Kaempferol induces apoptosis in ovarian cancer cells through activating p53 in the intrinsic pathway

Network Pharmacology Approach Reveals the Potential Immune Function Activation and Tumor Cell Apoptosis Promotion of Xia Qi Decoction in Lung Cancer

As the leading cause of cancer death worldwide, lung cancer (LC) has seriously affected human health and longevity. Chinese medicine is a complex system guided by traditional Chinese medicine theories (TCM). Nowadays, the clinical application of TCM for LC patients has become the focus for its effectiveness and security. In this paper, we will analyze and study the mechanism of Xia Qi Decoction (XQD) in the treatment of LC. The results collectively show that XQD could act on 41 therapeutic targets of LC. At the same time, 8 of 41 targets were significantly expressed in immune tissues and cells by activating CD8+T cells to promote apoptosis of cancer cells. It reveals the molecular mechanism of XQD in the treatment of LC from the perspective of network pharmacology. In addition, in the treatment of LC, XQD can activate (up-regulate) the function of immune cells, promote the apoptosis of tumor cells, and have an active anti-tumor immune effect. In conclusion, this study reveals the unique advantages of traditional Chinese medicine in the treatment of cancer, in reinforcing the healthy qi and eliminating the pathogenic factors. More research, however, is needed to verify the potential mechanisms.

Selective toxicity of chrysin on mitochondria isolated from liver of a HCC rat model

Flavonoids are natural compounds that show various biological effects, such as the anti-cancer effect. Chrysin is a flavonoid compound found in honey and propolis. Studies have shown that chrysin has anti-cancer activity due to induction of apoptosis signaling. In the present study, we examined the cytotoxic effect of chrysin against liver mitochondria obtained from the hepatocellular carcinoma (HCC) rat model. Diethylnitrosamine (DEN) and 2-acetylaminofluorene (2-AAF) was used for induction of HCC. Mitochondria were isolated from liver hepatocytes using differential centrifugation. Then, hepatocytes and mitochondria markers related to apoptosis signaling were investigated. Our finding indicated an increase in mitochondrial reactive oxygen species (ROS) generation, collapse in the mitochondrial membrane potential (MMP), swelling in mitochondria, and cytochrome c release (about 1.6 fold) after exposure of mitochondria obtained from the HCC rats group with chrysin (10, 20, and 40 µM) compared to the normal rats group. Furthermore, Chrysin was able to increase caspase-3 activity in the HCC rats group (about 2.4 fold) compared to the normal rats group. According to the results, we proposed that chrysin could be considered as a promising complementary therapeutic candidate for the treatment of HCC, but it requires a further in vivo and clinical studies.

Kaempferol Promotes Apoptosis While Inhibiting Cell Proliferation via Androgen-Dependent Pathway and Suppressing Vasculogenic Mimicry and Invasion in Prostate Cancer

Kaempferol is a well-known natural flavonol reported to be a potential treatment for multiple cancers. In this study, we demonstrated that cell growth of androgen-sensitive LNCaP cells could be inhibited 33% by 5 μM kaempferol, around 60% by 10 μM kaempferol, and almost 100% by 15 μM kaempferol. Also, kaempferol showed relatively limited effect on PC-3 cells and nonmalignant RWPE-1 cells. In the presence of DHT, the IC₅₀ for kaempferol was 28.8 ± 1.5 μM in LNCaP cells, 58.3 ± 3.5 μM in PC-3 cells, and 69.1 ± 1.2 μM in RWPE-1 cells, respectively. Kaempferol promotes apoptosis of LNCaP cells in a dose-dependent manner in the presence of dihydrotestosterone (DHT). Then, luciferase assay data showed that kaempferol could inhibit the activation of androgen receptors induced by DHT significantly. The downstream targets of androgen receptors, such as PSA, TMPRSS2, and TMEPA1, were found decreased in the presence of kaempferol in qPCR data. It was then confirmed that the protein level of PSA was decreased. Kaempferol inhibits AR protein expression and nuclear accumulation. Kaempferol suppressed vasculogenic mimicry of PC-3 cells in an in vitro study. In conclusion, kaempferol is a promising therapeutic candidate for treatment of prostate cancer, where the androgen signaling pathway as well as vasculogenic mimicry are involved.

Isolation of Phytochemicals from Bauhinia variegata L. Bark and Their In Vitro Antioxidant and Cytotoxic Potential

Plants have been the basis of traditional medicine since the dawn of civilizations. Different plant parts possess various phytochemicals, playing important roles in preventing and curing diseases. Scientists, through extensive experimental studies, are playing an important part in establishing the use of phytochemicals in medicine. However, there are still a large number of medicinal plants which need to be studied for their phytochemical profile. In this study, the objective was to isolate phytochemicals from bark of Bauhinia variegata L. and to study them for their antioxidant and cytotoxic activities. The bark was extracted with methanol, followed by column chromatography and thus isolating kaempferol, stigmasterol, protocatechuic acid-methyl ester (PCA-ME) and protocatechuic acid (PCA). 2,2-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) and 2, 2'-diphenyl-1-picrylhydrazyl radical (DPPH) radical scavenging assays were utilized for assessment of antioxidant activity, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) dye reduction assay was used to determine cytotoxic activity against C-6 glioma rat brain, MCF-7 breast cancer, and HCT-15 colon cancer cell lines. The compounds were found to have significant antioxidant and cytotoxic activity. Since there is a considerable increase in characterizing novel chemical compounds from plant parts, the present study might be helpful for chemotaxonomic determinations, for understanding of medicinal properties as well as for the quality assessment of herbal supplements containing B. variegata bark, thus establishing its use in traditional medicine.

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.

Identification and quantification of phenolic compounds of Western Siberia Astragalus danicus in different regions

The potential of phenolic compounds of medicinal plants including Astragalus danicus L is determined by but not limited to their antioxidant activity. Their anti-inflammatory, antitumor, and other useful properties are known, which allows using these phytochemicals within preventive activities to reduce the risk of many serious diseases. Chromatographic analysis of the Astragalus danicus L. biomaterial from the plant samples collected in three regions of the Kemerovo region (Western Siberia, Russia) established the presence of compounds of flavonols (isorhamnetin glucoside, kaempferol glucoside), flavones (apigenin 7-glucoside), phenylpropanoids (chlorogenic acid) in the aerial part of plants. The total content of phenolic compounds in plant samples ranged from 100.75 ± 3.87 mg/g (Yashkinsky district) to 190.95 ± 7.34 mg/g (Belovsky district). The content of chlorogenic acid in the studied samples was from 0.14 ± 0.01 mg/g to 1.16 ± 0.04 mg/g. Isorhamnetin glucoside was found only in samples of plants from two districts - Prokopievsky (41.39 ± 1.58 mg/g) and Belovsky (95.0 ± 3.66 mg/g). The content of glucosides of kaempferol ranged from 0.38 ± 0.01 mg/g to 0.55 ± 0.02 mg/g. Its content is almost twice as high as the content in the well-known analogues of Astragalus. Apigenin-7-glucoside was isolated in Astragalus samples for the first time, in a small amount (3.34 ± 0.13 mg/g) in a sample of plants of one growing zone. Studies have confirmed that the content of flavonoids in plants significantly depends not only on the genetic characteristics of plants, but also on the hydrothermal regime, the climatic conditions of different botanical and geographical areas of the habitat. This work shows that Astragalus danicus L. growing in Kemerovo region is a promising raw material for pharmacological preparations.

