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Hypericum perforatum is a perennial herb that produces anti-depression metabolite hypericin (Hyp) as well as flavonoids and polyphenols. In order to find the optimization of harvest stage to increase bioactive compounds production, the levels of Hyp, flavonoids and polyphenols as well as antioxidant capacity were evaluated by the assays of high performance liquid chromatography (HPLC), NaNO2-AlCl3-NaOH and Folin-Ciocalteu as well as 1, 1-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP), respectively. The results showed that there was no difference in antioxidant capacity of extracts from aerial parts between floral budding stage (FBS) and blooming stage (BS), while significant decrease was observed at fruit set stage (FSS) compared to BS (P<0.05). On a per plant basis, biomass and the levels of Hyp, flavonoids and polyphenols in aerial parts decreased during harvest stages, even if bioactive compounds contents in flower reached the highest at BS on a dry weight basis. These findings indicated that the optimization of harvest stage of H. perforatum should be at FBS. [ABSTRACT FROM AUTHOR]

Traditional Chinese herbal medicines (TCHMs) have been used to treat diseases for thousands of years because of high therapeutic performance and low toxicity. To mine for new natural sources of antioxidants, 93 TCHMs were screened for activity, based on classical antioxidant capacity assays. Substantial differences in antioxidant capacity were coupled with phenolic and flavonoid content for each of the examined species. Species that exhibited both high antioxidant capacity and specialized-phytochemical content included: Angelica dahurica, Atractylodes macrocephala, Paeonia lactiflora, Paeonia suffruticosa and Perilla frutescens. These species have been identified as promising sources for natural antioxidants. [ABSTRACT FROM AUTHOR]