Chemoprevention of Colon Cancer by DFMO, Sulindac, and NO-Sulindac Administered Individually or in Combinations in F344 Rats.

Non-steroidal anti-inflammatory drugs (NSAIDs) are promising colorectal cancer (CRC) chemopreventive drugs; however, to overcome NSAIDs' associated side effects, there is a need to develop safer and efficacious approaches. The present study was designed to evaluate (i) the efficacy of nitric-oxide releasing (NO)-Sulindac as compared to Sulindac; (ii) whether NO-Sulindac is superior to Sulindac in enhancing low-dose difluoromethylornithine (DFMO)-induced chemopreventive efficacy, and (iii) assessing the key biomarkers associated with colon tumor inhibition by these combinations. In F344 rats, colonic tumors were induced by azoxymethane (AOM). At the adenoma stage (13 weeks post AOM), groups of rats were fed the experimental diets containing 0 ppm, 500 ppm DFMO, 150 ppm Sulindac, and 200 ppm NO-Sulindac, individually or in combinations, for 36 weeks. Colon tumors were evaluated histopathologically and assayed for expression levels of proliferative, apoptotic, and inflammatory markers. Results suggest that (except for NO-Sulindac alone), DFMO, Sulindac individually, and DFMO combined with Sulindac or NO-Sulindac significantly suppressed AOM-induced adenocarcinoma incidence and multiplicities. DFMO and Sulindac suppressed adenocarcinoma multiplicity by 63% (p < 0.0001) and 51% (p < 0.0011), respectively, whereas NO-Sulindac had a modest effect (22.8%, p = 0.09). Combinations of DFMO plus Sulindac or NO-Sulindac suppressed adenocarcinoma incidence (60%, p < 0.0001; 50% p < 0.0004), and multiplicity (81%, p < 0.0001; 62%, p < 0.0001). Rats that were fed the combination of DFMO plus Sulindac showed significant inhibition of tumor cell proliferation and induction of apoptosis. In addition, enhancement of p21, Bax, and caspases; downregulation of Ki-67, VEGF, and ß-catenin; and modulation of iNOS, COX-2, and ODC activities in colonic tumors were observed. These observations show that a lower-dose of DFMO and Sulindac significantly enhanced CRC chemopreventive efficacy when compared to NO-Sulindac alone, and the combination of DFMO and NO-Sulindac was modestly efficacious as compared to DFMO alone.

Experimental Studies Indicate That ST-2223, the Antagonist of Histamine H3 and Dopamine D2/D3 Receptors, Restores Social Deficits and Neurotransmission Dysregulation in Mouse Model of Autism.

Altered regulation of neurotransmitters may lead to many pathophysiological changes in brain disorders including autism spectrum disorder (ASD). Given the fact that there are no FDA-approved effective treatments for the social deficits in ASD, the present study determined the effects of chronic systemic treatment of the novel multiple-active H3R/D2R/D3R receptor antagonist ST-2223 on ASD-related social deficits in a male Black and Tan Brachyury (BTBR) mice. ST-2223 (2.5, 5, and 10 mg/kg, i.p.) significantly and dose-dependently mitigated social deficits and disturbed anxiety levels of BTBR mice (p < 0.05) in comparison to the effects of aripiprazole (1 mg/kg, i.p.). Moreover, levels of monoaminergic neurotransmitters quantified by LC-MS/MS in four brain regions including the prefrontal cortex, cerebellum, striatum, and hippocampus unveiled significant elevation of histamine (HA) in the cerebellum and striatum; dopamine (DA) in the prefrontal cortex and striatum; as well as acetylcholine (ACh) in the prefrontal cortex, striatum, and hippocampus following ST-2223 (5 mg/kg) administration (all p < 0.05). These in vivo findings demonstrate the mitigating effects of a multiple-active H3R/D2R/D3R antagonist on social deficits of assessed BTBR mice, signifying its pharmacological potential to rescue core ASD-related behaviors and altered monoaminergic neurotransmitters. Further studies on neurochemical alterations in ASD are crucial to elucidate the early neurodevelopmental variations behind the core symptoms and heterogeneity of ASD, leading to new approaches for the future therapeutic management of ASD.

