Kaempferol inhibits the growth and metastasis of cholangiocarcinoma in vitro and in vivo

Mechanistic Insight into the Autophagic and Apoptotic Activity of Kaempferol on Liver Cancer Cells

Background

The accumulation of poorly folded protein in the endoplasmic reticulum (ER) promotes ER stress and contributes to the pathogenesis of hepatocellular carcinoma (HCC). Current therapies have various adverse effects, therefore, laying the need for an alternative approach. Kaempferol (KP), a naturally occurring flavonoid, possesses potent anti-proliferative properties against various cancer cells. Nevertheless, its involvement in HCC remains relatively unexplored, particularly regarding its influence on apoptosis and autophagy pathways.

Methods

The effect of KP on cell viability, and motility of Hep3B cells was evaluated by MTT, and scratch assay, respectively. Hoechst staining and FACS analysis were done to check the effect of KP on apoptosis and cell cycle progression. qRTPCR was used to evaluate the expression of several apoptosis and autophagy-related genes. KP was docked with several ER stress-related proteins involved in HCC to gain further insights into molecular mechanisms. The results of docking studies were validated with MD simulation and in vitro studies.

Results

Treatment with KP at different time intervals showed dose- and time-dependent growth inhibition of liver cancer cells. KP decreased motility and arrested the cell cycle at the G0/G1 phase in Hep3B cells. Additionally, in the context of HCC, the relationship between KP, apoptosis, and autophagy is significant. It induced apoptosis and autophagy in Hep3B cells by downregulating the expression of Bcl-2 and upregulated Bax and Bid, Caspase-3, Beclin-1, and LC3. KP showed a better binding affinity with Nrf2, PERK, and IRE1α among all selected proteins. Further, it reversed the protective effect of 4-PBA (ER Stress inhibitor) by inducing apoptosis and autophagy in Hep3B cells.

Conclusion

The study suggested KP as a potential chemopreventive agent for managing HCC by effectively inducing apoptosis and autophagy in Hep3B cells.

Kaempferol efficacy in metabolic diseases: Molecular mechanisms of action in diabetes mellitus, obesity, non-alcoholic fatty liver disease, steatohepatitis, and atherosclerosis

The incidence of metabolic diseases has progressively increased, which has a negative impact on human health and life safety globally. Due to the good efficacy and limited side effects, there is growing interest in developing effective drugs to treat metabolic diseases from natural compounds. Kaempferol (KMP), an important flavonoid, exists in many vegetables, fruits, and traditional medicinal plants. Recently, KMP has received widespread attention worldwide due to its good potential in the treatment of metabolic diseases. To promote the basic research and clinical application of KMP, this review provides a timely and comprehensive summary of the pharmacological advances of KMP in the treatment of four metabolic diseases and its potential molecular mechanisms of action, including diabetes mellitus, obesity, non-alcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH), and atherosclerosis. According to the research, KMP shows remarkable therapeutic effects on metabolic diseases by regulating multiple signaling transduction pathways such as NF-κB, Nrf2, AMPK, PI3K/AKT, TLR4, and ER stress. In addition, the most recent literature on KMP's natural source, pharmacokinetics studies, as well as toxicity and safety are also discussed in this review, thus providing a foundation and evidence for further studies to develop novel and effective drugs from natural compounds. Collectively, our manuscript strongly suggested that KMP could be a promising candidate for the treatment of metabolic diseases.

Unveiling the power of flavonoids: A dynamic exploration of their impact on cancer through matrix metalloproteinases regulation

Cancer stands as a significant contributor to global mortality rates, primarily driven by its progression and widespread dissemination. Despite notable strides in cancer therapy, the efficacy of current treatment strategies is compromised due to their inherent toxicity and the emergence of chemoresistance. Consequently, there is a critical need to evaluate alternative therapeutic approaches, with natural compounds emerging as promising candidates, showcasing demonstrated anticancer capabilities in various research models. This review manuscript presents a comprehensive examination of the regulatory mechanisms governing the expression of matrix metalloproteinases (MMPs) and delves into the potential therapeutic role of flavonoids as agents exhibiting specific anticancer activity against MMPs. The primary aim of this study is to elucidate the diverse functions associated with MMP production in cancer and to investigate the potential of flavonoids in modulating MMP expression to inhibit metastasis.

Phytochemical analysis and anticancer effect of Camellia oleifera bud ethanol extract in non-small cell lung cancer A549 cells

Camellia oleifera is a medicine food homology plant widely cultivated in the Yangtze River Basin and southern China due to its camellia oil. Camellia oleifera bud and fruit exist simultaneously, and its bud is largely discarded as waste. However, C. oleifera bud has been used in traditional Chinese medicine to treat a variety of ailments. Thus, the purpose of this study was to identify the chemical components of C. oleifera bud ethanol extract (EE) and first evaluate its anticancer effects in non-small cell lung cancer A549 cells. Based on UHPLC-Q-Orbitrap-MS analysis, seventy components were identified. For anticancer activity, C. oleifera bud EE had remarkable cytotoxic effect on non-small cell lung cancer A549 (IC50: 57.53 ± 1.54 μg/mL) and NCI-H1299 (IC50: 131.67 ± 4.32 μg/mL) cells, while showed lower cytotoxicity on non-cancerous MRC-5 (IC50 > 320 μg/mL) and L929 (IC50: 179.84 ± 1.08 μg/mL) cells. It dramatically inhibited the proliferation of A549 cells by inducing cell cycle arrest at the G1 phase. Additionally, it induced apoptosis in A549 cells through a mitochondria-mediated pathway, which decreased mitochondrial membrane potential, upregulated Bax, activated caspase 9 and caspase 3, and resulted in PARP cleavage. Wound healing and transwell invasion assays demonstrated that C. oleifera bud EE inhibited the migration and invasion of A549 cells in a dose-dependent manner. The above findings indicated that C. oleifera bud EE revealed notable anticancer effects by inhibiting proliferation, inducing apoptosis, and suppressing migration and invasion of A549 cells. Hence, C. oleifera bud ethanol extract could serve as a new source of natural anticancer drugs.

Potential mechanisms underlying inhibition of xenograft lung cancer models by kaempferol: modulation of gut microbiota in activating immune cell function

Context: As a flavonoid compound, kaempferol has great potential in anti-lung cancer therapy, but the mechanism of its therapeutic effect needs further exploration. Objective: To explore the therapeutic effect of kaempferol on lung cancer, as well as its capability to regulate the gut microbiota and stimulate immune function. Materials & methods: Twenty-four BALB/c mice were divided into four groups. The first two groups, consisting of 12 normal mice, were administered either PBS or Kaempferol (Kaem) via gavage. The remaining 12 mice, which were subcutaneously inoculated with Lewis Lung Carcinoma (LLC) cells, were similarly divided and subjected to the same treatments respectively. The inhibitory effect of kaempferol on xenograft lung cancer models was explored with in vivo experiments, the diversity of gut microbiota was investigated by 16S rDNA sequencing, and the treatment effect on immune cells was quantified using flow cytometry. Results: Kaempferol exerted a significant inhibitory effect on xenograft lung cancer models in vivo. It effectively inhibited the proliferation of LLC cells and significantly activated cytotoxic T cells, natural killer cells, and other immune cells in mice. 16S rRNA sequencing of fecal samples from tumor-bearing mice treated with kaempferol showed a significant increase in the abundances of potentially advantageous microbial species such as c_Bacilli, o_Lactobacillales, f_Lachnospiraceae, s_uncultured_bacterium_g_Lactobacillus, g_Lactobacillus, f_Bacteroidaceae, g_Bacteroides, and s_uncultured_bacterium_g_Bacteroides, s_Bacteroides_acidifaciens. An increase in the proportions of three types of immune cells might associated with the above dominant bacterial species. Conclusion: Kaempferol can inhibit xenograft lung cancer models. Such inhibition effect might come from the activation of T cells, NK cells, and other immune cells which are modulated by the gut microbiota.

