Excellent Radical Scavenging Activity Research Articles

In vitro and in vivo antioxidant activities of the leaves of Chrysophyllum albidum

Chrysophyllum albidum G. Don. (Sapotaceae) which is distributed in Nigeria is used for the treatment of yellow fever, malaria, diarrhea, vaginal disorders, etc [1]. The study was aimed at investigating the antioxidant properties using in vitro and in vivo models. The effect of 1,1-diphenyl-2-picrylhydrazyl (DPPH) antiradical activity on ethanol, petroleum ether, ethylacetate, butanol, and water fractions of C. albidum was determined. The ethylacetate fraction was purified in column chromatography which led to the isolation and characterization of a myricetin rhamnoside [2]. The structure was elucidated by NMR and mass spectroscopic techniques. Furthermore, ethanol extract was administered to five groups of eight rats per group.The positive control animals were administered with vehicle on the first four days, and with the vehicle and CCl4 on the fifth, sixth and seventh day [3]. The animals in the treatment category were respectively administered (by gastric intubation) with 500, 1000 and 1500mg/kg bw of extract & distilled water for the first four days, and with distilled water, extract and CCl4 on the last three days. Animals were anaesthetized and blood samples were collected for some antioxidant assays. Petroleum ether fraction showed the least antiradical activity (4057.5±809.6g/kg) while ethyl ether fraction exhibited the highest activity (414.4±92.0g/kg). Myricetin rhamnoside also exhibited an excellent radical scavenging activity (314.1±60.2). C. albidum exhibited significant (p<0.05) differences on the activity of malondialdehyde, catalase, and reduced gluthathione. The plant therefore possesses antioxidant activities and could be employed as natural antioxidant boosters.

Synthesis and antioxidant, cytotoxicity and antimicrobial activities of novel curcumin mimics

Claisen-Schmidt condensation of 3-(1,2,3,6-tetrahydro-1-methylpyridin-4-yl)-2,4,5- trimethoxybenzaldehyde 3 and various aromatic, heterocyclic and alicyclic amides of 3- aminoacetophenone 6(a–s) afforded novel curcumin mimics. All the synthesized compounds were characterized by IR, 1H NMR, Mass spectroscopy and evaluated for antioxidant, cytotoxicity and antimicrobial activity. Out of the 20 compounds screened, compounds 7i, 7l, 7q, and 7n have shown excellent radical scavenging activity, compounds 7o, 7t, 7f, and 7r have shown significant xanthine oxidase inhibition, and compounds 7a, 7k and 7l were found to be potent inhibitors of selected cancer cell lines. Compounds 7h, 7t, 7l, 7i, and 7e have shown good antibacterial activity, whereas compounds 7j, 7f, 7o, 7h, and 7t exhibited significant antifungal activity.

Standardized extract of Syzygium aqueum: a safe cosmetic ingredient

Syzygium aqueum, a species in the Myrtaceae family, commonly called the water jambu is native to Malaysia and Indonesia. It is well documented as a medicinal plant, and various parts of the tree have been used in traditional medicine, for instance as an antibiotic. In this study, we show S. aqueum leaf extracts to have a significant composition of phenolic compounds, protective activity against free radicals as well as low pro-oxidant capability. Its ethanolic extract, in particular, is characterized by its excellent radical scavenging activity of EC(50) of 133 μg mL(-1) 1,1-diphenyl-2-picryl-hydrazyl (DPPH), 65 μg mL(-1) 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and 71 μg mL(-1) (Galvinoxyl), low pro-oxidant capabilities and a phenolic content of 585-670 mg GAE g(-1) extract. The extract also displayed other activities, deeming it an ideal cosmetic ingredient. A substantial tyrosinase inhibition activity with an IC(50) of about 60 μg mL(-1) was observed. In addition, the extract was also found to have anti-cellulite activity tested for its ability to cause 98% activation of lipolysis of adipocytes (fat cells) at a concentration of 25 μg mL(-1). In addition, the extract was not cytotoxic to Vero cell lines up to a concentration of 600 μg mL(-1). Although various parts of this plant have been used in traditional medicine, this is the first time it has been shown to have cosmeceutical properties. Therefore, the use of this extract, alone or in combination with other active principles, is of interest to the cosmetic industry.

&lt;i&gt;In Vitro&lt;/i&gt; Studies on the Radical Scavenging Activity of Hulless Barley Pigment

In the present study, the in-vitro scavenging activities of hydroxyl, superoxide anion and DPPH radical of hulless barley pigment were studied. The results indicated that hulless barley pigment had excellent radical scavenging activity which was equivalent to the standard antioxidant, vitamin C. It was found that the radical scavenging effect of hulless barley pigment is gradually strengthened along with the increasing of concentration. In the range of test concentration, the maximum scavenging rate of the pigment to hydroxyl, superoxide anion and DPPH radical was 92.9%, 90.6% and 88.3% and the IC50was 4.2, 5.0 and 1.6 mg/L, respectively. Moreover, the scavenging velocity of hulless barley pigment was examined. It was observed that the radical scavenging activities of hulless barley pigment also increased with reaction time. These results suggested that colored hulless barley can be used for a new source of natural pigment with antioxidant activity.

Synthesis of Some N, N′‐Diacylhydrazine Derivatives with Radical‐Scavenging and Antifungal Activity

A series of N,N'-diacylhydrazines were prepared and their structures were confirmed by 1H NMR, MS and FTICR-MS. They were tested radical-scavenging activity in vitro. The preliminary bioassays of title compounds showed that two compounds had excellent radical-scavenging activity comparable with vitamin C, while the activity is highly relative to the substituents. Surprisingly, several compounds also exhibit favorable fungicidal activities. To further explore the comprehensive structure-activity relationships about the fungicidal activity, a three-dimensional quantitative structure-activity relationship analysis using the method of comparative molecular field analysis was performed.

Enzyme inhibition and radical scavenging activities of aerial parts of Paeonia emodi Wall. (Paeoniaceae)

The ethanolic extract derived from aerial parts of an indigenous medicinal plant Paeonia emodi was screened for enzyme inhibition activities against Urease (jack bean and Bacillus pasteurii) and α-Chymotrypsin. The extract was also investigated for its radical scavenging activity using DPPH assay. The crude extract was found to possess significant enzyme inhibition activities against jack bean (74%) and Bacillus pasteurii (80%) urease and a moderate activity (54%) against α-Chymotrypsin. The extract also displayed excellent (83%) radical scavenging activity. On the basis of these results, the crude extract was subsequently fractionated into n-hexane, chloroform, ethyl acetate, n-butanol and water fractions and tested independently for the aforesaid activities. Significant inhibitory activity against urease enzyme was observed for the ethyl acetate, n-butanol and water fractions while the n-hexane and chloroform fractions were devoid of any such activity. In the α-Chymotrypsin enzyme inhibition studies the activity was concentrated into the ethyl acetate fraction. All the fractions displayed potent radical scavenging activity. The crude extract and fractions thereof were also subjected to total phenolic content determination. A correlation between radical scavenging capacities of extracts and total phenolic content was observed in the majority of cases.