showed a minimal reduction (10%) in mitochondrial activity even at the highest combined concentration of aKG + 5-HMF. The CP levels in MTC-SK cells were measured at 8.7 nmol/mg protein, while NCI-H23 cells exhibited CP levels of 1.4 nmol/mg protein. The combination of aKG + 5-HMF led to a decrease in CP levels specifically in MTC-SK cells. The correlation between mitochondrial activity and CP levels in the presence of different concentrations of combined aKG + 5-HMF in MTC-SK cells demonstrated a linear and concentration-dependent decline in CP levels and mitochondrial activity. Conversely, the effect was less pronounced in NCI-H23 cells. Cell growth of MTC-CK cells was reduced to 60% after 48 h and maintained at 50% after 72 h incubation when treated with 500 µg/mL aKG (IC50%). Addition of 500 µg/mL 5-HMF inhibited cell growth completely regardless of the incubation time. The IC50% for 5-HMF on MTC-CK cell growth was calculated at 375 µg/mL after 24 h incubation and 200 µg/mL 5-HMF after 72 h. MTC-SK cells treated with 500 µg/mL aKG + 167 µg/mL 5-HMF showed no cell growth. The calculated IC50% for the combined substances was 250 µg/mL aKG + 83.3 µg/mL 5-HMF (48 h incubation) and 200 µg/mL aKG + 66.7 µg/mL 5-HMF (72 h incubation). None of the tested concentrations of aKG, 5-HMF, or the combined solution had any effect on NCI-H23 cell growth at any incubation time. Caspase-3 activity increased to 21% in MTC-CK cells in the presence of 500 µg/mL aKG, while an increase to 59.6% was observed using 500 µg/mL 5-HMF. The combination of 500 µg/mL aKG + 167.7 µg/mL 5-HMF resulted in a caspase-3 activity of 55.2%. No caspase-3 activation was observed in NCI-H23 cells when treated with aKG, 5-HMF, or the combined solutions.

CONCLUSION

CPs may serve as potential markers for distinguishing between cancer cells regulated by RONS. The combination of aKG + 5-HMF showed induced cell death in high-RONS-generating cancer cells compared to low-RONS-generating cancer cells.

Bioactive PI3-kinase/Akt/mTOR Inhibitors in Targeted Lung Cancer Therapy

One of the central signaling pathways with a regulatory effect on cell proliferation and survival is Akt/mTOR. In many human cancer types, for instance, lung cancer, the overexpression of Akt/mTOR has been reported. For this reason, either targeting cancer cells by synthetic or natural products affecting the Akt/mTOR pathway down-regulation is a useful strategy in cancer therapy. Direct inhibition of the signaling pathway or modulation of each related molecule could have significant feedback on the growth and proliferation of cancer cells. A variety of secondary metabolites has been identified to directly inhibit the AKT/mTOR signaling, which is important in the field of drug discovery. Naturally occurring nitrogenous and phenolic compounds can emerge as two pivotal classes of natural products possessing anticancer abilities. Herein, we have summarized the alkaloids and flavonoids for lung cancer treatment together with all the possible mechanisms of action relying on the Akt/mTOR pathway down-regulation. This review suggested that in search of new drugs, phytochemicals could be considered as promising scaffolds to be developed into efficient drugs for the treatment of cancer. In this review, the terms "Akt/mTOR", "Alkaloid", "flavonoid", and "lung cancer" were searched without any limitation in search criteria in Scopus, PubMed, Web of Science, and Google scholar engines.

Network pharmacology and experimental validation to explore the potential mechanism of Sanjie Zhentong Capsule in endometriosis treatment

PURPOSE

Sanjie Zhentong Capsule (SZC) is gradually becoming widely used in the treatment of endometriosis (EMs) and has demonstrated an excellent curative effect in the clinic. However, the active components and mechanisms of Sanjie Zhentong Capsule (SZC) in the treatment of endometriosis (EMs) remain unclear, and further research is needed to explore the effects of Sanjie Zhentong Capsule (SZC).

