Free radical scavenging activity

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In cells, free radicals are continuously produced either as by-products of metabolism or deliberately as in phagocytes (Cheeseman and Slater 1993). The model of scavenging DPPH radical is especially useful in evaluating chain-breaking activity in the propagation phase of lipid (and protein) oxidation (Manzocco et al. 1998). The effect of antioxidants on DPPH radical scavenging was thought to be a result of their hydrogen donating ability (Gulcin et al. 2004). Figure 1 shows the dose-response curves for DPPH radical scavenging activities of five nanoemulsions the DPPH scavenging activity of the aqueous extracts of E. ulmoides increased with increasing amount of the extract. Extract from the leaf showed a significant (p BHT >leaf>male flower >cortex >fruit.

Metal chelating result

Metal chelating capacity is claimed as one of the antioxidant activity mechanisms (Diplock (1996, Yildirim et al. 2001), since it reduces the concentration of the catalyzing transition metal in lipid peroxidation (Hsu et al. 2003). It has been reported that chelating agents, which complex with metal by [sigma]-bonds, are effective as secondary antioxidants because they reduce the redox potential, thereby stabilizing the oxidized form of the metal ion (Gordon 1990). Ferrozine can quantitatively form complexes with [Fe. sup. 2+]. In the presence of extract of E. ulmoides, the complex formation is disrupted with the result that the red color of the complex is decreased. As shown in Table 1, leaf extract and ascorbic acid exhibit significantly higher metal chelating effect than other extracts and BHT. In the concentration of 1 mg/mL, their metal chelating effects were 69. 73 [+ or -] 2. 12 percent and 67. 70 [+ or -] 2. 43 percent respectively. The extracts from fruit and cortex also demonstrated a certain ability to chelate metal ion. However, BHT and extract from male flower shows very poor (negligible) ferrous chelating ability. The decreasing order of the metal chelating effect was leaf >ascorbic acid >fruit >cortex >male flower and BHT.

Reducing electrical power

The reducing capacity of a compound may serve as an indicator of its potential antioxidant activity (Meir et al. 1995). In the reducing power assay, the antioxidant activity of samples was measured by their ability to reduce the [Fe. sup. 3+]/ ferricyanide complex by forming ferrous products. Figure 2 shows the reductive power of E. ulmoides compared with BHT and ascorbic acid. Similar to the antioxidant activity, the reducing power of E. ulmoides increases with increasing dosage. All the extracts of the E. ulmoides showed a certain extent of reducing power. However, the reducing powers of BHT and ascorbic acid were found to be significantly more pronounced than that of E. ulmoides. Among the plant parts tested, the leaf extract and male flower extract exhibited greater reducing power than that of cortex and fruit, which is partly related to their different polyphenolic contents. The order of reducing power in E. ulmoides extracts at the amount of 2 mg/mL, compared with positive controls, was BHT >ascorbic acid >leaf>male flower >cortex >fruit. This kind of order was similar to those of free radical scavenging impact but unlike the material chelating effect.

Antioxidant activity in linoleic acid emulsion

For evaluation of the antioxidant activity of E. ulmoides, the inhibition effect on the peroxidation of linoleic acid was investigated. As shown in Table 1, leaf extract could inhibit 59 percent peroxidation of linoleic acid, however, male flower extract, cortex extract and ascorbic acid only could suppress 40 percent, 29 percent and 30 percent of linoleic acid lipid peroxidation, respectively. Moreover, fruit extract showed very poor capacity to inhibit peroxidation of linoleic acid. The antioxidant activity of BHT was significantly higher than that any of all the plant extracts. The decreasing order of antioxidant activity in linoleic acid emulsion was BHT >leaf>male flower >ascorbic acid >cortex >fruit. This kind of order was also near to that of free radical scavenging effect and reducing electrical power, but totally different from that of steel chelating impact.

Total polyphenolic compounds

Polyphenolic chemical substances and flavonoids are the many active anti-oxidants derived from crops (Aruoma 1997). The antioxidant activity of drinking water extract via E. ulmoides leaves and cortex was correlated to their polyphenol content (gallic acidity equivalent, GAE) (Yen and Hsieh 1998), especially for their protocatechuic chemical p content (Yen and Hsieh 2000). To clarify whether the polyphenolic compounds had been the main antioxidant compounds in extracts of male floral and fruits, the total polyphenolics compounds articles (gallic chemical p equivalent, GAE) of all the several extracts was determined by using the Folin-Ciocalteu method. As displayed in Desk 1, tea leaf extract covered much more polyphenolic compounds than any other extracts, and extracts of male bloom and cortex contained an identical number of polyphenolics. The antioxidant activity of it extract was significantly less than the other three extracts except for the metal chelating effect. Moreover, its polyphenolic compounds content material was also significant lower than other extracts. Although the polyphenolics content with the extract of male bloom and cortex was comparable, the antioxidant activity of men flower remove was significantly higher than those of cortex draw out except for the metal ion chelating result. From this it might be assumed not only the articles but also properties of polyphenolic substances contribute to different activities in different extracts.

The above results indicate the water remove from the leaf of E. ulmoides shows a stronger antioxidant activity than those through the other grow parts. It seems like the reason for this difference only is that the polyphenolic content in the water extract from the leaf is much higher than in those from other parts. On the other hand, however was no factor in the content of polyphenolics, the water get from the male flower also showed substantially higher reducing power, DPPH scavenging result and lipid peroxidation of inhibition than those from the emballage. This trend suggests that the properties of polyphenolic compounds in the guy flower and cortex were different inside their chemical make up and composition. It also could possibly be assumed from your results that not only the content but as well properties of polyphenolic substances contribute to diverse activities in several extracts. A further study, consequently , is necessary to have the bioactive ingredients in the male flower of E. ulmoides, which is currently under analysis in our laboratory.

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