Targeting specific cell signaling transduction pathways by dietary and medicinal phytochemicals in cancer chemoprevention

Mechanistic evaluation of myristicin on apoptosis and cell cycle regulation in breast cancer cells

The current study was focused on the anticancer activity of myristicin against MCF-7 human breast cancer (BC) cells. BC is the most common and leading malignant disease in women worldwide. Now-a-days, various conventional therapies are used against BC and still represent a chief challenge because those treatments fail to differentiate normal cells from malignant cells, and they have severe side effects also. So, there is a need develop new therapies to decrease BC-related morbidity and mortality. Myristicin, a 1‑allyl‑5‑methoxy‑3, 4‑methylenedioxybenzene, is a main active aromatic compound present in various spices, such as nutmeg, mace, carrot, cinnamon, parsely and some essential oils. Myristicin has a wide range of effects, including antitumor, antioxidative and antimicrobial activity. Nevertheless, the effects of myristicin on human BC cells remain largely unrevealed. The cytotoxicity effect of myristicin on MCF‑7 cells was increased dose dependently detected by (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and Lactate Dehydrogenase assays. Myristicin was found to be significantly inducing the cell apoptosis, as compared to control, using acridine orange/ethidium bromide, Hoechst stain and annexin V. Moreover, it activates cell antimigration, intracellular reactive oxygen species generation and cell cycle arrest in the G1/S phase. In addition, myristicin induces the expression of apoptosis and cell cycle genes (Caspases8, Bax, Bid, Bcl2, PARP, p53, and Cdk1) was demonstrated by quantitative polymerase chain reaction and apoptosis proteins (c-PARP, Caspase 9, Cytochrome C, PDI) expression was also analyzed with western blot. Overall, we illustrated that myristicin could regulate apoptosis signaling pathways in MCF-7 BC cells.

Platycodin D induces apoptosis via regulating MAPK pathway and promotes autophagy in colon cancer cell

Platycodin D (PD) is the main component of triterpene saponins found in Platycodi radix. In this study, we observed a decrease in cell viability, an increase in apoptotic bodies, and an increase in the rate of apoptosis. Also, we observed an increase in cleaved PARP and Bax, a decrease in Bcl-2, and p-ERK, and an increase in p-p38 and p-JNK. Furthermore, a change in cell viability and the expression of p-p38, Bax, and Bcl-2 using the p38 inhibitor revealed a decrease in p-p38 and Bax and an increase in Bcl-2 in the inhibitor treatment group. In addition, we observed an increase in vacuole formation through morphological changes and an increase in acidic vesicular organelles (AVOs). We also observed an increase in the expression of beclin 1, LC 3-I, and -II. There was no significant decrease in cell viability in the group treated with 3-MA, but a decrease in cell viability was noted in the group treated with HCQ. HCQ treatment resulted in an increase in Bax and a decrease in Bcl-2. These findings reveal that in HT-29 colon cancer cells, PD induces apoptosis through the MAPK pathway, thereby exerting anticancer effects. Moreover, autophagy caused by PD inhibits apoptosis by protecting the cells.

In Vitro Modulation of Genotoxicity and Oxidative Stress by Polyphenol-Rich Fraction of Chinese Ladder Brake (Pteris vittata L.)

Pteris vittata L. is a terrestrial genus growing in moist, shady forests and on hillsides. The plant has considerable ethnomedicinal importance. Investigations have been carried out on chemical profiling and antioxidant compounds from some genera of pteridophytes but studies on the biological properties of P. vittata are lacking. Therefore, the present study investigates antioxidant, antigenotoxic, and antiproliferative potential of the aqueous fraction of P. vittata (PWE). A battery of assays were carried out to assess the antioxidant potential of the PWE. SOS chromotest and DNA nicking assay were used to evaluate the antigenotoxicity of the fraction. The cytotoxic effect of PWE was analyzed using MTT and Neutral Single Cell Gel Electrophoresis comet assay. EC50 of 90.188 µg/ml, 80.13 µg/ml, 142.836 µg/ml, and 12.274 µg/ml was obtained in DPPH, superoxide anion scavenging, reducing power and lipid peroxidation assays, respectively. PWE was potent in inhibiting Fenton's reagent-induced nicking of pBR322 plasmid. The fraction significantly inhibited hydrogen peroxide (H2O2) and 4-nitroquinoline-N-oxide (4NQO) induced mutagenicity and a reduction in induction factor was found with increased PWE concentration. GI50 of 147.16 µg/ml was obtained in MTT assay in human MCF-7 breast cancer cell line. PWE induced apoptosis as confirmed from confocal microscopy studies. The protective effects can be attributed to the presence of the phytochemicals in PWE. These results will be helpful in the development of functional food characteristics, as well as unravel the benefits of pteridophytes as promoters of health.

c-Jun N-terminal Kinase (JNK), p38, and Caspases: Promising Therapeutic Targets for the Regulation of Apoptosis in Cancer Cells by Phytochemicals

Abstract:

Carcinogenesis is a process in which uncontrolled cell proliferation forms preneoplastic nodules which precede the appearance of cancer. In normal cells, growth and proliferation are regulated by certain growth and hormonal stimulation, while mutational alterations in these signals render the cells independent and resistant to these signals. In cancer, the critical homeostatic balance between cell growth and apoptosis is lost and the cells continue to survive beyond their normal life span. The activation of c-Jun N-terminal kinase (JNK), p38 and caspases are involved in potential proapoptotic signaling pathways. JNK, p38 MAPK pathway and caspases play a crucial role in the control of apoptosis in response to stress. The most recent and up-to-date literature was evaluated in this study, which describes the role of JNK, p38 MAPK pathway and caspases as therapeutic target in cancer. Chemotherapy uses drugs that are cytotoxic to highly proliferating tumor cells but also kills the non-tumor rapidly proliferating cells in the hair, skin and gastrointestinal tract epithelium, thereby accounting the side effects of these types of treatments. Recently, chemopreventive modalities derived from phytoconstituents present in plants provide a broad-spectrum strategy to overcome the incidence of cancer. Non-toxic, safe and affordable bioavailabilities of chemopreventive agents provide credence support in the field of cancer research compared to conventional therapies that cause serious consequences. Chemoprevention envisages the basic mechanisms like modulating the activity of xenobiotic-metabolizing enzymes, induction of apoptosis, immune system activation, suppressing angiogenesis and the formation of metastasis, antioxidant and anti-inflammatory properties. The present review highlighted the role of phytoconstituents derived from food, vegetables and medicinal plants in the induction of apoptosis in cancer cells, which in turn is mediated by the activation of JNK, p38 MAPK pathways, and caspases.

Antioxidant and Antitumor Potential of Micropropagated Balkan Endemic Sideritis scardica Griseb

Sideritis scardica Griseb. is a critically endangered Balkan endemic species, known for its antioxidant, neuroprotective and anti-inflammatory properties. The aim of the present study was to detail an efficient protocol for the micropropagation of S. scardica. In vitro cultures were initiated from the shoot tips of 40 days-old in vivo seedlings and the effects of different plant growth regulator treatments were examined. A Murashige and Skoog nutrient medium (MS) containing 1 mg/L zeatin and 0.1 mg/L indole-3-acetic acid (IAA) proved to be the most efficient for shoot multiplication as it produced quality, vigorous shoots with a mean number of six shoots per explant. For the first time, the antioxidant and antitumor activities of extracts from in vitro-obtained plants were evaluated. In vitro cultivated plants grown in the field revealed a higher total polyphenol content (3929.1 ± 112.2 mg GAE/100 g vs. 3563.5 ± 52.8 mg GAE/100 g) and higher ORAC antioxidant activity (1211.6 ± 27.3 µmol TE/g vs. 939.9 ± 52.4 µmol TE/g) than in situ cultivated plants. A comparison of the antitumor activities of extracts from in vitro propagated shoots, field-grown in vitro-obtained plants and in situ plants on HeLa (cervical adenocarcinoma), HT-29 (colorectal adenocarcinoma) and MCF-7 (breast cancer) human cancer cell lines showed that in vitro propagated shoots had a significant concentration-dependent cytotoxic effect on the cervical adenocarcinoma cell line HeLa, while the field-grown in vitro-obtained and in situ-collected samples induced the highest reduction in the viability of the mammary carcinoma cell line MCF-7. In both cases, the cells of the control non-tumor cell line, BALB/3T3, were significantly less affected. The results showed that the in vitro multiplication protocol ensured the obtainment of numerous plants with antioxidant and antitumor potential.

