Water extract of brewers' rice induces antiproliferation of human colorectal cancer (HT-29) cell lines via the induction of apoptosis.

OBJECTIVE: Brewers' rice, a mixture of broken rice, rice bran, and rice germ, is a rice by-product in the rice industry. The present study was designed to investigate the in vitro cytotoxicity of the water extract of brewers' rice (WBR) against colorectal cancer (HT-29) cells. MATERIALS AND METHODS: The cytotoxicity activity was determined using the lactate dehydrogenase (LDH) assay. The morphological changes of the HT-29 cells were observed using inverted light and fluorescence microscope. Cell cycle and apoptotic cell death analyses were performed using flow cytometer. Besides that, the selected polyphenolic compounds in WBR were also analyzed using ultra performance liquid chromatography (UPLC). RESULTS: The cytotoxicity results showed that WBR was more cytotoxic (but not significantly different) in HT-29 cells compared to the MBR, with IC50 value of 21.88 ± 12.43 µg/mL and 34.50 ± 5.92 µg/mL for WBR and MBR, respectively (p > 0.05). WBR-treated HT-29 cells displayed the typical characteristics of apoptosis, as visualized using inverted light and fluorescence microscope. WBR also significantly increased the number of early and late apoptotic HT-29 cells compared to control cells (p < 0.05). Results from UPLC analysis demonstrated that ferulic acid (36.42 ± 2.97 µg/g) was found the highest level in WBR, followed by gallic acid (26.09 ± 2.01 µg/g) and p-coumaric acid (7.13 ± 0.36 µg/g). These phenolics are speculated to partially contribute to apoptotic cell death. CONCLUSIONS: Our results suggested that WBR derived from natural sources might represent a potential chemopreventive agent against colon cancer.

The trans fatty acids content of selected foods in Malaysia.

INTRODUCTION: There is a lack of information on the trans fatty acid (TFA) content in Malaysian foods. The objective of this study is to determine the TFA content of bakery products, snacks, dairy products, fast foods, cooking oils and semisolid fats, and breakfast cereals and Malaysian fast foods. This study also estimated the quantity of each isomer in the foods assayed. METHODS: The trans fatty acid content of each food sample was assessed in duplicate by separating the fatty acid methyl esters (FAME) in a gas chromatography system equipped with HP-88 column (USA: split ratio 10: 1) for cis/trans separation. Five major TFA isomers, palmitoelaidic acid (16: 1t9), petroselaidic acid (18:1t6), elaidic acid (18:1t9), vaccenic acid (18: 1t11) and linoelaidic acid (18:2t9, 12), were measured using gas chromatography (GC) and the data were expressed in unit values of g/100 g lipid or g/100 g food. RESULTS: The total TFA contents in the studied foods were < 0.001 g-8.77 g/100 g lipid or < 0.001 g-5.79 g/100 g foods. This value falls within the standard and international recommendation level for TFA. The measured range of specific TFA isomers were as follows: palmitoelaidic acid (< 0.001 g-0.26 g/100 g lipid), petroselaidic acid (< 0.001 g - 3.09 g/100 g lipid), elaidic acid (< 0.001 g-0.87 g/100 g lipid), vaccenic acid (< 0.001 g-0.41 g/100 g lipid) and linoelaidic acid (< 0.001 g-6.60 g/100 g lipid). CONCLUSION: These data indicate that most of the tested foods have low TFA contents (< 1 g/100 g lipid).

Antioxidant and cytotoxicity effect of rice bran phytic acid as an anticancer agent on ovarian, breast and liver cancer cell lines.

INTRODUCTION: Phytic acid (PA) has been shown to have positive nutritional benefits. There are also claims that it is able to prevent cancer through its antioxidant capability. This study investigated antioxidant activity and cytotoxic effect of PA extracted from rice bran against selected cancer cell lines (i.e. ovarian, breast and liver cancer). METHODS: Cytotoxicity activity of PA was investigated using MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)]-2H-tetrazolium, inner salt] assay while the antioxidant activity of PA extract, commercial PA and butylated hydroxytoluene (BHT) was determined by using five different assays: ferric thiocyanate (FTC) and thiobarbituric acid (TBA) assay, beta-carotene bleaching method, DPPH radical scavenging assay and ferric reducing antioxidant power (FRAP) assay. RESULTS: PA extracted from rice bran induced marked growth inhibition in ovary, breast and liver cancer cells with 50% growth inhibition concentration (IC50) values of 3.45, 3.78 and 1.66 mM, respectively but exhibited no sensitivity towards a normal cell line (3T3). The PA extract was also found to exert antioxidant activity when tested using the FTC, TBA, FRAP and beta-carotene bleaching methods but antioxidant activity could not be attributed to scavenging free radical species as measured by DPPH radical scavenging assay. CONCLUSION: The PA extract from rice bran displayed safe and promising anticancer properties in selected cancer cell lines and it is believed that its antioxidant capability is the likely contributor to the observed anticancer properties.