The Effects of the Dietary and Nutrient Intake on Gynecologic Cancers

The contribution of diet to cancer risk has been considered to be higher in advanced countries than in developing countries. In this paper, I review the current issues (a review of the relevant literature), and the effects of the dietary and nutrient intake on three types of gynecologic cancer (cervical, endometrial and ovarian cancers). In cervical cancer, the most important roles of diet/nutrition in relation to cancer are prophylaxis and countermeasures against human papillomavirus (HPV) infection. The main preventive and reductive factors of cervical cancer are antioxidants, such as vitamin A, C, D and E, carotenoids, vegetables and fruits. These antioxidants may have different abilities to intervene in the natural history of diseases associated with HPV infection. For endometrial cancer, the increase in peripheral estrogens as a result of the aromatization of androgens to estrogens in adipose tissue in obese women and insulin resistance are risk factors. Thus, we must mainly take care to avoid the continuous intake of fat energy and sugar. In ovarian cancer, the etiology has not been fully understood. To the best of our knowledge, the long-term consumption of pro-inflammatory foods, including saturated fat, carbohydrates and animal proteins is a risk factor. The intake of acrylamide is also a risk factor for both endometrial and ovarian cancer. Most papers have been epidemiological studies. Thus, further research using in vitro and in vivo approaches is needed to clarify the effects of the dietary and nutrient intake in detail.

Synergistic effect of kaempferol and 5‑fluorouracil on the growth of colorectal cancer cells by regulating the PI3K/Akt signaling pathway

Combination chemotherapy with chemosensitizers can exert synergistic therapeutic effects, reduce toxicity, and delay the induction of drug resistance. In the present study, the antitumor effects were investigated, and the possible underlying mechanisms of kaempferol combined with 5‑fluorouracil (5‑FU) in colorectal cancer cells were explored. HCT‑8 or HCT‑116 cells were treated with various concentrations of kaempferol and/or 5‑FU for the indicated time‑points. An MTT assay was used to determine cell viability, whereas the synergistic effects were assessed by calculating the combination indices of kaempferol and 5‑FU. Annexin V analysis and Hoechst staining were used to determine cell apoptosis. q‑PCR and western blotting were performed to determine the expression levels of Bax, Bcl‑2, thymidylate synthase (TS), PTEN, PI3K, AKT, and p‑AKT. The combination of kaempferol and 5‑FU was determined to be more effective in inhibiting cell viability than either of the agents alone. The inhibition of tumors in response to kaempferol and 5‑FU was associated with the reduction in proliferation ability and stimulation of apoptosis. The protein results indicated that kaempferol and 5‑FU could significantly upregulate the expression levels of Bax and downregulate the expression levels of Bcl‑2 and TS. Furthermore, the combination treatment greatly inhibited the activation of the PI3K/Akt pathway, suggesting the involvement of this pathway in the synergistic effects. The present study demonstrated that kaempferol has a synergistic effect with 5‑FU by inhibiting cell proliferation and inducing apoptosis in colorectal cancer cells via suppression of TS or attenuation of p‑Akt activation. The combination of kaempferol and 5‑FU may be used as an effective therapeutic strategy for colorectal cancer.

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.

DNA damage response and repair in ovarian cancer: Potential targets for therapeutic strategies

Ovarian cancer is among the most lethal gynecologic malignancies with a poor survival prognosis. The current therapeutic strategies involve surgery and chemotherapy. Research is now focused on novel agents especially those targeting DNA damage response (DDR) pathways. Understanding the DDR process in ovarian cancer necessitates having a detailed knowledge on a series of signaling mediators at the cellular and molecular levels. The complexity of the DDR process in ovarian cancer and how this process works in metastatic conditions is comprehensively reviewed. For evaluating the efficacy of therapeutic agents targeting DNA damage in ovarian cancer, we will discuss the components of this system including DDR sensors, DDR transducers, DDR mediators, and DDR effectors. The constituent pathways include DNA repair machinery, cell cycle checkpoints, and apoptotic pathways. We also will assess the potential of active mediators involved in the DDR process such as therapeutic and prognostic candidates that may facilitate future studies.

Antiproliferative and pro-apoptotic activities of wild asparagus (Asparagus acutifolius L.), black bryony (Tamus communis L.) and butcher's broom (Ruscus aculeatus L.) aqueous extracts against T24 and A549 cancer cell lines

The aim of this study was to determine the phenolic profile, antiproliferative, and pro-apoptotic activities of Asparagus acutifolius, Tamus communis, and Ruscus aculeatus aqueous extracts against human bladder (T24) and lung cancer (A549) cell lines. Antiproliferative activity of the extracts at the concentration range from 0.5 to 4 mg/ml was measured by MTT test, after the incubation period of 4, 24, 48, or 72 hr. Pro-apoptotic activity of selected plant extracts against T24 and A549 cells was analyzed by flow cytometry at the concentrations of 0.5, 1, and 2 mg/ml. The highest antiproliferative activity against both cancer cell lines was detected by T. communis aqueous extract. The highest pro-apoptotic effect was achieved by A. acutifolius aqueous extract and its effect was similar against A549 and T24 cells. PRACTICAL APPLICATIONS: Wild edible plants, such as wild asparagus, black bryony, and butcher's broom represent important aspect of the Mediterranean diet. They are rich source of various natural bioactive compounds which express different biological activities (antioxidative, antiproliferative, antibacterial, anti-inflammatory…). The current trend for natural and healthy diet, such as the Mediterranean diet, is in relation to the rapidly growing problem of chronic diseases in a modern society. Wild edible plants have a high direct-use value using them in dishes containing mixed vegetables, in soup preparation, as natural additives in fermented natural products containing cheese or fish, in water infusions (natural drinks).

Diet, menopause and the risk of ovarian, endometrial and breast cancer

Menopause, the permanent cessation of the menstrual cycle, marks the end of a woman's reproductive lifespan. In addition to changes in sex hormone levels associated with menopause, its timing is another predictor of future health outcomes such as duration of the presence of vasomotor symptoms (VMS) and the risk of hormone-related cancers. With ageing of the population, it is estimated that worldwide 1·2 billion women will be menopausal by the year 2030. Previously the effects of reproductive factors (e.g. parity, age at menarche, pregnancy) and socio-demographic factors on intermediate and long-term health outcomes of menopause have been widely documented. However, little is known about whether diet could have an impact on these. Therefore, we review current evidence on the associations of diet with menopause, presence of VMS and the risk of hormone-related cancers such as ovarian, endometrial and breast cancer. Dietary factors could influence the lifespan of the ovaries and sex-hormones levels, hence the timing of natural menopause. Few studies reported an association between diet, in particular soya consumption, and a reduced risk of VMS. Sustained oestrogen exposure has been associated with a higher risk of hormone-related cancers and thus high-fat and meat diets have been linked with an increased risk of these cancers. However, to better understand the mechanistic pathways involved and to make stronger conclusions for these relationships, further studies investigating the associations of dietary intakes and dietary patterns with menopause, presence of VMS and the risk of hormone-related cancers are required.

Flavonoids in Cancer and Apoptosis

Cancer is the second leading cause of death globally. Although, there are many different approaches to cancer treatment, they are often painful due to adverse side effects and are sometimes ineffective due to increasing resistance to classical anti-cancer drugs or radiation therapy. Targeting delayed/inhibited apoptosis is a major approach in cancer treatment and a highly active area of research. Plant derived natural compounds are of major interest due to their high bioavailability, safety, minimal side effects and, most importantly, cost effectiveness. Flavonoids have gained importance as anti-cancer agents and have shown great potential as cytotoxic anti-cancer agents promoting apoptosis in cancer cells. In this review, a summary of flavonoids and their effectiveness in cancer treatment targeting apoptosis has been discussed.

