AIM OF THE STUDY: To determine the antidiabetic activities of chloroform fraction (CF) of Anthocleista vogelii Planch root bark in rats with diet- and alloxan-induced obesity-diabetes.
MATERIALS AND METHODS: Inhibitory activities of CF against α-amylase and α-glucosidase activities were determined in vitro. Three weeks old rats were fed with high-fat diet for 9 weeks to induce obesity prior to further induction of diabetes using alloxan (150mg/kg body weight, i.p.). Blood glucose levels and body weight were measured every 7 days throughout the experiment. Glucose tolerance was assessed in normal and CF-treated rats on day 21. Terminal blood samples were collected from sacrificed animals for the measurement of serum insulin levels. Pancreases were excised from treated and untreated animals for histopathological examination.
RESULTS: LCMS/MS chromatographic profile of CF via positive and negative modes revealed 13 and 23 compounds respectively. Further analysis revealed quebrachitol (QCT), loganin, sweroside, oleoside 11-methyl ester and ferulic acid, which have been previously reported for their antidiabetic activities, as constituents of CF. CF inhibited activities of α-amylase (IC50 = 51.60 ± 0.92µg/ml) and α-glucosidase (IC50 = 5.86 ± 0.97µg/ml) in a dose-dependent manner. Treatment of animals with obesity-diabetes with 100 and 200mg/kg CF significantly improved glucose tolerance (P<0.001) and enhanced serum insulin levels (P<0.05) compared to diabetic control rats.
CONCLUSIONS: Antidiabetic activities of CF might be mediated via inhibition of α-amylase and α-glucosidase activities, elevation of serum insulin concentration, and enhancement of insulin and leptin sensitivity in obesity-diabetes rats. This study further substantiates the traditional use of A. vogelii in the management and treatment of diabetes in Africa and encourages further studies to investigate its mechanism of action.
OBJECTIVE: We previously identified AtWRKY50 as a transcriptional activator of SAR gene PR1. Although PR1 accumulates to high levels in plants after attack by pathogens, its function is still elusive. Here we investigated the effects of overexpression of several WRKY proteins, including AtWRKY50, on the metabolome of Arabidopsis thaliana.
METHODS: The influence of overexpression of WRKY proteins on the metabolites of Arabidopsis was investigated by using an NMR spectroscopy-based metabolomic approach. The 1H NMR data was analysed using the multivariate data analysis methods, such as principal component analysis, hierarchical cluster analysis and partial least square-discriminant analysis.
RESULTS: The results showed that the metabolome of transgenic Arabidopsis seedlings overexpressing AtWRKY50 was different from wild type Arabidopsis and transgenic Arabidopsis overexpressing other WRKY genes. Amongst other metabolites, sinapic acid and 1-O-sinapoyl-β-D-glucose especially appeared to be the most prominent discriminating metabolites, accumulating to levels 2 to 3 times higher in the AtWRKY50 overexpressor lines.
CONCLUSION: Our results indicate a possible involvement of AtWRKY50 in secondary metabolite production in Arabidopsis, in particular of hydroxycinnamates such as sinapic acid and 1-O-sinapoyl-β-D-glucose.
OBJECTIVES: GST inhibition activity and characterization of Kanji and methanol extract of D. carota roots, and oral absorption pattern of ferulic acid from Kanji in rats.
MATERIALS AND METHODS: GST inhibition activity of Kanji and methanol extract of D. carota roots in concentration range 0.001-100.00 mg/mL was determined using Sprague Dawley rat liver cytosolic fraction. Methanol extract upon column chromatography gave ferulic acid, which was used to characterize Kanji and determine its oral absorption pattern in Wistar rats.
RESULTS: The GST inhibition activity of Kanji (100.00 μg/mL), methanol extract of D. carota roots (100.00 μg/mL) and tannic acid (10.00 μg/mL, positive control) was found to be 0.162 ± 0.016, 0.106 ± 0.013 and 0.073 ± 0.004 μM/min/mg, respectively. Different Kanji samples and methanol extract contained ferulic acid (0.222-0.316 mg/g) and 0.77 mg/g, respectively. Ferulic acid did not appear in plasma after oral administration of Kanji.
DISCUSSION: Kanji having solid contents 80.0 μg/mL, equivalent to 0.0025 μg/mL ferulic acid, does not inhibit the activity of GST. The oral administration of Kanji, in human equivalent dose (528 mg/kg, 16.67 μg ferulic acid), to rats indicated poor absorption of ferulic acid.
CONCLUSION: Kanji having solid contents 14-36 mg/mL does not inhibit GST activity, hence may not interfere with drugs that are the substrates of GST, if taken concomitantly.
METHODS: This study examined polyphenol intake estimated from 3- and 7-day food diaries in a sample of 246 UK women aged 18-50 years. Estimation of the intake of 20 polyphenol subclasses commonly present in foods consumed by the sample studied was done using Phenol-Explorer(®) and USDA polyphenol databases. Women were participants in the Leeds Women's Wellbeing Study (LWW) (n = 143), a dietary intervention study aimed at overweight women (mean age 37.2 ± 9.4 years; mean BMI 30.8 ± 3.1 kg/m(2)), and the Diet and Health Study (DH) (n = 103) which aimed to examine the relationship between polyphenol intake and cognitive function (mean age 25.0 ± 9.0 years; mean BMI 24.5 ± 4.6 kg/m(2)).
RESULTS: The estimated intake of polyphenol subclasses was significantly different between the two samples (p