Kaempferol induces apoptosis through the MAPK pathway and regulates JNK-mediated autophagy in MC-3 cells

This study sought to determine the anticancer effect of kaempferol, a glycone-type flavonoid glycoside with various pharmacological benefits, on human oral cancer MC-3 cells. In vitro studies comprised a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, annexin V and propidium iodide staining, western blotting analysis, and acridine orange staining, while the in vivo studies entailed a xenograft model, hematoxylin and eosin staining, and TdT-mediated dUTP-biotin nick end labelling. In vitro, kaempferol reduced the rate of survival of MC-3 cells, mediated intrinsic apoptosis, increased the number of acidic vesicular organelles, and altered the expression of autophagy-related proteins. Further, treatment with the autophagy inhibitors revealed that the induced autophagy had a cytoprotective effect on apoptosis in kaempferol-treated MC-3 cells. Kaempferol also decreased the expression of phosphorylated extracellular signal-regulated kinase and increased that of phosphorylated c-Jun N-terminal kinase (p-JNK) and phosphorylated p38 kinase in MC-3 cells, suggesting the occurrence of mitogen-activated protein kinase-mediated apoptosis and JNK-mediated autophagy. In vivo, kaempferol reduced tumor growth inducing apoptosis and autophagy. These results showed that kaempferol has the potential use as an adjunctive agent in treating oral cancer.

Bioactive compounds from Actinidia arguta fruit as a new strategy to fight glioblastoma

In recent years, there has been a significant demand for natural products as a mean of disease prevention or as an alternative to conventional medications. The driving force for this change is the growing recognition of the abundant presence of valuable bioactive compounds in natural products. On recent years Actinia arguta fruit, also known as kiwiberry, has attracted a lot of attention from scientific community due to its richness in bioactive compounds, including phenolic compounds, organic acids, vitamins, carotenoids and fiber. These bioactive compounds contribute to the fruit's diverse outstanding biological activities such as antioxidant, anti-inflammatory, neuroprotective, immunomodulatory, and anti-cancer properties. Due to these properties, the fruit may have the potential to be used in the treatment/prevention of various types of cancer, including glioblastoma. Glioblastoma is the most aggressive form of brain cancer, displaying 90 % of recurrence rate within a span of 2 years. Despite the employment of an aggressive approach, the prognosis remains unfavorable, emphasizing the urgent requirement for the development of new effective treatments. The preclinical evidence suggests that kiwiberry has potential impact on glioblastoma by reducing the cancer self-renewal, modulating the signaling pathways involved in the regulation of the cell phenotype and metabolism, and influencing the consolidation of the tumor microenvironment. Even though, challenges such as the imprecise composition and concentration of bioactive compounds, and its low bioavailability after oral administration may be drawbacks to the development of kiwiberry-based treatments, being urgent to ensure the safety and efficacy of kiwiberry for the prevention and treatment of glioblastoma. This review aims to highlight the potential impact of A. arguta bioactive compounds on glioblastoma, providing novel insights into their applicability as complementary or alternative therapies.

Flavonoids as promising anticancer therapeutics: Contemporary research, nanoantioxidant potential, and future scope

Flavonoids are natural polyphenolic compounds considered safe, pleiotropic, and readily available molecules. It is widely distributed in various food products such as fruits and vegetables and beverages such as green tea, wine, and coca-based products. Many studies have reported the anticancer potential of flavonoids against different types of cancers, including solid tumors. The chemopreventive effect of flavonoids is attributed to various mechanisms, including modulation of autophagy, induction of cell cycle arrest, apoptosis, and antioxidant defense. Despite of significant anticancer activity of flavonoids, their clinical translation is limited due to their poor biopharmaceutical attributes (such as low aqueous solubility, limited permeability across the biological membranes (intestinal and blood-brain barrier), and stability issue in biological systems). A nanoparticulate system is an approach that is widely utilized to improve the biopharmaceutical performance and therapeutic efficacy of phytopharmaceuticals. The present review discusses the significant anticancer potential of promising flavonoids in different cancers and the utilization of nanoparticulate systems to improve their nanoantioxidant activity further to enhance the anticancer activity of loaded promising flavonoids. Although, various plant-derived secondary metabolites including flavonoids have been recommended for treating cancer, further vigilant research is warranted to prove their translational values.

Effects and Mechanisms of Kaempferol in the Management of Cancers through Modulation of Inflammation and Signal Transduction Pathways

Cancer is the principal cause of death and its incidence is increasing continuously worldwide. Various treatment approaches are in practice to treat cancer, but these treatment strategies may be associated with severe side effects and also produce drug resistance. However, natural compounds have established their role in cancer management with minimal side effects. In this vista, kaempferol, a natural polyphenol, mainly found in vegetables and fruits, has been revealed to have many health-promoting effects. Besides its health-promoting potential, its anti-cancer potential has also been described in in vivo as well as in in vitro studies. The anti-cancer potential of kaempferol has been proven through modulation of cell signaling pathways in addition to the induction of apoptosis and cell cycle arrest in cancer cells. It leads to the activation of tumor suppressor genes, inhibition of angiogenesis, PI3K/AKT pathways, STAT3, transcription factor AP-1, Nrf2 and other cell signaling molecules. Poor bioavailability of this compound is one of the major limitations for its proper and effective disease management actions. Recently, some novel nanoparticle-based formulations have been used to overcome these limitations. The aim of this review is to provide a clear picture regarding the mechanism of action of kaempferol in different cancers through the modulation of cell signaling molecules. Besides this, strategies to improve the efficacy and synergistic effects of this compound have also been described. However, more studies are needed based on clinical trials to fully explore the therapeutic role of this compound, especially in cancer treatment.

Exploring the Remarkable Chemotherapeutic Potential of Polyphenolic Antioxidants in Battling Various Forms of Cancer

Plant-derived compounds, specifically antioxidants, have played an important role in scavenging the free radicals present under diseased conditions. The persistent generation of free radicals in the body leads to inflammation and can result in even more severe diseases such as cancer. Notably, the antioxidant potential of various plant-derived compounds prevents and deregulates the formation of radicals by initiating their decomposition. There is a vast literature demonstrating antioxidant compounds' anti-inflammatory, anti-diabetic, and anti-cancer potential. This review describes the molecular mechanism of various flavonoids, such as quercetin, kaempferol, naringenin, epicatechin, and epicatechin gallate, against different cancers. Additionally, the pharmaceutical application of these flavonoids against different cancers using nanotechnologies such as polymeric, lipid-based nanoparticles (solid-lipid and liquid-lipid), liposomes, and metallic nanocarriers is addressed. Finally, combination therapies in which these flavonoids are employed along with other anti-cancer agents are described, indicating the effective therapies for the management of various malignancies.

Junctional adhesion molecule-like protein as a novel target for kaempferol to ameliorate lung adenocarcinoma

OBJECTIVE

Although there have been improvements in targeted therapy and immunotherapy, the majority of lung adenocarcinoma (LUAD) patients still lack effective therapies. Consequently, it is urgent to screen for new diagnosis biomarkers and pharmacological targets. Junctional adhesion molecule-like protein (JAML) was considered to be an oncogenic protein and may be a novel therapeutic target in LUAD. Kaempferol is a natural flavonoid that exhibits antitumor activities in LUAD. However, the effect of kaempferol on JAML is still unknown.