The Novel Pimavanserin Derivative ST-2300 with Histamine H3 Receptor Affinity Shows Reduced 5-HT2A Binding, but Maintains Antidepressant- and Anxiolytic-like Properties in Mice.

The therapy of depression is challenging and still unsatisfactory despite the presence of many antidepressant drugs on the market. Consequently, there is a continuous need to search for new, safer, and more effective antidepressant therapeutics. Previous studies have suggested a potential association of brain histaminergic/serotoninergic signaling and antidepressant- and anxiolytic-like effects. Here, we evaluated the in vivo antidepressant- and anxiolytic-like effects of the newly developed multiple-active ligand ST-2300. ST-2300 was developed from 5-HT2A/2C inverse agonist pimavanserin (PIM, ACP-103) and incorporates a histamine H3 receptor (H3R) antagonist pharmacophore. Despite its parent compound, ST-2300 showed only moderate serotonin 5-HT2A antagonist/inverse agonist affinity (Ki value of 1302 nM), but excellent H3R affinity (Ki value of 14 nM). In vivo effects were examined using forced swim test (FST), tail suspension test (TST), and the open field test (OFT) in C57BL/6 mice. Unlike PIM, ST-2300 significantly increased the anxiolytic-like effects in OFT without altering general motor activity. In FST and TST, ST-2300 was able to reduce immobility time similar to fluoxetine (FLX), a recognized antidepressant drug. Importantly, pretreatment with the CNS-penetrant H3R agonist (R)-α-methylhistamine reversed the antidepressant-like effects of ST-2300 in FST and TST, but failed to reverse the ST-2300-provided anxiolytic effects in OFT. Present findings reveal critical structural features that are useful in a rational multiple-pharmacological approach to target H3R/5-HT2A/5-HT2C.

Simultaneous Antagonism at H3R/D2R/D3R Reduces Autism-like Self-Grooming and Aggressive Behaviors by Mitigating MAPK Activation in Mice.

Dysregulation in brain neurotransmitters underlies several neuropsychiatric disorders, e.g., autism spectrum disorder (ASD). Also, abnormalities in the extracellular-signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) pathway pave the way for neuroinflammation, neurodegeneration, and altered learning phenotype in ASD. Therefore, the effects of chronic systemic administration of the multiple-targeting antagonist ST-713 at the histamine H3 receptor (H3R) and dopamine D2/D3 receptors (D2/D3R) on repetitive self-grooming, aggressive behaviors, and abnormalities in the MAPK pathway in BTBR T + Itpr3tf/J (BTBR) mice were assessed. The results showed that ST-713 (2.5, 5, and 10 mg/kg, i.p.) mitigated repetitive self-grooming and aggression in BTBR mice (all p < 0.05), and the ameliorative effects of the most promising dose of ST-713 (5 mg/kg, i.p.) on behaviors were completely abrogated by co-administration of the H3R agonist (R)-α-methylhistamine or the anticholinergic drug scopolamine. Moreover, the elevated levels of several MAPK pathway proteins and induced proinflammatory markers such as tumor necrosis factor (TNF-α), interleukin-1ß (IL-1ß), and IL-6 were significantly suppressed following chronic administration of ST-713 (5 mg/kg, i.p.) (all p < 0.01). Furthermore, ST-713 significantly increased the levels of histamine and dopamine in hippocampal tissue of treated BTBR mice (all p < 0.01). The current observations signify the potential role of such multiple-targeting compounds, e.g., ST-713, in multifactorial neurodevelopmental disorders such as ASD.

The Multi-Targeting Ligand ST-2223 with Histamine H3 Receptor and Dopamine D2/D3 Receptor Antagonist Properties Mitigates Autism-Like Repetitive Behaviors and Brain Oxidative Stress in Mice.

