A Review on Dietary Intervention in Obesity Associated Colon Cancer

Background: Colorectal cancer (CRC) is one of the major causes of morbidity and mortality. According to National Cancer Registry, the incidence of colorectal cancer in Peninsular Malaysia increases with age. The incidence is highest among Chinese population but lower among Indians and Malays. Many reviews have suggested that obesity may be associated with a higher risk (>50%) of colorectal cancer. Methods: This study collects a comprehensive data from the literature review available from respective journals on dietary intervention and the chemo-protective mechanisms of a few natural resources in obesity -associated colon cancer based on previous and current studies. Results: In obesity-associated colon cancer, the genes of interest and pathways that are mainly involved include NFκB, P13K/Akt, and MAPK pathways, and FTO, leptin, Cyclin D, MMPs, and STAT3 genes. Dietary modification is one of the alternative steps in early prevention of colon cancer. It has been proposed that the components present in certain foods may have the ability to protect against many diseases including the prevention of cancer. Conclusion: There are many factors that lead to obesity-associated colon cancer and the mechanisms behind it is still undergoing intensive research. This review aims to scrutinize research as well as reviews that have been previously reported on obesity associated colorectal cancer and the beneficial effects of including antioxidants-rich foods such as vegetables and fruits in the diet to reduce the risk of obesity associated colorectal cancer.

Thermosonication and optimization of stingless bee honey processing.

The effects of thermosonication on the quality of a stingless bee honey, the Kelulut, were studied using processing temperature from 45 to 90 ℃ and processing time from 30 to 120 minutes. Physicochemical properties including water activity, moisture content, color intensity, viscosity, hydroxymethylfurfural content, total phenolic content, and radical scavenging activity were determined. Thermosonication reduced the water activity and moisture content by 7.9% and 16.6%, respectively, compared to 3.5% and 6.9% for conventional heating. For thermosonicated honey, color intensity increased by 68.2%, viscosity increased by 275.0%, total phenolic content increased by 58.1%, and radical scavenging activity increased by 63.0% when compared to its raw form. The increase of hydroxymethylfurfural to 62.46 mg/kg was still within the limits of international standards. Optimized thermosonication conditions using response surface methodology were predicted at 90 ℃ for 111 minutes. Thermosonication was revealed as an effective alternative technique for honey processing.

Tableting Properties and Compression Models of Labisia pumila Tablets.

The tableting properties of Labisia pumila herbal powder, which is well known for its therapeutic benefits was investigated. The herbal powder was compressed into tablets using a stainless steel cylindrical uniaxial die of 13-mm- diameter with compaction pressures ranging from 7 to 25 MPa. Two feed weights, 0.5 and 1.0 g were used to form tablets. Some empirical models were used to describe the compressibility behavior of Labisia pumila tablets. The strength and density of tablets increased with increase in compaction pressure and resulted in reduction in porosity of the tablets. Smaller feeds, higher forces and increase in compaction pressure, contributed to more coherent tablets. These findings can be used to enhance the approach and understanding of tableting properties of Labisia pumila herbal powder tablets.

Quality changes of stabilizer-free natural peanut butter during storage.

The storage stability of preservative-free peanut butter was evaluated for changes in physicochemical quality including moisture content and water activity, microbiological properties, oxidative stability and textural quality in terms of spreadability and firmness. The study was conducted for 16 weeks at storage temperature of 10, 25 and 35 °C on natural and pure peanut butter produced from two varieties of peanuts, the Virginia and Spanish TMV-2 varieties of China and India origin, respectively. The peanuts were ground using a high speed grinder for 2.5 and 3.0 min to produce peanut butter without addition of other ingredient. The natural peanut butter exhibited stability and had acceptable microbial count during storage. Storage at 10 °C gave similar textural quality with commercial product until week 8 and without appreciable loss in oxidative stability until week 12. At higher storage temperatures of 25 and 35 °C, oxidative stability was shortened to 4 weeks of storage. Among the factors of storage temperature and time, grinding time and peanut variety, storage temperature had the most significant effects on quality changes of natural peanut butter.

