Antioxidant, antiglycation and inhibitory potential of Saraca ashoka flowers against the enzymes linked to type 2 diabetes and LDL oxidation.

OBJECTIVE: The present study investigated the antioxidant, antiglycation and inhibitory potential of flavonoid fraction of Saraca ashoka flowers (SAF) against alpha-glucosidase and alpha-amylase (the enzymes linked to type 2 diabetes) and LDL oxidation. MATERIALS AND METHODS: Antioxidant capacity of SAF was evaluated by estimating total antioxidant activity (TAA) and its protective effects against the oxidative stress induced by H2O2 on C2C12 cells. Cytotoxicity by MTT assay and markers of oxidative stress: reduced glutathione (GSH), malondialdehyde (MDA) and reactive oxygen species (ROS) were measured. RESULTS: Pre-treatment of C2C12 cells with SAF prevented the increased formation of MDA and depletion of GSH induced by H2O2. The increased ROS generation induced by H2O2 was also reduced by a pretreatment with SAF. Significant inhibitory potential against alpha-glucosidase and alpha-amylase enzymes revealed the therapeutic potential of SAF as an antihyperglycemic agent. SAF also demonstrated potent antiglycation property and inhibited LDL oxidation under in vitro conditions. CONCLUSIONS: The overall results demonstrate that SAF can be used as an ideal natural remedy for preventing oxidative stress and other complications associated with diabetes.

Process development for the enrichment of curcuminoids in turmeric spent oleoresin and its inhibitory potential against LDL oxidation and angiotensin-converting enzyme.

Turmeric (Curcuma longa) contains biologically active colouring constituents, curcuminoids, which are isolated from the turmeric rhizome by solvent extraction. The mother liquor left after the separation of curcuminoids is known as turmeric spent oleoresin (SOT). The present study developed a method for the enrichment of curcuminoids in SOT. By using this method, curcuminoids in the SOT (8.4%) were doubled (17.5%). Presence of curcuminoids in enriched fraction was confirmed by high performance liquid chromatography (HPLC) and liquid chromatography coupled with mass spectroscopy analysis. Further studies on this fraction showed that it can effectively inhibit angiotensin-converting enzyme and low-density lipoprotein oxidation with IC(50) values of 19.45 µg/ml and 30.52 µg/ml, respectively. The results showed that curcuminoids enriched fraction (CEF) can reduce the risk of hypertension and cardiovascular diseases. In addition to this fraction, a turmerone-rich hexane fraction was also separated from the spent oleoresin.

In vitro antioxidant activities of the methanol extract and its different solvent fractions obtained from the fruit pericarp of Terminalia bellerica.

Terminalia bellerica has been used as a traditional medicine in a variety of ailments including anaemia, asthma, cancer, inflammation, rheumatism and hypertension. In this study, the free radical scavenging and antioxidant activities of methanol extract (ME) and its different solvent fractions (namely hexane (HE), ethyl acetate (EA), butanol (BL) and water (WA)) of the T. bellerica fruit pericarp were evaluated and compared with standard antioxidant compounds like gallic acid (GA), catechin and ascorbic acid. Among the different fractions tested, the EA fraction exhibited higher antioxidant and radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide and hydroxyl radicals than the other fractions, which may be attributed to its higher phenolic and flavonoid content, since a linear relation was observed between the phenolic content and the antioxidant parameters. The HPTLC analysis of the EA fraction revealed that it mainly contains GA and ferulic acid (FA) as major phenolics, and the higher antioxidant activities of EA fraction may be due to the presence of these compounds.

In vitro antiperoxidative, free radical scavenging and xanthine oxidase inhibitory potentials of ethyl acetate fraction of Saraca ashoka flowers.

Saraca ashoka is a widely used medicinal herb claimed to cure many diseases. This study investigated the antiperoxidative, free radical scavenging and xanthine oxidase (XO) inhibitory potential of the ethyl acetate fraction of S. ashoka flowers (SAF) and compared it with standard compounds like gallic acid, ascorbic acid, butylated hydroxyl toluene and allopurinol. The ethyl acetate fraction of SAF exhibited free radical scavenging activity against the 1,1-diphenyl-2-picrylhydrazyl radical and superoxide radical, along with hydroxyl radical scavenging activity. Lipid peroxidation inhibitory potential of SAF was studied using a linoleic acid emulsion system, which shows significant antioxidant potential. SAF also demonstrated significant XO (key enzyme linked to inflammation) inhibitory activity, which revealed its therapeutic potential as an antioxidant and XO inhibitor. HPLC profiling of the ethyl acetate fraction of SAF revealed that it contains ellagic acid as a major compound and thus the beneficial effects of this fraction may be due to the presence of this compound.

In vitro antioxidant and inhibitory potential of Terminalia bellerica and Emblica officinalis fruits against LDL oxidation and key enzymes linked to type 2 diabetes.

The present study evaluated the free radical scavenging capacity and antioxidant potential of different solvent extracts (Hexane (HE), ethyl acetate (EA), methanol (ME), 70% methanol (MW) and Water (WA)) of Terminalia bellerica (TB) and Emblica officinalis (EB) fruits. Methanol extract (ME) of TB and EB fruits exhibited maximum scavenging activity against DPPH, superoxide, hydroxyl and nitric oxide radicals. Cell based antioxidant activity was assayed by flow cytometry using DCFH-DA as probe. Methanol extracts were also screened for their antidiabetic activity via inhibition of α-amylase, α-glucosidase and antiglycation assays. Results showed that ME of TB and EB can act as potent α-amylase and α-glucosidase inhibitor. Significant antiglycation activity also confirms the therapeutic potential of these extracts against diabetes. Both the extracts significantly inhibited the oxidation of LDL under in vitro conditions. Liquid chromatography-mass spectroscopy (LC-MS) analysis revealed that methanol extract of TB and EB contains ellagic acid and ascorbic acid as the major compound respectively.

Cardioprotective effects of aqueous extract of Oxalis corniculata in experimental myocardial infarction.

The present study evaluated the protective potential of aqueous extract of Oxalis corniculata (OCE) against isoproterenol (ISO) induced myocardial infarction in rats. Myocardial infarction in rats was induced by isoproterenol (200 mg/kg) at an interval of 24 h for 2 days. OCE was given to rats as pretreatment for 30 days orally using an intragastric tube. Isoproterenol caused a significant increase in the activity of cardiac injury marker enzymes like creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) and increased the concentration of serum lipids. OCE pretreatment significantly reduced the concentration of CPK, LDH, serum total cholesterol, LDL cholesterol and triglycerides. OCE also reduced the activity of lipogenic enzyme, glucose-6-phosphate dehydrogenase in ISO administered rats. Oxidative stress produced by isoproterenol was significantly lowered by the administration of OCE which was evident from increased activities of antioxidant enzymes (catalase and superoxide dismutase) and reduced concentration of lipid peroxidation products (TBARS and conjugated dienes). Concentration of vitamin C, protein sulfhydryl groups and reduced glutathione (GSH) was also high in OCE pretreated rats. Histopathology of heart of ISO administered rat pretreated with OCE showed normal myocardium with very little evidence of inflammatory infiltration. Results of our in vitro findings also confirmed that OCE exhibits significant antioxidant and radical scavenging activity against DPPH, superoxide and nitric oxide radicals. These findings provided evidence that O. corniculata was found to be protecting the myocardium against ischemic insult and the protective effect could attribute to its antioxidative and antihyperlipidemic activities.