METHODS

Small interfering RNA was used to knockdown JAML expression. The cell viability was determined using the cell counting kit-8 assay. The proliferation of LUAD cells was evaluated using the 5-ethynyl-2'-deoxyuridine incorporation assay. The migration and invasion of LUAD cells were evaluated by transwell assays. Molecular mechanisms were explored by Western blotting.

RESULTS

JAML knockdown suppressed proliferation, migration and invasion of LUAD cells, and JAML deficiency restrained epithelial-mesenchymal transition (EMT) via inactivating the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway. Using a PI3K activator (740Y-P), rescue experiments showed that phenotypes to JAML knockdown in LUAD cells were dependent on the PI3K/AKT/mTOR pathway. Kaempferol also inhibited proliferation, migration and invasion of A549 and H1299 cells and partially suppressed EMT through the PI3K/AKT/mTOR pathway. Knockdown of JAML ameliorated the inhibitory effect of kaempferol on LUAD cells. Kaempferol exerted anticancer effects by targeting JAML.

CONCLUSION

JAML is a novel target for kaempferol against LUAD cells. Please cite this article as: Wu Q, Wang YB, Che XW, Wang H, Wang W. Junctional adhesion molecule-like protein as a novel target for kaempferol to ameliorate lung adenocarcinoma. J Integr Med. 2023; Epub ahead of print.

Therapeutic Importance of Kaempferol in the Treatment of Cancer through the Modulation of Cell Signalling Pathways

Plant-derived flavonoids are considered natural nontoxic chemo-preventers and have been widely studied for cancer treatment in recent decades. Mostly all flavonoid compounds show significant anti-inflammatory, anticancer and antioxidant properties. Kaempferol (Kmp) is a well-studied compound and exhibits remarkable anticancer and antioxidant potential. Kmp can regulate various cancer-related processes and activities such as cell cycle, oxidative stress, apoptosis, proliferation, metastasis, and angiogenesis. The anti-cancer properties of Kmp primarily occur via modulation of apoptosis, MAPK/ERK1/2, P13K/Akt/mTOR, vascular endothelial growth factor (VEGF) signalling pathways. The anti-cancer property of Kmp has been recognized in several in-vivo and in-vitro studies which also includes numerous cell lines and animal models. This flavonoid possesses toxic activities against only cancer cells and have restricted toxicity on healthy cells. In this review, we present extensive research investigations about the therapeutic potential of Kmp in the management of different types of cancers. The anti-cancer properties of Kmp are discussed by concentration on its capability to target molecular-signalling pathway such as VEGF, STAT, p53, NF-κB and PI3K-AKT signalling pathways. The anti-cancer property of Kmf has gained a lot of attention, but the accurate action mechanism remains unclear. However, this natural compound has a great pharmacological capability and is now considered to be an alternative cancer treatment.

Exploring the mechanism of Tengli Kangliu Decoction in the prevention and treatment of colorectal cancer precancerous based on network pharmacology

OBJECTIVE

This study aimed to predict the targets and signaling pathways affected by Tengli Kangliu Decoction (TKD) in the treatment of colorectal cancer (CRC) precursor lesions and to determine TKDs mechanism of action based on previous experimental results using network pharmacology techniques and methods.

METHODS

Using the traditional Chinese medicine systems pharmacology database (TCMSP) and UniProt database, the active ingredients and potential targets of TKD were identified. Human colorectal adenoma (CRA) targets were analyzed using the GeneCards database, the Online mendelian inheritance in man (OMIM) database, and the NCBI database. The common targets of drug-disease interactions were input into the String database to construct a protein-protein interaction (PPI) network. These data were then used to construct the network diagram. Gene ontology (GO) function analysis and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis were performed on the target genes. Finally, the component-disease-pathway-target network file was imported into Cytoscape 3.8.0 and used to construct the pathway network diagram.

RESULTS

Compounds with a drug-likeness (DL) score ≥ 0.18 and an oral bioavailability (OB) ≥ 30% were selected as the active constituents of TKD. Two hundred eighty eight chemical constituents were screened and 305 chemical drug targets were predicted. After further screening, 1942 disease-related targets, which are hypothesized to be the main chemical components of TKD, were obtained. When comparing the targets of action and CRA treatment targets, 172 common targets were identified. Using GO enrichment analysis of common targets of drug diseases, 2550 biological processes (BP) were predicted, 164 items of which were related to molecular functioning (MF), and 67 items related to cell composition. KEGG pathway analysis was performed on the common targets of drug diseases, and a total of 178 signaling pathways were enriched.

CONCLUSION

Using network pharmacology research, this study reports on the synergistic effect of the multiple components of TKD on the multi-target, and multiple pathways of colorectal precancerous lesions. These findings lay a theoretical foundation for further colorectal precancerous lesions research.

Unravelling Potential Health-Beneficial Properties of Corema album Phenolic Compounds: A Systematic Review

Corema (C.) album belongs to the family Ericaceae and can be found in the Iberian Peninsula, especially on the coastal areas facing the Atlantic coast. C. album berries have been used for centuries in traditional medicine. Recent studies have revealed that not only the berries but also the leaves have relevant antioxidant, antiproliferative, and anti-inflammatory properties, bringing this plant to the forefront of discussion. A systematic review of the literature was carried out to summarize the phenolic compounds and bioactive properties identified in C. album berries and leaves and to search for research gaps on this topic. The search was conducted in three electronic databases (PubMed, SCOPUS, and Web of Science) using PRISMA methodology. The inclusion criteria were the chemical compositions of the berries, leaves, or their extracts and their bioactive properties. The exclusion criteria were agronomic and archaeological research. The number of studies concerning phenolic compounds' composition and the bioactive properties of C. album berries and leaves is still limited (11 articles). However, the variety of polyphenolic compounds identified make it possible to infer new insights into their putative mechanism of action towards the suppression of NF-kB transcription factor activation, the modulation of inflammatory mediators/enzymes, the induction of apoptosis, the modulation of mitogen activated protein kinase, cell cycle arrest, and the reduction of oxidative stress. These factors can be of major relevance concerning the future use of C. album as nutraceuticals, food supplements, or medicines. Nevertheless, more scientific evidence concerning C. album's bioactivity is required.

Flavonoids as regulators of TIMPs expression in cancer: Consequences, opportunities, and challenges

Cancer is one of the leading causes of death in patients worldwide, where invasion and metastasis are directly responsible for this statement. Although cancer therapy has progressed in recent years, current therapeutic approaches are ineffective due to toxicity and chemoresistance. Therefore, it is essential to evaluate other treatment options, and natural products are a promising alternative as they show antitumor properties in different study models. This review describes the regulation of tissue inhibitors of metalloproteinases (TIMPs) expression and the role of flavonoids as molecules with the antitumor activity that targets TIMPs therapeutically. These inhibitors regulate tissue extracellular matrix (ECM) turnover; they inhibit matrix metalloproteinases (MMPs), cell migration, invasion, and angiogenesis and induce apoptosis in tumor cells. Data obtained in cell lines and in vivo models suggest that flavonoids are chemopreventive and cytotoxic against various types of cancer through several mechanisms. Flavonoids also regulate crucial signaling pathways such as focal adhesion kinase (FAK), phosphatidylinositol-3-kinase (PI3K)-Akt, signal transducer and activator of transcription 3 (STAT3), nuclear factor κB (NFκB), and mitogen-activated protein kinase (MAPK) involved in cancer cell migration, invasion, and metastasis. All these data reposition flavonoids as excellent candidates for use in cancer therapy.

