Cancer chemoprevention and apoptosis mechanisms induced by dietary polyphenolics

Potential Anticancer Activity of Juniperus procera and Molecular Docking Models of Active Proteins in Cancer Cells

Medicinal plants provide a wide range of active compounds that can be exploited to create novel medicines with minimal side effects. The current study aimed to identify the anticancer properties of Juniperus procera (J. procera) leaves. Here, we demonstrate that J. procera leaves' methanolic extract suppresses cancer cells in colon (HCT₁₁₆), liver (HepG2), breast (MCF-7), and erythroid (JK-1) cell lines. By applying GC/MS, we were able to determine the components of the J. procera extract that might contribute to cytotoxicity. Molecular docking modules were created that used active components against cyclin-dependent kinase 5 (Cdk5) in colon cancer, aromatase cytochrome P450 in the breast cancer receptor protein, the -N terminal domain in the erythroid cancer receptor of the erythroid spectrin, and topoisomerase in liver cancer. The results demonstrate that, out of the 12 bioactive compounds generated by GC/MS analysis, the active ingredient 2-imino-6-nitro-2H-1-benzopyran-3-carbothiamide proved to be the best-docked chemical with the chosen proteins impacted by DNA conformational changes, cell membrane integrity, and proliferation in molecular docking studies. Notably, we uncovered the capacity of J. procera to induce apoptosis and inhibit cell growth in the HCT₁₁₆ cell line. Collectively, our data propose that J. procera leaves' methanolic extract has an anticancer role with the potential to guide future mechanistic studies.

Bioactivity, Molecular Mechanism, and Targeted Delivery of Flavonoids for Bone Loss

Skeletal disabilities are a prominent burden on the present population with an increasing life span. Advances in osteopathy have provided various medical support for bone-related diseases, including pharmacological and prosthesis interventions. However, therapeutics and post-surgery complications are often reported due to side effects associated with modern-day therapies. Thus, therapies utilizing natural means with fewer toxic or other side effects are the key to acceptable interventions. Flavonoids constitute a class of bioactive compounds found in dietary supplements, and their pharmacological attributes have been well appreciated. Recently, flavonoids' role is gaining renowned interest for its effect on bone remodeling. A wide range of flavonoids has been found to play a pivotal role in the major bone signaling pathways, such as wingless-related integration site (Wnt)/β-catenin, bone morphogenetic protein (BMP)/transforming growth factor (TGF)-β, mitogen-activated protein kinase (MAPK), etc. However, the reduced bioavailability and the absorption of flavonoids are the major limitations inhibiting their use against bone-related complications. Recent utilization of nanotechnological approaches and other delivery methods (biomaterial scaffolds, micelles) to target and control release can enhance the absorption and bioavailability of flavonoids. Thus, we have tried to recapitulate the understanding of the role of flavonoids in regulating signaling mechanisms affecting bone remodeling and various delivery methods utilized to enhance their therapeutical potential in treating bone loss.

Natural flavonoids exhibit potent anticancer activity by targeting microRNAs in cancer: A signature step hinting towards clinical perfection

Cancer prevalence and its rate of incidence are constantly rising since the past few decades. Owing to the toxicity of present-day antineoplastic drugs, it is imperative to explore safer and more effective molecules to combat and/or prevent this dreaded disease. Flavonoids, a class of polyphenols, have exhibited multifaceted implications against several diseases including cancer, without showing significant toxicity towards the normal cells. Shredded pieces of evidence suggest that flavonoids can enhance drug sensitivity and suppress proliferation, metastasis, and angiogenesis of cancer cells by modulating several oncogenic or oncosuppressor microRNAs (miRNAs, miRs). They play pivotal roles in regulation of various biological and pathological processes, including various cancers. In the present review, the structure, chemistry and miR targeting efficacy of quercetin, luteolin, silibinin, genistein, epigallocatechin gallate, and cyanidin against several cancer types are comprehensively discussed. miRs are considered as next-generation medicine of recent times, and their targeting by naturally occurring flavonoids in cancer cells could be deemed as a signature step. We anticipate that our compilations related to miRNA-mediated regulation of cancer cells by flavonoids might catapult the clinical investigations and affirmation in the future.

Proanthocyanidins alleviate pentylenetetrazole-induced epileptic seizures in mice via the antioxidant activity

The role of oxidative stress in the initiation and progress of epilepsy is well established. Proanthocyanidins (PACs), a naturally occurring polyphenolic compound, have been reported to possess a broad spectrum of pharmacological and therapeutic properties against oxidative stress. However, the protective effects of proanthocyanidins against epilepsy have not been clarified. In the present study, we used the pentylenetetrazole (PTZ)-induced epilepsy mouse model to explore whether proanthocyanidins could help to reduce oxidative stress and protect against epilepsy. Mice were allocated into four groups (n = 14 per each group): control, PTZ (60 mg/kg, intraperitoneally), PACs + PTZ (200 mg/kg, p.o.) and sodium valproate (VPA) + PTZ (200 mg/kg, p.o.). PTZ injection caused oxidative stress in the hippocampal tissue as represented by the elevated lipid peroxidation and NO synthesis and increased expression of iNOS. Furthermore, depleted levels of anti-oxidants, GSH, GR, GPx, SOD, and CAT also indicate that oxidative stress was induced in mice exposed to PTZ. Additionally, a state of neuroinflammation was recorded following the developed seizures. Moreover, neuronal apoptosis was recorded following the development of epileptic convulsions as confirmed by the elevated Bax and caspase-3 and the decreased Bcl2 protein. Moreover, AChE activity, DA, NE, 5-HT, brain-derived neurotrophic factor levels, and gene expression of Nrf2 have decreased in the hippocampal tissue of PTZ exposed mice. However, pre-treatment of mice with PACs protected against the generation of oxidative stress, apoptosis, and neuroinflammation in the PTZ exposed mice brain as the biomarkers for all these conditions was bought to control levels. In addition, the gene expression of Nrf2 was significantly upregulated following PACs treatment. These results suggest that PACs can ameliorate oxidative stress, neuroinflammation, and neuronal apoptosis by activating the Nrf2 signaling pathway in PTZ induced seizures in mice.