Bioactive compounds from Cudrania tricuspidata: A natural anticancer source

The tumor is becoming a critical threat to our lives in these years. Searching for antitumor substances from natural products is a great interest of scientists. Cudrania tricuspidata (C. tricuspidata) is a regional plant containing 158 flavonoids and 99 xanthones, and others ingredients with favorable bioactivity. This review comprehensively analyzes the antitumor compounds from C. tricuspidata against different tumors, and 78 flavonoids plus xanthones are considered as underlying antineoplastic. Importantly, the structure of preylation groups is the primary source of antitumor activity among 45 flavonoids plus xanthones, which could be a direction of structural modification for a better antitumor ability. Additionally, the fruits are also preferable sources of antitumor compounds compared to the roots and barks due to the abundant isoflavones and sustainability. However, many studies only focused on the cells viability inhibition of the compounds, the underlying molecular mechanisms, and the intracellular targets remain ambiguous. In conclusion, C. tricuspidata has a great potential for anti-tumor prevention or therapy, but more attention should be paid to deeper research in vitro and in vivo models.

Corilagin from longan seed: Identification, quantification, and synergistic cytotoxicity on SKOv3ip and hey cells with ginsenoside Rh2 and 5-fluorouracil

Corilagin content from different parts of longan (Dimocarpus longan Lour.) was determined by ultra performance liquid chromatography (UPLC) method. Additionally, the potential synergistic effects of corilagin + ginsenoside Rh2 (Rh2), and corilagin + 5-fluorouracil (5-FU) on ovarian cancer cells, and cancer-preventing activities, including inhibition of tyrosinase, properties of antioxidant and nitrite-scavenging, and blocking of nitrosamine synthesis were investigated. The results showed the content of corilagin from different parts of longan varied widely, while corilagin content in longan seed was high with a value of 542.15 ± 10.30 μg/g. Then the corilagin from longan seed was chosen for further study, since longan seed was easily obtained from by-product of longan fruit processing with low cost. Furthermore, the combinations of corilagin + Rh2, and corilagin + 5-FU showed an increased synergistic cytotoxicity on SKOv3ip and Hey cells. Moreover, corilagin inhibited exhibited effects of inhibiting tyrosinase, antioxidation, scavenging nitrite and blocking nitrosamine synthesis.

Kaempferol, a natural dietary flavonoid, suppresses 17β-estradiol-induced survivin expression and causes apoptotic cell death in endometrial cancer

Endometrioid endometrial carcinoma, commonly known as type 1 endometrial cancer, accounts for >80% of endometrial carcinomas and is dependent on estrogen. We recently reported on the prognostic significance of the BIRC5 survivin gene in endometrial cancer. Estradiol induces survivin expression in estrogen receptor-positive, but not in estrogen receptor-negative, cancer cells. Kaempferol, a bioflavonoid, reportedly inhibits estrogen receptor-α (ERα) in hormone receptor-positive breast cancer cells. However, whether kaempferol-mediated inhibition of ERα suppresses survivin and induces cell death in endometrial cancer remains unclarified. The present study evaluated the antitumor effects of kaempferol on endometrial cancer cells. Cell viability assays, flow cytometry analysis, western blotting and annexin V analyses were used to analyze the antitumor effects of kaempferol. The results demonstrated that kaempferol successfully suppressed the viability of two ER-positive endometrial cancer cell lines, with IC₅₀ values of 83 and 65 µM. In addition, kaempferol induced sub-G1 cell accumulation and apoptotic cell death (P<0.01) in a dose-dependent manner. Treatment of cells with estradiol significantly induced co-expression of nuclear ERα and survivin proteins (P<0.001). Further evaluation revealed that kaempferol causes apoptotic cell death largely by suppressing ERα, survivin and Bcl-2 protein. Therefore, the results of the present study suggested that targeting ERα and survivin with kaempferol may be a novel therapeutic option against endometrial carcinoma.

Kaempferol Induces G2/M Cell Cycle Arrest via Checkpoint Kinase 2 and Promotes Apoptosis via Death Receptors in Human Ovarian Carcinoma A2780/CP70 Cells

Kaempferol is a widely distributed dietary flavonoid. Epidemiological studies have demonstrated kaempferol consumption lowers the risk of ovarian cancer. Our previous research proved that kaempferol suppresses human ovarian cancer cells by inhibiting tumor angiogenesis. However, the effects of kaempferol on the cell cycle and extrinsic apoptosis of ovarian cancer cells have not yet been studied. In the present study, we demonstrated that kaempferol induced G2/M cell cycle arrest via the Chk2/Cdc25C/Cdc2 pathway and Chk2/p21/Cdc2 pathway in human ovarian cancer A2780/CP70 cells. Chk2 was not responsible for kaempferol-induced apoptosis and up-regulation of p53. Kaempferol stimulated extrinsic apoptosis via death receptors/FADD/Caspase-8 pathway. Our study suggested that Chk2 and death receptors played important roles in the anticancer activity of kaempferol in A2780/CP70 cells. These findings provide more evidence of the anti-ovarian cancer properties of kaempferol and suggest that kaempferol could be a potential candidate for ovarian cancer adjuvant therapy.

Selective Cytotoxicity of Luteolin and Kaempferol on Cancerous Hepatocytes Obtained from Rat Model of Hepatocellular Carcinoma: Involvement of ROS-Mediated Mitochondrial Targeting

To evaluate the cytotoxicity effects of luteolin (LUT) and kaempferol (KAE) via reactive oxygen species (ROS) mediated mitochondrial targeting on hepatocytes obtained from the liver of hepatocellular carcinoma (HCC) rats. In this study, HCC induced by diethylnitrosamine (DEN) and 2-acetylaminofluorene (2-AAF). In the following, rat liver hepatocytes and mitochondria were isolated and tested for every eventual apoptotic and anti-HCC effects of LUT and KAE. The results of MTT assay showed that LUT and KAE were able to induce selective cytotoxicity in hepatocytes of HCC group in a dose- and time-dependent manner. Treatment of mitochondria from hepatocytes of HCC group with LUT and KAE were accompanied by loss of mitochondrial membrane potential (MMP) and mitochondrial swelling and release of cytochrome c (P < 0.001) via reactive oxygen species (ROS) generation before cytotoxicity ensued. LUT and KAE also increased activation of caspase-3 (P < 0.001 and P < 0.01, respectively). Flow-cytometry analysis indicated that the mode of cell death induced by these flavonoids were mostly apoptosis. Importantly, LUT and KAE were nontoxic for healthy hepatocytes and mitochondria. Therefore, we suggest that LUT and KAE are a good candidate for the complementary therapeutic agent against HCC.

Kaempferol increases apoptosis in human acute promyelocytic leukemia cells and inhibits multidrug resistance genes

Acute promyelocytic leukemia (APL) is one of the most life-threatening hematological malignancies. Defects in the cell growth and apoptotic pathways are responsible for both disease pathogenesis and treatment resistance. Therefore, pro-apoptotic agents are potential candidates for APL treatment. Kaempferol is a flavonoid with antioxidant and anti-tumor properties. This study was designed to investigate the cytotoxic, pro-apoptotic, and differentiation-inducing effects of kaempferol on HL-60 and NB4 leukemia cells. Resazurin assay was used to determine cell viability following treatment with kaempferol (12.5-100 μM) and all-trans retinoic acid (ATRA; 10 μM; used as a positive control). Apoptosis and differentiation were also detected using propidium iodide and NBT staining techniques, respectively. Furthermore, the expression levels of genes involved in apoptosis (PI3 K, AKT, BCL2, BAX, p53, p21, PTEN, CASP3, CASP8, and CASP9), differentiation (PML-RAR and HDAC1), and multi-drug resistance (ABCB1 and ABCC1) were determined using quantitative real-time PCR. The protein expressions of Bax/Bcl2 and casp3 were confirmed using Western blot. The results showed that kaempferol decreased cell viability and increased subG1 population in the tested leukemic cells. This effect was associated with decreased expression of Akt, BCL2, ABCB1, and ABCC1 genes, while the expression of CASP3 and BAX/BCL-2 ratio were significantly increased at both gene and protein levels. Kaempferol promoted apoptosis and inhibited multidrug resistance in a concentration-dependent manner, without any differential effect on leukemic cells. In conclusion, this study suggested that kaempferol may be utilized as an appropriate alternative for ATRA in APL patients.