Therapeutic efficacy of sorafenib and plant-derived phytochemicals in human colorectal cancer cells

BACKGROUND

The present study aimed to investigate the sequence-dependent anticancer effects of combined treatment with sorafenib (Sora), a Food and Drug Administration-approved multikinase inhibitor drug, and plant-derived phytochemicals (PPCs) on human colorectal cancer (CRC) cell growth, and proteins associated with the control of cell cycle and apoptosis.

METHODS

The cytotoxic effects of 14 PPCs on CRL1554 fibroblast cells were determined using an MTT assay. Moreover, the cytotoxicity of Sora, PPCs, and a combination of both on CRC cells were also investigated. Cell cycle analysis was performed using flow cytometry, and cell apoptosis was investigated using DNA fragmentation, Annexin V/propidium iodide double staining, and mitochondrial membrane potential analyses. The cell cycle- and apoptosis-associated protein expression levels were analysed using western blotting.

RESULTS

Based on their low levels of cytotoxicity in CRL1554 cells at ≤ 20%, curcumin, quercetin, kaempferol, and resveratrol were selected for use in subsequent experiments. The combined treatment of sora and PPCs caused levels of CRC cytotoxicity in a dose-, cell type-, and schedule-dependent manner. Moreover, the combined treatment of CRC cells arrested cell growth at the S and G2/M phases, induced apoptotic cell death, caused extensive mitochondrial membrane damage, and altered the expression of the cell cycle and apoptotic proteins.

CONCLUSIONS

Results of the present study highlighted a difference in the level of sora efficacy in CRC cells when combined with PPCs. Further in vivo and clinical studies using the combined treatment of sora and PPCs are required to determine their potential as a novel therapeutic strategy for CRCs.

ZnO Nanocomposites of Juniperus procera and Dodonaea viscosa Extracts as Antiproliferative and Antimicrobial Agents

Cancer and microbial infections constitute a major burden and leading cause of death globally. The development of therapeutic compounds from natural products is considered a cornerstone in drug discovery. Therefore, in the present study, the ethanolic extract and the fractions of Dodonaea viscosa and Juniperus procera were evaluated for anticancer and antimicrobial activities. It was found that two fractions, JM and DC, exhibited promising anticancer and antimicrobial activities. The JM and DC fractions were further modified into ZnO nanocomposites, which were characterized by SEM, XRD, TGA, and EDX. It was noted that the synthesized nanocomposites displayed remarkable enhancement in cytotoxicity as well as antibacterial activity. Nanocomposite DC–ZnO NRs exhibited cytotoxicity with IC₅₀ values of 16.4 ± 4 (HepG2) and 29.07 ± 2.7 μg/mL (HCT-116) and JM–ZnO NRs with IC₅₀ values of 12.2 ± 10.27 (HepG2) and 24.1 ± 3.0 μg/mL (HCT-116). In addition, nanocomposites of DC (i.e., DC–ZnO NRs) and JM (i.e., JM–ZnO NRs) displayed excellent antimicrobial activity against Staphylococcus aureus with MICs of 2.5 and 1.25 μg/mL, respectively. Moreover, these fractions and nanocomposites were tested for cytotoxicity against normal fibroblasts and were found to be non-toxic. GC-MS analysis of the active fractions were also carried out to discover the possible phytochemicals that are responsible for these activities.

Farnesol alleviates diethyl nitrosamine induced inflammation and protects experimental rat hepatocellular carcinoma

Hepatocellular carcinoma is a well-known internal malignancy with increased worldwide mortality. The increased progression rate is closely associated with chronic liver diseases such as cirrhosis. Chemical carcinogens cause tumor advocacy over free radical metabolites to causes numerous biochemical and molecular changes that bring oxidative stress. In addition, inflammatory cells and its growth factor promotes the progression of liver cancer through deregulates the numerous cellular signaling pathways involved in normal cellular proliferation. Plant derived phytochemicals have a better complimentary potency to defend against a wide array of free radical mediated diseases such as cancer. More recently, we have evaluated the anticancer effect of Farnesol against DEN induced hepatocellular carcinoma in male wistar albino rats. However, the possible mechanism in which Farnesol attributes its anticancer effect against DEN induced liver cancer remains unknown. Hence in the present study, an attempt has been made to reduce the oxidative stress by appraise the antioxidant effect by Farnesol in DEN induced hepatocellular carcinoma. Elevated oxidative stress markers with concomitant decreased cellular antioxidants levels were observed in DEN induced hepatic tissues. Further, proliferating nuclei with increased proliferating cell nucleolar antigen (PCNA) and inflammatory mediator expression were observed in DEN induced rats. Oral supplementation of Farnesol to DEN induced rats significantly decrease the oxidative stress markers and increase the cellular antioxidant status. Moreover, Farnesol treatment decreases the argyrophilic nuclear organizer region and PCNA along with decreased expression of inflammatory mediators suggest that Farnesol treatment restores DEN induced hepatic abnormalities and protects liver from cancer progression.

Phytodentistry in Africa: prospects for head and neck cancers

Background

Orthodox dentistry has undergone significant changes in recent times with the introduction of various omics and molecular targeted therapies both at the experimental/trial and clinical implementation level. Although, significant milestones have been achieved in the molecular dentistry field in the past decade, there remains a dearth of application of phytopharmacological innovation in personalized and targeted therapies for dental diseases.

Main body

From time immemorial, plant products have long been an integral aspect of dental practice ranging from chewing sticks/herbal kinds of toothpaste to dental/impression materials. The current era of precision medicine seeks to apply a multipronged molecular and bio-computational approaches to solve fundamental medical problems that have hitherto remained difficult. Remarkable changes in the molecular/omics era, have transformed empirical therapies into personalized/individualized ones. Furthermore, the combinatorial application and the widespread introduction of high-throughput molecular tools such as pharmacogenomics, phytopharmacology, metabolomics, mathematical modelling, and genetic engineering inter alia, has tremendously improved the diagnostic and therapeutic landscape of medicine. Additionally, the variable molecular epidemiology of diseases among different population and emerging molecular evidence warrants the use of customized novel theranostic techniques. Unfortunately, the footprint of such emerging application is sparse in dental diseases such as maxillofacial cancers.

Conclusion

Hence, this review seeks to evaluate the potential application of phytopharmacological approaches to head and neck cancers in a resource-limited environment, such as Africa.

Quercetin and Luteolin Improve the Anticancer Effects of 5-Fluorouracil in Human Colorectal Adenocarcinoma In Vitro Model: A Mechanistic Insight

The aim of this study was to investigate the antitumor effects of quercetin and luteolin combined with 5-Fluorouracil (5-FU) in HT-29 human colorectal cancer cells. Cell viability induced by quercetin, luteolin and combination of these compounds with 5-FU were determined by MTT assay, also Cell death detection Elisa assay and fluorescence microscopy were performed to investigate apoptotic effects. Hu-VEGF Elisa assay was employed to determine the effects of treatments on angiogenesis. Western blot and qRT-PCR analysis were performed to investigate effects on p53, Bax, Bcl-2, p38 MAPK, mTOR, PTEN, and Akt proteins and genes. The results indicated that quercetin, luteolin and combinations of these compounds with 5-FU inhibited the growth of HT 29 cells. Compared to the control, apoptosis were triggered 8.1 and 10.1 fold in HT-29 cells, that treated with quercetin + 5-FU and luteolin + 5-FU, respectively. VEGF amount significantly decreased by combined treatments. qRT-PCR and western blot results demonstrated that quercetin, luteolin and the combinations of these flavonoids with 5-FU, modulate the apoptotic pathways in HT-29 cells. The increase in p53, Bax, p38 MAPK, and PTEN gene expression levels compared to the control group was 1.71, 1.42, 3.26, and 3.29-fold with 5-FU + L treatment, respectively, while this increase was 8.43, 1.65, 3.55, and 3.54-fold with 5-FU + Q treatment, respectively. In addition, when the anti-apoptotic Bcl-2, mTOR, and Akt gene expression levels were normalized as 1 in the control group, they were 0.28, 0.41, and 0.22 with 5-FU + L treatment, and 0.32, 0.46, and 0.39, respectively, with 5-FU + Q treatment. These findings suggested that quercetin and luteolin synergistically enhanced the anticancer effect of 5-FU in HT 29 cells and may therefore minimize the toxic effects of 5-FU in the clinical treatment of colorectal cancer.