Autism spectrum disorder (ASD) is a complex heterogeneous neurodevelopmental disorder characterized by social and communicative impairments, as well as repetitive and restricted behaviors (RRBs). With the limited effectiveness of current pharmacotherapies in treating repetitive behaviors, the present study determined the effects of acute systemic treatment of the novel multi-targeting ligand ST-2223, with incorporated histamine H3 receptor (H3R) and dopamine D2/D3 receptor affinity properties, on ASD-related RRBs in a male Black and Tan BRachyury (BTBR) mouse model of ASD. ST-2223 (2.5, 5, and 10 mg/kg, i.p.) significantly mitigated the increase in marble burying and self-grooming, and improved reduced spontaneous alternation in BTBR mice (all p < 0.05). Similarly, reference drugs memantine (MEM, 5 mg/kg, i.p.) and aripiprazole (ARP, 1 mg/kg, i.p.), reversed abnormally high levels of several RRBs in BTBR (p < 0.05). Moreover, ST-2223 palliated the disturbed anxiety levels observed in an open field test (all p < 0.05), but did not restore the hyperactivity parameters, whereas MEM failed to restore mouse anxiety and hyperactivity. In addition, ST-2223 (5 mg/kg, i.p.) mitigated oxidative stress status by decreasing the elevated levels of malondialdehyde (MDA), and increasing the levels of decreased glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) in different brain parts of treated BTBR mice (all p < 0.05). These preliminary in vivo findings demonstrate the ameliorative effects of ST-2223 on RRBs in a mouse model of ASD, suggesting its pharmacological prospective to rescue core ASD-related behaviors. Further confirmatory investigations on its effects on various brain neurotransmitters, e.g., dopamine and histamine, in different brain regions are still warranted to corroborate and expand these initial data.

The histamine H3R and dopamine D2R/D3R antagonist ST-713 ameliorates autism-like behavioral features in BTBR T+tf/J mice by multiple actions.

Several brain neurotransmitters, including histamine (HA), acetylcholine (ACh), and dopamine (DA) are suggested to be involved in several brain disorders including cognitive deficits, depression, schizophrenia, anxiety, and narcolepsy, all of which are comorbid with Autism spectrum disorder (ASD). Therefore, the ameliorative effects of the novel multiple-active compound ST-713 with high binding affinities at histamine H3 receptor (H3R), dopamine D2sR and D3R on ASD-like behaviors in male BTBR T+tf/J mice model were assessed. ST-713 (3-(2-chloro-10H-phenothiazin-10-yl)-N-methyl-N-(4-(3-(piperidin-1-yl)propoxy)benzyl)propan-1-amine; 2.5, 5, and 10 mg/kg, i.p.) ameliorated dose-dependently social deficits, and significantly alleviated the repetitive/compulsive behaviors of BTBR mice (all P < 0.05). Moreover, ST-713 modulated disturbed anxiety levels, but failed to obliterate increased hyperactivity of tested mice. Furthermore, ST-713 (5 mg/kg) attenuated the increased levels of hippocampal and cerebellar protein expressions of NF-κB p65, COX-2, and iNOS in BTBR mice (all P < 0.05). The ameliorative effects of ST-713 on social parameters were entirely reversed by co-administration of the H3R agonist (R)-α-methylhistamine or the anticholinergic drug scopolamine. The obtained results demonstrate the potential of multiple-active compounds for the therapeutic management of neuropsychiatric disorders, e.g. ASD.

Dietary Phytochemicals as a Potential Source for Targeting Cancer Stem Cells.

The tumor microenvironment is composed of various types of cells that lead to tumor heterogeneity. In the middle of these populations, cancer stem cells play a vital role in the initiation and progression of cancer cells and are capable of self-renewal and differentiation processes. These cancer stem cells are resistant to conventional therapy such as chemotherapy and radiotherapy. To eradicate the cancer stem cells in the tumor environment, various natural product has been found in recent years. In this review, we have selected some of the natural products based on anticancer potential including targeting cancer cells and cancer stem cells. Further, this review explains the molecular mechanism of action of these natural products in various cancer stem cells. Therefore, targeting a multi-drug resistant cancer stem cell by natural products is a novel method to reduce drug resistance and adverse effect during conventional therapy.

Morin treatment for acute ethanol exposure in rats.