Kaempferol mitigates Endoplasmic Reticulum Stress Induced Cell Death by targeting caspase 3/7

The Endoplasmic Reticulum (ER) plays a fundamental role in executing multiple cellular processes required for normal cellular function. Accumulation of misfolded/unfolded proteins in the ER triggers ER stress which contributes to progression of multiple diseases including neurodegenerative disorders. Recent reports have shown that ER stress inhibition could provide positive response against neuronal injury, ischemia and obesity in in vivo models. Our search towards finding an ER stress inhibitor has led to the functional discovery of kaempferol, a phytoestrogen possessing ER stress inhibitory activity in cultured mammalian cells. We have shown that kaempferol pre-incubation significantly inhibits the expression of GRP78 (a chaperone) and CHOP (ER stress associated pro-apoptotic transcription factor) under stressed condition. Also, our investigation in the inhibitory specificity of kaempferol has revealed that it inhibits cell death induced by diverse stimuli. Further study on exploring the molecular mechanism implied that kaempferol renders protection by targeting caspases. Both the in silico docking and in vitro assay using recombinant caspase-3 enzyme confirmed the binding of kaempferol to caspases, through an allosteric mode of competitive inhibition. Altogether, we have demonstrated the ability of kaempferol to alleviate ER stress in in vitro model.

Extraction of Kaempferol and Its Glycosides Using Supercritical Fluids from Plant Sources: A Review

Research has focused on the study and design of new products containing phytochemicals (polyphenolic acids, flavonoids and anthocyanins, among others) that contribute to a better life quality for consumers, as well as techniques to improve the extraction of these compounds. In this regard, extraction with supercritical fluids (usually CO₂) is a technology that has better advantages than organic solvents, since lower temperatures that are used do not damage the product, and is more effective at high pressures. Extracts from plant sources contain significant concentrations of flavonols, one of the main compounds being kaempferol. Research has proven the antioxidant, anticarcinogenic, antidiabetic, cardioprotective, neuroprotective and antimicrobial properties of kaempferol and its glycosides. This review aims to present the main functional properties and extraction with supercritical fluids of kaempferol and its glycosides, as well as the application of this technology in the food area.

The Role of Secondary Metabolites on Gynecologic Cancer Therapy: Some Pathways and Mechanisms

Gynecologic cancers are among the most common cancers in humans and animals. Treatment success depends on several factors including stage at diagnosis, tumor type, origin and metastasis. Currently, surgery, chemotherapy, and radiotherapy are preferred in the treatment of these cancers. However, many anticarcinogenic drugs can cause severe adverse effects and also the expected response to treatment may not be obtained. In recent studies, the importance of the relationship between cancer and inflammation has been emphasized. Therefore, several phytochemicals that exhibit beneficial bioactive effects towards inflammatory pathways were proven to have anticarcinogenic potential for gynecologic cancer therapy. This review summarizes the role of inflammatory pathways in gynecologic cancers and effective secondary metabolites for cancer therapy.

Astragalin Reduces Hexokinase 2 through Increasing miR-125b to Inhibit the Proliferation of Hepatocellular Carcinoma Cells in Vitro and in Vivo

Astragalin (ASG) can be found in a variety of food components. ASG exhibits cytotoxic effects on several different types of malignant cells. However, its effects on hepatocellular carcinoma (HCC) cells and the underlying molecular mechanisms have remained to be fully elucidated. Here, we revealed that ASG remarkably suppressed the proliferation of HCC cells. In HCC cells, ASG inhibited glucose glycolysis and promoted oxidative phosphorylation, resulting in a surge of reactive oxygen species (ROS). Mechanistically, ASG suppressed the expression of hexokinase 2 (HK2). This event was indispensible for ASG-mediated metabolic reprogramming, ROS accumulation, and subsequent growth arrest. Our further investigations unveiled that ASG repressed HK2 expression via increasing miR-125b. In vivo experiments showed that gavage of ASG decreased the proliferation of Huh-7 HCC xenografts in nude mice and inhibited the growth of transplanted H22 HCC cells in Kunming mice. Declined HCC tumor growth in vivo was associated with boosted miR-125b and reduced expression of HK2 in tumor tissues. Collectively, our results demonstrated that ASG is able to suppress the proliferation of HCC cells both in vitro and in vivo. Inhibition of HK2 through upregulating miR-125b and subsequent metabolic reprogramming is implicated in the antiproliferative effects of ASG on HCC cells.

LFG-500, a newly synthesized flavonoid, induces apoptosis in human ovarian carcinoma SKOV3 cells with involvement of the reactive oxygen species-mitochondria pathway

Ovarian cancer is the main cause of gynecologic malignancy-related mortality in women. Therefore, the disease requires improvements in treatment options and in the potency of chemotherapeutic drugs. The study of apoptosis in tumor cells is an important field for cancer therapy and cancer molecular biology. It has recently been established that LFG-500, a new synthesized flavonoid with a piperazine and benzyl group substitution, has strong anticancer activity. However, its exact molecular mechanism is not fully understood. The present study aimed to examine the effects of LFG-500 on human ovarian cancer SKOV3 cells, as well as to identify its underlying mechanisms. The data showed that LFG-500 inhibited the growth of SKOV3 cells in a concentration-dependent manner. It was found that LFG-500 induced apoptosis in SKOV3 cells, detected by DAPI staining and an Annexin V/PI double-staining assay. Moreover, LFG-500 reduced caspase-3 protein expression and increased the Bcl-2-associated X protein/B-cell lymphoma 2 protein ratio. Further findings revealed that LFG-500 treatment resulted in reactive oxygen species (ROS) accumulation and loss of mitochondrial transmembrane potential. Collectively, these results demonstrated that LFG-500 efficiently induced apoptosis in SKOV3 cells, an event possibly associated with the trigging of the mitochondrial apoptotic pathway through ROS accumulation. Therefore, LFG-500 shows potential as a potent anticancer agent for the treatment of ovarian cancer.

Functional Vegetable Guar (Cyamopsis tetragonoloba L. Taub.) Accessions for Improving Flavonoid Concentrations in Immature Pods

Dry guar (Cyamopsis tetragonoloba L. Taub) seeds are primarily used to extract galactomannan gum for oil fracking, however, the immature pods are used as a vegetable in India and sold in ethnic grocery stores in the Atlanta, Georgia area. Nineteen guar genotypes were grown in the field at Griffin, GA, USA for two years (2010-2011). Since the determination of flavonoid concentration would add value to the guar accessions for use as a functional food vegetable, immature guar pods were evaluated for flavonoid concentration. In this study, the immature pods from these 19 guar accessions were analyzed for flavonoid concentration using high-performance liquid chromatography. Several accessions including PI 253182, PI 262152, PI 263698, and PI 288357 showed significantly greater daidzein concentration than all three controls based on seed production in 2010. However, PI 179926, PI 180434, PI 182969, PI 183400, PI 253182, PI 262152, PI 263882, and PI 263897 exhibited significantly greater genistein concentration than the second and third best controls in 2011. Both PI 180434 and PI 288359 produced significantly higher kaempferol concentration than the third best control. Daidzein concentration was significantly correlated with genistein concentration (r² = 0.47*) for both years. Luteolin concentration showed a significant negative correlation with genistein (r² = -0.45*). Quercetin concentration significantly correlated with kaempferol (r² = 0.854***) and genistein (r² = 0.455*) concentrations. The accession, PI 542608 was observed to contain high concentrations of kaempferol and quercetin in the cluster analyses. These results will help plant breeders develop guar cultivars with superior flavonoid concentrations.

