Indian gooseberry (Emblica officinalis Gaertn.) (Euphorbiaceae) has a distinguished history in Ayurveda medicine and is ascribed a number of medicinal properties and as a dietary supplement, its use is increasing in Western countries. It is thought that its beneficial properties are a function of its antioxidant potency. The study investigated the chemistry and antioxidant properties of four commercial E. officinalis fruit extracts in order to determine if there are any qualitative-quantitative differences. All extracts produced positive responses in the total phenol, total flavonoid and total tannin assays. The presence of predominantly (poly)phenolic analytes, e.g. ellagic and gallic acids and corilagin, was confirmed by RP-HPLC coupled with photodiode array detection. Despite ascorbic acid being a major constituent of E. officinalis fruits, the furanolactone could not be identified in one of the samples. The extracts demonstrated varying degrees of antioxidative efficacy. The extract designated IG-3 was consistently amongst the most effective extracts in the iron(III) reduction and 1,1-diphenyl-2-picrylhydrazyl and superoxide anion radical scavenging assays while the extract designated IG-1 demonstrated the best hydroxyl radical scavenging activity. All extracts appeared to be incapable of chelating iron(II) at realistic concentrations.

Five commercially available water-soluble extracts prepared from the aerial parts of Epilobium angustifolium L. (Onagraceae) were screened for antioxidant-related properties in a battery of six in vitro assays. Total phenol content and qualitative-quantitative analyses were also carried out. The extracts demonstrated varying degrees of efficacy in each screen. Two extracts, denoted as nonfermented and Tver, were the most effective toward reducing iron(III), scavenging 1,1-diphenyl-2-picrylhydrazyl free radicals, inhibiting hydroxyl radical-catalyzed bovine brain-derived phospholipid degradation, and non-site- and site-specific hydroxyl radical-catalyzed 2-deoxy-D-ribose degradation. The activity profile of the extracts changed, however, when their iron(II) chelating ability was assessed. The nonfermented and Tver extracts were not as effective iron(II) chelators as the extract denoted as Lotos. All the extracts contained Folin-Ciocalteu-reactive substances, which was confirmed by the presence of predominantly polar phenolic analytes (i.e., hydroxylated benzoic acid derivatives and flavonoids).

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