Apoptotic and Anti-metastatic Effects of Atractylodes lancea (Thunb.) DC. in a Hamster Model of Cholangiocarcinoma

OBJECTIVES

Cholangiocarcinoma (CCA) is a highly aggressive tumor with a greater risk of distant metastasis. The promising anti-CCA activity and safety profile of Atractylodes lancea (AL) have previously been reported in a series of in vitro, in vivo and clinical studies. The present study investigated the effect of AL extract on apoptosis and metastasis signaling pathways in the Opisthorchis viverrini/dimethylnitrosamine (OV/DMN)-induced CCA hamster model.

MATERIALS AND METHODS

Hamster liver tissues were obtained from the four groups (n = 5 per group), i.e., (i) 5-FU treated CCA (40 µg/mL); (ii) CCA; (iii) AL-treated CCA (5,000 mg/kg), and (iv) normal hamsters. Total RNA was isolated, and the expression levels of apoptosis-related and metastasis-related genes were determined by qRT-PCR analysis.

RESULTS

The expression levels of p16, caspase-3, caspase-8, caspase-9, Apaf-1, p53 and Eef1a1 were downregulated, while that of the remaining genes were upregulated in CCA hamsters compared with normal hamsters. AL treatment increased the expression of p16, caspase-9, caspase-3, Apaf-1, p53 and E-cadherin and decreased the expression of cyclin D1, cdk4, Bax, Akt/PKB, Bcl-2, Mfge-8, Lass4, S100A6, TGF-β, Smad-2, Smad-3, Smad-4, MMP-9, and N-cadherin. The expression of Eef1a1 was unchanged.

CONCLUSION

The anti-CCA activity of AL in OV/DMN-induced CCA hamsters could be due to the induction of cell cycle arrest at the G1 phase and activation of the apoptosis pathway, resulting in cancer cell death. The activation of the apoptosis pathway mainly involved the intrinsic pathway (activation of caspase-3 and caspase-9 through p53 and Mfge-8 modulation and downregulation of anti-apoptotic genes Akt and Bcl-2). In addition, AL could also inhibit the canonical TGF-β signaling pathway, MMP-9 and N-cadherin to suppress tumor metastasis.

A systematic review of anti-cancer roles and mechanisms of kaempferol as a natural compound

It has been shown in multiple experimental and biological investigations that kaempferol, an edible flavonoid generated from plants, may be used as an anti-cancer drug and has been shown to have anti-cancer properties. Many signaling pathways are altered in cancer cells, resulting in cell growth inhibition and death in various tumor types. Cancer is a multifaceted illness coordinated by multiple external and internal mechanisms. Natural extracts with the fewest side effects have piqued the attention of researchers in recent years, attempting to create cancer medicines based on them. An extensive array of natural product-derived anti-cancer agents have been examined to find a successful method. Numerous fruits and vegetables have high levels of naturally occurring flavonoid kaempferol, and its pharmacological and biological effects have been studied extensively. Certain forms of cancer are sensitive to kaempferol-mediated anti-cancer activity, although complete research is needed. We have endeavored to concentrate our review on controlling carcinogenic pathways by kaempferol in different malignancies. Aside from its extraordinary ability to modify cell processes, we have also discussed how kaempferol has the potential to be an effective therapy for numerous tumors.

Network Pharmacology Analysis, Molecular Docking, and In Vitro Verification Reveal the Action Mechanism of Prunella vulgaris L. in Treating Breast Cancer

Background

Prunella vulgaris L. is effective in the treatment of breast cancer (BRCA); however, the underlying mechanism is still unclear. The aim of this study was to elucidate the mechanism of treatment of BRCA by P. vulgaris using network pharmacology and molecular docking technology, and to verify the experimental results using human BRCA MDA-MB-231 cells.

Methods

Active components and action targets of P. vulgaris were determined using the TCMSP™, SwissTarget Prediction™, and TargetNet™ databases. GeneCards™ and OMIM™ provided BRCA targets. After obtaining common targets, a protein-protein interaction (PPI) network was constructed using the STRING™ database, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were conducted using the Xiantao™ academic database. Cytoscape™ was used to construct "single drug-disease-component-target" and "single drug-disease-component-target-pathway" networks. The Human Protein Atlas™ was used to determine protein expression levels in BRCA cell lines. AutoDock tools™ were used to carry out molecular docking for the first 10 targets of quercetin and the PPI network. Finally, the abovementioned results were verified using cell experiments.

Results

We obtained 11 active components, 198 targets, and 179 common targets, including DUOX2, MET, TOP2A, and ERBB3. The results of KEGG pathway analysis screened 188 related signaling pathways and indicated the potential key role of PI3K-Akt and MAPK signaling pathways in the antibreast cancer process of P. vulgaris. The results of molecular docking showed that the first 10 targets of quercetin interacted well with the protein network. Cell experiments showed that quercetin effectively inhibited the proliferation of MDA-MB-231 cells by regulating apoptosis and cell cycle, which may be partly related to the MAPK signaling pathway.

Conclusion

Synergistic effects of multiple components, targets, and pathways on the anti-BRCA activity of P. vulgaris could provide a theoretical basis for further study on its complex anti-BRCA mechanism.

In Vitro Evaluation of Kaempferol-Loaded Hydrogel as pH-Sensitive Drug Delivery Systems

The purpose of this study was to prepare and evaluate kaempferol-loaded carbopol polymer (acrylic acid) hydrogel, investigate its antioxidant activity in vitro, and compare the effects on drug release under different pH conditions. Drug release studies were conducted in three different pH media (pH 3.4, 5.4, and 7.4). The kaempferol-loaded hydrogel was prepared by using carbopol 934 as the hydrogel matrix. The morphology and viscosity of the preparation were tested to understand the fluidity of the hydrogel. The antioxidant activity of the preparation was studied by scavenging hydrogen peroxide and 2,2-diphenyl-1-picrilhidrazil (DPPH) radicals in vitro and inhibiting the production of malondialdehyde in mouse tissues. The results showed that kaempferol and its preparations had high antioxidant activity. In vitro release studies showed that the drug release at pH 3.4, 5.4, and 7.4 was 27.32 ± 3.49%, 70.89 ± 8.91%, and 87.9 ± 10.13%, respectively. Kaempferol-loaded carbopol hydrogel displayed greater swelling and drug release at higher pH values (pH 7.4).

Advance toward isolation, extraction, metabolism and health benefits of kaempferol, a major dietary flavonoid with future perspectives

As a major ubiquitous secondary metabolite, flavonoids are widely distributed in planta. Among flavonoids, kaempferol is a typical natural flavonol in diets and medicinal plants with myriad bioactivities, such as anti-inflammatory activity, anti-cancer activity, antioxidant activity, and anti-diabetic activity. However, the natural sources, absorption and metabolism as well as the bioactivities of kaempferol have not been reviewed comprehensively and systematically. This review highlights the latest research progress and the effect of kaempferol in the prevention and treatment of various chronic diseases, as well as its protective health effects, and provides a theoretical basis for future research to be used in nutraceuticals. Further, comparison of the different extraction and analytical methods are presented to highlight the most optimum for PG recovery and its detection in plasma and body fluids. Such review aims at improving the value-added applications of this unique dietary bioactive flavonoids at commercial scale and to provide a reference for its needed further development.

Bioassay-Guided Identification of the Antiproliferative Compounds of Cissus trifoliata and the Transcriptomic Effect of Resveratrol in Prostate Cancer Pc3 Cells

The bioassay-guided fractionation of a CHCl₃-MeOH extract from the stems of Cissus trifoliata identified an active fraction against PC3 prostate cancer cells. The treatment for 24 h showed an 80% reduction in cell viability (p ≤ 0.05) by a WST-1 assay at a concentration of 100 μg/mL. The HPLC-QTOF-MS analysis of the fraction showed the presence of coumaric and isoferulic acids, apigenin, kaempferol, chrysoeriol, naringenin, ursolic and betulinic acids, hexadecadienoic and octadecadienoic fatty acids, and the stilbene resveratrol. The exposure of PC3 cells to resveratrol (IC₂₅ = 23 μg/mL) for 24 h induced significant changes in 847 genes (Z-score ≥ ±2). The functional classification tool of the DAVID v6.8 platform indicates that the underlying molecular mechanisms against the proliferation of PC3 cells were associated (p ≤ 0.05) with the process of differentiation and metabolism. These findings provide experimental evidence suggesting the potential of C. trifoliata as a promising natural source of anticancer compounds.