Kaempferol - A dietary anticancer molecule with multiple mechanisms of action: Recent trends and advancements

The consumption of diet-based naturally bioactive metabolites is preferred to synthetic material in order to avert health-associated disorders. Among the plant-derived polyphenols, kaempferol (KMF) is considered as a valuable functional food ingredient with a broad range of therapeutic applications such as anti-cancer, antioxidant and anti-inflammatory uses. KMF acts on a range of intracellular as well as extracellular targets involved in the cell signaling pathways that in turn are known to regulate the hallmarks of cancer growth progressions like apoptosis, cell cycle, invasion or metastasis, angiogenesis and inflammation. Importantly, the understanding of mechanisms of action of KMF-mediated therapeutic effects may help the scientific community to design novel strategies for the treatment of dreadful diseases. The current review summarizes the various types of molecular targets of KMF in cancer cells as well as other health-associated disorders. In addition, this review also highlights the absorption, metabolism and epidemiological findings.

Kaempferol increases apoptosis in human cervical cancer HeLa cells via PI3K/AKT and telomerase pathways

Cervical cancer is one of the most frequent cancers in women worldwide. Defects in the apoptotic pathways are responsible for both the disease pathogenesis and its therapy resistance. It is thus a good candidate for treatment by pro-apoptotic agents. Kaempferol as a flavonoid has antioxidant and anti-tumor properties. Kaempferol has been shown to induce apoptosis and cell death in cancer cells. However, due to the problems in the treatment of cervical cancer, this study is designed to investigate the molecular mechanism by which kaempferol suppresses the growth of cervical cancer HeLa cell as compared with HFF cells (normal cells). Cells treated with kaempferol (12-100μM) and 5-FU (1-10μM), as the positive control, up to 72h. Cell viability was determined by MTT assay and real time PCR was used to investigate apoptosis and telomerase genes expression. The results showed that kaempferol decreased cell viability as concentration- and time-dependently. IC₅₀ values were 10.48μM for HeLa and 707.00μM for HFF cells, as compared with 1.40μM and 16.38μM for 5-FU after 72h treatment, respectively. Also, kaempferol induced cellular apoptosis and aging through down-regulating the PI3K/AKT and hTERT pathways. This study suggests that kaempferol may be a useful adjuvant therapeutic agent in the treatment of cervical cancer.

Honey and Cancer: Current Status and Future Directions

Cancer is a leading cause of death worldwide and poses a challenge to treatment. With overwhelming evidence of the role played by diet and lifestyle in cancer risk and prevention, there is a growing interest into the search for chemopreventative or chemotherapeutic agents derived from natural products. Honey is an important source of bioactive compounds derived from plants and recent years have seen an increased interest in its anticancer properties. This review examines the role of honey in targeting key hallmarks of carcinogenesis, including uncontrolled proliferation, apoptosis evasion, angiogenesis, growth factor signalling, invasion, and inflammation. The evidence for honey as an adjunct to conventional cancer therapy is also presented. The review also highlights gaps in the current understanding and concludes that, before translation of evidence from cell culture and animal studies into the clinical setting, further studies are warranted to examine the effects of honey at a molecular level, as well as on cells in the tumour environment.

Optimization, formulation, and characterization of multiflavonoids-loaded flavanosome by bulk or sequential technique

This study involves adaptation of bulk or sequential technique to load multiple flavonoids in a single phytosome, which can be termed as "flavonosome". Three widely established and therapeutically valuable flavonoids, such as quercetin (Q), kaempferol (K), and apigenin (A), were quantified in the ethyl acetate fraction of Moringa oleifera leaves extract and were commercially obtained and incorporated in a single flavonosome (QKA-phosphatidylcholine) through four different methods of synthesis - bulk (M1) and serialized (M2) co-sonication and bulk (M3) and sequential (M4) co-loading. The study also established an optimal formulation method based on screening the synthesized flavonosomes with respect to their size, charge, polydispersity index, morphology, drug-carrier interaction, antioxidant potential through in vitro 1,1-diphenyl-2-picrylhydrazyl kinetics, and cytotoxicity evaluation against human hepatoma cell line (HepaRG). Furthermore, entrapment and loading efficiency of flavonoids in the optimal flavonosome have been identified. Among the four synthesis methods, sequential loading technique has been optimized as the best method for the synthesis of QKA-phosphatidylcholine flavonosome, which revealed an average diameter of 375.93±33.61 nm, with a zeta potential of -39.07±3.55 mV, and the entrapment efficiency was >98% for all the flavonoids, whereas the drug-loading capacity of Q, K, and A was 31.63%±0.17%, 34.51%±2.07%, and 31.79%±0.01%, respectively. The in vitro 1,1-diphenyl-2-picrylhydrazyl kinetics of the flavonoids indirectly depicts the release kinetic behavior of the flavonoids from the carrier. The QKA-loaded flavonosome had no indication of toxicity toward human hepatoma cell line as shown by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide result, wherein even at the higher concentration of 200 µg/mL, the flavonosomes exert >85% of cell viability. These results suggest that sequential loading technique may be a promising nanodrug delivery system for loading multiflavonoids in a single entity with sustained activity as an antioxidant, hepatoprotective, and hepatosupplement candidate.

Theaflavin-3, 3'-digallate induces apoptosis and G2 cell cycle arrest through the Akt/MDM2/p53 pathway in cisplatin-resistant ovarian cancer A2780/CP70 cells

Ovarian cancer is the most lethal gynecological cancer among women worldwide. Adverse side effects and acquired resistance to conventional platinum based chemotherapy are major impediments in ovarian cancer treatment, and drive the development of more selective anticancer drugs that target cancer-specific defects. In this study, theaflavin-3, 3′-digallate (TF3), the major theaflavin monomer in black tea, exhibited a potent growth inhibitory effect on the cisplatin-resistant ovarian cancer A2780/CP70 cells (IC₅₀, 23.81 μM), and was less cytotoxic to a normal ovarian IOSE-364 cells (IC₅₀, 59.58 μM) than to the cancer cells. Flow cytometry analysis indicated that TF3 induced preferential apoptosis and G2 cell cycle arrest in A2780/CP70 cells with respect to IOSE-364 cells. TF3 induced apoptosis through both the intrinsic and extrinsic apoptotic pathways, and caused G2 cell cycle arrest via cyclin B1 in A2780/CP70 cells. The p53 protein played an important role in TF3-induced apoptosis and G2 cell cycle arrest. TF3 might upregulate the p53 expression via the Akt/MDM2 pathway. Our findings help elucidate the mechanisms by which TF3 may contribute to the prevention and treatment of platinum-resistant ovarian cancer.