Ethanol intoxication increases oxidative stress and pro-inflammatory proteins, which cause neurodegeneration. Morin is a natural flavonoid obtained from plants of the Moraceae family that exhibits antioxidant, anti-inflammatory, hepatoprotective, anticancer and cardioprotective properties. We investigated the neuroprotective effect of morin on ethanol intoxicated rats. Rats exposed to ethanol exhibit increased cholesterol, triglycerides, phospholipids, free fatty acids, and lipid oxidative byproducts, and decreased the activity of antioxidant enzymes and membrane ATPase. We found that ethanol increased activation of microglia and astrocytes in the brain. Administration of morin to rats exposed to ethanol significantly decreased lipid oxidative byproducts, enhanced antioxidant enzymes, normalized lipid levels and decreased microglia and astrocyte activation. Morin exhibits neuroprotective properties against ethanol intoxication by increasing the antioxidant defense mechanism and decreasing the inflammatory response caused by neuroglia and astrocytes.

Folic acid functionalized starch encapsulated green synthesized copper oxide nanoparticles for targeted drug delivery in breast cancer therapy.

This work aimed to synthesis copper oxide nanoparticles (CuONPs) using the Helianthus tuberosus (Ht) extracts then encapsulated with starch (ST) followed by conjugated with folic acid (FA) to facilitate the targeted release in MDA-MB-231 cells and this nanoparticles (NPs) was named as FA-ST-HtCuONPs. The TEM and DLS revealed that the FA-ST-HtCuONPs was hexagonal, oval-shaped with size of ~108.83 nm, and zeta potential of 43.26 mV. FTIR analysis indicated the presence of functional derivatives related to starch, folic acid and phytomolecules in NPs. Besides, the about 241.25 nmol/mg of folic accumulation on surface of the FA-ST-HtCuONPs were confirmed by UV-visible spectroscopic method. The cytotoxicity results revealed that among the samples, the inhibitory concentration (IC50) of FA-ST-HtCuONPs (21.03 ± 1.85 µg/mL) was exhibited higher cytotoxicity to human breast cancer (MDA-MB-231) cells through activating reactive oxygen species (ROS) generation, nuclear damage and reduction of mitochondrial membrane potential and activating the apoptosis-related protein expression. Overall, the results proved that folic acid and starch decoration were increased the NPs penetration in cell through folate receptor-based endocytosis for enhanced breast cancer therapy.

Biochemical and molecular aspects of 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis: a review.

1,2-dimethylhydrazine (DMH) is a member in the class of hydrazines, strong DNA alkylating agent, naturally present in cycads. DMH is widely used as a carcinogen to induce colon cancer in animal models. Exploration of DMH-induced colon carcinogenesis in rodent models provides the knowledge to perceive the biochemical, molecular, and histological mechanisms of different stages of colon carcinogenesis. The procarcinogen DMH, after a series of metabolic reactions, finally reaches the colon, there produces the ultimate carcinogen and reactive oxygen species (ROS), which further alkylate the DNA and initiate the development of colon carcinogenesis. The preneolpastic lesions and histopathological observations of DMH-induced colon tumors may provide typical understanding about the disease in rodents and humans. In addition, this review discusses about the action of biotransformation and antioxidant enzymes involved in DMH intoxication. This understanding is essential to accurately identify and interpret alterations that occur in the colonic mucosa when evaluating natural or pharmacological compounds in DMH-induced animal colon carcinogenesis.

Antidiabetic Activity of Gold Nanoparticles Synthesized Using Wedelolactone in RIN-5F Cell Line.

We synthesized the gold nanoparticles (AuNPs) using wedelolactone (WDL) and characterized them using UV-visible spectroscopy, fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopic (SEM), transmission electron microscopic (TEM), energy dispersive X-ray diffraction, and atomic force microscopic (AFM) studies. The electronic spectrum exhibited an absorption peak at 535 nm. The FT-IR results proved that WDL was stabilized on the surface of AuNPs by acting as a capping or reducing agent. The crystalline structure was affirmed by XRD pattern and the spherical shape of WDL-AuNPs was evidenced by SEM, TEM, and AFM. The synthesized WDL-AuNPS were evaluated for anti-diabetic activity in pancreatic RIN-5F cell lines. In vitro results showed that WDL-AuNPs did not only improve the insulin secretion affected by di-(2-ethylhexyl) phthalate (DEHP), but also the cell viability in RIN5F cells. WDL-AuNPs treatment modulates the pro-apoptotic proteins and anti-apoptotic proteins expression to prevent the cells undergoing apoptosis in DEHP-exposed RIN-5F cells. The exposure of DEHP causes an increase in ROS production and lipid peroxidation levels. The free radical scavenging and antioxidant properties of WDL-AuNPs increase the deleterious effect caused by DEHP. On the other side, WDL-AuNPs increase mRNA expressions of insulin-signaling proteins in RIN-5F cells. This study concludes that WDL-AuNPs can be successfully used to regulate the expression of Bcl-2 family proteins, reduce lipid peroxidation, and to improve the secretion of antioxidants and insulin through the GLUT2 pathway in RIN-5F cell lines.

