<i>In-vitro</i> antioxidant and <i>in-vivo</i> anti-aging with stress resistance on <i>Caenorhabditis elegans</i> of herbaceous peony stamen tea

Herbaceous peony (<i>Paeonia lactiflora</i> Pall.) is a traditional Chinese medicinal herb with roots; however, the flowers, specifically the stamens have not been exploited. In this study, the main active components of <i>P. lactiflora</i> stamens (PLS) were identified, and <i>in vitro</i> antioxidant, <i>in vivo</i> anti-aging and stress resistance properties were examined using the nematode <i>Caenorhabditis elegans</i>. Our results showed that PLS contains 350 active components including flavonoids, phenolic acids, terpenoids, alkaloids, and others. PLS extracts at concentrations of 0.2–1.2 mg·mL⁻¹ had strong antioxidant activity <i>in vitro</i> and showed a linear increase of concentration. The value of absorbance, scavenging activity of ·OH, DPPH and ABTS was 0.84, 31.55%, 84.67%, and 99.49% at 1.2 mg·mL⁻¹, respectively. Moreover, PLS extracted at the same concentrations had no toxic effects on <i>C. elegans</i>, and the treatment with 1.2 mg·mL⁻¹ PLS extract significantly extended <i>C. elegans</i> lifespan that was not at the expense of reducing its reproduction and <i>Escherichia coli</i> OP50 growth. Furthermore, the same treatment extract enhanced their locomotion behavior and decreased their intestinal autofluorescence during the aging process. Additionally, the stress resistance of <i>C. elegans</i> under both heat and oxidative stress conditions were significantly induced by 1.2 mg·mL⁻¹ PLS extract treatment. Collectively, these results demonstrated that PLS extract exerted both <i>in vitro</i> antioxidant and <i>in vivo</i> anti-aging together with stress resistance properties, which could provide the theoretical basis for its production and popularization in China.