Shortened leukocyte telomere length in type 2 diabetes mellitus: genetic polymorphisms in mitochondrial uncoupling proteins and telomeric pathways

Current debate in type 2 diabetes (T2DM) has focused on shortened leukocyte telomere length (LTL) as the result of a number of possible causes, including polymorphisms in mitochondrial uncoupling proteins (UCPs) leading to oxidative stress, telomere regulatory pathway gene polymorphisms, or as a direct result of associated cardiovascular complications inducing tissue organ inflammation and oxidative stress. There is evidence that a heritable shorter telomere trait is a risk factor for development of T2DM. This review discusses the contribution and balance of genetic regulation of UCPs and telomere pathways in the context of T2DM. We discuss genotypes that are well known to influence the shortening of LTL, in particular OBFC1 and telomerase genotypes such as TERC. Interestingly, the interaction between short telomeres and T2DM risk appears to involve mitochondrial dysfunction as an intermediate process. A hypothesis is presented that genetic heterogeneity within UCPs may directly affect oxidative stress that feeds back to influence the fine balance of telomere regulation, cell cycle regulation and diabetes risk and/or metabolic disease progression.

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

Kaempferol is a flavonoid that has been reported to exhibit antitumor activity in various malignant tumors. However, the role of kaempferol on cholangiocarcinoma (CCA) is largely unknown. In this article, we found that kaempferol inhibited proliferation, reduced colony formation ability, and induced apoptosis in HCCC9810 and QBC939 cells in vitro. Results from transwell assay and wound-healing assay demonstrated that kaempferol significantly suppressed the migration and invasion abilities of HCCC9810 and QBC939 cells in vitro. Kaempferol was found to decrease the expression of Bcl-2 and increase the expressions of Bax, Fas, cleaved-caspase 3, cleaved-caspase 8, cleaved-caspase 9, and cleaved-PARP. In addition, kaempferol also downregulated the levels of phosphorylated AKT, TIMP2, and MMP2. In vivo, it was found that the volume of subcutaneous xenograft (0.15 cm(3)) in the kaempferol-treated group was smaller than that (0.6 cm(3)) in the control group. Kaempferol also suppressed the number and volume of metastasis foci in the lung metastasis model, with no marked effects on body weight of mice. Immunohistochemistry assay showed that the number of Ki-67-positive cells was lower in the kaempferol-treated group than that in the control group. We further confirmed that the changes of apoptosis- and invasion-related proteins after kaempferol treatment in vivo were similar to the results in vitro. These data suggest that kaempferol may be a promising candidate agent for the treatment of CCA.

Kaempferol inhibits cell proliferation and glycolysis in esophagus squamous cell carcinoma via targeting EGFR signaling pathway

Antitumor activity of kaempferol has been studied in various tumor types, but its potency in esophagus squamous cell carcinoma is rarely known. Here, we reported the activity of kaempferol against esophagus squamous cell carcinoma as well as its antitumor mechanisms. Results of cell proliferation and colony formation assay showed that kaempferol substantially inhibited tumor cell proliferation and clone formation in vitro. Flow cytometric analysis demonstrated that tumor cells were induced G0/G1 phase arrest after kaempferol treatment, and the expression of protein involved in cell cycle regulation was dramatically changed. Except the potency on cell proliferation, we also discovered that kaempferol had a significant inhibitory effect against tumor glycolysis. With the downregulation of hexokinase-2, glucose uptake and lactate production in tumor cells were dramatically declined. Mechanism studies revealed kaempferol had a direct effect on epidermal growth factor receptor (EGFR) activity, and along with the inhibition of EGFR, its downstream signaling pathways were also markedly suppressed. Further investigations found that exogenous overexpression of EGFR in tumor cells substantially attenuated glycolysis suppression induced by kaempferol, which implied that EGFR also played an important role in kaempferol-mediated glycolysis inhibition. Finally, the antitumor activity of kaempferol was validated in xenograft model and kaempferol prominently restrained tumor growth in vivo. Meanwhile, dramatic decrease of EGFR activity and hexokinase-2 expression were observed in kaempferol-treated tumor tissue, which confirmed these findings in vitro. Briefly, these studies suggested that kaempferol, or its analogues, may serve as effective candidates for esophagus squamous cell carcinoma management.

Evasion of anti-growth signaling: A key step in tumorigenesis and potential target for treatment and prophylaxis by natural compounds

The evasion of anti-growth signaling is an important characteristic of cancer cells. In order to continue to proliferate, cancer cells must somehow uncouple themselves from the many signals that exist to slow down cell growth. Here, we define the anti-growth signaling process, and review several important pathways involved in growth signaling: p53, phosphatase and tensin homolog (PTEN), retinoblastoma protein (Rb), Hippo, growth differentiation factor 15 (GDF15), AT-rich interactive domain 1A (ARID1A), Notch, insulin-like growth factor (IGF), and Krüppel-like factor 5 (KLF5) pathways. Aberrations in these processes in cancer cells involve mutations and thus the suppression of genes that prevent growth, as well as mutation and activation of genes involved in driving cell growth. Using these pathways as examples, we prioritize molecular targets that might be leveraged to promote anti-growth signaling in cancer cells. Interestingly, naturally occurring phytochemicals found in human diets (either singly or as mixtures) may promote anti-growth signaling, and do so without the potentially adverse effects associated with synthetic chemicals. We review examples of naturally occurring phytochemicals that may be applied to prevent cancer by antagonizing growth signaling, and propose one phytochemical for each pathway. These are: epigallocatechin-3-gallate (EGCG) for the Rb pathway, luteolin for p53, curcumin for PTEN, porphyrins for Hippo, genistein for GDF15, resveratrol for ARID1A, withaferin A for Notch and diguelin for the IGF1-receptor pathway. The coordination of anti-growth signaling and natural compound studies will provide insight into the future application of these compounds in the clinical setting.

Kaempferol induces DNA damage and inhibits DNA repair associated protein expressions in human promyelocytic leukemia HL-60 cells

Numerous evidences have shown that plant flavonoids (naturally occurring substances) have been reported to have chemopreventive activities and protect against experimental carcinogenesis. Kaempferol, one of the flavonoids, is widely distributed in fruits and vegetables, and may have cancer chemopreventive properties. However, the precise underlying mechanism regarding induced DNA damage and suppressed DNA repair system are poorly understood. In this study, we investigated whether kaempferol induced DNA damage and affected DNA repair associated protein expression in human leukemia HL-60 cells in vitro. Percentages of viable cells were measured via a flow cytometry assay. DNA damage was examined by Comet assay and DAPI staining. DNA fragmentation (ladder) was examined by DNA gel electrophoresis. The changes of protein levels associated with DNA repair were examined by Western blotting. Results showed that kaempferol dose-dependently decreased the viable cells. Comet assay indicated that kaempferol induced DNA damage (Comet tail) in a dose-dependent manner and DAPI staining also showed increased doses of kaempferol which led to increased DNA condensation, these effects are all of dose-dependent manners. Western blotting indicated that kaempferol-decreased protein expression associated with DNA repair system, such as phosphate-ataxia-telangiectasia mutated (p-ATM), phosphate-ataxia-telangiectasia and Rad3-related (p-ATR), 14-3-3 proteins sigma (14-3-3σ), DNA-dependent serine/threonine protein kinase (DNA-PK), O(6)-methylguanine-DNA methyltransferase (MGMT), p53 and MDC1 protein expressions, but increased the protein expression of p-p53 and p-H2AX. Protein translocation was examined by confocal laser microscopy, and we found that kaempferol increased the levels of p-H2AX and p-p53 in HL-60 cells. Taken together, in the present study, we found that kaempferol induced DNA damage and suppressed DNA repair and inhibited DNA repair associated protein expression in HL-60 cells, which may be the factors for kaempferol induced cell death in vitro.

