Expression of alcohol acyltransferase is a potential determinant of fruit volatile ester variations in Capsicum.

KEY MESSAGE: The transcript level of alcohol acyltransferase 1 (AAT1) may be the main factor influencing the variations in volatile esters that characterizing the fruity/exotic aroma of pepper fruit. Volatile esters are key components for characterizing the fruity/exotic aroma of pepper (Capsicum spp.) fruit. In general, the volatile ester content in the fruit is the consequence of a delicate balance between their synthesis by alcohol acyltransferases (AATs) and degradation by carboxylesterases (CXEs). However, the precise role of these families of enzymes with regard to volatile ester content remains unexplored in Capsicum. In this study, we found that the volatile ester content was relatively low in C. annuum and much higher in C. chinense, particularly in pungent varieties. Additionally, fruits collected from multiple non-pungent C. chinense varieties, which harbor loss-of-function mutations in capsaicinoid biosynthetic genes, acyltransferase (Pun1), putative aminotransferase (pAMT), or putative ketoacyl-ACP reductase (CaKR1) were analyzed. The volatile ester contents of non-pungent C. chinense varieties (pamt/pamt) were equivalent to those of pungent varieties, but their levels were significantly lower in non-pungent NMCA30036 (pun12/pun12) and C. chinense (Cakr1/Cakr1) varieties. Multiple AAT-like sequences were identified from the pepper genome sequences, whereas only one CXE-like sequence was identified. Among these, AAT1, AAT2, and CXE1 were isolated from fruits of C. chinense and C. annuum. Gene expression analysis revealed that the AAT1 transcript level is a potential determinant of fruit volatile ester variations in Capsicum. Furthermore, enzymatic assays demonstrated that AAT1 is responsible for the biosynthesis of volatile esters in pepper fruit. Identification of a key gene for aroma biosynthesis in pepper fruit will provide a theoretical basis for the development of molecular tools for flavor improvement.

[Relationship between cytokine concentration and activities of daily living in rehabilitation patients with stroke].

Stroke rehabilitation is effective in some patients, however not so effective in others. Our ultimate aim is to use the clinical laboratory assessment as a tool for effectiveness discrimination in rehabilitation. Subjects were 15 stroke patients (68.1 +/- 12.7 years old) who were admitted to our convalescent rehabilitation wards. Fasting blood samples were analyzed for serum concentrations of hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF) and insulin-like growth factor-I (IGF-I) which are considered to be involved in hypermyotrophy using ELISA methods on admission and at discharge. Sixteen healthy control subjects (63.0 +/- 7.6 years old) were also employed. As accuracy control of these analyses, decrease of serum HGF after keeping at -20 degrees C for 499 days were measured. The concentration was 0.66ng/mL from 0.71 ng/mL and residual ratio was 94.0%. Reaction specificity to MW 60 kDa HGF antibody using the Western blot method was confirmed. Average HGF and VEGF were higher in stroke patients than those in control subjects. Average IGF-I was lower in stroke patients. The correlations between HGF, VEGF, and IGF-I and the score of activities of daily living expressed by the Functional Independence Measure (FIM) were calculated. Highest correlation coefficient of 0.67 (p < 0.01) was obtained between HGF at discharge and the FIM efficiency (the gain of the FIM during hospitalization divided by length of stay). The correlation coefficients related to VEGF or IGF showed lower value. High FIM efficiency denotes rapid recovery with vigorous exercise. HGF at discharge would reflect the result of high activity.

Antidiabetic effects of dietary administration of Aloe arborescens Miller components on multiple low-dose streptozotocin-induced diabetes in mice: investigation on hypoglycemic action and systemic absorption dynamics of aloe components.

We carried out three experimental trials to determine antidiabetic effects of Aloe arborescens Miller components. Firstly, ICR mice which received frequent injections of streptozotocin (Sz) in small doses (low-dose Sz-induced diabetes mice) were fed ad libitum with basal diets supplemented with components of Aloe arborescens Miller var. natalensis Berger (Kidachi aloe) and Aloe vera Linne from 31 days before to 73 days after the Sz injections. Variation in blood glucose levels, incidence rates of insulitis and blood insulin levels were examined during the trial. As a result, groups receiving diets supplemented at the rate of 2% with whole leaf of Kidachi aloe and 10 KDa fraction powder (a fraction with less than 10 KDa molecular weight derived from Kidachi aloe leaf skin juice by ultra filtration) significantly suppressed the elevation of blood sugar as compared to a control group receiving basal diet. In contrast, there was no significant effect with Aloe vera leaf pulp powder. Insulitis emerged at the rate of 87% in the basal diet group. On the contrary, the whole aloe leaf and 10 KDa fraction groups significantly decreased the incidence of insulitis and incidence rates of whole aloe leaf and 10 KDa fraction powder were 51 and 38%, respectively. While insulin levels in the basal diet group averaged at 0.05 ng, more than four times the insulin level was observed in the 10 KDa group relative to the basal diet group. Secondary, the inhibitory effects of test materials on intestinal glucose absorption were observed using the jejunum of rats. A strong inhibitory action on intestinal glucose absorption was observed in the 10 KDa fraction powder group. Thirdly, phenol compounds derived from aloe in the blood serum and organs were quantitatively measured by a HPLC following forced administration of aloe components to rats to determine absorption kinetics of aloe components inside the body. The primary component of aloe phenol compounds is the same component of the 10 KDa fraction powder and it was found in the pancreas and liver in addition to in the blood serum. The above results indicate that fore and aft when Sz injections could cause selective toxicity to B cells of islets, the dietary administration of 10 KDa fraction powder to mice would lead to the persistence of aloe phenol compound having an antioxidant activity in the pancreas and blood, which could protect islets of Langerhans from the destruction caused by methyl radical derived from Sz. The results also suggested the possibility of the 10 KDa fraction powder to alleviate the burden of insulin secretion as it has an inhibitory action on glucose absorption in the jejunum of rats.