[Possible hypoglycemic effect of aloe vera L. high molecular weight fractions on type 2 diabetic patients]

Aloe vera L. high molecular weight fractions [AHM] containing less than 10 ppm of barbaloin and polysaccharide [MW: 1.000KD] with glycoprotein, verectin [MW 29KD], were prepared by patented hyper-dry system in combination of freeze-dry technique with micro wave and far infrared radiation. AHM produced significant decrease in blood glucose level sustained for 6 weeks of the start of the study. Significant decrease in triglycerides was only observed 4 weeks after treatment and continued thereafter. No deterious effects on kidney and liver functions were apparent. Treatment of diabetic patients with AHM may relief vascular complications probably via activation of immunosystem

Isolation and identification of a new homoisoflavan with potent antioxidant activity from commelina elegans

Potent antioxidative compounds have been isolated from the ethyl acetate extract of Commelina elegans, Commelinaceae, using a repeated column chromatography. On the basis of spectral analyses, the compounds were identified as brazilin, brazilein and the new homoisoflavan-3, 7, 9, 3', 4'-ol [4-4] dimer with X- and Y-conformers. The compounds inhibited both enzymatic lipid peroxidation using rat liver microsomes and mitochondria and non-enzymatic reactions. The compounds completely protected the activities of the mitochondrial enzymes NADH- and succinate-cytochrome c reductase. Furthermore, the radical scavenging activity on enzymatically and non-enzymatically generated superoxide anion was investigated. Electron spin resonance using the spin trapping method suggested that the compounds have potent superoxide anion scavenging activities

Supercritical carbon dioxide extraction of Aloe emodin and barbaloin from Aloe vera L. leaves and their in-vitro cytotoxic activity

Aloe emodin and barbaloin, isolated as the active principles of the medicinal plant Aloe vera L., were extracted by supercritical fluid extraction [SFE] and analyzed by high performance liquid chromatography [HPLC]. With optimized operating conditions for SFE, Aloe emodin and barbaloin were quantitatively extracted from A. vera leaves within 20 minutes at a flow rate of 0.3 ml/min, temperature and pressure at 40 °C and 3200 Psi respectively with the addition of 1 ml of methanol as a modifier. Separation of Aloe emodin and barbaloin, in a pure form, from the SFE extract was achieved using a semi-preparative column. The cytotoxic activity of both aloe emodin and barbaloin were evaluated using the in-vitro MTT colorimetric assay. Aloe emodin showed a cytotoxic activity on two human colon cancer cells lines [DLD-1 and HT-29] with IC[50] 8.94 and 10.78 micro M respectively, while barbaloin had no effect

Ribosomal DNA sequence analysis of different geographically distributed aloe vera plants: comparison with clonally regenerated plants

A comparison of the sequences in an internally transcribed spacer [ITS] 1 region of rDNA between clonally regenerated A. vera and the same species in Japan, USA and Egypt revealed the presence of two types of nucleotide sequences, 252 and 254 bps. Based on the findings in the ITS 1 region, A.vera having 252 and 254 bps clearly showed a stable sequence similarity, suggesting high conservation of the base peak sequence in the ITS 1 region. However, frequent base substitutions in the 252 bps sample leaves that came from callus tissue and micropropagated plants were observed around the regions of nucleotide positions 66, 99 and 199-201.The minor deviation in clonally regenerated A.vera may be due to the stage of regeneration and cell specification in cases of the callus tissue. In the present study, the base peak sequence of the ITS 1 region of rDNA was adopted as a molecular marker for differentiating A.vera plants from geographically distributed and clonally regenerated A.vera plants, and it was suggested that the base peak substitutions in the ITS 1 region may arise from the different nutritional and environmental factors in cultivation and plant growth stages