The chemopreventive effect of the dietary compound kaempferol on the MCF-7 human breast cancer cell line is dependent on inhibition of glucose cellular uptake

Our aim was to investigate the effect of several dietary polyphenols on glucose uptake by breast cancer cells. Uptake of (3)H-deoxy-D-glucose ((3)H-DG) by MCF-7 cells was time-dependent, saturable, and inhibited by cytochalasin B plus phloridzin. In the short-term (26 min), myricetin, chrysin, genistein, resveratrol, kaempferol, and xanthohumol (10-100 µM) inhibited (3)H-DG uptake. Kaempferol was found to be the most potent inhibitor of (3)H-DG uptake [IC50 of 4 µM (1.6-9.8)], behaving as a mixed-type inhibitor. In the long-term (24 h), kaempferol (30 µM) was also able to inhibit (3)H-DG uptake, associated with a 40% decrease in GLUT1 mRNA levels. Interestingly enough, kaempferol (100 µM) revealed antiproliferative (sulforhodamine B and (3)H-thymidine incorporation assays) and cytotoxic (extracellular lactate dehydrogenase activity determination) properties, which were mimicked by low extracellular (1 mM) glucose conditions and reversed by high extracellular (20 mM) glucose conditions. Finally, exposure of cells to kaempferol (30 µM) induced an increase in extracellular lactate levels over time (to 731 ± 32% of control after a 24 h exposure), due to inhibition of MCT1-mediated lactate cellular uptake. In conclusion, kaempferol potently inhibits glucose uptake by MCF-7 cells, apparently by decreasing GLUT1-mediated glucose uptake. The antiproliferative and cytotoxic effect of kaempferol in these cells appears to be dependent on this effect.

Stimulatory effect of Brazilian propolis on hair growth through proliferation of keratinocytes in mice

Propolis is a natural honeybee hive product with the potential for use in the treatment of dermatological conditions, such as cutaneous abrasions, burns, and acne. In this study, we investigated whether propolis stimulates hair growth in mice. Ethanol-extracted propolis, which contains various physiologically active substances such as caffeic acid and kaempferol, stimulated anagen induction in shaved back skin. Anagen induction occurred without any detectable abnormalities in the shape of the hair follicles (HFs), hair stem cells in the bulge, proliferating hair matrix keratinocytes in the hair bulb, or localization of versican in the dermal papilla. Propolis treatment also stimulated migration of hair matrix keratinocytes into the hair shaft in HFs during late anagen in the depilated back skin. Organotypic culture of skin containing anagen stage HFs revealed significant stimulation of hair matrix keratinocyte proliferation by propolis. Furthermore, propolis facilitated the proliferation of epidermal keratinocytes. These results indicate that propolis stimulates hair growth by inducing hair keratinocyte proliferation.

Kaempferol inhibits gastric cancer tumor growth: An in vitro and in vivo study

Kaempferol, which is one of the general flavonoids, has recently been reported to suppress proliferation, induce cell cycle arrest and promote apoptosis in various human cancer cell lines. In the present study, the effect and mechanism of kaempferol on gastric cancer (GC) was examined. The results showed that kaempferol significantly inhibited the proliferation of MKN28 and SGC7901 cell lines. However, no significant inhibition in the GSE-1 normal gastric epithelial cell line in our experimental dose was detected. Additionally, significant apoptosis and G2/M phase cell cycle arrest were identified following the treatment of kaempferol. More importantly, we observed that kaempferol inhibited the growth of the tumor xenografts although no marked effects on liver, spleen or body weight were induced. The expression levels of G2/M cell cycle‑regulating factors, cyclin B1, Cdk1 and Cdc25C, were significantly reduced. In addition, kaempferol treatment markedly decreased the level of Bcl-2 concomitant with an increase in Bax expression, resulting in the upregulation of cleaved caspase-3 and -9, which promoted PARP cleavage. Kaempferol-treated cells also led to a decrease in p-Akt, p-ERK and COX-2 expression levels. The present study therefore provided evidence that kaempferol may be a therapeutic agent for GC.

Flavonol content, oil%, and fatty acid composition variability in seeds of Teramnus labialis and T. uncinatus accessions with nutraceutical potential

Teramnus labialis and T. uncinatus are both underutilized legume species. Teramnus labialis is used as food in India while T. uncinatus has potential use in pasture mixes. Photoperiod-sensitive Teramnus accessions were grown in the greenhouse from 2010 to 2011 and evaluated for flavonol content, oil%, and fatty acid compositions. Significant variations for seed numbers produced, flavonol content, oil%, and fatty acid compositions were detected. Seed numbers ranged from 16 to 3,792 in both species. Teramnus accessions produced more quercetin (ranging from 0.615 to 2.228 mg/g) in their seeds than the other flavonols. However kaempferol and isorhamnetin content ranged from 0 to 0.066 and 0 to 0.086 mg/g (dry seed weight basis), respectively among all accessions. Oil% ranged from 2.65 to 5.64% and more oleic, linoleic, and linolenic acids ranging from 6.69 to 25.97, 31.82 to 41.44, and 17.7 to 32.66%, respectively, were produced among all Teramnus accessions. The seeds from all Teramnus accessions also produced the least saturated fatty acid compositions (ranging from 0.08 to 15.36%). Several significant correlations were also detected for these traits among the accessions. Quercetin showed highly significant positive correlations with kaempferol (r = 0.59, p < .0001), oil% (r = 0.58, p < .0001), and oleic acid (r = 0.31, p < .001). Quercetin also showed a significant negative correlation with linoleic acid (r = -0.49, p < .0001). These correlations are important because useful breeding procedures could be conducted on improving flavonol, oil%, and fatty acid compositions in Teramnus labialis and T. uncinatus accessions.

Cytotoxicity of dietary flavonoids on different human cancer types

Flavonoids are ubiquitous in nature. They are also in food, providing an essential link between diet and prevention of chronic diseases including cancer. Anticancer effects of these polyphenols depend on several factors: Their chemical structure and concentration, and also on the type of cancer. Malignant cells from different tissues reveal somewhat different sensitivity toward flavonoids and, therefore, the preferences of the most common dietary flavonoids to various human cancer types are analyzed in this review. While luteolin and kaempferol can be considered as promising candidate agents for treatment of gastric and ovarian cancers, respectively, apigenin, chrysin, and luteolin have good perspectives as potent antitumor agents for cervical cancer; cells from main sites of flavonoid metabolism (colon and liver) reveal rather large fluctuations in anticancer activity probably due to exposure to various metabolites with different activities. Anticancer effect of flavonoids toward blood cancer cells depend on their myeloid, lymphoid, or erythroid origin; cytotoxic effects of flavonoids on breast and prostate cancer cells are highly related to the expression of hormone receptors. Different flavonoids are often preferentially present in certain food items, and knowledge about the malignant tissue-specific anticancer effects of flavonoids could be purposely applied both in chemoprevention as well as in cancer treatment.

Fruit-derived phenolic compounds and pancreatic cancer: perspectives from Australian native fruits

ETHNOPHARMACOLOGICAL RELEVANCE

Pancreatic cancer is a devastating cancer that presents late, is rapidly progressive and has current therapeutics with only limited efficacy. Bioactive compounds are ubiquitously present in fruits and numerous studies in vitro are addressing the activity of these compounds against pancreatic cancer, thus studies of specific bioactive compounds could lead to new anti-pancreatic cancer strategies. Australian native fruits have been used as foods and medicines by Australian Aboriginals for thousands of years, and preliminary studies have found these fruits to contain rich and diversified bioactive components with high antioxidant activity. Thus, Australian native fruits may possess key components for preventing or delaying the onset of tumorigenesis, or for the treatment of existing cancers, including pancreatic cancer.