Resveratrol Modulation of Apoptosis and Cell Cycle Response to Cisplatin in Head and Neck Cancer Cell Lines

In head and neck cancers, the effectiveness of cisplatin (CisPt) treatment is limited by its toxicity, especially when higher doses are necessary, and the possible occurrence of cisplatin resistance. This study evaluated the effects of resveratrol (RSV) on the expression of different genes involved in the response of human tumor cells (FaDu, PE/CA-PJ49) to cisplatin therapy. Our results revealed that RSV induced apoptosis amplification in both FaDu and PE/CA-PJ49 cells and modulated the expression of specific genes differently than in normal HaCaT cells. In FaDu cells, combined CisPt + RSV treatment induced an increase in apoptosis, which was associated with an increase in c-MYC and TP53 and a decrease in BCL-2 expression. While CisPt + RSV treatment induced apoptosis in PE/CA-PJ49 cells by inhibition of BCL-2 associated with high levels of MDM-2 and subsequently led to inhibition of TP53 gene expression. Decreased c-MYC expression in PE/CA-PJ49 treated with CisPt + RSV was accompanied by cell cycle blockage in G0/G1 phase. In conclusion, RSV influences tumor cell response to CisPt by inducing apoptosis and modulating gene expression. In addition, in normal HaCaT cells, RSV was able to reduce the harmful effects of CisPt.

Emu Oil Attenuates Disease Severity and Results in Fewer Large Colonic Tumors in a Mouse Model of Colitis-Associated Colorectal Cancer

Ulcerative colitis patients have an increased risk of developing colorectal cancer (CRC). The aim of the current study was to determine whether Emu Oil (EO) could reduce the severity of colitis, thereby inhibiting colitis-associated CRC (CA-CRC) development. Female C57BL/6 mice (n = 8/group) were injected (i.p.) with saline or azoxymethane (AOM) (7.4 mg/kg). Mice underwent three dextran sulfate sodium (DSS)/water cycles. Mice were orally-administered either water (160 µL) or EO (80 µL or 160 µL) thrice weekly and euthanized after 12 weeks. AOM/DSS decreased bodyweight compared with normal controls (max. 20%; p < 0.05). In AOM/DSS mice, EO (160 µL) increased bodyweight compared with untreated and 80 µL EO-treated mice (max. 10%; p < 0.05). Both volumes of EO reduced disease activity index (DAI) scores on day 49, 56-63 (max. 40%; p < 0.05), compared with AOM/DSS controls. Histological damage was increased in the distal colon of AOM/DSS mice, and reduced by EO (160 µL; p < 0.05). Mucin-secreting goblet cells were increased by AOM/DSS compared to normal, with no effect observed following EO treatment (p > 0.05). Large tumor numbers were decreased in EO-treated mice (160 µL; 2 ± 0.6) compared with AOM/DSS controls (5 ± 0.7; p < 0.05). EO did not impact overall tumor number (p > 0.05). Other analyses remained unchanged across groups (p > 0.05). EO demonstrates promise as an adjunct to conventional treatment options for colitis management.

Essential oil chemical composition, antimicrobial, anticancer, and antioxidant effects of Thymus convolutus Klokov in Turkey

In this study, the chemical composition, antimicrobial, antioxidant, and anticancer effects of Thymus convolutus Klokov oil and its main compound camphor were investigated. The oil was isolated from T. convolutus using hydrodistillation method, analyzed by gas chromatography/mass spectrometry (GC-MS), and 66 compounds were identified. The main component was determined as camphor at 16.6%. The antioxidant properties were identified with the DPPH (2,2'-diphenyl-1-picrylhydrazyl) radical-scavenging method and, 33.39 ± 0.25% DPPH was scavenging in 1000 μg/mL of essential oil. The strong antimicrobial activity was observed against Escherichia coli, Enterobacter aerogenes, Proteus vulgaris, and Pseudomonas aeruginosa with MIC values of 125 μg/mL. Aspergillus flavus was more sensitive (28%) against T. convolutus essential oil than other fungi. The cytotoxic effect of oil was analyzed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) method. Camphor was effective on human hepatoma cells (Hep3B) at concentrations of 1 mg/mL, 500, 250, and 125 μg/mL, while essential oil of T. convolutus was found to be effective at concentrations of 250 and 125 μg/mL. A reduction in cell proliferation was observed in colon carcinoma cells (HT-29) treated with 500 μg/mL camphor for 48 h. No statistically significant effect was found in Umbilical Vein Endothelial Cells (HUVEC) treated with essential oil and camphor.

Nanotechnology-Based Strategies for Berberine Delivery System in Cancer Treatment: Pulling Strings to Keep Berberine in Power

Cancer is a multifactorial disease characterized by complex molecular landscape and altered cell pathways that results in an abnormal cell growth. Natural compounds are target-specific and pose a limited cytotoxicity; therefore, can aid in the development of new therapeutic interventions for the treatment of this versatile disease. Berberine is a member of the protoberberine alkaloids family, mainly present in the root, stem, and bark of various trees, and has a reputed anticancer activity. Nonetheless, the limited bioavailability and low absorption rate are the two major hindrances following berberine administration as only 0.5% of ingested berberine absorbed in small intestine while this percentage is further decreased to 0.35%, when enter in systemic circulation. Nano-based formulation is believed to be an ideal candidate to increase absorption percentage as at nano scale level, compounds can absorb rapidly in gut. Nanotechnology-based therapeutic approaches have been implemented to overcome such problems, ultimately promoting a higher efficacy in the treatment of a plethora of diseases. This review present and critically discusses the anti-proliferative role of berberine and the nanotechnology-based therapeutic strategies used for the nano-scale delivery of berberine. Finally, the current approaches and promising perspectives of latest delivery of this alkaloid are also critically analyzed and discussed.

Castanea sativa Mill. bark extract cardiovascular effects in a rat model of high-fat diet

Ellagitannins may have a beneficial impact in cardiovascular diseases. The aim of the study was to evaluate the effect of high-fat diet (HFD) and the efficacy of Castanea sativa Mill. bark extract (ENC) on cardiac and vascular parameters. Rats were fed with regular diet, (RD, n = 15), HFD (n = 15), RD + ENC (20 mg/kg/day by gavage, n = 15), and HFD + ENC (same dose, n = 15) and the effects on body weight, biochemical serum parameters, and inflammatory cytokines determined. Cardiac functional parameters and aorta contractility were also assessed on isolated atria and aorta. Results showed that ENC reduced weight gain and serum lipids induced by HFD. In in vitro assays, HFD decreased the contraction force of left atrium, increased right atrium chronotropy, and decreased aorta K⁺ -induced contraction; ENC induced transient positive inotropic and negative chronotropic effects on isolated atria from RD and HFD rats and a spasmolytic effect on aorta. In ex vivo experiments, ENC reverted inotropic and chronotropic changes induced by HFD and enhanced Nifedipine effect more on aorta than on heart. In conclusion, ENC restores metabolic dysfunction and cardiac cholinergic muscarinic receptor function, and exerts spasmolytic effect on aorta in HFD rats, highlighting its potential as nutraceutical tool in obesity.

Anti-Proliferative and Genotoxic Activities of the Helichrysum petiolare Hilliard & B.L. Burtt

Helichrysum petiolare (Asteraceae family) is part of the Helichrysum genus which comprises of an estimated 600 species. Several parts of the plant have been used traditionally for the treatment of various ailments, such as cough, infection, asthma, chest problems, diabetes and wounds. Given its various chemical constituents with anticancer properties, there has been no scientific evidence of its usage for the treatment of cancer. This study aims to investigate the anti-proliferative and genotoxic activities of H. petiolare methanol extract. The cytotoxic effect and cell cycle analysis of mouse melanoma cells (B16F10) and human melanoma cells (MeWo) were assessed using the ImageXpress Micro XLS Widefield High-Content Analysis System. The genotoxic potential of the extract towards Vero cells was also assessed using the micronucleus assay. The extract displayed cytotoxicity towards B16F10 and MeWo skin melanoma cells, thereby showing a dose-dependent decrease in cell density. This was preceded by cell cycle arrest in B16F10 cells at the S phase and MeWo cell arrest at the early M phase with a significant increase in apoptosis in both cells. Furthermore, the extract displayed genotoxic potential at the tested concentrations (12.5–200 μg/mL). Overall, the results revealed that H. petiolare extract may have the potential to eradicate skin cancer.