Phloretin loaded chitosan nanoparticles enhance the antioxidants and apoptotic mechanisms in DMBA induced experimental carcinogenesis.

The main aim of this study was to investigate the effects of phloretin loaded chitosan nanoparticles (PhCsNPs) on 7,12-dimethylbenz[a]anthracene (DMBA) induced experimental cancer in hamsters. Oral squamous cell carcinoma (OSCC) was induced in male golden Syrian hamsters by painting with 0.5% DMBA three times a week for 14 weeks. Varying concentration of PhCsNPs (5, 10, and 20 mg/kg b.wt.) was orally administered on alternative days to evaluate the optimum dose. The experiment design was terminated at the end of the 14th week. The development of OSCC was confirmed by histopathological and biochemical analysis (lipid peroxidation, antioxidant profile, and detoxification enzymes) in plasma, erythrocyte, buccal, and liver tissues. Significant increases in oxidation and lipid peroxidation were noticed in DMBA-painted hamsters. Oral administration of PhCsNPs in various doses on alternate days reversed the deleterious effects induced by DMBA. In addition, immunoblot analyses of PhCsNPs treatment enhanced the release of Bcl-2 associated X protein (Bax), cytochrome c, caspase-3, 9 and suppressed the B-cell lymphoma 2 (Bcl-2) expression, which the use of PhCsNPs for mitochondrial-mediated apoptosis. These findings suggest biofabricated PhCsNPs may act as a potent antioxidant and anti-carcinogenic in DMBA induced oral cancer in experimental animals.

Anti-inflammatory and anticancer effects of p-methoxycinnamic acid, an active phenylpropanoid, against 1,2-dimethylhydrazine-induced rat colon carcinogenesis.

p-methoxycinnamic acid (p-MCA) is an active phenolic acid found in rice bran, turmeric, brown rice, Kaempferia galanga, buckwheat inflorescence, etc. Earlier, we have reported that p-methoxycinnamic acid possesses antioxidant and antilipidperoxidative effects on 1,2-dimethylhyrdrazine (DMH)-induced colon carcinogenesis. The purpose of this study is to unravel the anti-inflammatory and anticancer properties of p-MCA against DMH-induced colon carcinogenesis. Male albino Wistar rats were randomly divided into six groups. Group 1 served as control, group 2 rats received 40 mg/kg b.wt. of p-MCA in 0.1% carboxymethylcellulose (CMC) every day, and colon cancer was induced in groups 3-6 using DMH at the dose of (20 mg/kg b.wt. subcutaneously) once a week for 15 weeks. In addition, along with DMH, groups 4 (initiation), 5 (post initiation) and 6 (entire period) rats received p-MCA (40 mg/kg b.wt.) p.o. every day during different time periods for the total experimental period of 30 weeks. Colon of animals treated with DMH showed an increased number of aberrant crypt foci (ACFs), increased nuclear translocation of transcription factor NF-κB p65 subunit, increased expression of inflammatory markers (iNOS, COX-2), cytokines (tumour necrosis factor-α, interleukin-6), cyclin D1, antiapoptotic protein (Bcl-2), metastasis marker (matrix metalloproteinase-2 (MMP-2)) and angiogenic marker (vascular endothelial growth factor VEGF) and decreased expression of pro-apoptotic proteins (Bax, caspases 3 and 9). On supplementing with p-MCA (40 mg/kg b.wt.) throughout the entire experimental period, DMH-induced pathological alterations reversed significantly to normal.