MATERIALS AND METHODS

Numerous databases including PubMed, SciFinder, Web of Knowledge, Scopus, and Sciencedirect were analysed for correlations between bioactive components from fruits and pancreatic cancer, as well as studies concerning Australian native fruits.

RESULTS

In this review, we comprehensively highlight the proposed mechanisms of action of fruit bioactives as anti-cancer agents, update the potential anti-pancreatic cancer activity of various major classes of bioactive compounds derived from fruits, and discuss the existence of bioactive compounds identified from a selection Australian native fruits for future studies.

CONCLUSION

Bioactive compounds derived from fruits possess the potential for the discovery of new anti-pancreatic cancer strategies. Further, Australian native fruits are rich in polyphenols including some flora that contain unique phenolic compounds, thereby warranting further investigations into their anti-cancer properties.

Reality check: there is no such thing as a miracle food

A recent episode of the Dr. Oz Show suggested endive, red onion, and sea bass as foods that can decrease the risk of ovarian cancer by up to 75%. However, the scientific evidence supporting these recommendations is limited. This commentary discusses some of the concerns related to the promotion of "miracle foods" by the media. Nutritional scientists and epidemiologists should be cognizant of the public health messages that are taken from their individual studies and not sensationalize the findings of a single study.

Assessment of Augmented Immune Surveillance and Tumor Cell Death by Cytoplasmic Stabilization of p53 as a Chemopreventive Strategy of 3 Promising Medicinal Herbs in Murine 2-Stage Skin Carcinogenesis

Cancer is the final outcome of a plethora of events. Targeting the proliferation or inducing programmed cell death in a proliferating population is a major standpoint in the cancer therapy. However, proliferation is regulated by several cellular and immunologic processes. This study reports the inhibition of proliferation by augmenting immune surveillance, silencing acute inflammation, and inducing p53-mediated apoptosis of skin cancer by 3 promising medicinal extracts. We used the well-characterized model for experimental skin carcinogenesis in mice for 32 weeks to study the chemopreventive effect of the methanolic extracts of Trigonella foenumgraecum, Eclipta alba, and Calendula officinalis. All 3 extracts reduced the number, incidence, and multiplicity of tumors, which was confirmed by the pathologic studies that showed regressed tumors. There was a significant reduction in the PCNA+ nuclei in all treatment groups 32 weeks after the initiation. Mechanistic studies revealed that proliferative population in tumors is diminished by the restoration of the endogenous antioxidant defense, inhibition of the stress-related signal-transducing element NFκB, reduction of inflammation, enhancement of immunosurveillance of the genetically mutated cells, along with silencing of the cell cycle progression signals. Finally, all 3 medicinal extracts induced stable expression of p53 within the tumors, confirmed by the CFDA-Cy3 apoptosis assay. Results of our study confirm that these extracts not only limit the rate of proliferation by inhibition of the processes integral to cancer development but also induce stable cytoplasmic expression of p53-mediated apoptosis, leading to fewer and regressed tumors in mice.

Impact of apigenin and kaempferol on human head and neck squamous cell carcinoma

OBJECTIVE

Apigenin and kaempferol are plant flavonoids with reported chemopreventive activities. This study aimed to determine the effect of apigenin and kaempferol on cell viability in cultured cells derived from the pharynx (FaDu cell line), an oral cavity carcinoma (PCI-13 cell line), and a metastatic lymph node (PCI-15B cell line) and in explanted FaDu cells.

STUDY DESIGN

The in vitro viability of FaDu, PCI-13, and PCI-15B cells treated with apigenin and kaempferol was determined. Tumor growth of FaDu explants was evaluated in athymic mice that were gavaged with either apigenin or kaempferol.

RESULTS

Although apigenin and kaempferol treatment decreased viability of cells in vitro, cell-type-dependent differences in responsiveness were observed. In vivo apigenin treatment significantly increased the tumor size of FaDu explants. Results obtained using kaempferol were similar.

CONCLUSIONS

The in vitro decrease in FaDu cell viability by apigenin and kaempferol was not observed in in vivo tumor explants using the conditions described in this study.

Kaempferol promotes apoptosis in human bladder cancer cells by inducing the tumor suppressor, PTEN

Kaempferol (Kae), a natural flavonoid, is widely distributed in fruits and vegetables. Previous studies have identified Kae as a possible cancer preventive and therapeutic agent. We found Kae to exhibit potent antiproliferation and anti-migration effects in human bladder cancer EJ cells. Kaempferol robustly induced apoptosis in EJ cells in a dose-dependent manner, as evidenced by increased cleavage of caspase-3. Furthermore, we found Kae-induced apoptosis in EJ cells to be associated with phosphatase and the tensin homolog deleted on the chromosome 10 (PTEN)/PI3K/Akt pathway. Kae significantly increased PTEN and decreased Akt phosphorylation. Kae-induced apoptosis was partially attenuated in PTEN-knockdown cells. Our findings indicate that Kae could be an alternative medicine for bladder cancer, based on a PTEN activation mechanism.

Venus Flytrap (Dionaea muscipula Solander ex Ellis) Contains Powerful Compounds that Prevent and Cure Cancer

Chemoprevention uses natural or synthetic molecules without toxic effects to prevent and/or block emergence and development of diseases including cancer. Many of these natural molecules modulate mitogenic signals involved in cell survival, apoptosis, cell cycle regulation, angiogenesis, or on processes involved in the development of metastases occur naturally, especially in fruits and vegetables bur also in non-comestible plants. Carnivorous plants including the Venus flytrap (Dionaea muscipula Solander ex Ellis) are much less investigated, but appear to contain a wealth of potent bioactive secondary metabolites. Aim of this review is to give insight into molecular mechanisms triggered by compounds isolated from these interesting plants with either therapeutic or chemopreventive potential.

Acceleration of pro-caspase-3 maturation and cell migration inhibition in human breast cancer cells by phytoconstituents of Rheum emodi rhizome extracts

The aggressive nature of estrogen receptor (ER)-negative breast cancer subtype obligates for innovative targeted therapies. The present study aimed to investigate the phytoconstituents and specific anticancer activities of Rheum emodi rhizome, a known food source used locally to treat various ailments. Petroleum ether extracts (hot [PHR] and cold [PCR]) of R. emodi, exhibited significant free radical scavenging potentials through DPPH and reducing power assays, rendering them as good sources of antioxidants. The extracts, PHR and PCR had shown significant (P < 0.05) cancer-cell-specific cytotoxicity in the assayed cells (MDA-MB-231 [breast carcinoma] and WRL-68 [non-tumoral]) at 100 μg/ml, and 50 and 100 μg/ml concentrations respectively. Extracts also induced fervent apoptosis in ER-negative cells (MDA-MB-231) compared to ER-positive subtype (MCF-7), and found to involve CPP32/caspase-3 in its apoptosis induction mechanism. Moreover, extracts had an inevitable potential to inhibit the migration of metastatic breast cancer cells (MDA-MB-231) in vitro. Further, the active principles of extracts were identified through HPLC and GC-MS analysis to reveal major polyphenolics, 4,7-Dimethyl-(octahydro)indolo[4,3-fg]quinolin-10-one, 5-Oxo-isolongifolene, Valencene-2, and other quinone, quinoline and anthraquinone derivatives. The extracts are thus good candidates to target malignant ER-negative breast cancer, and the identified phytoconstituents could be eluted in further exploratory studies for use in dietary-based anti-breast cancer therapies.