MATERIALS AND METHODS

First, a drug target database of Sanjie Zhentong capsule (SZC) was established by consulting the TCMSP database and related literature. An endometriosis (EMs) disease target database was then established by consulting the GeneCards, OMIM and Drug Bank databases. The overlapping genes of SZC and EMs were determined, and protein-protein interactions (PPIs), gene ontology (GO) and Kyoto Gene and Genome Encyclopedia (KEGG) analyses were performed to predict the potential therapeutic mechanisms. Molecular docking was used to observe whether the key active ingredients and targets predicted by network pharmacology had good binding energy. Finally, in vitro experiments such as CCK-8, flow cytometry and RT-PCR assays were carried out to preliminarily verify the potential mechanisms.

RESULTS

Through the construction of a pharmacological network, we identified a total of 28 active components in SZC and 52 potential therapeutic targets. According to GO and KEGG enrichment analyses, the effects of SZC treatment may be related to oxidative stress, steroid metabolism, apoptosis and proliferation. We also experimentally confirmed that SZC can regulate the expression of steroid hormone biosynthesis-related genes, inhibit ectopic endometrial stromal cell (EESC) proliferation and oxidative stress, and promote apoptosis.

CONCLUSION

This study explored the potential mechanism of SZC in the treatment of EMs through network pharmacology and experiments, providing a basis for further future research on SZC in the treatment of EMs.

Systemic and Anticancer Potential of Adaptogenic Constituents Isolated from Traditional Herbs - A Mini-Review

Adaptogens were initially recognized as stress-resistance inducing compounds. Recent studies reveal that adaptogens are pleiotropically-acting chemical constituents that can be isolated from traditional herbs. They are gaining increasing attention in cancer chemotherapy. This review summarizes the physiological action of adaptogens isolated from the 9 most widely used traditional herbs implicated in cancer therapy viz., Withania somnifera, Tinospora cordifolia, Rhodiola rosea, Emblica officinalis, Glycyrrhiza glabra, Bacopa monnieri, Asparagus racemosus, Ocimum sanctum, and Panax notoginseng. The studies were identified through a systematic search of major computerized databases such as Pubmed, Embase, Medline, Inflibnet, Google Scholar, and Cochrane Library. Individual names of each herb and biological action were the search terms employed. In this review, we have enlisted the chemical constituents and their mechanism of action in a few organ systems as well as in cancer cells. Studies indicate that the adaptogens isolated from these herbs can be broadly arranged into 2 classes based on their chemical structure. These molecules exert a positive influence on several organ systems such as respiratory, nervous, cardiovascular, immune, and gastrointestinal tract. It is also clear that adaptogens act as effective chemopreventive agents alone or in combination with chemo drugs in multiple cancers by targeting multiple intracellular target proteins. Therefore, we conclude that adaptogens are versatile ligands capable of eliciting many systemic effects. Their biological functions are complex, varied, and context-dependent in various cancers. This offers great scope for personalized treatment and cancer chemoprevention in the future.

Molecular Docking Analysis of Flavonoid Compounds with Matrix Metalloproteinase- 8 for the Identification of Potential Effective Inhibitors

Background:

Matrix metalloproteinase-8 (MMP-8) participates in the degradation of different types of collagens in the extracellular matrix and basement membrane. Up-regulation of the MMP-8 has been demonstrated in many disorders including cancer development, tooth caries, periodontal/ peri-implant soft and hard tissue degeneration, and acute/chronic inflammation. Therefore, MMP-8 has become an encouraging target for therapeutic procedures for scientists. We carried out a molecular docking approach to study the binding affinity of 29 flavonoids, as drug candidates, with the MMP-8. Pharmacokinetic and toxicological properties of the compounds were also studied. Moreover, it was attempted to identify the most important amino acids participating in ligand binding based on the degree of each of the amino acids in the ligand-amino acid interaction network for MMP-8.

Methods:

Three-dimensional structure of the protein was gained from the RCSB database (PDB ID: 4QKZ). AutoDock version 4.0 and Cytoscape 3.7.2 were used for molecular docking and network analysis, respectively. Notably, the inhibitor of the protein in the crystalline structure of the 4QKZ was considered as a control test. Pharmacokinetic and toxicological features of compounds were predicted using bioinformatics web tools. Post-docking analyses were performed using BIOVIA Discovery Studio Visualizer version 19.1.0.18287.