Myricitrin - a flavonoid isolated from the Indian olive tree (Elaeocarpus floribundus) - inhibits Monoamine oxidase in the brain and elevates striatal dopamine levels: therapeutic implications against Parkinson's disease

Flavonoids exhibit several biological activities including inhibition of Monoamine oxidase (MAO), an enzyme that metabolizes several neurotransmitters. Thus, MAO inhibitors are well included in traditional therapeutic practices to fine-tune neuromotor behavior. This study aims to isolate flavonoids from a less explored plant of northeast India, named Indian olive (Elaeocarpus floribundus; Ef, family Elaeocarpaceae), and evaluate their MAO inhibitory properties. Four flavonoids from Ef leaf extract, namely, myricitrin, mearnsitrin, myricetin, and mearnsetin, are taken into consideration. Spectrofluorimetric assay is carried out to determine the MAO inhibitory properties. Next, in vitro and in vivo toxicity studies are performed in neuronal cell line and Drosophila, respectively. Furthermore, MAO inhibition by the selected compounds and their effect on dopamine levels are examined in the mouse brain. We evaluated the therapeutic potential in a mouse model of Parkinson's disease (PD) in terms of behavior, neurotransmitter levels, and dopaminergic neuronal loss. In an in vitro setup, all four compounds inhibited total MAO, whereas myricitrin exhibited some selectivity against MAO-B at 100 μM. Myricitrin and mearnsitrin exhibited no toxicity, in vitro or in vivo. However, only myricitrin inhibited MAO in the mouse brain and elevated dopamine levels. Myricitrin was able to attenuate motor incoordination in the mouse model of PD and improved dopamine levels in the striatum.

Comparative Analysis of Proanthocyanidin Metabolism and Genes Regulatory Network in Fresh Leaves of Two Different Ecotypes of Tetrastigma hemsleyanum

Tetrastigma hemsleyanum Diels et Gilg is a rare and wild medicinal resource. Metabolites, especially secondary metabolites, have an important influence on T. hemsleyanum adaptability and its medicinal quality. The metabolite proanthocyanidin (PA) is a polyphenol compound widely distributed in land plants, which can be used as antioxidants and anticancer agents. Here, we discovered that three types of PA accumulated in large amounts in purple leaves (PL), but not in green leaves (RG), based on widely non-targeted metabolomics. In addition, we further found that catechins and their derivatives, which are the structural units of PA, are also enriched in PL. Afterwards, we screened and obtained five key genes, DNR1/2, ANS, ANR and LAR closely related to PA biosynthesis through transcriptome analysis and found they were all highly expressed in PL compared to RG. Therefore, observed the regulatory relationship between the main compounds and genes network, and the PA metabolism regulatory pathway was complicated, which may be different to other species.

Differential effects of cisplatin combined with the flavonoid apigenin on HepG2, Hep3B, and Huh7 liver cancer cell lines

The potential of apigenin (APG) to enhance cisplatin's (CDDP) chemotherapeutic efficacy was investigated in HepG2, Hep3B, and Huh7 liver cancer cell lines. The presence of 20 μM APG sensitized all cell lines to CDDP treatment (degree of sensitization based on the MTT assay: HepG2>Huh7>Hep3B). As reflected by sister chromatid exchange levels, the degree of genetic instability as well as DNA repair by homologous recombination differed among cell lines. CDDP and 20 μM APG cotreatment exhibited a synergistic genotoxic effect on Hep3B cells and a less than additive effect on HepG2 and Huh7 cells. Cell cycle delays were noticed during the first mitotic division in Hep3B and Huh7 cells and the second mitotic division in HepG2 cells. CDDP and CDDP + APG treatments reduced the clonogenic capacity of all cell lines; however, there was a discordance in drug sensitivity compared with the MMT assay. Furthermore, a senescence-like phenotype was induced, especially in Hep3B and Huh7 cells. Unlike CDDP monotherapy, the combined treatment exhibited a significant anti-invasive and anti-migratory action in all cancer cell lines. The fact that the three liver cancer cell lines responded differently, yet positively, to CDDP + APG cotreatment could be attributed to variations they present in gene expression. Complex mechanisms seem to influence cellular responses and cell fate.

Potential Adverse Effects of Resveratrol: A Literature Review

Due to its health benefits, resveratrol (RE) is one of the most researched natural polyphenols. Resveratrol's health benefits were first highlighted in the early 1990s in the French paradox study, which opened extensive research activity into this compound. Ever since, several pharmacological activities including antioxidant, anti-aging, anti-inflammatory, anti-cancerous, anti-diabetic, cardioprotective, and neuroprotective properties, were attributed to RE. However, results from the available human clinical trials were controversial concerning the protective effects of RE against diseases and their sequelae. The reason for these conflicting findings is varied but differences in the characteristics of the enrolled patients, RE doses used, and duration of RE supplementation were proposed, at least in part, as possible causes. In particular, the optimal RE dosage capable of maximizing its health benefits without raising toxicity issues remains an area of extensive research. In this context, while there is a consistent body of literature on the protective effects of RE against diseases, there are relatively few reports investigating its possible toxicity. Indeed, toxicity and adverse effects were reported following consumption of RE; therefore, extensive future studies on the long-term effects, as well as the in vivo adverse effects, of RE supplementation in humans are needed. Furthermore, data on the interactions of RE when combined with other therapies are still lacking, as well as results related to its absorption and bioavailability in the human body. In this review, we collect and summarize the available literature about RE toxicity and side effects. In this process, we analyze in vitro and in vivo studies that have addressed this stilbenoid. These studies suggest that RE still has an unexplored side. Finally, we discuss the new delivery methods that are being employed to overcome the low bioavailability of RE.