Biochemical and molecular mechanisms underlying the chemopreventive efficacy of rosmarinic acid in a rat colon cancer.

To shed light on colon cancer chemoprevention, natural phytochemicals attract researchers by virtue of their beneficial biological effects. The chemopreventive potential of rosmarinic acid (RA) was tested by using the colon carcinogen, 1,2-dimethylhydrazine (DMH) by evaluating the Aberrant crypt foci (ACF), tumour incidence, lipid peroxidative byproducts, phase I & II drug metabolizing enzymes, cell proliferative and apoptotic proteins. Rats were divided into six groups and received modified pellet diet. Group 1 served as control rats, group 2 rats received RA (5mg/kg b.w. p.o.), rats in groups 3-6 received DMH (20mg/kg b.w., s.c.) for the first fifteen weeks. In addition to DMH, groups 4-6 received RA at the dose of 5mg/kg b.w. during initiation, post initiation stages and also for the entire study period. DMH treated rats showed an increase in the development of ACF, tumour formation and multiplicity and decrease in lipid peroxidative byproducts. Moreover, it modulates xenobiotic enzymes and reduces the expressions of proapoptotic proteins; increases expressions of anti apoptotic proteins at the end of the study. Supplementation with RA to carcinogen treated rats protected them from the above deleterious effects caused by DMH and thus RA may be used as a potent chemopreventive agent.

Modulatory effects of condensed tannin fractions of different molecular weights from a Leucaena leucocephala hybrid on the bovine rumen bacterial community in vitro.

BACKGROUND: Condensed tannin (CT) fractions of different molecular weights (MWs) may affect rumen microbial metabolism by altering bacterial diversity. In this study the effects of unfractionated CTs (F0) and five CT fractions (F1-F5) of different MWs (F1, 1265.8 Da; F2, 1028.6 Da; F3, 652.2 Da; F4, 562.2 Da; F5, 469.6 Da) from Leucaena leucocephala hybrid-Rendang (LLR) on the structure and diversity of the rumen bacterial community were investigated in vitro. RESULTS: Real-time polymerase chain reaction assay showed that the total bacterial population was not significantly (P > 0.05) different among the dietary treatments. Inclusion of higher-MW CT fractions F1 and F2 significantly (P < 0.05) increased the Fibrobacter succinogenes population compared with F0 and CT fractions F3-F5. Although inclusion of F0 and CT fractions (F1-F5) significantly (P < 0.05) decreased the Ruminococcus flavefaciens population, there was no effect on the Ruminococcus albus population when compared with the control (without CTs). High-throughput sequencing of the V3 region of 16S rRNA showed that the relative abundance of genera Prevotella and unclassified Clostridiales was significantly (P < 0.05) decreased, corresponding with increasing MW of CT fractions, whereas cellulolytic bacteria of the genus Fibrobacter were significantly (P < 0.05) increased. Inclusion of higher-MW CT fractions F1 and/or F2 decreased the relative abundance of minor genera such as Ruminococcus, Streptococcus, Clostridium XIVa and Anaeroplasma but increased the relative abundance of Acinetobacter, Treponema, Selenomonas, Succiniclasticum and unclassified Spirochaetales compared with the control and lower-MW CT fractions. CONCLUSION: This study indicates that CT fractions of different MWs may play an important role in altering the structure and diversity of the rumen bacterial community in vitro, and the impact was more pronounced for CT fractions with higher MW. © 2016 Society of Chemical Industry.

p-Methoxycinnamic acid, an active phenylpropanoid induces mitochondrial mediated apoptosis in HCT-116 human colon adenocarcinoma cell line.