Berberine reverses epithelial-mesenchymal transition and modulates histone methylation in osteosarcoma cells

Osteosarcoma is the most frequently occurring cancer in children as well as young adolescents and the metastatic forms worsen this condition to a further great extent. The metastatic dissemination of cancer cells is often acquired through a process of epithelial-mesenchymal transition (EMT). Since, phytochemicals have attracted intense interest in recent years due to their diverse pharmacological effects, in the present study, we investigated if berberine, a naturally occurring isoquinoline quaternary alkaloid, could modulate the EMT in osteosarcoma cells. Our experimental studies showed that berberine reduced cell viability, colony formation, wound healing ability and migration of osteosarcoma cells. Also, berberine significantly reduced the expression of matrix metalloproteinase (MMP)-2, suggesting its inhibitory action on the matrix metalloproteinases that are required for cancer cell invasion. The significant reduction in the expression of vimentin, N-cadherin, fibronectin and increased expression of E-cadherin further suggested its role in the inhibition of EMT in osteosarcoma cells. The downregulation of H3K27me3, as well as the decreased expression of the histone methyl transferase enzyme EZH2, further substantiated the fact that the plant alkaloid can be used as an epigenetic modulator in the treatment of osteosarcoma. In conclusion, our findings suggest that berberine inhibits proliferation and migration of osteosarcoma cells and most importantly reverses EMT along with modulation of key epigenetic regulators.

Antiproliferative and apoptogenic effects of Cassia fistula L. n-hexane fraction against human cervical cancer (HeLa) cells

The current study was performed to evaluate the antiproliferative and apoptosis-inducing potential of n-hexane fraction from Cassia fistula L. (Caesalpinioideae) fruits. The antiproliferative property of the fraction was determined by MTT assay against cancer cell lines including HeLa, MG-63, IMR-32, and PC-3 with GI50 value of 97.69, 155.2, 143, and 160.2 μg/ml respectively. The fraction was further explored for its apoptotic effect using confocal, SEM, and flow cytometry studies in HeLa cells. It was observed that the treatment of fraction revealed fragmentation of DNA, chromatin condensation, membrane blebbing, and formation of apoptotic bodies in a dose-dependent manner. The fraction also showed a remarkable increase in the level of ROS, mitochondrial depolarization and G0/G1 phase cell cycle arrest, and induction in the phosphatidylserine externalization analyzed using Annexin V-FITC/PI double staining assay in HeLa cells. Kaempferol, Ellagic acid, and Epicatechin are the major phytoconstituents present in the fraction as revealed by the HPLC. The treatment of n-hexane fraction showed downregulation in the gene expression of Bcl-2 and upregulation in the expression level of p53, Bad, and caspase-3 genes analyzed using semi-quantitative RT-PCR in HeLa cells. These results suggest that n-hexane fraction from C. fistula inhibited the proliferation of cervical cancer cells efficiently by the induction of apoptosis. Graphical abstract.

Antiproliferative Effect and Cell Cycle Alterations Induced by Salvia officinalis Essential Oil and Its Three Main Components in Human Colon Cancer Cell Lines

Colon cancer is one of the most common human malignancies, and chemotherapy cannot yet prevent recurrence in all patients. Essential oils are phytocomplexes with antiproliferative properties. In this study, we elucidated the antiproliferative properties and the effect on cell cycle progression of Sicilian Salvia officinalis essential oil and its three main compounds, α-thujone, 1,8-cineole (eucalyptol) and camphor, on three human colon cancer cell lines. The essential oil was obtained by hydrodistillation and analyzed by gas chromatography. Cell proliferation was evaluated by MTT assay, and the cell cycle distribution was determined by flow cytometry. Thirty-four compounds were identified in the tested essential oil. Growth inhibition was observed after 72 h, with an impact on cell cycle progression and no effect on the viability of normal colonic epithelial cells. The study shows that S. officinalis essential oil and its three main components have an in vitro antiproliferative effect on colon cancer cells.

Citrus auraptene induces drug efflux transporter P-glycoprotein expression in human intestinal cells

P-glycoprotein (encoded by MDR1) is a membrane transport protein expressed in the intestine, liver, kidney, placenta, and blood-brain barrier. It excludes various clinically important drugs from cells, such as verapamil, digoxin, tacrolimus, and vinblastine. Therefore, human P-glycoprotein plays important roles in drug absorption, distribution, and excretion. We reported previously that auraptene, a natural compound occurring widely in citrus fruit (e.g., grapefruit), inhibited P-glycoprotein-mediated drug transport. In this study, we investigated the effects of auraptene and other phenylpropanoids on P-glycoprotein expression using human intestinal epithelial LS174T cells and a reporter plasmid expressing 10.2 kbp of the upstream regulatory region of MDR1. Auraptene (7-geranyloxycoumarin), a prenylated coumarin, and several phenylpropanoids, such as 3-(4'-geranyloxy-3'-methoxyphenyl)-2-trans propenoic acid, derricidin [2'-hydroxy-4'-(prenyloxy)chalcone], and 3-(4'-geranyloxyphenyl)-propanoic acid, induced MDR1 promoter activity in LS174T cells. Overexpression of the nuclear receptor human pregnane X receptor gene (NR1I2) enhanced auraptene-induced MDR1 activation. Nuclear factor-kappaB inhibitors, Bay11-7082 and JSH-23, repressed MDR1 activation by auraptene. Western blot analyses showed the induction of P-glycoprotein expression in the auraptene-treated LS174T cells. The citrus phytochemical auraptene can induce the drug efflux transporter P-glycoprotein in human intestinal cells, and thus has the potential to cause food-drug interactions.

Diet-Derived Phytochemicals Targeting Colon Cancer Stem Cells and Microbiota in Colorectal Cancer

Colorectal cancer (CRC) is a fatal disease caused by the uncontrolled propagation and endurance of atypical colon cells. A person's lifestyle and eating pattern have significant impacts on the CRC in a positive and/or negative way. Diet-derived phytochemicals modulate the microbiome as well as targeting colon cancer stem cells (CSCs) that are found to offer significant protective effects against CRC, which were organized in an appropriate spot on the paper. All information on dietary phytochemicals, gut microbiome, CSCs, and their influence on CRC were accessed from the various databases and electronic search engines. The effectiveness of CRC can be reduced using various dietary phytochemicals or modulating microbiome that reduces or inverses the progression of a tumor as well as CSCs, which could be a promising and efficient way to reduce the burden of CRC. Phytochemicals with modulation of gut microbiome continue to be auspicious investigations in CRC through noticeable anti-tumorigenic effects and goals to CSCs, which provides new openings for cancer inhibition and treatment.

Cytotoxic and Apoptotic Induction Potential of Extracts from Fermented Citrullus vulgaris Thunb. Seeds on Cervical and Liver Cancer Cells

The anti-cancer activities of many fermented foods and beverages are now scientifically established. Ogiri-egusi is a condiment prepared from fermentation of Citrullus vulgaris (melon) seeds and consumed in many countries of West Africa. Its anti-oxidative and anti-hyperlipidaemic properties have been reported. This study investigated the anti-cancer activities of the aqueous and methanolic extracts from ogiri-egusi. Cytotoxicity was investigated using the MTT and colony-formation inhibition assays while flow-cytometer based Apopercentage assay was used to quantify apoptosis in extracts-treated cervical and liver cancer and normal human fibroblast cells. The inhibitory concentration responsible for killing 50% of cells after 24 h by the aqueous extract in KMST-6, HeLa, and Hep-G2 cells were estimated at 1.610, 1.020, and 1.507 mg/mL respectively. While these values reduced with increasing incubation time in cancer cells it increased in the non-cancer cell. Furthermore, the extract significantly induced apoptosis in HeLa (97 ± 0.18%) and Hep-G2 (73 ± 6.73%) cells. These findings were corroborated by cells morphologic presentations and inhibition of colony formation assay. These findings suggest that the aqueous extract from fermented Citrullus vulgaris seeds might be a nutraceutical with potential anti-cancer properties.