Tocotrienol-rich fraction prevents cellular aging by modulating cell proliferation signaling pathways.

BACKGROUND AND OBJECTIVE: Vitamin E has been suggested as nutritional intervention for the prevention of degenerative and age-related diseases. In this study, we aimed to elucidate the underlying mechanism of tocotrienol-rich fraction (TRF) in delaying cellular aging by targeting the proliferation signaling pathways in human diploid fibroblasts (HDFs). MATERIALS AND METHODS: Tocotrienol-rich fraction was used to treat different stages of cellular aging of primary human diploid fibroblasts viz. young (passage 6), pre-senescent (passage 15) and senescent (passage 30). Several selected targets involved in the downstream of PI3K/AKT and RAF/MEK/ERK pathways were compared in total RNA and protein. RESULTS: Different transcriptional profiles were observed in young, pre-senescent and senescent HDFs, in which cellular aging increased AKT, FOXO3, CDKN1A and RSK1 mRNA expression level, but decreased ELK1, FOS and SIRT1 mRNA expression level. With tocotrienol-rich fraction treatment, gene expression of AKT, FOXO3, ERK and RSK1 mRNA was decreased in senescent cells, but not in young cells. The three down-regulated mRNA in cellular aging, ELK1, FOS and SIRT1, were increased with tocotrienol-rich fraction treatment. Expression of FOXO3 and P21Cip1 proteins showed up-regulation in senescent cells but tocotrienol-rich fraction only decreased P21Cip1 protein expression in senescent cells. CONCLUSIONS: Tocotrienol-rich fraction exerts gene modulating properties that might be responsible in promoting cell cycle progression during cellular aging.

Targeting genes in insulin-associated signalling pathway, DNA damage, cell proliferation and cell differentiation pathways by tocotrienol-rich fraction in preventing cellular senescence of human diploid fibroblasts.

BACKGROUND AND OBJECTIVES: Tocotrienols have been known for their antioxidant properties besides their roles in cellular signalling, gene expression, immune response and apoptosis. This study aimed to determine the molecular mechanism of tocotrienol-rich fraction (TRF) in preventing cellular senescence of human diploid fibroblasts (HDFs) by targeting the genes in senescence-associated signalling pathways. MATERIALS AND METHODS: Real time quantitative PCR (qRT-PCR) was utilized to evaluate the expression of genes involved in these pathways. RESULTS: Our findings showed that SOD1 and CCS-1 were significantly down-regulated in pre-senescent cells while CCS-1 and PRDX6 were up-regulated in senescent cells (p<0.05). Treatment with TRF significantly down-regulated SOD1 in pre-senescent and senescent HDFs, up-regulated SOD2 in senescent cells, CAT in young HDFs, GPX1 in young and pre-senescent HDFs, and CCS-1 in young, pre-senescent and senescent HDFs (p<0.05). TRF treatment also caused up-regulation of FOXO3A in all age groups of cells (p<0.05). The expression of TP53, PAK2 and CDKN2A was significantly increased in senescent HDFs and treatment with TRF significantly down-regulated TP53 in senescent cells (p<0.05). MAPK14 was significantly up-regulated (p<0.05) in senescent HDFs while no changes was observed on the expression of JUN. TRF treatment, however, down-regulated MAPK14 in young and senescent cells and up-regulated JUN in young and pre-senescent HDFs (p<0.05). CONCLUSIONS: TRF modulated the expression of genes involved in senescence-associated signalling pathways during replicative senescence of HDFs.

Does gamma irradiation affect physicochemical properties of honey?

