Purpose: To determine the potent antioxidants among six hydroxy-bearing cinnamaldehyde compounds and their corresponding acids. Methods: The antioxidative activities were evaluated by scavenging 2, 2’-diphenyl-1-picrylhydrazyl (DPPH) free radicals and anti-hemolysis of human red blood cells (RBCs). Fourier transform infrared spectrometry(FT-IR, nuclear magnetic resonance (NMR)and mass spectrome...

In order to maximize the yield of the total phenolic content (TPC) and total monomeric anthocyanin (TMA) from Brosimum alicastrum leaf and to study the radical-scavenging activity, a three-level three-factor Box-Behnken design (BBD) was used to determine the optimal points for ultrasound-assisted extraction (UAE). In this study, we analyzed the extraction time (10, 20, and 30 min), temperature ...

The aim of the study was to perform a quantitative analysis of fluid extracts of maidenhair tree (Ginkgo biloba L.), motherwort (Leonurus cardiaca L.) and hawthorn (Crataegus monogyna Jacq.), to evaluate their antioxidant activity and to compare their ability to inactivate free radicals. The antioxidant activity was measured using the DPPH*and the ABTS*+ radical scavenging reaction systems. The...

The enhanced antioxidant activity of surface-functionalized gold nanoparticles (AuNPs) synthesized by self-assembly has attracted great attention, but little is known about the mechanism behind the enhanced activity. To address this challenge, the antioxidant activity of Au@PEG3SA (i.e., surface-functionalization of spherical AuNPs with the antioxidant salvianic acid A) was used as an example t...

The antioxidant potential of N-acetylcysteine amide (NACA), also known as AD4, was assessed by employing different in vitro assays. These included reducing power, free radical scavenging capacities, peroxidation inhibiting activity through linoleic acid emulsion system and metal chelating capacity, as compared to NAC and three widely used antioxidants, alpha-tocopherol, ascorbic acid and butyla...

Essential oils from plants have been proven safe as natural antioxidants, and few are already marketed as digestive enhancers as well as in prevention of several degenerative diseases. This study evaluated the antioxidant capacity of seed and shell essential oils of Abrus precatorius (L), a herb used for ethno-medicinal practices in Nigeria. The essential oils were obtained by hydro-distillatio...

BACKGROUND 2-t-Butyl-4-methoxyphenol (BHA) has considerable toxicity and undesirable potential tumor-promoting activities. To clarify the free radical mechanism of BHA-induced toxicity, the comparative radical-scavenging activity of BHA and its dimer (bis-BHA, 3,3'-ditert-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diol) with or without 2-mercapto-1-methylimidazole (MMI) was studied using the induc...

The air dried powdered plant materials were extracted with different organic solvents, screened for phytochemicals and analyzed for their biological activities. The antioxidant potential was evaluated by scavenging of DPPH radical, TPC and TFC, while antimicrobial activity by disc diffusion assay against a set of bacterial and fungal strains. Ethylacetate extracts showed higher free radical sca...

Vitexin (1), isovitexin (2), orientin (3), isoorientin (4) and 1,3dihydroxy6, 7dimethoxyxanthone (5) were isolated from the whole plant of Begonia picta, a Nepalese crude drug commonly known as “Magarkaanche”. Structures were elucidated on the basis of chemical and spectroscopic methods. All of these compounds were isolated for the first time from B. picta and their in vitro antioxidant acti...

In present study, the comparative in vitro free radical scavenging activities of methanol extracts from three indigenous medicinal plants viz. Amla, Bitter gourd and Neem were evaluated by 1, 1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging method. Ascorbic acid was used as the reference. All of the plant extracts exhibited promising antiradical effects in a concentration dependent manner...