Propolis attenuates lipopolysaccharide-induced inflammatory responses through intracellular ROS and NO levels along with downregulation of IL-1β and IL-6 expressions in murine RAW 264.7 macrophages

Propolis had a wide spectrum of biological activities. In the current study, antioxidative and the immunomodulatory effects of the Polur ethanol extract of propolis (PEEP) in murine macrophage (RAW 264.7) cells were investigated. Bioactive composition of the PEEP was determined by HPLC analysis. Cells were treated with different concentrations of PEEP and LPS, then cell viability, NO levels, and expression of inflammatory factors were evaluated. HPLC analysis of PEEP indicated the presence of flavonoids and phenolic acid. The PEEP inhibited the proliferation of RAW 264.7 cells with IC₅₀ 15 ± 3.2 µg/ml. Reactive oxygen species (ROS) and NO production was significantly reduced by 0.15 µg/ml of PEEP. Additionally, expression of Cox-2, IL-1β and IL-6 significantly decreased. The obtained results supported the PEEP anti-inflammatory effects on RAW 264.7 cells may be applied via reducing ROS and NO production along with COX-2, IL-1β, and IL-6 expression. PRACTICAL APPLICATIONS: Propolis is a resinous substance produced by the honeybee that has been adopted as a form of traditional medicine since ancient times. The main compounds found in propolis are typically various and depend on the type of plants and climatic region. In this respect, a wide spectrum of biological activities for propolis has been identified including antioxidant, antimicrobial, anticarcinogenic, anti-inflammatory, as well as antifungal properties. This extraordinary substance is rich in flavonoids and antioxidants. Therefore, it is now widely used in foods and drinks with the claim that it can maintain or improve human health.

Luteolin Shifts Oxaliplatin-Induced Cell Cycle Arrest at G₀/G₁ to Apoptosis in HCT116 Human Colorectal Carcinoma Cells

Certain antioxidative flavonoids are known to activate nuclear factor E2-related factor 2 (Nrf2), a transcription factor that regulates cellular antioxidants and detoxifying response and is reportedly highly activated in many types of cancers. Few studies on the potential undesired effects of flavonoid intake during chemotherapy have been conducted, yet Nrf2 activators could favor cancer cell survival by attenuating chemotherapeutic efficiency. This study aimed to examine if luteolin, an Nrf2 activator, hinders chemotherapeutic activity of oxaliplatin, a potent anticancer agent for colorectal cancer, in HCT116 cells. Luteolin treatment strongly increased the transcriptional activity of the antioxidant response element in HCT116 cells and induced the protein expression of heme oxygenase-1, which were indicative of its Nrf2-inducing potential. Intriguingly, 25 μM luteolin reduced cell viability through apoptotic induction, which was intensified in p53-expressing cells while 1 μM oxaliplatin caused cell cycle arrest at G₀/G₁-phase via the p53/p21-dependent mechanism. Moreover, luteolin treatment was found to reduce oxaliplatin-treated p53-null cell viability and colony counts further, thereby demonstrating an additional effect of luteolin in the killing of human colorectal tumor HCT116 cells not expressing functional p53 protein. The findings suggest that luteolin can induce p53-mediated apoptosis regardless of oxaliplatin treatment and may eliminate oxaliplatin-resistant p53-null colorectal cells.

Protection against nonalcoholic steatohepatitis through targeting IL-18 and IL-1alpha by luteolin

BACKGROUND

The management of nonalcoholic steatohepatitis (NASH) is still a crosstalk so the current study was designed to evaluate the effect of different luteolin doses on an experimental model of NASH and to elucidate novel anti-inflammatory pathways underlying its effect.

METHODS

Adult male Wistar rats (200-220 g; n = 60) were used. Rats were fed a high carbohydrate/high fat diet (˜ 30% carbohydrate and 42% fat) daily for 12 weeks to induce NASH. Luteolin (10, 25, 50 or 100 mg/kg/day) was administered as a suspension (10% w/v in 0.9% NaCl) using an oral gavage. Histopathological changes (necrosis, inflammation and steatosis) were evaluated. Biomarkers for liver function, lipid peroxidation, extracellular matrix deposition and anti-oxidant activity were measured. Levels of IFN-γ, TNF-α and IL-1α and IL-18 were measured.

RESULTS

Obtained results showed ability of luteolin to reduce activity of ALT and AST and to decrease levels of bilirubin, hyaluronic acid and malondialdehyde significantly (p <  0.05). Also, luteolin showed an anti-oxidant activity as indicated by the significant (p <  0.05) increase in reduced glutathione. Finally, a significant (p <  0.05) decrease in IFN-γ, TNF-α, IL-1α and IL-18 levels was observed most notably in groups that received high doses of luteolin (50 and 100 mg/kg).

CONCLUSIONS

Luteolin can protect against non-alcoholic steatohepatitis through targeting the pro-inflammatory IL-1 and Il-18 pathways in addition to an antioxidant effect.

Hesperidin exhibits in vitro and in vivo antitumor effects in human osteosarcoma MG-63 cells and xenograft mice models via inhibition of cell migration and invasion, cell cycle arrest and induction of mitochondrial-mediated apoptosis

The objective of the present study was to investigate the anticancer properties of hesperidin against human osteosarcoma MG-63 cells. Its effects on apoptosis, cell migration, cell invasion and cell cycle arrest, and its effects on tumor volume and weight were also evaluated in the present study. MTS assay was used to study the cytotoxic effects of the compound on cell viability. Effects on apoptosis and cell cycle arrest were evaluated by flow cytometry. In vitro wound healing assay and Matrigel assay were performed to study the effects of hesperidin on cell migration and cell invasion, respectively. Hesperidin exerted dose-dependent and time-dependent growth inhibitory effects on cervical cancer cells with IC50 values of 33.5, 23.8 and 17.6 µM, respectively, at 24, 48 and 72 h time intervals. Hesperidin led to early and late apoptosis induction in these cells. Hesperidin-treated cells also led to G2/M phase cell cycle arrest, which exhibited strong dose-dependence. Hesperidin treatment also led to inhibition of cell migration and invasion.

Ferruginol induced apoptosis on SK-Mel-28 human malignant melanoma cells mediated through P-p38 and NF-κB

In the present investigation, the antitumor effect of ferruginol (FGL) in SK-Mel-28 human malignant melanoma cells was studied. To investigate the cytotoxic property of FGL, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used. Results revealed that prolonged treatment duration decreases the IC25, IC50, and IC75 concentrations of FGL. The cytotoxicity was further confirmed by lactate dehydrogenase assay. As evident from comet assay, FGL induces DNA damage in a dose-dependent manner. Annexin V and 7-ADD assays showed that FGL-induced DNA damage triggers apoptosis-mediated cell death as confirmed by caspase-3 activity assay. As seen through Western blotting, FGL increases phosphorylation of p38 and nuclear translocation of NF-κB. Further, it was observed that p38 phosphorylation is responsible for NF-κB translocation to the nucleus. Further, inhibition of p38 phosphorylation and translocation of NF-κB decrease caspase-3 activity. The above finding confirms that caspase-3 activation is mediated through P-p38 and nuclear translocation of NF-κB. The present findings indicate that FGL significantly suppresses the proliferation of SK-Mel-28 cells in a dose- and time-dependent manner through induction of apoptosis. Furthermore, FGL executes apoptosis through phosphorylation of key protein such as p38 and translocation of NF-κB into the nucleus.