BACKGROUND AND AIMS: Honey is a supersaturated solution of sugars, enriched with proteins, minerals, vitamins, organic acids and polyphenols. Gamma irradiation is a physical technique of food preservation which protects the honey from insects' and microbial contamination during storage. We investigated the effect of gamma irradiation on physicochemical properties in two types of Malaysian honey, Gelam and Nenas. MATERIALS AND METHODS: Both honeys were irradiated at the dose 25 kGy in a cobalt-60 irradiator. The physicochemical properties pH, moisture, acidity, color, and sugar content as well as vitamins C and E, hydroxymethylfurfural (HMF) and mineral contents, for the irradiated and non-irradiated honeys were assessed. RESULTS: The results revealed that pH, acidity, minerals and sugar contents in both types of honey were not affected significantly by gamma irradiation, while moisture, vitamin E contents and HMF level decreased significantly with gamma irradiation. However, significant increased in color intensity and vitamin C were observed after gamma irradiation for both types of honey. DISCUSSION: In summary, gamma irradiation treatment of honey (in the dose mentioned above) did not cause significant changes in the physicochemical and mineral contents, except for significant alterations in color intensity, moisture, vitamins (C and E), and HMF contents.

Comparable down-regulation of TYR, TYRP1 and TYRP2 genes and inhibition of melanogenesis by tyrostat, tocotrienol-rich fraction and tocopherol in human skin melanocytes improves skin pigmentation.

BACKGROUND AND OBJECTIVE: Antioxidant has been recognized to inhibit UV-induced melanogenesis. This study aimed to elucidate the molecular mechanism of tyrostat, tocopherol and tocotrienol-rich fraction in inhibiting melanogenesis in human skin melanocytes. MATERIALS AND METHODS: Primary culture of melanocytes was exposed to repeated doses of 0.6 J/cm2 UVA for 6 days and treated with tyrostat, tocotrienol-rich fraction or tocopherol alone or in combination. RESULTS: UVA irradiation increased melanin content and tyrosinase activity and up-regulated TYR, TYRP1 and TYRP2 genes. Treatment with tyrostat, tocotrienol-rich fraction or tocopherol decreased melanin content and down-regulated TYR, TYRP1 and TYRP2 genes with decreased tyrosinase activity. Combined treatment exerted better effects as compared to treatment with single compound in decreasing the melanin content and down-regulating TYR, TYRP1 and TYRP2 genes. These findings indicated that tyrostat, tocotrienol-rich fraction and tocopherol inhibit melanogenesis by modulating the expression of genes involved in the regulation of melanin synthesis and inhibiting tyrosinase activity. CONCLUSIONS: Tyrostat, tocopherol and tocotrienol-rich fraction possessed anti-melanogenic properties and might be useful in improving skin pigmentation caused by UVA exposure.

Comparison of Chlorella vulgaris dressing and sodium alginate dressing: an experimental study in rats.

BACKGROUND AND AIMS: Chlorella vulgaris (CV) is a green microalgae enriched with nutrients, vitamins, minerals and chlorophyll. The aim of our study was to evaluate the potential wound healing effects of CV as a dressing while comparing it to sodium alginate dressing. MATERIALS AND METHODS: Fifteen Sprague-Dawley rats were divided into three groups consisting of control (normal-wound with no dressing), CV and sodium alginate dressings. Wound was created on the dorsal surface of rats using a 6-mm sterilized punch biopsy. The wounds were examined on days 3, 6, 9 and 12 for dryness, exudation, contraction, period of epithelialization, complete wound closure and scar formation. All rats were sacrificed on day 12 and the granulation tissue formed on the wound was excised for the histological examination using Hematoxylin and Eosin stain (H&E). RESULTS: The wound's size treated with CV dressing was significantly reduced (p<0.05) compared to the control and sodium alginate treated wounds. H&E staining showed that CV dressing minimized the formation of scar tissue during the healing process. Although there was no statistically significant difference in the complete wound closure and period of epithelialization among the groups, a significant difference was observed regarding the dryness, exudation and scar formation in the wound. CONCLUSION: CV extract can be used as an effective supplement for wound dressing.

Apoptosis changes and SA-beta galactosidase expression in stress-induced premature senescence (SIPS) model of human skin fibroblasts.