Chemopreventive Effect of the Germinated Oat and its Phenolic-AVA Extract in Azoxymethane/Dextran Sulfate Sodium (AOM/DSS) Model of Colon Carcinogenesis in Mice

The consumption of fruits, vegetables, nuts, legumes, and whole grains has been associated with a lower risk of colorectal cancer (CRC) due to the content of natural compounds with antioxidant and anticancer activities. The oat (Avena sativa L.) is a unique source of avenanthramides (AVAs), among other compounds, with chemopreventive effects. In addition, oat germination has shown enhanced nutraceutical and phytochemical properties. Therefore, our objective was to evaluate the chemopreventive effect of the sprouted oat (SO) and its phenolic-AVA extract (AVA) in azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced CRC mouse model. Turquesa oat seeds were germinated (five days at 25 °C and 60% relative humidity) and, after 16 weeks of administration, animals in the SO- and AVA-treated groups had a significantly lower inflammation grade and tumor (38–50%) and adenocarcinoma (38–63%) incidence compared to those of the AOM+DSS group (80%). Although both treatments normalized colonic GST and NQO1 activities as well as erythrocyte GSH levels, and significantly reduced cecal and colonic β-GA, thus indicating an improvement in the intestinal parameters, the inflammatory states, and the redox states of the animals, SO exerted a superior chemopreventive effect, probably due to the synergistic effects of multiple compounds. Our results indicate that oats retain their biological properties even after the germination process.

Engineering Plant Cytochrome P450s for Enhanced Synthesis of Natural Products: Past Achievements and Future Perspectives

Cytochrome P450s (P450s) are the most versatile catalysts and are widely used by plants to synthesize a vast array of structurally diverse specialized metabolites that not only play essential ecological roles but also constitute a valuable resource for the development of new drugs. To accelerate the metabolic engineering of these high-value metabolites, it is imperative to identify and characterize pathway P450s, and to further improve their activities through protein engineering. In this review, we focus on P450 engineering and summarize the major strategies for enhancing the stability and activity of P450s and successful cases of P450 engineering. Studies in which the functions of P450s were altered to create de novo metabolic pathways or novel compounds are discussed as well. We also overview emerging tools, specifically DNA synthesis, machine learning, and de novo protein design, as well as the evolutionary patterns of P450s unveiled from a massive number of DNA sequences that could be integrated to accelerate the engineering of these enzymes. These approaches would greatly aid in the exploitation of plant-specialized metabolites or derivatives for various uses including medical applications.

Comparison between tumors in plants and human beings: Mechanisms of tumor development and therapy with secondary plant metabolites

BACKGROUND

Human tumors are still a major threat to human health and plant tumors negatively affect agricultural yields. Both areas of research are developing largely independent of each other. Treatment of both plant and human tumors remains unsatisfactory and novel therapy options are urgently needed.

HYPOTHESIS

The concept of this paper is to compare cellular and molecular mechanisms of tumor development in plants and human beings and to explore possibilities to develop novel treatment strategies based on bioactive secondary plant metabolites. The interdisciplinary discourse may unravel commonalities and differences in the biology of plant and human tumors as basis for rational drug development.

RESULTS

Plant tumors and galls develop upon infection by bacteria (e.g. Agrobacterium tumefaciens and A. vitis, which harbor oncogenic T-DNA) and by insects (e.g. gall wasps, aphids). Plant tumors are benign, i.e. they usually do not ultimately kill their host, but they can lead to considerable economic damage due to reduced crop yields of cultivated plants. Human tumors develop by biological carcinogenesis (i.e. viruses and other infectious agents), chemical carcinogenesis (anthropogenic and non-anthropogenic environmental toxic xenobiotics) and physical carcinogenesis (radioactivity, UV-radiation). The majority of human tumors are malignant with lethal outcome. Although treatments for both plant and human tumors are available (antibiotics and apathogenic bacterial strains for plant tumors, cytostatic drugs for human tumors), treatment successes are non-satisfactory, because of drug resistance and the severe adverse side effects. In human beings, attacks by microbes are repelled by cellular immunity (i.e. innate and acquired immune systems). Plants instead display chemical defense mechanisms, whereby constitutively expressed phytoanticipin compounds compare to the innate human immune system, the acquired human immune system compares to phytoalexins, which are induced by appropriate biotic or abiotic stressors. Some chemical weapons of this armory of secondary metabolites are also active against plant galls. There is a mutual co-evolution between plant defense and animals/human beings, which was sometimes referred to as animal plant warfare. As a consequence, hepatic phase I-III metabolization and excretion developed in animals and human beings to detoxify harmful phytochemicals. On the other hand, plants invented "pro-drugs" during evolution, which are activated and toxified in animals by this hepatic biotransformation system. Recent efforts focus on phytochemicals that specifically target tumor-related mechanisms and proteins, e.g. angiogenic or metastatic inhibitors, stimulators of the immune system to improve anti-tumor immunity, specific cell death or cancer stem cell inhibitors, inhibitors of DNA damage and epigenomic deregulation, specific inhibitors of driver genes of carcinogenesis (e.g. oncogenes), inhibitors of multidrug resistance (i.e. ABC transporter efflux inhibitors), secondary metabolites against plant tumors.

CONCLUSION

The exploitation of bioactive secondary metabolites to treat plant or human tumors bears a tremendous therapeutic potential. Although there are fundamental differences between human and plant tumors, either isolated phytochemicals and their (semi)synthetic derivatives or chemically defined and standardized plant extracts may offer new therapy options to decrease human tumor incidence and mortality as well as to increase agricultural yields by fighting crown galls.

Bioactivity and modulatory functions of Napoleona vogelii on oxidative stress-induced micronuclei and apoptotic biomarkers in mice

Napoleona vogelii is used in traditional medicine for the management of pain, inflammatory conditions and cancer. This study was conducted to investigate the modulatory mechanisms of methanol stem bark extract of N. vogelii on induction of micronuclei, apoptotic biomarkers and in vivo antioxidant enzymes in mice. Forty male albino mice were randomly divided into eight groups (n = 5) and were administered distilled water (DW, 5 mL/kg) as negative control, 100, 200 or 400 mg/kg of the extract respectively for 28 days before the injection of cyclophosphamide (CP, 40 mg/kg) i.p. on the 28th day. The remaining groups were administered 100, 200 or 400 mg/kg of the extract only for 28 days. Twenty four hours after injection of CP or administration of the last dose of extract, animals were euthanized by cervical dislocation and blood samples collected for determination of in vivo antioxidants, the spleen harvested for immunohistochemical expression of NFκB, Bcl-2, Bax and p53. Bone marrow smears were also made for the micronucleus assay. Treatment with the extract resulted in a significant (p < 0.0001) reduction in frequency of micronucleated polychromatic erythrocytes (MNPCEs) compared to CP exposed control conferring protection of 75.09, 94.74 and 96.84% at 100, 200 or 400 mg/kg respectively. In extract and CP exposed animals, there were significant (p < 0.05) increases in GSH, GST and SOD with a corresponding significant (p < 0.05) reduction in MDA. In addition, the extract significantly downregulated cytoplasmic levels of NFκB and Bcl-2 and upregulated Bax and p53. These findings demonstrate that N. vogelli may serve as an interesting lead for chemo-preventive drug development.

Inhibitory effect of purple rice husk extract on AFB1-induced micronucleus formation in rat liver through modulation of xenobiotic metabolizing enzymes

Background

Rice husk, a waste material produced during milling, contains numerous phytochemicals that may be sources of cancer chemopreventive agents. Various biological activities of white and colored rice husk have been reported. However, there are few comparative studies of the cancer chemopreventive effects of white and colored rice husk.

Methods

This study investigated the cancer chemopreventive activities of two different colors of rice husk using in vitro and in vivo models. A bacterial mutation assay using Salmonella typhimurium strains TA98 and TA100 was performed; enzyme induction activity in murine hepatoma cells was measured, and a liver micronucleus test was performed in male Wistar rats.

Results

The white rice husk (WRHE) and purple rice husk (PRHE) extracts were not mutagenic in Salmonella typhimurium TA98 or TA100 in the presence or absence of metabolic activation. However, the extracts exhibited antimutagenicity against aflatoxin B₁ (AFB₁) and 2-amino-3,4 dimethylimidazo[4,5-f]quinolone (MeIQ) in a Salmonella mutation assay. The extracts also induced anticarcinogenic enzyme activity in a murine Hepa1c1c7 hepatoma cell line. Interestingly, PRHE but not WRHE exhibited antigenotoxicity in the rat liver micronucleus test. PRHE significantly decreased the number of micronucleated hepatocytes in AFB₁-initiated rats. PRHE contained higher amounts of phenolic compounds and vitamin E than WRHE in both tocopherols and tocotrienols as well as polyphenol such as cyanidin-3-glucoside, protocatechuic acid and vanillic acid. Furthermore, PRHE increased CYP1A1 and 1A2 activities while decreasing CYP3A2 activity in the livers of AFB₁-treated rats. PRHE also enhanced various detoxifying enzyme activities, including glutathione S-transferase, NAD(P)H quinone oxidoreductase and heme oxygenase.