Proanthocyanidins against Oxidative Stress: From Molecular Mechanisms to Clinical Applications

Proanthocyanidins (PCs) are naturally occurring polyphenolic compounds abundant in many vegetables, plant skins (rind/bark), seeds, flowers, fruits, and nuts. Numerous in vitro and in vivo studies have demonstrated myriad effects potentially beneficial to human health, such as antioxidation, anti-inflammation, immunomodulation, DNA repair, and antitumor activity. Accumulation of prooxidants such as reactive oxygen species (ROS) exceeding cellular antioxidant capacity results in oxidative stress (OS), which can damage macromolecules (DNA, lipids, and proteins), organelles (membranes and mitochondria), and whole tissues. OS is implicated in the pathogenesis and exacerbation of many cardiovascular, neurodegenerative, dermatological, and metabolic diseases, both through direct molecular damage and secondary activation of stress-associated signaling pathways. PCs are promising natural agents to safely prevent acute damage and control chronic diseases at relatively low cost. In this review, we summarize the molecules and signaling pathways involved in OS and the corresponding therapeutic mechanisms of PCs.

The cytotoxic, apoptotic and oxidative effects of carbonic anhydrase IX inhibitor on colorectal cancer cells

Colorectal cancer (CRC) is the third most common tumor, malignant and has developed one of the main reasons of cancer mortality. According to studies conducted recently; carbonic anhydrase 9 (CAIX) is an especially attractive target for cancer therapy, in part since it is limited way expressed in normal tissues on the other hand in a wide variety of solid neoplasia are overexpressed. The aim of this study was to appreciate the effects of CAIX inhibitor, namely novel synthesized sulfonamide derivative (H-4i) with high affinity for CAIX, in CAIX-positive human colorectal cancer cell (HT-29) and CAIX-negative human normal embryonic kidney cell line (HEK-293). For this reason, we planned to investigate apoptotic, cytotoxic and oxidative stress activity of H-4i on HT-29 and HEK-293 cell lines. Cell viability determined by WST-1 assay afterwards IC₅₀ values, apoptosis and cell cycle induction measured by flow cytometric analysis, intracellular free radical induction performed by reactive oxygen species (ROS) analyses. The IC₅₀ value of the sulfonamide derivative compound was found to be very low, especially in HT-29 cells, when compared to human normal cells. This research found that H-4i significantly increased cytotoxicity and ROS production, caused significant signs of apoptosis level. High level of ROS and apoptosis lead to arrest the cell cycle and reduce cell survival. The most obvious finding to emerge from the analysis that novel synthesized sulfonamide derivative H-4i is effective on HT-29 more than HEK-293. Therefore, novel derivative H-4i might be used as an anti-cancer potential compound on CRC.

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.

Biochanin A induces anticancer effects in SK-Mel-28 human malignant melanoma cells via induction of apoptosis, inhibition of cell invasion and modulation of NF-κB and MAPK signaling pathways

The present study aimed to investigate the antitumor activity of Biochanin A in SK-Mel-28 human malignant melanoma cells. An MTT assay was used to study the cytotoxic effects of Biochanin A. In vitro wound healing and invasion assays were used to investigate the effects on cell migration and invasion. Fluorescence microscopy using acridine orange/propidium iodide was used to study effects on cell morphology and apoptosis. Nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) protein expression levels were determined by western blot analysis. The results indicated that Biochanin A significantly inhibited the growth of SK-Mel-28 cells in a dose and time dependent manner. Treatment of the cells with Biochanin A induced apoptosis in a dose dependent manner. Additionally, Biochanin A led to inhibition of cell migration and invasion in a dose-dependent manner and upregulated the expression of key proteins in the NF-κB and MAPK signaling pathways.

The Anti-Cancer Effect of Polyphenols against Breast Cancer and Cancer Stem Cells: Molecular Mechanisms

The high incidence of breast cancer in developed and developing countries, and its correlation to cancer-related deaths, has prompted concerned scientists to discover novel alternatives to deal with this challenge. In this review, we will provide a brief overview of polyphenol structures and classifications, as well as on the carcinogenic process. The biology of breast cancer cells will also be discussed. The molecular mechanisms involved in the anti-cancer activities of numerous polyphenols, against a wide range of breast cancer cells, in vitro and in vivo, will be explained in detail. The interplay between autophagy and apoptosis in the anti-cancer activity of polyphenols will also be highlighted. In addition, the potential of polyphenols to target cancer stem cells (CSCs) via various mechanisms will be explained. Recently, the use of natural products as chemotherapeutics and chemopreventive drugs to overcome the side effects and resistance that arise from using chemical-based agents has garnered the attention of the scientific community. Polyphenol research is considered a promising field in the treatment and prevention of breast cancer.

Nexrutine inhibits azoxymethane-induced colonic aberrant crypt formation in rat colon and induced apoptotic cell death in colon adenocarcinoma cells

Colon cancer is the third most common cause of death in the United States. Therefore, new preventive strategies are warranted for preventing colon cancer. Nexrutine (NX), an herbal extract from Phellodendron amurense, has been shown to have anti-inflammatory, anti-microbial and anti-cancer activity for various tissue specific cancers, but its chemopreventive efficacy has not been evaluated against colon cancer. Here, we explored the mechanism of chemopreventive/chemotherapeutic efficacy of NX against colon cancer. We found that dietary exposure of NX significantly reduced the number of azoxymethane (AOM)-induced aberrant crypt foci (ACF) in rats. In addition, significant inhibition in AOM-induced cell proliferation and reduced expression of the inflammatory markers COX-2, iNOS as well as the proliferative markers PCNA and cyclin D1 were also seen. Moreover, NX exposure significantly enhanced apoptosis in the colon of AOM treated rats. Furthermore, in in vitro studies, NX (2.5, 5, 10 μg/ml, 48 h) decreased cell survival and colony formation while inducing G0/G1 cell cycle arrest and apoptosis in colon adenocarcinoma cells COLO205 and HCT-15. However, NX had minimal cytotoxic effect on IEC-6 normal rat intestinal cells, suggesting its high therapeutic index. NX treatment also modulates the level of Bax and Bcl-2 proteins along with cytochrome c release, cleavage and enhanced expression of poly (adenosine diphosphate-ribose) polymerase as well as the catalytic activity of caspase 3 and caspase 9 in both COLO205 and HCT-15 cells. Based on these in vivo and in vitro findings, we suggest that NX could be useful candidate agent for colon cancer chemoprevention and treatment. © 2015 Wiley Periodicals, Inc.