Among the eight phytochemicals (dihydrocarveol, sinapic acid, vanillic acid, ethylgallate, myrtenol, transcarveol, p-methoxycinnamic acid, and isoferulic acid) we tested, p-methoxycinnamic acid (p-MCA) [10 µM] showed the most potent in vitro growth inhibition on human colon adenocarcinoma (HCT-116 cells). Antiproliferative activity of p-MCA at 24h was associated with DNA damage, morphological changes and the results were comparable with doxorubicin. p-MCA induced phosphatidylserine translocation, increased the levels of reactive oxygen species (ROS), thiobarbituric acid reactive substances (TBARS), protein carbonyl content (PCC) and decreased enzymic antioxidant status (SOD, CAT, GPx) in HCT-116. p-MCA treatment increased the percentage of apoptotic cells, decreased the mitochondrial membrane potential and triggered cytochrome C release to cytosol. The induction of apoptosis by p-MCA was accompanied by an increase in caspase 3 and caspase 9 activities, increased expression of Bax and decreased expression of Bcl-2. Thus p-MCA induces mitochondria mediated intrinsic pathway of apoptosis in HCT-116 and has potential for treatment and prevention of colon cancer.

Protective effect of p-methoxycinnamic acid, an active phenolic acid against 1,2-dimethylhydrazine-induced colon carcinogenesis: modulating biotransforming bacterial enzymes and xenobiotic metabolizing enzymes.

Objective of the study is to evaluate the modifying potential of p-methoxycinnamic acid (p-MCA), an active rice bran phenolic acid on biotransforming bacterial enzymes and xenobiotic metabolizing enzymes in 1,2-dimethylhydrazine-induced rat colon carcinogenesis. 48 male albino wistar rats were divided into six groups. Group1 (control) received modified pellet diet and 0.1 % carboxymethylcellulose; group2 received modified pellet diet along with p-MCA (80 mg/kg b.wt. p.o.) everyday for 16 weeks; groups 3-6 received 1,2-dimethylhydrazine (DMH) (20 mg/kg b.wt.) subcutaneous injection once a week for the first 4 weeks, while groups 4-6 received p-MCA at three different doses of 20, 40 and 80 mg/kg b.wt. p.o. everyday for 16 weeks. A significant increase in carcinogen-activating enzymes (cytochrome P450, cytochrome b5, cytochrome P4502E1, NADH-cytochrome-b5-reductase and NADPH-cytochrome-P450 reductase) with concomitant decrease in phaseII enzymes, DT-Diaphorase, glutathione S-transferase, UDP-glucuronyl-transferase and gamma glutamyltransferase were observed in group3 compared to control. DMH treatment significantly increased the activities of feacal and colonic bacterial enzymes (ß-glucosidase, ß-galactosidase, ß-glucuronidase, nitroreductase, sulphatase and mucinase). p-MCA supplementation (40 mg/kg b.wt) to carcinogen exposed rats inhibited these enzymes, which were near those of control rats. The formation of dysplastic aberrant crypt foci in the colon and the histopathological observations of the liver also supports our biochemical findings. p-MCA (40 mg/kg b.wt.) offers remarkable modulating efficacy of biotransforming bacterial and xenobiotic metabolizing enzymes in colon carcinogenesis.

The effect of rosmarinic acid on 1,2-dimethylhydrazine induced colon carcinogenesis.

This study was carried out to investigate the chemopreventive potential of rosmarinic acid (RA) against 1,2-dimethylhydrazine (DMH) induced rat colon carcinogenesis by evaluating the effect of RA on tumour formation, antioxidant enzymes, cytochrome P450 content, p-nitrophenol hydroxylase and GST activities. Rats were divided into six groups and fed modified pellet diet for the entire experimental period. Group 1 served as control, group 2 received RA (10 mg/kgb.w.). Groups 3-6 were induced colon cancer by injecting DMH (20 mg/kgb.w.) subcutaneously once a week for the first four weeks (groups 3-6). In addition, RA was administered at the doses of 2.5, 5 and 10 mg/kgb.w. to groups 4-6 respectively. DMH treated rats showed large number of colonic tumours; decreased lipid peroxidation; decreased antioxidant status; elevated CYP450 content and PNPH activities; and decreased GST activity in the liver and colon. Supplementation with RA (5 mgkg/b.w.) to DMH treated rats significantly decreased the number of polyps (50%); reversed the markers of oxidative stress (21.0%); antioxidant status (38.55%); CYP450 content (29.41%); and PNPH activities (21.9%). RA at the dose of 5 mg/kgb.w. showed a most pronounced effect and could be used as a possible chemopreventive agent against colon cancer.