Conclusions

PRHE showed potent cancer chemopreventive activity in a rat liver micronucleus assay through modulation of phase I and II xenobiotic metabolizing enzymes involved in AFB₁ metabolism. Vitamin E and phenolic compounds may be candidate antimutagens in purple rice husk.

Electronic supplementary material

The online version of this article (10.1186/s12906-019-2647-9) contains supplementary material, which is available to authorized users.

Reduction of Preneoplastic Lesions Induced by 1,2-Dimethylhydrazine in Rat Colon by Maslinic Acid, a Pentacyclic Triterpene from Olea europaea L

Maslinic acid triggers compelling antiproliferative and pro-apoptotic effects in different human cancer cell lines. Hence, the chemopreventive activity was investigated on early stages of carcinogenesis induced by 1,2-dimethylhydrazine (DMH) which is a model that mimics human sporadic colorectal cancer. Male Sprague-Dawley rats were orally administered either maslinic acid at 5, 10 or 25 mg/kg dissolved in (2-hydroxypropyl)-β-cyclodextrin 20% (w/v) or the solvent for 49 days. After one week of treatment, animals received three weekly intraperitoneal injections of DMH at the dose of 20 mg/kg. Maslinic acid reduced the preneoplastic biomarkers, aberrant crypt foci (ACF) and mucin-depleted foci (MDF), already at 5 mg/kg in a 15% and 27%, respectively. The decline was significant at 25 mg/kg with decreases of 33% and 51%, respectively. Correlation analysis showed a significant association between the concentrations of maslinic acid found in the colon and the reduction of ACF (r = 0.999, p = 0.019) and MDF (r = 0.997, p = 0.049). The present findings demonstrate that maslinic acid induced an inhibition of the initiation stages of carcinogenesis. The assessment of this pentacyclic triterpene at the colon sheds light for designing diets with foods rich in maslinic acid to exert a chemopreventive activity in colorectal cancer.

Secoiridoids of olive and derivatives as potential coadjuvant drugs in cancer: A critical analysis of experimental studies

Phenolic secoiridoids from olive, including oleocanthal, oleuropein and related derivatives, are bioactive natural products with documented anticancer activities, that have mainly been attributed to their antioxidant, anti-inflammatory and antiproliferative effects. This review summarizes the results of the preclinical studies on the natural secoiridoids of olive used as single agents or in combination with other chemotherapeutics against cancer cells. The molecular targets of their action are described. A critical analysis of the importance of the experimental studies in view of the possible use in humans is also discussed.

"Picrosides" from Picrorhiza kurroa as potential anti-carcinogenic agents

The steady rise in life expectancy, modern life style and changing environmental conditions are responsible for increasing incidence of cancer. A number of chemical drugs have been used for cancer treatment; however the induction of genotoxic, carcinogenic and teratogenic effects limits their use. Alternatively, plant phytochemicals have been proven effective chemopreventive agents. This review illustrates the use of "picrosides" derived from Picrorhiza kurroa for the treatment of cancer. We have detailed the anti-oxidant and anti-inflammatory action of picrosides as the key mechanism in reducing oncogenesis. Action of picrosides on detoxifying enzymes, cell cyle regulation and induction of signal transducers inhibiting apoptosis has also been reviewed. The present review highlights the use of picrosides as an important therapeutic agent against different types of cancer.

Future in the Past: Azorella glabra Wedd. as a Source of New Natural Compounds with Antiproliferative and Cytotoxic Activity on Multiple Myeloma Cells

Multiple myeloma (MM) is the second most common hematologic malignancy and, although the development of novel agents has improved survival of patients, to date, it remains incurable. Thus, newer and more effective therapeutic strategies against this malignancy are necessary. Plant extracts play an important role in anti-tumor drug discovery. For this reason, in the investigation of novel natural anti-MM agents, we evaluated the phytochemical profiles, in vitro antioxidant activity, and effects on MM cells of Azorella glabra (AG) Wedd. Total polyphenols (TPC), flavonoids (TFC), and terpenoids (TTeC) contents were different among samples and the richest fractions in polyphenols demonstrated a higher antioxidant activity in in vitro assays. Some fractions showed a dose and time dependent anti-proliferative activity on MM cells. The chloroform fraction (CHCl₃) showed major effects in terms of reduction of cell viability, induction of apoptosis, and cell cycle arrest on MM cells. The apoptosis induction was also confirmed by the activation of caspase-3. Importantly, the CHCl₃ fraction exhibited a negligible effect on the viability of healthy cells. These results encourage further investigations on AG extracts to identify specific bioactive compounds and to define their potential applications in MM.

Cytotoxic Profiling of Endogenous Metabolites Relevant to Chronic Fatigue Immune Dysfunction Syndrome (CFIDS) on p53 Variant Human Colon Carcinoma Cell Lines

Chemoprophylatic strategies against development of multifactorial diseases utilize compounds to block the multistep events in chronic inflammation and carcinogenesis. The successful chemopreventative candidate must therefore selectively inhibit growth of transformed cells and be administered frequently to confer maximal protection with minimal side effects. In addition to synthetic and exogenous natural compounds, endogenous metabolites represent another class of compounds that exhibit anticarcinogenic and anti-inflammatory properties contributing to proper cell function. To assess the effectiveness of these compounds warrants an understanding of their cytotoxic mode of action. In this study, p53 variant human colon carcinoma cell lines were chronically exposed to varying concentrations of the endogenous metabolites—phenyl acetate, ursodeoxycholate, and tauroursodeoxycholate—to determine the role of p53-induced cytotoxicity, with p53 mutant and deficient cell lines representing precancerous lesions. Cytotoxicity was assessed using clonogenic assays, and macroscopic colony counts were used to quantify cell survival. The results demonstrate that the bile acids, ursodeoxycholate and tauroursodeoxycholate, exhibit selective cytotoxicity toward nonfunctional p53 cell lines suggesting a p53-mediated role in inhibition of cell clonogenicity and potential chemopreventative properties. Although each compound displays this described effect, the tauroursodeoxycholate demonstrates high significance suggesting it might have practical uses in vivo.

Phenolics extracted from tartary (Fagopyrum tartaricum L. Gaerth) buckwheat bran exhibit antioxidant activity, and an antiproliferative effect on human breast cancer MDA-MB-231 cells through the p38/MAP kinase pathway

Phenolics extracted from tartary buckwheat (Fagopyrum tartaricum L. Gaerth) bran were analyzed quantitatively and qualitatively. The bioactivity of the phenolic extracts was evaluated, such as the antioxidant activity, and the inhibition capacity on the growth of cancer cells. The molecular mechanism for the inhibitive effect on cancer cells was explored. Results indicated that tartary buckwheat bran phenolics mainly exist in a free form, and free phenolics were twice as abundant as bound phenolics. Free caffeic acid (119.75 μg per 100 mg DW) and bound rutin (51.66 μg per 100 mg DW) represented the main free and bound phenolic compounds, respectively. The free phenolic extract contributed to the major (>90%) antioxidant activities including the oxygen radical antioxidant capacity (ORAC) and cellular antioxidant activity (CAA). The free phenolic extract exhibited anticancer activity for human breast cancer MDA-MB-231 cells in a dose-dependent manner. This significant inhibition effect was achieved through the p38/MAP kinase pathway by inducing cell apoptosis (up-regulating p-p38 and p-ASK1 expressions and down-regulating TRAF2 and p-p53 expressions), and negatively regulating the progression of the cell cycle from the G1 to S phase (increased expression of p21 and suppressed expressions of PCNA, cyclin D1 and CDK4). All these results indicated that tartary buckwheat bran could be a rich resource of natural antioxidants and inhibitors for the growth of MDA-MB-231 cells.