Protective effects of Sesamum indicum extract against oxidative stress induced by vanadium on isolated rat hepatocytes

Vanadium toxicity is a challenging problem to human and animal health with no entirely understanding cytotoxic mechanisms. Previous studies in vanadium toxicity showed involvement of oxidative stress in isolated liver hepatocytes and mitochondria via increasing of ROS formation, release of cytochrome c and ATP depletion after incubation with different concentrations (25-200 µM). Therefore, we aimed to investigate the protective effects of Sesamum indicum seed extract (100-300 μg/mL) against oxidative stress induced by vanadium on isolated rat hepatocytes. Our results showed that quite similar to Alpha-tocopherol (100 µM), different concentrations of extract (100-300 μg/mL) protected the isolated hepatocyte against all oxidative stress/cytotoxicity markers induced by vanadium in including cell lysis, ROS generation, mitochondrial membrane potential decrease and lysosomal membrane damage. Besides, vanadium induced mitochondrial/lysosomal toxic interaction and vanadium reductive activation mediated by glutathione in vanadium toxicity was significantly (P < 0.05) ameliorated by Sesamum indicum extracts. These findings suggested a hepato-protective role for extracts against liver injury resulted from vanadium toxicity. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 979-985, 2016.

Sulforaphane and Other Nutrigenomic Nrf2 Activators: Can the Clinician's Expectation Be Matched by the Reality?

The recognition that food-derived nonnutrient molecules can modulate gene expression to influence intracellular molecular mechanisms has seen the emergence of the fields of nutrigenomics and nutrigenetics. The aim of this review is to describe the properties of nutrigenomic activators of transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2), comparing the potential for sulforaphane and other phytochemicals to demonstrate clinical efficacy as complementary medicines. Broccoli-derived sulforaphane emerges as a phytochemical with this capability, with oral doses capable of favourably modifying genes associated with chemoprevention. Compared with widely used phytochemical-based supplements like curcumin, silymarin, and resveratrol, sulforaphane more potently activates Nrf2 to induce the expression of a battery of cytoprotective genes. By virtue of its lipophilic nature and low molecular weight, sulforaphane displays significantly higher bioavailability than the polyphenol-based dietary supplements that also activate Nrf2. Nrf2 activation induces cytoprotective genes such as those playing key roles in cellular defense mechanisms including redox status and detoxification. Both its high bioavailability and significant Nrf2 inducer capacity contribute to the therapeutic potential of sulforaphane-yielding supplements.

Reversed-phase high-performance Liquid Chromatography-ultraviolet Photodiode Array Detector Validated Simultaneous Quantification of six Bioactive Phenolic Acids in Roscoea purpurea Tubers and their In vitro Cytotoxic Potential against Various Cell Lines

BACKGROUND

Roscoea purpurea or Roscoea procera Wall. (Zingiberaceae) is traditionally used for nutrition and in the treatment of various ailments.

OBJECTIVE

Simultaneous reversed-phase high-performance liquid chromatography-ultraviolet (RP-HPLC) photodiode array detector identification of phenolic acids (PA's) was carried out in whole extract of tuber and their cytotoxic potential was estimated along with radical scavenging action. Bioactivity guided fractionation was also done to check the response potential against the same assay.

MATERIALS AND METHODS

Identification and method validation was performed on RP-HPLC column and in vitro assays were used for bioactivity.

RESULTS

Protocatechuic acid, syringic acid, ferulic acid, rutin, apigenin, and kaempferol were quantified as 0.774%, 0.064%, 0.265%, 1.125%, 0.128%, and 0.528%, respectively. Validated method for simultaneous determination of PA's was found to be accurate, reproducible, and linearity was observed between peak area response and concentration. Recovery of identified PA's was within the acceptable limit of 97.40-104.05%. Significant pharmacological response was observed in whole extract against in vitro cytotoxic assay, that is, Sulforhodamine B assay, however, fractionation results in decreased action potential. Similar pattern of results were observed in the antioxidant assay, as total phenolic content and total flavonoid content were highest in whole extract and decreases with fractionation. Radical scavenging activity was prominent in chloroform fraction, exhibiting IC50 at 0.25 mg/mL.

CONCLUSION

Study, thus, reveals that R. purpurea exhibit significant efficacy in cytotoxic activity with the potentiality of scavenging free radicals due the presence of PA's as reported through RP-HPLC.

SUMMARY

Proto-catechuic acid, syringic acid, ferulic acid, rutin, apigenin and kaempferol were quantified as 0.774, 0.064, 0.265, 1.125, 0.128 and 0.528 %Preliminary cytotoxic activity revealed that whole extract of R. purpurea exhibit promising effect and after fractionation the potentiation of action reducesThe radical scavenging potential of whole extract and fractions are well reflected by TPC, TFC and DPPH assay.

WTC-01, a novel synthetic oxime-flavone compound, destabilizes microtubules in human nasopharyngeal carcinoma cells in vitro and in vivo

BACKGROUND AND PURPOSE

Dynamic polymerization of microtubules is essential for cancer cell growth and metastasis, and microtubule-disrupting agents have become the most successful anti-cancer agents in clinical use. Besides their antioxidant properties, flavonoids also exhibit strong microtubule-disrupting activity and inhibit tumour growth. We have designed, synthesized and tested a series of oxime/amide-containing flavone derivatives. Here we report the evaluation of one compound, WTC-01 for its anti-proliferative effects in human cancer cells.