Anticarcinogenic efficacy of phytic acid extracted from rice bran on azoxymethane-induced colon carcinogenesis in rats.

This study is carried out to determine the potential of phytic acid extracted from rice bran in the suppression of colon carcinogenesis induced by azoxymethane (AOM) in rats. Seventy-two male Sprague-Dawley rats were divided into 6 groups with 12 rats in each group. The intended rats for cancer treatment received two intraperitoneal injections of AOM in saline (15mg/kg bodyweight) over a 2-week period. The treatments of phytic acid were given in two concentrations: 0.2% (w/v) and 0.5% (w/v) during the post-initiation phase of carcinogenesis phase via drinking water. The colons of the animals were analyzed for detection and quantification of aberrant crypt foci (ACF) after 8 weeks of treatment. The finding showed treatment with 0.2% (w/v) extract phytic acid (EPA) gave the greatest reduction in the formation of ACF. In addition, phytic acid significantly suppressed the number of ACF in the distal, middle and proximal colon as compared to AOM alone (p<0.05). For the histological classification of ACF, treatment with 0.5% (w/v) commercial phytic acid (CPA) had the highest percentage (71%) of non-dysplastic ACF followed by treatment with 0.2% (w/v) EPA (61%). Administration of phytic acid also reduced the incidence and multiplicity of total tumors even though there were no significant differences between groups. In conclusion, this study found the potential value of phytic acid extracted from rice bran in reducing colon cancer risk in rats.

Obesity among Mongolian Adults from Urban and Rural Areas.

Shifts in lifestyles and eating patterns have led to an increasing prevalence of chronic non-communicable diseases in the adult population in Mongolia. This article reports the prevalence of obesity, abdominal obesity and body fat among 408 Mongolian adults aged 25 years and above. The subjects included 61.2% from urban areas and 38.8% from rural areas, reflective of the 60: 40 urban rural ratio in the general population. Anthropometric measurements were taken according to standard methods. Classification of overweight/obesity was based on body mass index of WHO while abdominal obesity was based on WPRO for Asians. Men made up 47.8% (200) and women 52.2% (218) of the sample. The mean age of the subjects was 46.7±12.7 years. About one-third (32.8%) of the subjects were overweight and 10.5% obese. A higher proportion of women (13.3%) than men were obese (7.5%). The age groups of 35-54 years in men and 55-64 years in women showed the highest prevalence of overweight. Prevalence of abdominal obesity was found in 46.5% of the men and in 65.1% of the women. Women aged 55-64 years had the highest proportion (78.4%) of abdominal obesity. In terms of body fat, 20.0 % and 51.5% of the men had high and very high levels of body fat respectively, while among the women, 15.1% and 55.5% respectively had high and very high levels of body fat. Mongolian adults face serious risk of cardiovascular diseases and other aspects of ill-health brought about by obesity. Prevention and control of obesity should be targeted as an urgent public health agenda in Mongolia.

Determination of phytate, iron, zinc, calcium contents and their molar ratios in commonly consumed raw and prepared food in malaysia.

The inhibitory effect of phytate on the bioavailability of iron, zinc and calcium was determined by measuring their molar ratios. A total of 29 food samples consisting of 12 rice and rice products, 5 wheat and wheat products, 5 grains and cereal based products and 7 different popular varieties of cooked rice and rice products were selected. The phytate content was analysed using anion-exchange chromatography whereas mineral contents were analysed using atomic absorption spectrophotometry(AAS). One-way ANOVA test was used to statistically analyse the mean difference between the phytate and mineral contents between the food group samples. In general, results show that cooked products have lower content of phytate and minerals as compared to raw products. This could be due to the influence of the cooking method on phytate and mineral content in the food. Based on one-way ANOVA test, there were no significant difference in phytate and zinc content between four food groups (p >0.05). Significant differences were found only in iron and calcium content (p <0.05). Of the 29 food samples, 25 food samples had a phytate/iron molar ratio > 1, 5 food samples had a phytate/zinc molar ratio > 15 and 23 food samples had a phytate/calcium molar ratio of 0.24. These results show that although many of the food samples analysed had high mineral content, the high phytate content may impair the bioavailability of the mineral in the body.