Astragalin: A Bioactive Phytochemical with Potential Therapeutic Activities

Natural products, an infinite treasure of bioactive chemical entities, persist as an inexhaustible resource for discovery of drugs. This review article intends to emphasize on one of the naturally occurring flavonoids, astragalin (kaempferol 3-glucoside), which is a bioactive constituent of various traditional medicinal plants such as Cuscuta chinensis. This multifaceted compound is well known for its diversified pharmacological applications such as anti-inflammatory, antioxidant, neuroprotective, cardioprotective, antiobesity, antiosteoporotic, anticancer, antiulcer, and antidiabetic properties. It carries out the aforementioned activities by the regulation and modulation of various molecular targets such as transcription factors (NF-κB, TNF-α, and TGF-β1), enzymes (iNOS, COX-2, PGE2, MMP-1, MMP-3, MIP-1α, COX-2, PGE-2, HK2, AChe, SOD, DRP-1, DDH, PLCγ1, and GPX), kinases (JNK, MAPK, Akt, ERK, SAPK, IκBα, PI3K, and PKCβ2), cell adhesion proteins (E-cadherin, vimentin PAR-2, and NCam), apoptotic and antiapoptotic proteins (Beclin-1, Bcl-2, Bax, Bcl-xL, cytochrome c, LC3A/B, caspase-3, caspase-9, procaspase-3, procaspase-8, and IgE), and inflammatory cytokines (SOCS-3, SOCS-5, IL-1β, IL-4, IL-6, IL-8, IL-13, MCP-1, CXCL-1, CXCL-2, and IFN-γ). Although researchers have reported multiple pharmacological applications of astragalin in various diseased conditions, further experimental investigations are still mandatory to fully understand its mechanism of action. It is contemplated that astragalin could be subjected to structural optimization to ameliorate its chemical accessibility, to optimize its absorption profiles, and to synthesize its more effective analogues which will ultimately lead towards potent drug candidates.

Molecular characterization of the grape seeds extract's effect against chemically induced liver cancer: In vivo and in vitro analyses

The purpose of this study was to investigate the anti-cancer property of grape seed extract (GSE) during early stages of developing liver cancer using a two-stage carcinogenic model combining diethylnitrosamine (DEN) and 2-Acetyl Aminofluorene (2-AAF). Administration of GSE at doses 25, 50 and 100 mg/kg per day started at the beginning of promotion periods and continued for 14 weeks. GSE dramatically inhibited pre-neoplastic foci formation as well as significantly decreased the number and the area of placental glutathione-S-transferase in livers of DEN-2AAF-treated rats by approximately 4 & 10 fold deductions, respectively. GSE's effects were associated with induced apoptosis, reduced cell proliferation, decreased oxidative stress and down regulation of histone deacetylase activity and inflammation makers, such as cyclooxygenase 2, inducible nitric oxide synthase, nuclear factor-kappa B-p65 and p- phosphorylated tumor necrosis factor receptor expressions in liver. GSE treatment also decreased the viability of HepG2 cells and induced early and late apoptosis through activating caspase-3 and Bax. Furthermore, GSE induced G2/M and G1/S cell cycle arrest. The present study provides evidence that the GSE's anticancer effect is mediated through the inhibition of cell proliferation, induction of apoptosis, modulating oxidative damage and suppressing inflammatory response.

Role of ginsenosides in reactive oxygen species-mediated anticancer therapy

Cancer is still a global public health problem, which is the leading cause of death in most countries. Ginseng has been used for centuries all over the world as a panacea that promotes longevity. As the king of herb plants, ginseng holds great promise as a new treatment option which is used either by itself or in combination with other medicinal ingredients that is widely accepted as complementary and alternative medicine in cancer therapy. Ginsenosides, the major pharmacologically active ingredients of ginseng, have been shown to have multiple medicinal effects including prominent anticancer activity. The purpose of this review is to give our perspective about the roles of ginsenosides in reactive oxygen species (ROS)-mediated anticancer therapy. Additionally, to provide new sheds light for further improvement and carry out pre-clinical and clinical trials to develop it successfully into a potential anticancer agent. Panax herbs and their derivate/metabolites ginsenosides exert beneficial effects for treating various types of cancers. The mechanism of ROS-mediated anticancer activities of ginsenosides varies depending on the specific type of cancer cells involved. Ginsenosides may suppress cancer cell proliferation through anti-oxidation on tumor initiation and induce apoptosis, paraptosis or autophagy via generation of ROS on tumor progression, promotion, angiogenesis, invasion and metastasis by various signaling pathways e.g., activation of AMPK, MEK, ASK-1/JNK, ESR2-NCF1-ROS, ER-dependent PI3K/Akt/Nrf2, P53-CHOP, ROS-JNK-autophagy, and/or inhibition of PI3K/Akt signaling pathways. These multiple effects rather than a single may play a crucial role in emerging ginsenosides as a successful anticancer drug.

The Role of Resveratrol in Cancer Therapy

Natural product compounds have recently attracted significant attention from the scientific community for their potent effects against inflammation-driven diseases, including cancer. A significant amount of research, including preclinical, clinical, and epidemiological studies, has indicated that dietary consumption of polyphenols, found at high levels in cereals, pulses, vegetables, and fruits, may prevent the evolution of an array of diseases, including cancer. Cancer development is a carefully orchestrated progression where normal cells acquires mutations in their genetic makeup, which cause the cells to continuously grow, colonize, and metastasize to other organs such as the liver, lungs, colon, and brain. Compounds that modulate these oncogenic processes can be considered as potential anti-cancer agents that may ultimately make it to clinical application. Resveratrol, a natural stilbene and a non-flavonoid polyphenol, is a phytoestrogen that possesses anti-oxidant, anti-inflammatory, cardioprotective, and anti-cancer properties. It has been reported that resveratrol can reverse multidrug resistance in cancer cells, and, when used in combination with clinically used drugs, it can sensitize cancer cells to standard chemotherapeutic agents. Several novel analogs of resveratrol have been developed with improved anti-cancer activity, bioavailability, and pharmacokinetic profile. The current focus of this review is resveratrol’s in vivo and in vitro effects in a variety of cancers, and intracellular molecular targets modulated by this polyphenol. This is also accompanied by a comprehensive update of the various clinical trials that have demonstrated it to be a promising therapeutic and chemopreventive agent.

Berberine Induces Apoptotic Cell Death via Activation of Caspase-3 and -8 in HL-60 Human Leukemia Cells: Nuclear Localization and Structure–Activity Relationships

Berberine (BBR), an isoquinoline alkaloid, is a well-known bioactive compound contained in medicinal plants used in traditional and folk medicines. In this study, we investigated the subcellular localization and the apoptotic mechanisms of BBR were elucidated. First, we confirmed the incorporation of BBR into the cell visually. BBR showed antiproliferative activity and promptly localized to the nucleus from 5[Formula: see text]min to 15[Formula: see text]min after BBR treatment in HL-60 human promyelocytic leukemia cells. Next, we examined the antiproliferative activity of BBR (1) and its biosynthetically related compounds (2-7) in HL-60 cells. BBR exerted strongest antiproliferative activity among 1-7 and the results of structures and activity relation suggested that a methylenedioxyl group in ring A, an [Formula: see text]-alkyl group at C-9 position, and the frame of isoquinoline may be necessary for antiproliferative activity. Moreover, BBR showed the most potent antiproliferative activity in HL-60 cells among human cancer and normal cell lines tested. Next, we examined the effect of BBR on molecular events known as apoptosis induction. In HL-60 cells, BBR induced chromatin condensation and DNA fragmentation, and triggered the activation of PARP, caspase-3 and caspase-8 without the activation of caspase-9. BBR-induced DNA fragmentation was abolished by pretreatment with inhibitors against caspase-3 and caspase-8, but not against caspase-9. ERK and p38 were promptly phosphorylated after 15 min of BBR treatment, and this was correlated with time of localization to the nucleus of BBR. These results demonstrated that BBR translocated into nucleus immediately after treatments and induced apoptotic cell death by activation of caspase-3 and caspase-8.