EXPERIMENTAL APPROACH

We used a range of cancer cell lines including two human nasopharyngeal carcinoma (NPC) cell lines, measuring proliferation, cell cycle and apoptosis, along with caspase levels and mitochondrial membrane potentials. Assays of tubulin polymerisation in vitro and computer modelling of the colchicine binding site in tubulin were also used. In mice, pharmacokinetics and growth of NPC-derived tumours were studied.

KEY RESULTS

WTC-01 was most potent against proliferation of NPC cells (IC50 = 0.45 μM), inducing accumulation of cells in G2 /M and increasing apoptosis, time- and concentration-dependently. The colchicine competition-binding experiments and computer modelling results suggested that WTC-01 causes microtubule disruption via binding to the colchicine-binding site of tubulin resulting in mitochondrial membrane damage and cell apoptosis via activation of caspase-9/-3 without noticeable activation of the caspase-8. Notably, our in vivo studies demonstrated that at doses of 25 and 50 mg·kg(-1) , WTC-01 exhibited good pharmacokinetic properties and completely inhibited the growth of NPC-TW01 cells in a xenograft nude mouse model.

CONCLUSIONS AND IMPLICATIONS

WTC-01, a new synthetic oxime-containing flavone, exhibited potent anti-tumour activity against NPC cells and merits further investigation.

Apoptotic effects of 7,8-dihydroxyflavone in human oral squamous cancer cells through suppression of Sp1

7,8-Dihydroxyflavone (7,8-DHF) is a member of the flavonoid family and has recently been identified as a brain-derived neurotrophic factor mimetic that selectively activates tropomyosin-receptor kinase B with high affinity. The antioxidant and anticancer effects of 7,8-DHF have been reported. However, the pharmacological mechanisms of 7,8-DHF in oral cancer are unclear. Thus, we investigated the mechanisms of the antiproliferative action of 7,8-DHF on HN22 and HSC4 oral squamous cell carcinoma cell lines. We demonstrated that 7,8-DHF decreased cell growth and induced apoptosis in the HN22 and HSC4 cells through regulation of specificity protein 1 (Sp1) using the MTS assay, DAPI staining, Annexin V, propidium iodide staining, reverse transcription-polymerase chain reaction, immunocytochemistry, pull-down assay and western blot analysis. The results showed that the Sp1 protein bound with 7,8-DHF in the HN22 and HSC4 cells. Taken together, the results suggest that 7,8-DHF could modulate Sp1 transactivation and induce apoptotic cell death by regulating the cell cycle and suppressing antiapoptotic proteins. Furthermore, 7,8-DHF may be valuable for cancer prevention and better clinical outcomes.

Dietary administration of Nexrutine inhibits rat liver tumorigenesis and induces apoptotic cell death in human hepatocellular carcinoma cells

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Nexrutine has anti-tumor potential in Solt-Farber rat liver tumorigenesis model.

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Nexrutine caused decreased cell proliferation in the DEN/2-AAF treated rats.

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It decreases cell viability of liver cancer cells and modulates pro- and anti-apoptotic markers.

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Nexrutine modulates the cell cycle regulatory proteins and MAPKs.

Epidemiological studies suggested that plant-based dietary supplements can reduce the risk of liver cancer. Nexrutine (NX), an herbal extract from Phellodendronamurense, has been shown to have anti-inflammatory, anti-microbial and anti-tumor activities. In the present study, we have shown the anti-tumor potential of NX against Solt-Farber model with elimination of PH, rat liver tumor induced by diethylnitrosoamine (DEN) as carcinogen and 2-acetylaminofluorene (2-AAF) as co-carcinogen. The elucidation of mechanistic pathways was explored in human liver cancer cells. Dietary intake of NX significantly decreased the cell proliferation and inflammation, as well as increased apoptosis in the liver sections of DEN/2-AAF-treated rats. Moreover, NX (2.5–10 μg/ml) exposure significantly decreased the viability of liver cancer cells and modulated the levels of Bax and Bcl-2 proteins levels. NX treatment resulted in increased cytochrome-c release and cleavage of caspases 3 and 9. In addition, NX decreased the expression of CDK2, CDK4 and associated cyclins E1 and D1, while up-regulated the expression of p21, p27 and p53 expression. NX also enhanced phosphorylation of the mitogen-activated protein kinases (MAPKs) ERK1/2, p38 and JNK1/2. Collectively, these findings suggested that NX-mediated protection against DEN/2-AAF-induced liver tumorigenesis involves decrease in cell proliferation and enhancement in apoptotic cell death of liver cancer cells.

In vitro anticancer activity of loquat tea by inducing apoptosis in human leukemia cells

Fresh loquat leaves have been used as folk health herb in Asian countries for long time, although the evidence supporting their functions is still minimal. This study aimed to clarify the chemopreventive effect of loquat tea extract (LTE) by investigating the inhibition on proliferation, and underlying mechanisms in human promyelocytic leukemia cells (HL-60). LTE inhibited proliferation of HL-60 in a dose-dependent manner. Molecular data showed that the isolated fraction of LTE induced apoptosis of HL-60 as characterized by DNA fragmentation; activation of caspase-3, -8, and -9; and inactivation of poly(ADP)ribose polymerase. Moreover, LTE fraction increased the ratio of pro-apoptotic Bcl-2-associated X protein (Bax)/anti-apoptotic myeloid cell leukemia 1 (Mcl-1) that caused mitochondrial membrane potential loss and cytochrome c released to cytosol. Thus, our data indicate that LTE might induce apoptosis in HL-60 cells through a mitochondrial dysfunction pathway. These findings enhance our understanding for chemopreventive function of loquat tea.

Review of the anticancer activities of bee products

Bee products have long been used in traditional medicine. The raw materials, crude extracts and purified active compounds from them have been found to exhibit interesting bioactivities, such as antimicrobial, anti-inflammatory and antioxidant activities. In addition, they have been widely used in the treatment of many immune-related diseases, as well as in recent times in the treatment of tumors. Bee product peptides induce apoptotic cell death in vitro in several transformed (cancer) human cell lines, including those derived from renal, lung, liver, prostate, bladder and lymphoid cancers. These bioactive natural products may, therefore, prove to be useful as part of a novel targeted therapy for some types of cancer, such as prostate and breast cancer. This review summarizes the current knowledge regarding the in vivo and in vitro potential of selective bee products against tumor cells.