Results and Discussions:

According to results, 24 of the studied compounds were considered to be top potential inhibitors for MMP-8 based on their salient estimated free energy of binding and inhibition constant as compared with the control test: Apigenin-7-glucoside, nicotiflorin, luteolin, glabridin, taxifolin, apigenin, licochalcone A, quercetin, isorhamnetin, myricetin, herbacetin, kaemferol, epicatechin, chrysin, amentoflavone, rutin, orientin, epiafzelechin, quercetin-3- rhamnoside, formononetin, isoliquiritigenin, vitexin, catechine, and isoquercitrin. Moreover, His- 197 was found to be the most important amino acid involved in the ligand binding for the enzyme.

Conclusion:

The results of the current study could be used in the prevention and therapeutic procedures of a number of disorders such as cancer progression and invasion, oral diseases, and acute/chronic inflammation. Although, in vitro and in vivo tests are inevitable in the future.

The interplay of ROS and the PI3K/Akt pathway in autophagy regulation

Autophagy causes the breakdown of damaged proteins and organelles to their constituent components. The phosphatidylinositol 3-kinase (PI3K) pathway played an important role in regulating the autophagic response of cells in response to changing reactive oxygen species (ROS) levels. The PI3K α catalytic subunit inhibits autophagy, while its β catalytic subunit promotes autophagy in response to changes in ROS levels. The downstream Akt protein acts against autophagy initiation in response to increases in ROS levels under nutrient-rich conditions. Akt acts by activating a mechanistic target of the rapamycin complex 1 (mTORC1) and by arresting autophagic gene expression. The AMP-activated protein kinase (AMPK) protein counteracts the Akt actions. mTORC1 and mTORC2 inhibit autophagy under moderate ROS levels, but under high ROS levels, mTORC2 can promote cellular senescence via autophagy. Phosphatase and tensin homolog (PTEN) protein are the negative regulators of the PI3K pathway, and it has proautophagic activities. Studies conducted on cells treated with flavonoids and ionizing radiation showed that the moderate increase in ROS levels in the flavonoid-treated groups corresponded with higher PTEN levels and lowered Akt levels leading to a higher occurrence of autophagy. In contrast, higher ROS levels evoked by ionizing radiation caused a lowering of the incidence of autophagy.

Detection of flavone C-glycosides in the extracts from the bark of Prunus avium L. and Prunus cerasus L

The extracts from the bark of Prunus avium and Prunus cerasus have been analyzed by using high pressure liquid chromatography/electrospray ionization mass spectrometry. For the first time in the bark of Prunus species flavonoid C-glycosides have been detected. On the basis of the characteristic fragmentation patterns of their [M-H]^- and [M + H]⁺ ions, three flavonoid C-glycosides have been identified, namely apigenin-6,8-di-C-glucoside (vicenin-2), apigenin-6-C-glucoside (isovitexin) and chrysin-8-C-glucoside. Taking into account the widely studied biological activities of flavonoid C-glycosides, the barks of these common fruit trees seem to be interesting materials of potential medical or cosmetic application.

Structure Identification of ViceninII Extracted from Dendrobium officinale and the Reversal of TGF-β1-Induced Epithelial⁻Mesenchymal Transition in Lung Adenocarcinoma Cells through TGF-β/Smad and PI3K/Akt/mTOR Signaling Pathways

ViceninII is a naturally flavonoid glycoside extracted from Dendrobium officinale, a precious Chinese traditional herb, has been proven to be valuable for cancer treatment. Transforming growth factor-β1 (TGF-β1), promotes the induction of epithelial–mesenchymal transition (EMT), a process involved in the metastasis of cells that leads to enhanced migration and invasion. However, there is no previously evidence that ViceninII has an inhibitory effect on cancer metastasis, specifically on the TGF-β1-induced EMT process in lung adenocarcinoma cells. In this experiment, we used UV, ESIMS, and NMR to identify the structure of ViceninII.A549 and H1299 cells were treated with TGF-β1 in the absence and presence of ViceninII, and subsequent migration and invasion were measured by wound-healing and transwell assays. The protein localization and expressions were detected by immunofluorescence and Western blotting. The results indicated that TGF-β1 induced spindle-shaped changes, increased migration and invasion, and upregulated or downregulated the relative expression of EMT biomarkers. Meanwhile, these alterations were significantly inhibited when co-treated with ViceninII and inhibitors LY294002 and SB431542. In conclusion, ViceninII inhibited TGF-β1-induced EMT via the deactivation of TGF-β/Smad and PI3K/Akt/mTOR signaling pathways.This is the first time that the anti-metastatic effects of ViceninII have been demonstrated, and their molecular mechanisms provided.