Network pharmacology based research into the effect and mechanism of Yinchenhao Decoction against Cholangiocarcinoma

Background

Cholangiocarcinoma refers to an epithelial cell malignancy with poor prognosis. Yinchenhao decoction (YCHD) showed positive effects on cancers, and associations between YCHD and cholangiocarcinoma remain unclear. This study aimed to screen out the effective active components of Yinchenhao decoction (YCHD) using network pharmacology, estimate their potential targets, screen out the pathways, as well as delve into the potential mechanisms on treating cholangiocarcinoma.

Methods

By the traditional Chinese medicine system pharmacology database and analysis platform (TCMSP) as well as literature review, the major active components and their corresponding targets were estimated and screened out. Using the software Cytoscape 3.6.0, a visual network was established using the active components of YCHD and the targets of cholangiocarcinoma. Based on STRING online database, the protein interaction network of vital targets was built and analyzed. With the Database for Annotation, Visualization, and Integrated Discovery (DAVID) server, the gene ontology (GO) biological processes and the Kyoto encyclopedia of genes and genomes (KEGG) signaling pathways of the targets enrichment were performed. The AutoDock Vina was used to perform molecular docking and calculate the binding affinity. The PyMOL software was utilized to visualize the docking results of active compounds and protein targets. In vivo experiment, the IC₅₀ values and apoptosis rate in PI-A cells were detected using CCK-8 kit and Cell Cycle Detection Kit. The predicted targets were verified by the real-time PCR and western blot methods.

Results

32 effective active components with anti-tumor effects of YCHD were sifted in total, covering 209 targets, 96 of which were associated with cancer. Quercetin, kaempferol, beta-sitosterol, isorhamnetin, and stigmasterol were identified as the vital active compounds, and AKT1, IL6, MAPK1, TP53 as well as VEGFA were considered as the major targets. The molecular docking revealed that these active compounds and targets showed good binding interactions. These 96 putative targets exerted therapeutic effects on cancer by regulating signaling pathways (e.g., hepatitis B, the MAPK signaling pathway, the PI3K-Akt signaling pathway, and MicroRNAs in cancer). Our in vivo experimental results confirmed that YCHD showed therapeutic effects on cholangiocarcinoma by decreasing IC₅₀ values, down-regulating apoptosis rate of cholangiocarcinoma cells, and lowering protein expressions.

Conclusions

As predicted by network pharmacology strategy and validated by the experimental results, YCHD exerts anti-tumor effectsthrough multiple components, targets, and pathways, thereby providing novel ideas and clues for the development of preparations and the treatment of cholangiocarcinoma.

Kaempferol inhibits Nrf2 signalling pathway via downregulation of Nrf2 mRNA and induces apoptosis in NSCLC cells

Chemoprevention failure is considered to be the most emerging problem that makes non-small cell lung cancer (NSCLC) as one of the deadliest malignancies in the world. In NSCLC cells, Nuclear factor erythroid 2-related factor 2 (Nrf2), a redox sensitive transcription factor, promotes cancer cell survival and fosters mechanism for drug resistance. Here we report identification of Kaempferol, a dietary flavonoid, as a potent Nrf2 inhibitor using Nrf2 reporter assay in NSCLC cells (A549 and NCIH460). Kaempferol selectively reduces Nrf2 mRNA and protein levels and lower level of nuclear Nrf2 downregulates transcription of Nrf2 target genes (NQO1, HO1, AKR1C1 and GST). Kaempferol (25 μM) mediated downregulation of GST, NQO1 and HO1 expression is also observed even after stimulation of Nrf2 by tert-butylhydroquinone (tBHQ). Again, Kaempferol incubation does not change the levels of NFκBp65 and phospho NFκBp65, suggesting it hampers Nrf2 signalling pathway in these cells. Nrf2 inhibition by Kaempferol induces ROS accumulation after 48 h of treatment and makes NSCLC cells sensitive to apoptosis at physiological concentration. Taken together, our study demonstrates that Kaempferol is a potent inhibitor of Nrf2 and can be used as a natural sensitizer and anti-cancer agent for lung cancer therapeutics.

Antiangiogenic Activity of Flavonoids: A Systematic Review and Meta-Analysis

Abstract: An imbalance of angiogenesis contributes to many pathologies such as cancer, arthritis and retinopathy, hence molecules that can modulate angiogenesis are of considerable therapeutic importance. Despite many reports on the promising antiangiogenic properties of naturally occurring flavonoids, no flavonoids have progressed to the clinic for this application. This systematic review and meta-analysis therefore evaluates the antiangiogenic activities of a wide range of flavonoids and is presented in two sections. The first part of the study (Systematic overview) included 402 articles identified by searching articles published before May 2020 using ScienceDirect, PubMed and Web of Science databases. From this initial search, different classes of flavonoids with antiangiogenic activities, related pathologies and use of in vitro and/or in/ex vivo angiogenesis assays were identified. In the second part (Meta-analysis), 25 studies concerning the antiangiogenic evaluation of flavonoids using the in vivo chick chorioallantoic membrane (CAM) assay were included, following a targeted search on articles published prior to June 2020. Meta-analysis of 15 out of the 25 eligible studies showed concentration dependent antiangiogenic activity of six compared subclasses of flavonoids with isoflavones, flavonols and flavones being the most active (64 to 80% reduction of blood vessels at 100 µM). Furthermore, the key structural features required for the antiangiogenic activity of flavonoids were derived from the pooled data in a structure activity relationship (SAR) study. All in all, flavonoids are promising candidates for the development of antiangiogenic agents, however further investigations are needed to determine the key structural features responsible for their activity.

Anti-Cancer Potential of Cannabinoids, Terpenes, and Flavonoids Present in Cannabis

In recent years, and even more since its legalization in several jurisdictions, cannabis and the endocannabinoid system have received an increasing amount of interest related to their potential exploitation in clinical settings. Cannabinoids have been suggested and shown to be effective in the treatment of various conditions. In cancer, the endocannabinoid system is altered in numerous types of tumours and can relate to cancer prognosis and disease outcome. Additionally, cannabinoids display anticancer effects in several models by suppressing the proliferation, migration and/or invasion of cancer cells, as well as tumour angiogenesis. However, the therapeutic use of cannabinoids is currently limited to the treatment of symptoms and pain associated with chemotherapy, while their potential use as cytotoxic drugs in chemotherapy still requires validation in patients. Along with cannabinoids, cannabis contains several other compounds that have also been shown to exert anti-tumorigenic actions. The potential anti-cancer effects of cannabinoids, terpenes and flavonoids, present in cannabis, are explored in this literature review.