Stress-induced premature senescence (SIPS) model is in vitro model of cellular aging. In this study, apoptosis was evaluated in SIPS model and in replicative senescent fibroblasts. We also compared the activity of senescence-associated beta-galactosidase (SA-beta gal) as a biomarker of cellular aging. Our results suggested that SIPS model and senescent fibroblasts might share similar mechanism of aging and apoptosis pathway.

GAPDH as housekeeping gene for human skin fibroblast senescent model.

Validation of housekeeping gene is important for accurate quantitation of RNA in real time RT-PCR technique. The purpose of this study was to determine the validity of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as a housekeeping gene for quantitative real time RT-PCR assessment in human skin fibroblast senescent model. The cells were divided into different treatment groups; young (passage 4), senescent (passage 30), treatment with H2O2 and treatment with A-tocotrienol prior to H2O2 treatment. Our results showed that the expression level of GAPDH was constant with different treatment groups. Therefore, we concluded that GAPDH was suitable to be used as housekeeping gene in human skin fibroblast senescent model.

Infant feeding practices and attitudes of mothers in Kelantan towards breastfeeding.

The incidence of breastfeeding among 96 mothers (88/96 were Malays) who were attending various clinics at Universiti Sains Malaysia Hospital and Kota Bharu General Hospital was about 95%. The feeding patterns show that about 72% of mothers gave mixed feedings (breastmilk plus infant formula) while only 30% gave exclusive breastmilk to their infants in the first six months. Two main reasons for giving mixed feedings were that mothers had to start working soon after giving birth and reported "insufficient milk". Mixed feedings were seen to be more prevalent in the higher income group mothers (> RM1000 per month). About 64% of them who breastfed their child continued to do so beyond 6 months. Regarding their knowledge on breastfeeding, most mothers (98%) knew that breastmilk is good for baby's health, economical, strengthens bonding between mother and child, and was sufficient for the sustenance of the baby. However, when asked about colostrum, 66% of mothers who breastfed their child threw away the colostrum before feeding; some of the reasons given were that colostrum is dirty, and not suitable for the baby's health and it might cause some diseases.

Stimulation of DNA synthesis in primary rat hepatocyte cultures by liver tumor promoters: interactions with other growth factors.

Mechanism(s) of tumor promotion in liver by xenobiotics such as hexachlorocyclohexane (HCH), 1,1,1-trichloro-2,2-bis (4-chlorophenyl)ethane (DDT) and phenobarbital (PB) are not understood in detail although growth-stimulatory effects may be significant in their action. As a basis for studying mechanisms of growth control by liver tumor promoters, effects of xenobiotics on DNA synthesis have been examined in primary cultures of normal rat hepatocytes, maintained under fully-defined conditions. The xenobiotics alone were relatively ineffective but they exhibited synergism with epidermal growth factor (EGF), insulin and dexamethasone in stimulating DNA synthesis and were effective in moderate-to-low density cultures but not in confluent monolayers. Under conditions optimized for HCH or pregnenolone 16 alpha-carbonitrile (PCN) (i.e. subconfluent cultures exposed to insulin, EGF and dexamethasone), HCH, PCN, DDT or PB caused a transient stimulation of DNA synthesis, apparent after 2 days in culture. This probably reflected earlier entry of hepatocytes to S-phase. HCH was shown to increase total DNA, total numbers of nuclei and numbers of cells undergoing mitosis per culture. In optimized conditions, HCH or PCN were about additive with norepinephrine, dialyzed serum or pyruvate or with a small effect of tri-iodothyronine in stimulating DNA synthesis. Although conditions optimal for HCH or PCN were not necessarily optimal for detecting growth-stimulatory effects of other xenobiotics or steroids, these culture conditions were shown to support stimulation of DNA synthesis by a variety of known liver tumor promoters including barbiturates, estrogens, progestins, peroxisomal proliferators and bile acids. Several compounds known not to promote liver carcinogenesis failed to stimulate DNA synthesis in similar hepatocyte cultures.