[Effect of polar and non-polar Aloe vera L. leaf extracts on alpha-amylase and alpha-glucosidases inhibitory activity in vitro]

Intestinal alpha-glucosidase and alpha-amylase are two carbohydrate-hydrolysing enzymes that play a key role in conversion of disaccharide to glucose. Inhibition of these two enzymes provides a therapeutic option for treatment of postprandial hyperglycemia in diabetic patients. The aim of the current study was to evaluate the inhibitory effects of different Aloe vera L. extracts against alpha -amylase and alpha -glucosidase in vitro. Aloevera L. leaf was collected from the Institute of Medicinal Plants farm and several extracts were prepared by n-hexane, chloroform, ethyl acetate and methanol solvents. The inhibitory effects of the extracts were tested on alpha -amylase and alpha -glucosidase enzyme separately. In this experiment, the minimum concentration of the extract required for 50% inhibition of enzyme activity [IC[50]], was obtained and compared with acarbose as a positive control. The results showed that total methanol extract of Aloe vera L. leaf had significantly [p<0.001] higher alpha-amylase inhibitory [28.2 +/- 1.3 microg/ml] effect than other solvent fractions but lower than acarbose [25.4 +/- 1.9 microg/ml]. Furthermore total methanol extract and solvent fractions of methanol and ethyl acetate of Aloe vera L. leaf had significantly [p<0.001] higher inhibitory effect on alpha -glucosidase enzyme activity [2.3 +/- 0.1 microg/ml, 2.7 +/- 0.1 microg/ml, 3.4 +/- 0.1 microg/ml, respectively] than other solvent fractions as well as compared with acarbose [5.8 +/- 0.6 microg/ml]. Total methanol extracts of Aloe vera L leaf has strong alpha -amylase and alpha -glucosidase inhibitory activity than chloroform, n-hexane, chloroform, ethyl acetate and methanol solvent fraction

[Investigation of alpha amylase and alpha-glucosidases inhibitory effects of Silybum marianum [L. Gaertn] seed extracts in vitro]

The alpha-glucosidase and alpha-amylase are the key enzymes involved in broken down of dietary polysaccharides to monosaccharides or simple sugars molecules. Inhibition of these two gastrointestinal enzymes especially in diabetic patients can reduce glucose absorption and decreases postprandial hyperglycemia. The present study was undertaken to explore the alpha-glucosidase and alpha-amylase inhibitory effects of different silybum marianum seed extracts. Silybum marianum seeds were collected from the Institute of Medicinal Plants farm and total extract and different fractions were prepared by methanol, chloroform, hexane and ethyl acetate solvents. The inhibitory effects of the extracts were tested on alpha-amylase and alpha-glucosidase enzyme separately. In this experiment, the minimum concentration of the extract required for 50% inhibition of enzyme activity [IC50], was obtained and compared with acarbose as a positive control. The results showed that total methanol extract and hexane, chloroform, ethyl acetate and methanol fractions of silybum marianum seeds have inhibitory effects on alpha-amylase and alpha-glucosidase enzyme activity. Statestical analysis showed that total methanol extract of silybum marianum seeds have stronger inhibitory effect than other fractions on alpha-amylase and alpha-glucosidase enzyme activity compared to acarbose. Methanol extracts of silybum marianum seeds have stronger inhibitory effect than methanol, ethyl acetate, hexane and chloroform fraction on alpha-amylase and alpha-glucosidase enzyme activity

[ frequency of SspI polymorphism in intron II of beta globin gene in Mazandaran province]

Due to the high annual birth rate of thalassemia major in our country, its prevention by prenatal diagnosis is of important priority. Gene mutation remains unknown in 10-20% of thalassemia trait people in Iran. In these cases, linkage analysis using polymorphic sites which are located near or within the gene is necessary to follow the mutant or the normal chromosome. SspI polymorphic site which is studied for the first time in Iran is located in the second intron of beta globin gene. The aim of this study was to determine the polymorphism frequency of this site in Mazandaran province. Peripheral blood of 211 thalassemia trait patients living in Mazandaran province was collected. After DNA extraction and amplification of the beta globin gene region containing the SspI polymorphic site, the effect of SspI restriction enzyme was evaluated on agarose gel. In 422 analyzed chromosomes, 20.6% were negative for SspI polymorphic site. Negative sites were almost equally associated with normal and mutant alleles [11.9% and 14.3% respectively]. SspI site analysis can be applied to follow the normal or mutant alleles of beta globin gene