Natural compounds modulate the crosstalk between apoptosis- and autophagy-regulated signaling pathways: Controlling the uncontrolled expansion of tumor cells

Due to the high number of annual cancer-related deaths, and the economic burden that this malignancy affects today's society, the study of compounds isolated from natural sources should be encouraged. Most cancers are the result of a combined effect of lifestyle, environmental factors, and genetic and hereditary components. Recent literature reveals an increase in the interest for the study of phytochemicals from traditional medicine, this being a valuable resource for modern medicine to identify novel bioactive agents with potential medicinal applications. Phytochemicals are components of traditional medicine that are showing promising application in modern medicine due to their antitumor activities. Recent studies regarding two major mechanisms underlying cancer development and regulation, apoptosis and autophagy, have shown that the signaling pathways of both these processes are significantly interconnected through various mechanisms of crosstalk. Phytochemicals are able to activate pro-autophagic and pro-apoptosis mechanisms. Understanding the molecular mechanism involved in apoptosis-autophagy relationship modulated by phytochemicals plays a key role in development of a new therapeutic strategy for cancer treatment. The purpose of this review is to outline the bioactive properties of the natural phytochemicals with validated antitumor activity, focusing particularly on their role in the regulation of apoptosis and autophagy crosstalk that triggers the uncontrolled expansion of tumor cells. Furthermore, we have also critically discussed the limitations and challenges of existing research strategies and the prospective research directions in this field.

Ethyl acetate extract of Kaempferia parviflora inhibits Helicobacter pylori-associated mammalian cell inflammation by regulating proinflammatory cytokine expression and leukocyte chemotaxis

BACKGROUND

Kaempferia parviflora (KP) has been used in traditional Thai medicine to cure gastrointestinal disorders since ancient times. Helicobacter pylori is an initiating factor in gastric pathogenesis via activation of massive inflammation, the cumulative effect of which leads to gastric disease progression, including gastric carcinogenesis. Accordingly, the effect of a crude ethyl acetate extract of KP (CEAE-KP) on proinflammatory cytokine production and cell chemotaxis was the focus of this study.

METHODS

The cytotoxicity of CEAE-KP (8-128 μg/ml) on AGS (gastric adenocarcinoma) cells was determined at 6, 12 and 24 h using an MTT assay. The effect of CEAE-KP on H. pylori-induced interleukin (IL)-8 production by AGS cells was evaluated by ELISA and RT-PCR. The effect of CEAE-KP on monocyte and neutrophil chemotaxis to H. pylori soluble protein (sHP) and IL-8, respectively, was determined using a Boyden chamber assay with THP-1 or HL-60 cells.

RESULTS

CEAE-KP reduced AGS cell viability in a concentration- and time-dependent manner, but at 8-16 μg/ml, it was not cytotoxic after 6-24 h of exposure. Coculture of AGS cells with CEAE-KP at a noncytotoxic concentration of 16 μg/ml and H. pylori reduced IL-8 secretion by ~ 60% at 12 h, which was consistent with the decreased level of mRNA expression, and inhibited neutrophil chemotaxis to IL-8. sHP (100 ng/ml) induced marked monocyte chemoattraction, and this was decreased by ~ 60% by CEAE-KP.

CONCLUSION

CEAE-KP might serve as a potent alternative medicine to ameliorate the inflammation mediated by H. pylori infection.

Anticancer Effect of Radix Astragali on Cholangiocarcinoma In Vitro and Its Mechanism via Network Pharmacology

Background

This study used network pharmacology method and cell model to assess the effects of Radix Astragali (RA) on cholangiocarcinoma (CCA) and to predict core targets and molecular mechanisms.

Material/Methods

We performed an in vitro study to assess the effect of RA on CCA using CCK8 assay, the Live-Cell Analysis System, and trypan blue staining. The components and targets of RA were analyzed using the Traditional Chinese Medicine Systems Pharmacology database, and genes associated with CCA were retrieved from the GeneCards and OMIM platforms. Protein–protein interactions were analyzed with the STRING platform. The components–targets–disease network was built by Cytoscape. The TIMER database revealed the expression of core targets with diverse immune infiltration levels. GO and KEGG analyses were performed to identify molecular-biology processes and signaling pathways. The predictions were verified by Western blotting.

Results

Concentration-dependent antitumor activity was confirmed in the cholangiocarcinoma QBC939 cell line treated with RA. RA contained 16 active compounds, with quercetin and kaempferol as the core compounds. The most important biotargets for RA in CCA were caspase 3, MAPK8, MYC, EGFR, and PARP. The TIMER database revealed that the expression of caspase3 and MYC was related with diverse immune infiltration levels of CCA. The results of Western blotting showed RA significantly influenced the expression of the 5 targets that network pharmacology predicted.

Conclusions

RA is an active medicinal material that can be developed into a safe and effective multi-targeted anticancer treatment for CCA.

β-Eudesmol induces the expression of apoptosis pathway proteins in cholangiocarcinoma cell lines

Background:

Cholangiocarcinoma (CCA) is a neglected disease prevalent in developing countries with high burden and mortality rate, and there is no effective treatment. We aimed to investigate β-eudesmol molecular target of action in human CCA cell lines using the selected key molecules of apoptotic pathways.

Materials and Methods:

Two CCA cell lines (HuH28 and HuCCT1) were assessed at different time points after β-eudesmol treatment for mRNA and protein expression profiles of caspase-3, -8, -9, p53, p21, Bcl-2, and Bax by real-time polymerase chain reaction and western blot, respectively.

Results:

β-eudesmol induced expressions of p21 and p53 in mRNA/protein level in HuH28 and HuCCT1 cells. These CCA cells also expressed caspase-3, -8, -9 and bax (mRNA and/or protein level) among others after β-eudesmol treatment indicating its role in both intrinsic and extrinsic caspase-dependent apoptotic pathways.

Conclusion:

The study demonstrated that β-eudesmol induced the expression of apoptosis pathway proteins, suggesting its potential role in promoting the caspase-dependent apoptotic pathway, and induction of the cell cycle arrest in CCA cell lines. β-eudesmol can be considered as a potential compound for further investigation as an anti-CCA agent.

Therapeutic effects of kaempferol affecting autophagy and endoplasmic reticulum stress

Regulated cell death (RCD) guarantees to preserve organismal homeostasis. Apoptosis and autophagy are two major arms of RCD, while endoplasmic reticulum (ER) as a crucial organelle involved in proteostasis, promotes cells toward autophagy and apoptosis. Alteration in ER stress and autophagy machinery is responsible for a great number of diseases. Therefore, targeting those pathways appears to be beneficial in the treatment of relevant diseases. Meantime, among the traditional herb medicine, kaempferol as a flavonoid seems to be promising to modulate ER stress and autophagy and exhibits protective effects on malfunctioning cells. There are some reports indicating the capability of kaempferol in affecting autophagy and ER stress. In brief, kaempferol modulates autophagy in noncancerous cells to protect cells against malfunction, while it induces cell mortality derived from autophagy through the elevation of p-AMP-activated protein kinase, light chain-3-II, autophagy-related geness, and Beclin-1 in cancer cells. Noteworthy, kaempferol enhances cell survival through C/EBP homologous protein (CHOP) suppression and GRP78 increment in noncancerous cells, while it enhances cell mortality through the induction of unfolding protein response and CHOP increment in cancer cells. In this review, we discuss how kaempferol modulates autophagy and ER stress in noncancer and cancer cells to expand our knowledge of new pharmacological compounds for the treatment of associated diseases.