Comparison of Two Components of Propolis: Caffeic Acid (CA) and Caffeic Acid Phenethyl Ester (CAPE) Induce Apoptosis and Cell Cycle Arrest of Breast Cancer Cells MDA-MB-231

Studies show that caffeic acid (CA) and caffeic acid phenethyl ester (CAPE) are compounds with potent chemopreventive effects. Breast cancer is a common form of aggressive cancer among women worldwide. This study shows a comparison of CA and CAPE activity on triple-negative human caucasian breast adenocarcinoma line cells (MDA-MB-231). MDA-MB-231 cells were treated by CA and CAPE with doses of from 10 to 100 µM, for periods of 24 h and 48 h. Cytotoxicity MTT tests, apoptosis by Annexin V, and cell cycle with Dead Cell Assays were performed. Cytotoxic activity was greater for CAPE compared to CA (both incubation times, same dosage). IC₅₀ values for CAPE were 27.84 µM (24 h) and 15.83 µM (48 h) and for CA > 10,000 µM (24 h) and > 1000 µM (48 h). Polyphenols induced apoptosis, while CAPE (dose dependently), induced a higher apoptotic effect. CAPE also induced cell cycle arrest in S phase (time and dose dependently), CA did it only for 50 and 100 µM. A dose dependent decline was seen for the G0/G1 phase (CAPE, 48 h), as well as elimination of phase G2/M by 100 µM of CAPE (only mild effect for CA). Comparing CA and CAPE activity on MDA-MB-231, CAPE clearly showed better activity for the same dosages and experiment times.

Berberine and cinnamaldehyde together prevent lung carcinogenesis

Starving tumor cells by restricting nutrient sources is a promising strategy for combating cancer. Because both berberine and cinnamaldehyde can activate AMP-activated protein kinase (AMPK, a sensor of cellular energy status), we investigated whether the combination of berberine and cinnamaldehyde could synergistically prevent lung carcinogenesis through tumor cell starvation. Urethane treatment induced lung carcinogenesis in mice, downregulated AMPK and mammalian target of rapamycin (mTOR) while upregulating aquaporin-1 (AQP-1) and nuclear factor kappa B (NF-κB). Together, berberine and cinnamaldehyde reduced mouse susceptibility to urethane-induced lung carcinogenesis, and reversed the urethane-induced AMPK, mTOR, AQP-1, and NF-κB expression patterns. In vitro, berberine and cinnamaldehyde together induced A549 cell apoptosis, prevented cell proliferation, autophagy, and wound healing, upregulated AMPK, and downregulated AQP-1. The effects of the combined treatment were reduced by rapamycin (a mTOR inhibitor) or HgCL₂ (an AQP inhibitor), but not Z-VAD-FMK (a caspase inhibitor). The berberine/cinnamaldehyde combination also prevented A549 cell substance permeability and decreased intracellular ATP concentrations. These results suggest the combination of berberine and cinnamaldehyde limited both primary and adaptive nutrient acquisition by lung tumors via AMPK-reduced AQP-1 expression, which ultimately starved the tumor cells.

Structure-Dependent Cytotoxic Effects of Eremophilanolide Sesquiterpenes

The aim of this research was to determine the cytotoxic action of sixteen structurally-related eremophilane-type sesquiterpenes, isolated from several species of Senecio, against a panel of cancer cell lines. The cytotoxic activities were evaluated by WST-1 test and the IC50 values calculated. The investigated compounds exerted dose-dependent cytotoxic actions against selected cancer cell lines and no-tumoral HS5 cell line. The comparative structure-activity relationships demonstrated the importance of C-1, C-6, and C-8 substituents in the molecule. Our results show that eremophilane-type sesquiterpenes may represent an important source of novel potential antitumor agents due to their pronounced cytotoxic actions towards malignant cells.

Oleuropein and Cancer Chemoprevention: The Link is Hot

Cancer comprises a collection of related diseases characterized by the existence of altered cellular pathways resulting in an abnormal tendency for uncontrolled growth. A broad spectrum, coordinated, and personalized approach focused on targeting diverse oncogenic pathways with low toxicity and economic natural compounds can provide a real benefit as a chemopreventive and/or treatment of this complex disease. Oleuropein, a bioactive phenolic compound mainly present in olive oil and other natural sources, has been reported to modulate several oncogenic signalling pathways. This review presents and critically discusses the available literature about the anticancer and onco-suppressive activity of oleuropein and the underlying molecular mechanisms implicated in the anticarcinogenic and therapeutic effects. The existence of limitations and the promising perspectives of research on this phenolic compound are also critically analyzed and discussed.

Angiomodulators in cancer therapy: New perspectives

The formation of new blood vessels plays a crucial for the development and progression of pathophysiological changes associated with a variety of disorders, including carcinogenesis. Angiogenesis inhibitors (anti-angiogenics) are an important part of treatment for some types of cancer. Some natural products isolated from marine invertebrates have revealed antiangiogenic activities, which are diverse in structure and mechanisms of action. Many preclinical studies have generated new models for further modification and optimization of anti-angiogenic substances, and new information for mechanistic studies and new anti-cancer drug candidates for clinical practice. Moreover, in the last decade it has become apparent that galectins are important regulators of tumor angiogenesis, as well as microRNA. MicroRNAs have been validated to modulate endothelial cell migration or endothelial tube organization. In the present review we summarize the current knowledge regarding the role of marine-derived natural products, galectins and microRNAs in tumor angiogenesis.

Oleanolic Acid Alters Multiple Cell Signaling Pathways: Implication in Cancer Prevention and Therapy

Nowadays, much attention has been paid to diet and dietary supplements as a cost-effective therapeutic strategy for prevention and treatment of a myriad of chronic and degenerative diseases. Rapidly accumulating scientific evidence achieved through high-throughput technologies has greatly expanded the understanding about the multifaceted nature of cancer. Increasingly, it is being realized that deregulation of spatio-temporally controlled intracellular signaling cascades plays a contributory role in the onset and progression of cancer. Therefore, targeting regulators of oncogenic signaling cascades is essential to prevent and treat cancer. A plethora of preclinical and epidemiological evidences showed promising role of phytochemicals against several types of cancer. Oleanolic acid, a common pentacyclic triterpenoid, is mainly found in olive oil, as well as several plant species. It is a potent inhibitor of cellular inflammatory process and a well-known inducer of phase 2 xenobiotic biotransformation enzymes. Main molecular mechanisms underlying anticancer effects of oleanolic acid are mediated by caspases, 5' adenosine monophosphate-activated protein kinase, extracellular signal-regulated kinase 1/2, matrix metalloproteinases, pro-apoptotic Bax and bid, phosphatidylinositide 3-kinase/Akt1/mechanistic target of rapamycin, reactive oxygen species/apoptosis signal-regulating kinase 1/p38 mitogen-activated protein kinase, nuclear factor-κB, cluster of differentiation 1, CKD4, s6k, signal transducer and activator of transcription 3, as well as aforementioned signaling pathways . In this work, we critically review the scientific literature on the molecular targets of oleanolic acid implicated in the prevention and treatment of several types of cancer. We also discuss chemical aspects, natural sources, bioavailability, and safety of this bioactive phytochemical.

Sorbus rufopilosa Extract Exhibits Antioxidant and Anticancer Activities by Inducing Cell Cycle Arrest and Apoptosis in Human Colon Adenocarcinoma HT29 Cells

Background

Sorbus rufopilosa, a tsema rowan, is a species of the small ornamental trees in the genus Sorbus and the family Rosaceae found in East Asia. The bioactivities of S. rufopilosa have not yet been fully determined. The objective of this study is to evaluate the antioxidant and anticancer effects of ethanol extract of S. rufopilosa (EESR) and to determine the molecular mechanism of its anticancer activity in human colon carcinoma HT29 cells.

Methods

To examine the antioxidant activity of EESR, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity assay was performed. Inhibitory effect of EESR on cancer cell growth and proliferation was determined by water-soluble tetrazolium salt assay. To investigate the mechanism of EESR-mediated cytotoxicity, HT29 cells were treated with various concentrations of EESR and the induction of cell cycle arrest and apoptosis was analyzed by flow cytometry, 4,6-diamidino-2-phenylindole staining, and Western blot analysis.

Results

EESR showed significant antioxidant activity and inhibitory effect on HT29 cell growth in a dose-dependent manner. EESR induced cell cycle arrest at G2/M phase in a dose-dependent manner by modulating cyclin B, cyclin-dependent kinase 1 (CDK1), and CDK inhibitor p21 expression. EESR-induced apoptosis was associated with the upregulation of p53, a death receptor Fas, and a pro-apoptotic protein Bax and the activation of caspase 3, 8, and 9, resulting in the degradation of PARP.

Conclusions

EESR possessing antioxidant activity efficiently inhibits proliferation of HT29 cells by inducing both cell cycle arrest and apoptosis. EESR may be a possible candidate for the anticancer drug development.