A comparison of cardiomyocyte cytotoxic mechanisms for 5-fluorouracil and its pro-drug capecitabine

1. 5-Fluorouracil (5-FU) and its prodrug capecitabine are key chemotherapeutic agents in the treatment of many gastrointestinal tract adenocarcinomas. In addition to their beneficial antitumor effects, they also possess undesired cardiac toxicity. In the present study, we investigated the cytotoxic mechanisms of 5-FU and capecitabine in freshly isolated rat cardiomyocytes. 2. 5-FU and capecitabine cytotoxicities were associated with reactive oxygen species (ROS) formation, lipid peroxidation and rapid glutathione depletion. Increased intracellular ROS could target mitochondria, and our findings confirmed that the cardiomyocytes mitochondrial membrane potential (ΔΨm) was rapidly decreased by 5-FU and capecitabine. Mitochondrial dysfunction subsequently initiates downstream events that trigger caspase-3 activation, and our results showed that 5-FU and capecitabine activated caspase-3 which leads to apoptosis or necrosis. However, 5-FU acted much more powerful than capecitabine at inducing several cytotoxicity markers in heart cardiomyocytes. In addition, 5-FU but not capecitabine caused lysosomal membrane leakiness when it was incubated with cardiomyocytes. All cytotoxicity markers were prevented by antioxidants, ROS scavengers, mitochondrial permeability transition (MPT) pore sealing agents and lysosomotropic agents. 3. Our findings showed that the cytotoxic action of 5-FU and capecitabine on cardiomyocytes are mediated by oxidative stress and subsequent mitochondrial dysfunction which causes caspase-3 activation and cell death.

Bioactive Lignans from Zanthoxylum alatum Roxb. stem bark with cytotoxic potential

ETHNOPHARMACOLOGICAL RELEVANCE

Zanthoxylum alatum is used in traditional medicinal systems for number of disorders like cholera, diabetes, cough, diarrhea, fever, headache, microbial infections, toothache, inflammation and cancer. The aim of the present study was to evaluate Zanthoxylum alatum stem bark for its cytotoxic potential and to isolate the bioactive constituents.

MATERIAL AND METHODS

Cytotoxicity of the different extracts and isolated compounds was studied on lung carcinoma cell line (A549) and pancreatic carcinoma cell line (MIA-PaCa) using MTT assay. Isolation of compounds from most active extract (petroleum ether) was done on silica gel column. Structure elucidation was done by using various spectrophotometric techniques like UV, IR, (1)H NMR, (13)C NMR and mass spectroscopy. The type of cell death caused by most active compound C was explored by fluorescence microscopy using the acridine orange/ethidium bromide method.

RESULT

Petroleum ether extract of plant has shown significant cytotoxic potential. Three lignans sesamin (A), kobusin (B), and 4'O demethyl magnolin (C) has been isolated. All lignans showed cytotoxic activities in different ranges. Compound C was the novel bioactive compound from a plant source and found to be most active. In apoptosis study, treatment caused typical apoptotic morphological changes. It enhances the apoptosis at IC50 dose (21.72 µg/mL) however showing necrotic cell death at higher dose after 24h on MIA-PaCa cell lines.

CONCLUSION

Petroleum ether extract (60-80 °C) of Zanthoxylum alatum has cytotoxic potential. The lignans isolated from the petroleum ether extract were responsible for the cytotoxic potential of the extract. 4'O demethyl magnolin was novel compound from Zanthoxylum alatum. Hence the Zanthoxylum alatum can be further explored for the development of anticancer drug.

Cytotoxic and apoptotic activities of Amorphophallus campanulatus (Roxb.) Bl. tuber extracts against human colon carcinoma cell line HCT-15

Colorectal cancer is one of the leading causes of cancer death worldwide and is the third most common form of malignancy in both men and women. Several possible colon cancer chemopreventive agents are found in edible plants. Amorphophallus campanulatus (Roxb.) Blume (family: Araceae) is a tuber crop, largely cultivated throughout the plains of India for using its corm as food. This tuber has also been traditionally used for the treatment of abdominal tumors, liver diseases, piles etc. The aim of this study was to evaluate the dose-dependent cytotoxic and apoptosis inducing effects of the sub fractions of A. campanulatus tuber methanolic extract (ACME) viz. petroleum ether fraction (PEF), chloroform fraction (CHF), ethyl acetate fraction (EAF) and methanolic fraction (MEF) on the colon cancer cell line, HCT-15. Antiproliferative effects of the sub fractions of ACME were studied by MTT assay. Apoptotic activity was assessed by DAPI, Annexin V-FITC and JC-1 fluorescent staining. The chemotherapeutic drug, 5-flurouracil (5-FU) was used as positive drug control. The sub fractions of ACME significantly inhibited the proliferation of HCT-15 cells in a dose-dependent manner. In addition, the extracts were found to induce apoptosis and were confirmed by DAPI, Annexin V-FITC and JC-1 fluorescent staining. A pronounced results of cytotoxic and apoptotic activities were observed in the cells treated with 5-FU and CHF, whereas, EAF and MEF treated cells exhibited a moderate result and the least effect was observed in PEF treated cells. Our results suggested that, among the sub fractions of ACME, CHF had potent cytotoxic and apoptotic activity and thus it could be explored as a novel target for anticancer drug development. Furthermore, these findings confirm that the sub fractions of ACME dose-dependently suppress the proliferation of HCT-15 cells by inducing apoptosis.

Oxidative mechanisms of fish hepatocyte toxicity by the harmful dinoflagellate Cochlodinium polykrikoides

Harmful Algal Blooms caused by the marine ichthyotoxic dinoflagellate Cochlodinium polykrikoides are responsible for mass mortalities of wild and farmed fish worldwide. In this research, we investigated the cytotoxic mechanisms of aqueous extract of C. polykrikoides on isolated Rainbow trout (Oncorhynchus mykiss) liver hepatocytes. Algal extract exposure with isolated trout hepatocytes caused hepatocyte membrane lysis, reactive oxygen species (ROS) formation, glutathione depletion, lysosomal membrane rupture, collapse of mitochondrial membrane potential, ATP depletion and increase in ADP/ATP ratio, cytochrome C release into the hepatocyte cytosol, and activation of caspases cascade. Anti-oxidants, free radical scavengers, mitochondrial permeability transition (MPT) pore sealing agents, microsomal oxidases inhibitors, ATP generators and lysosomotropic agents protected fish hepatocytes against C. polykrikoides. Fish hepatocyte toxicity was also associated with mitochondrial and lysosomal membrane injury. These events caused cytochrome C release from the mitochondrial intra-membrane space into cytosol. The cytochrome C release could trigger activation of caspase-3 and apoptosis.