Kaempferol promotes bone formation in part via the mTOR signaling pathway

Previous research indicates that kaempferol (Kae) promotes osteogenesis, but its underlying mechanism of action remains unclear. The present study hypothesized that the osteogenic effects of Kae were mediated through mammalian target of rapamycin (mTOR). To validate this hypothesis, bone marrow mesenchymal stem cells (BMSCs) from ovariectomized (OVX) rats were differentiated into osteoblasts. The bone mineral density and bone microarchitecture of the OVX rats was measured in vivo, while osteogenesis was evaluated in vitro via Alizarin Red S staining and alkaline phosphatase activity measurements in cultured BMSCs. The levels of phosphorylated eukaryotic translation initiation factor 4E‑binding protein 1 (p‑4E/BP1) and phosphorylated ribosomal protein S6 kinase B1 (p‑S6K), and the expression of Runt‑related transcription factor 2 and Osterix, were concurrently quantified by western blot analysis. The data suggested that Kae prevented OVX‑induced osteoporosis in rats by promoting osteoblastogenesis. Furthermore, treatment with Kae in rat BMSCs enhanced mineralization, elevated ALP activity, increased the expression levels of Runx‑2 and Osterix and increased the levels of p‑S6K and decreased the levels of p‑4E/BP1 and, consistent with its ability to promote osteoblast differentiation. In contrast, treatment with rapamycin, an mTOR inhibitor, produced the opposite phenotype. Taken together, these data suggested that the protective effects of Kae in BMSCs and in the OVX rat model resulted from the induction of osteogenesis via mTOR signaling, or at least partially via the regulation of downstream effectors of the mTOR pathway.

Kaempferol attenuates imiquimod-induced psoriatic skin inflammation in a mouse model

Psoriasis is an immune-mediated inflammatory skin disease that mainly affects the skin barrier. Treatment for psoriasis mainly includes conventional immunosuppressive drugs. However, long-term treatment with global immunosuppressive agents may cause a variety of side effects, including nephrotoxicity and infections. Kaempferol, a natural flavonol present in various plants, is known to possess potent anti-inflammatory, anti-oxidant and anti-cancerous properties. However, it is unknown whether kaempferol is also anti-psoriatic. Here we established an imiquimod (IMQ)-induced psoriatic mouse model to explore the potential therapeutic effects of kaempferol on psoriatic skin lesions and inflammation. In this study, we demonstrated that treatment with kaempferol protected mice from developing psoriasis-like skin lesions induced by topical administration of IMQ. Kaempferol reduced CD3⁺ T cell infiltration and gene expression of major proinflammatory cytokines, including interleukin (IL)-6, IL-17A and tumor necrosis factor (TNF)-α, in the psoriatic skin lesion. It also down-regulated proinflammatory nuclear factor kappa B (NF-κB) signaling in the skin. The therapeutic effects were associated with a significant increase in CD4⁺ forkhead box protein 3 (FoxP3)⁺ regulatory T cell (T_reg ) frequency in the spleen and lymph nodes as well as FoxP3-positive staining in the skin lesion. Conversely, depletion of CD4⁺ CD25⁺ T_regs reversed the therapeutic effects of kaempferol on the skin lesion. Kaempferol also lowered the percentage of IL-17A⁺ CD4⁺ T cells in the spleen and lymph nodes of IMQ-induced psoriatic mice. Finally, kaempferol suppressed the proliferation of T cells in vitro and their mTOR signaling. Thus, our findings suggest that kaempferol may be a therapeutic drug for treating human psoriasis in the near future.

Recent progress regarding kaempferol for the treatment of various diseases

Kaempferol, also known as kaempferol-3 or kaempferide, is a flavonoid compound that naturally occurs in tea, as well as numerous common vegetables and fruits, including beans, broccoli, cabbage, gooseberries, grapes, kale, strawberries, tomatoes, citrus fruits, brussel sprouts, apples and grapefruit. The present review mainly summarizes the application of kaempferol in treating diseases and the underlying mechanisms that are currently being studied. Due to its anti-inflammatory properties, it may be used to treat numerous acute and chronic inflammation-induced diseases, including intervertebral disc degeneration and colitis, as well as post-menopausal bone loss and acute lung injury. In addition, it has beneficial effects against cancer, liver injury, obesity and diabetes, inhibits vascular endothelial inflammation, protects the cranial nerve and heart function, and may be used for treating fibroproliferative disorders, including hypertrophic scar.

Kaempferol: A Key Emphasis to Its Anticancer Potential

A marked decrease in human cancers, including breast cancer, bone cancer, and cervical cancer, has been linked to the consumption of vegetable and fruit, and the corresponding chemoprotective effect has been associated with the presence of several active molecules, such as kaempferol. Kaempferol is a major flavonoid aglycone found in many natural products, such as beans, bee pollen, broccoli, cabbage, capers, cauliflower, chia seeds, chives, cumin, moringa leaves, endive, fennel, and garlic. Kaempferol displays several pharmacological properties, among them antimicrobial, anti-inflammatory, antioxidant, antitumor, cardioprotective, neuroprotective, and antidiabetic activities, and is being applied in cancer chemotherapy. Specifically, kaempferol-rich food has been linked to a decrease in the risk of developing some types of cancers, including skin, liver, and colon. The mechanisms of action include apoptosis, cell cycle arrest at the G2/M phase, downregulation of epithelial-mesenchymal transition (EMT)-related markers, and phosphoinositide 3-kinase/protein kinase B signaling pathways. In this sense, this article reviews data from experimental studies that investigated the links between kaempferol and kaempferol-rich food intake and cancer prevention. Even though growing evidence supports the use of kaempferol for cancer prevention, further preclinical and clinical investigations using kaempferol or kaempferol-rich foods are of pivotal importance before any public health recommendation or formulation using kaempferol.

Molecular Targets of Genistein and Its Related Flavonoids to Exert Anticancer Effects

Increased health awareness among the public has highlighted the health benefits of dietary supplements including flavonoids. As flavonoids target several critical factors to exert a variety of biological effects, studies to identify their target-specific effects have been conducted. Herein, we discuss the basic structures of flavonoids and their anticancer activities in relation to the specific biological targets acted upon by these flavonoids. Flavonoids target several signaling pathways involved in apoptosis, cell cycle arrest, mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K)/AKT kinase, and metastasis. Polo-like kinase 1 (PLK1) has been recognized as a valuable target in cancer treatment due to the prognostic implication of PLK1 in cancer patients and its clinical relevance between the overexpression of PLK1 and the reduced survival rates of several carcinoma patients. Recent studies suggest that several flavonoids, including genistein directly inhibit PLK1 inhibitory activity. Later, we focus on the anticancer effects of genistein through inhibition of PLK1.

Chemo-preventive and therapeutic effect of the dietary flavonoid kaempferol: A comprehensive review

Kaempferol, a natural flavonoid present in several plants, possesses a wide range of therapeutic properties such as antioxidant, anticancer, and anti-inflammatory. It has a significant role in reducing cancer and can act as a therapeutic agent in the treatment of diseases and ailments such as diabetes, obesity, cardiovascular diseases, oxidative stress, asthma, and microbial contamination disorders. Kaempferol acts through different mechanisms: It induces apoptosis (HeLa cervical cancer cells), decreases cell viability (G2/M phase), downregulates phosphoinositide 3-kinase (PI3K)/AKT (protein kinase B) and human T-cell leukemia/lymphoma virus-I (HTLV-I) signaling pathways, suppresses protein expression of epithelial-mesenchymal transition (EMT)-related markers including N-cadherin, E-cadherin, Slug, and Snail, and metastasis-related markers such as matrix metallopeptidase 2 (MMP-2). Accordingly, the aim of the present review is to collect information pertaining to the effective role of kaempferol against various degenerative disorders, summarize the antioxidant, anti-inflammatory, anticancer, antidiabetic, and antiaging effects of kaempferol and to review the progress of recent research and available data on kaempferol as a protective and chemotherapeutic agent against several ailments.

