Properties Of Ethyl Acetate Extracts Research Articles

Antihyperglycaemic Properties of the Ethyl acetate Extract of Dennettia tripetala in Diabetic Rats

Antihyperglycemic properties of chloroform (CDT), ethyl acetate (EDT) and methanolic (MDT) extracts of D. tripetala were investigated using alloxan- and streptozotocin-induced hyperglycemic rats. An oral glucose tolerance test (OGTT) was performed in EDT-pretreated in both normal and alloxan-induced hyperglycemic rats. Tolbutamide (TLB) was used as the reference drug. TLB (100 mg/g), EDT (100 mg/kg), MDT (100 mg/kg) significantly (p<0.05) decreased the plasma glucose level at different time intervals after the administration of the extracts/drug. The antihyperglycemic activity of TLB and EDT started at 2 and 3h, respectively, and lasted till 10h. EDT caused the highest reduction (46%) in plasma glucose level in 10h after treatment. In OGTT, EDT (50 mg/kg) significantly (p<0.05) increased glucose tolerance in both normal and hyperglycemic rats. This activity was more prominent in the alloxan-induced hyperglycemic rats. TLB (100 mg/kg) initially caused a slight reduction in plasma glucose level followed by steady level throughout the period of the study. Furthermore, EDT (30 mg/kg) significantly (P<0.05) decreased the plasma glucose level at 6, 8 and 10 h post treatment, when compared with TLB (100 mg/kg). In conclusion, EDT showed promising antihyperglycemic activity, which justified the use of the plant extract by the natives in managing diabetes mellitus.

Antimutagenic, antioxidant and free radical scavenging activity of ethyl acetate extracts from white, yellow and red onions

The beneficial effects of red, yellow and white onion extracts have been assessed by antioxidant activity and antimutagenic activity. And the effects compared to BHT and ascorbic acid. Total phenolic compounds and flavonoids in onion extracts were determined. Yellow onion extract had more organic acid and free sugar than those detected in the white and red onion extract. The scavenging activity of DPPH radical and H 2O 2 were increased depending on the concentration. The antioxidant activities using β-carotene-linoleate system and reducing power were increased but the effect was small to that of BHT and ascorbic acid. After digested, extracts showed antimutagenic activities, and it seems that they inhibit the mutagenicity for digesting. This study demonstrated that the antimutagenicities and antioxidant properties of ethyl acetate extract against mutagens were related to their phenols and flavonoids, which are heat stable and losses digestive juices are relatively low.

Antioxidative properties of extracts from Aspergillus candidus broth filtrate

This work evaluated the antioxidative properties of ethyl acetate extracts from Aspergillus candidus CCRC 31543 broth filtrate (EAEAC). EAEAC markedly exhibited antioxidative activity in a soybean oil peroxidation system as measured by the Rancimat method. This finding significantly correlated (r=0·9702, P<0·05) with the extent of antioxidative activity in a linoleic acid peroxidation system as measured by the thiocyanate method. EAEAC also displayed good thermal stability when heated at 185°C for 2 h. Although the antioxidative activity of the EAEAC was unstable at the alkali pH value, it was more effective at the neutral and acidic pH values. EAEAC had synergistic effects with α-tocopherol and citric acid in linoleic acid peroxidation system. EAEAC showed no mutagenicity to Salmonella typhimurium TA98 and TA100 as evaluated by Ames test. These properties indicated that Aspergillus candidus CCRC 31543 might be a potential antioxidant for application in food products. ©1997 SCI

Antioxidative properties of extracts fromAspergillus candidus broth filtrate

This work evaluated the antioxidative properties of ethyl acetate extracts from Aspergillus candidus CCRC 31543 broth filtrate (EAEAC). EAEAC markedly exhibited antioxidative activity in a soybean oil peroxidation system as measured by the Rancimat method. This finding significantly correlated (r=0·9702, P<0·05) with the extent of antioxidative activity in a linoleic acid peroxidation system as measured by the thiocyanate method. EAEAC also displayed good thermal stability when heated at 185°C for 2 h. Although the antioxidative activity of the EAEAC was unstable at the alkali pH value, it was more effective at the neutral and acidic pH values. EAEAC had synergistic effects with α-tocopherol and citric acid in linoleic acid peroxidation system. EAEAC showed no mutagenicity to Salmonella typhimurium TA98 and TA100 as evaluated by Ames test. These properties indicated that Aspergillus candidus CCRC 31543 might be a potential antioxidant for application in food products. ©1997 SCI