Screening and structural analysis of flavones inhibiting tankyrases

Flavonoids are known for their beneficial effects on human health, and therefore the therapeutic potential of these compounds have been extensively studied. Flavone has been previously identified as a tankyrase inhibitor, and to further elucidate whether tankyrases would be inhibited by other flavonoids, we performed a systematic screening of tankyrase 2 inhibitory activity using 500 natural and naturally derived flavonoids covering nine different flavonoid classes. All identified tankyrase inhibitors were flavones. We report crystal structures of all the hit compounds in complex with the catalytic domain of human tankyrase 2. Flavone derivatives in all 10 crystal structures bind to the nicotinamide binding site of tankyrase 2. Potencies of the active flavones toward tankyrases vary between 50 nM and 1.1 μM, and flavones show up to 200-fold selectivity for tankyrases over ARTD1. The molecular details of the interactions revealed by cocrystal structures efficiently describe the properties of potent flavone derivatives inhibiting tankyrases.

Hesperidin alleviates oxidative stress and downregulates the expressions of proliferative and inflammatory markers in azoxymethane-induced experimental colon carcinogenesis in mice

OBJECTIVE

Colon cancer is a common malignant neoplasm causing huge morbidity and mortality worldwide. Current therapeutic interventions are unsatisfying, which necessitates novel chemopreventive strategies. The present study was intended to elucidate the chemopreventive efficacy of hesperidin against azoxymethane (AOM)-induced mouse colon carcinogenesis.

MATERIALS AND METHODS

Swiss albino mice were subjected to intraperitoneal injections of AOM once a week for 3 consecutive weeks. Hesperidin treatments were provided in the initiation or post-initiation phases. The number and multiplicity of aberrant crypt foci (ACF), tumor incidence and antioxidant status were determined. Histopathological analyses, proliferating cell nuclear antigen (PCNA) index and modulations in the expression of inflammatory markers such as nuclear factor kappa B (NF-κB), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were studied.

RESULTS

Hesperidin treatments significantly inhibited the number and multiplicities of AOM-induced ACF and tumor incidence. Hesperidin reduced oxidative stress parameters and enhanced antioxidant status. A marked decrease in the PCNA index was evident on hesperidin administration. Hesperidin treatments caused a prominent downregulation of NF-κB and its target molecules iNOS and COX-2, thereby combating inflammation.

CONCLUSION

This study proves the chemopreventive efficacy of hesperidin against the deleterious traits of colon carcinogenesis including accelerated proliferation, inflammation and persistent oxidative stress.

Nexrutine(R) inhibits tumorigenesis in mouse skin and induces apoptotic cell death in human squamous carcinoma A431 and human melanoma A375 cells

Nexrutine(®) (NX), a herbal extract from Phellodendron amurense, has been shown to possess antitumor, antimicrobial, anti-inflammatory and other biological activities. In the present investigation, we explored the mechanism of chemopreventive/chemotherapeutic efficacy of NX against skin cancer. Single application of NX (1.0mg/mouse) prior to 12-O-tetradecanoylphorbol 13-acetate (TPA) application significantly inhibited TPA-induced skin edema, hyperplasia, thymidine incorporation and ornithine decarboxylase (ODC) activity; expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS); phosphorylation of extracellular signal-regulated kinases (ERK) 1/2, p38 and c-jun N-terminal kinase (JNK) mitogen-activated protein kinases (MAPKs); and activation of I kappa B kinase (IKK), IκBα and nuclear factor-kappa B (NF-κB) in mouse skin. In a two-stage mouse skin tumorigenesis model, it was found that twice-weekly treatment of NX prior to TPA application in 7,12-dimethylbenz[α]anthracene (DMBA)-initiated animals showed reduced tumor incidence, lower tumor body burden and significant delay in latency period compared with DMBA-initiated and TPA-promoted animals. Furthermore, the therapeutic efficacy of NX was assessed against human squamous carcinoma (A431) and human melanoma (A375) cells. A431 and A375 cells treated with NX (2.5-10.0 μg/ml, 48h) showed a decrease in viability and enhanced cell cycle arrest at the G(0)/G(1) phase and apoptosis; however, NX had minimal cytotoxic effect on HaCaT cells and primary murine keratinocytes, suggesting its high therapeutic index. In addition, NX treatment also modulates the levels of Bax and Bcl-2 proteins along with cytochrome c release, cleavage and enhanced expression of poly (adenosine diphosphate-ribose) polymerase as well as catalytic activities of caspases 3 and 9 in both A431 and A375 cells. Based on our in vivo and in vitro studies, NX could be useful in the management (chemoprevention as well as chemotherapy) of skin cancer.

Antiproliferative and proapoptotic activities of methanolic extracts from Ligustrum vulgare L. as an individual treatment and in combination with palladium complex

The aim of this study is to examine the growth inhibitory effects of methanolic leaf and fruit extracts of L. vulgare on HCT-116 cells over different time periods and their synergistic effect with a Pd(apox) complex. The antiproliferative activity of plant extracts alone or in combination with the Pd(apox) complex was determined using MTT cell viability assay, where the IC(50) value was used as a parameter of cytotoxicity. Results show that antiproliferative effects of L. vulgare extracts increase with extension of exposure time, with decreasing IC(50) values, except for 72 h where the IC(50) values for methanolic leaf extract were lower than for the fruit extract. The Pd(apox) complex alone had a weak antiproliferative effect, but combination with L. vulgare extracts caused stronger effects with lower IC(50) values than with L. vulgare extracts alone. The type of cell death was explored by fluorescence microscopy using the acridin orange/ethidium bromide method. Treatments with plant extracts caused typical apoptotic morphological changes in HCT-116 cells and co-treatments with Pd(apox) complex caused higher levels of apoptotic cells than treatment with plant extracts alone. The results indicate that L. vulgare is a considerable source of natural bioactive substances with antiproliferative activity on HCT-116 cells and which have a substantial synergistic effect with the Pd(apox) complex.