Kaempferol protects against gamma radiation-induced mortality and damage via inhibiting oxidative stress and modulating apoptotic molecules in vivo and vitro

To investigate the potential protective effect of kaempferol, a representative flavonoid, against radiation induced mortality and injury in vivo and vitro.C57BL/6 male mice and human umbilical venous endothelial cells (HUVECs) were pretreated with kaempferol before radiation. We found that kaempferol can effectively increase 30-day survival rate after 8.5 Gy lethal total body irradiation (TBI). Mice were sacrificed at 7th day after 7 Gy TBI, we found kaempferol against radiation-induced tissues damage, by inhibiting the oxidative stress, and attenuating morphological changes and cell apoptosis. In vitro, kaempferol increased HUVECs cell viability and decrease apoptosis. It also mitigated oxidative stress and restored the abnormal expression of prx-5, Cyt-c, Caspase9 and Caspase3 in mRNA and protein level in HUVECs after radiation. Taken together, it suggests kaempferol can protect against gamma-radiation induced tissue damage and mortality. The present study is the first report of the radioprotective role of kaempferol in vivo and vitro.

Low dose of kaempferol suppresses the migration and invasion of triple-negative breast cancer cells by downregulating the activities of RhoA and Rac1

Purpose

Triple-negative breast cancer (TNBC) is an especially aggressive and hard-to-treat disease. Although the anticancer role of kaempferol has been reported in breast cancer, the effect of kaempferol on TNBC remains unclear.

Materials and methods

This experiment investigated the migration-suppressive role of a low dose of kaempferol in TNBC cells. Wound-healing assays and cell invasion assays were used to confirm the migration and invasion of cells treated with kaempferol or transfected indicated constructs. We evaluated the activations of RhoA, Rac1 and Cdc42 in TNBC cells with a Rho activation assay. A panel of inhibitors of estrogen receptor/progesterone receptor/human epidermal growth factor receptor 2 (ER/PR/HER2) treated non-TNBC (SK-BR-3 and MCF-7) cells and blocked the ER/PR/HER2 activity. Wound-healing assays and Rho activation assays were employed to measure the effect of kaempferol and ER/PR/HER2 inhibitors on Rho activation and cell migration rates.

Results

A low dose of kaempferol (20 μmol/L) had a potent inhibitory effect on the migration and invasion of TNBC cells, but not on the migration of non-TNBC (SK-BR-3 and MCF-7) cells. The low dose of kaempferol downregulated the activations of RhoA and Rac1 in TNBC cells. Moreover, the low dose of kaempferol also inhibited the migration and RhoA activations of HER2-silence SK-BR-3 and ER/PR-silence MCF-7 cells. Overexpressed HER2 rescued the cell migration and RhoA and Rac1 activations of kaempferol-treated MDA-MB-231 cells.

Conclusion

The low dose of kaempferol inhibits the migration and invasion of TNBC cells via blocking RhoA and Rac1 signaling pathway.

Kaempferol Inhibits the Invasion and Migration of Renal Cancer Cells through the Downregulation of AKT and FAK Pathways

Kaempferol, which is isolated from several natural plants, is a polyphenol belonging to the subgroup of flavonoids. Kaempferol exhibits various pharmacological activities, including anti-inflammatory, antioxidant, antimicrobial, and anticancer activities. In this study, kaempferol can significantly inhibit the invasion and migration of 786-O renal cell carcinoma (RCC) without cytotoxicity. We examined the potential mechanisms underlying its anti-invasive activities on 786-O RCC cells. Western blot was performed, and the results showed that kaempferol attenuates the manifestation of metalloproteinase-2 (MMP-2) protein and activity. The inhibitive effect of kaempferol on MMP-2 may be attributed to the downregulation of phosphorylation of Akt and focal adhesion kinase (FAK). By examining the SCID mice model, we found that kaempferol can safely inhibit the metastasis of the 786-O RCC cells into the lungs by about 87.4% as compared to vehicle treated control animals. In addition, the lung tumor masses of mice pretreated with 2-10 mg/kg kaempferol were reduced about twofold to fourfold. These data suggested that kaempferol can play a promising role in tumor prevention and cancer metastasis inhibition.

Kaempferol slows intervertebral disc degeneration by modifying LPS-induced osteogenesis/adipogenesis imbalance and inflammation response in BMSCs

Intervertebral disc (IVD) degeneration is a common disease that represents a significant cause of socio-economic problems. Bone marrow-derived mesenchymal stem cells (BMSCs) are a potential autologous stem cell source for the nucleus pulposus regeneration. Kaempferol has been reported to exert protective effects against both osteoporosis and obesity. This study explored the effect of kaempferol on BMSCs differentiation and inflammation. The results demonstrated that kaempferol did not show any cytotoxicity at concentrations of 20, 60 and 100μM. Kaempferol enhanced cell viability by counteracting the lipopolysaccharide (LPS)-induced cell apoptosis and increasing cell proliferation. Western blot analysis of mitosis-associated nuclear antigen (Ki67) and proliferation cell nuclear antigen (PCNA) further confirmed the increased effect of kaempferol on LPS-induced decreased viability of BMSCs. Besides, kaempferol elevated LPS-induced reduced level of chondrogenic markers (SOX-9, Collagen II and Aggrecan), decreased the level of matrix-degrading enzymes, i.e., matrix metalloprotease (MMP)-3 and MMP-13, suggesting the osteogenesis of BMSC under kaempferol treatment. On the other hand, kaempferol enhanced LPS-induced decreased expression of lipid catabolism-related genes, i.e., carnitine palmitoyl transferase-1 (CPT-1). Kaempferol also suppressed the expression of lipid anabolism-related genes, i.e., peroxisome proliferators-activated receptor-γ (PPAR-γ). The Oil red O staining further convinced the inhibition effect of kaempferol on BMSCs adipogenesis. In addition, kaempferol alleviated inflammatory by reducing the level of pro-inflammatory cytokines (i.e., interleukin (IL)-6) and increasing anti-inflammatory cytokine (IL-10) via inhibiting the nucleus translocation of nuclear transcription factor (NF)-κB p65. Taken together, our research indicated that kaempferol may serve as a novel target for treatment of IVD degeneration.

CXCL7 promotes proliferation and invasion of cholangiocarcinoma cells

CXCL7 is an important chemoattractant cytokine, which signals through binding to its receptor CXCR2. Recent studies have demonstrated that the CXCL7/CXCR2 signaling plays a promoting role in several common malignancies, including lung, renal, colon, and breast cancer. However, the regulatory role of CXCL7, in cholangiocarcinoma, as well as the underlying mechanism, has not been previously reported. Herein, we found more positive expression of CXCL7 in cholangiocarcinoma tissues compared to adjacent non-tumor tissues. High CXCL7 expression was significantly correlated with poor differentiation, lymph node metastasis, vascular invasion and advanced clinical stage, but was not associated with age, gender, or tumor size. Besides, the expression of CXCL7 was significantly associated with the Ki67 expression, but not associated with CA199, AFP, or P53 expression in cholangiocarcinoma. Moreover, the overall survival of cholangiocarcinoma patients with high CXCL7 expression was significantly shorter than those with low CXCL7 expression. In vitro study indicated that CXCL7 and CXCR2 were also positively expressed in several common cholangiocarcinoma cell lines, including HuCCT1, HuH28, QBC939, EGI-1, OZ and WITT. SiRNA-induced inhibition of CXCL7 significantly reduced the proliferation and invasion of QBC939 cells. On the contrary, overexpression of CXCL7 markedly promoted these malignant phenotypes of QBC939 cells. Of note, the conditioned medium of CXCL7-overexpresing human hepatic stellate cells could also promote the proliferation and invasion of QBC939 cells, suggesting that CXCL7 may also play an oncogenic role in cholangiocarcinoma in a paracrine-dependent manner, not only in an autocrine-dependent manner. Molecular assay data suggested that the AKT signaling pathway was involved in the CXCL7-mediated malignant phenotypes of QBC939 cells. In summary, our study suggests that CXCL7 plays a promoting role in regulating the growth and metastasis of cholangiocarcinoma.