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

Herbaceous peony (Paeonia lactiflora 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 P. lactiflora stamens (PLS) were identified, and in vitro antioxidant, in vivo anti-aging and stress resistance properties were examined using the nematode Caenorhabditis elegans. 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 in vitro 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 C. elegans, and the treatment with 1.2 mg·mL−1 PLS extract significantly extended C. elegans lifespan that was not at the expense of reducing its reproduction and Escherichia coli 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 C. elegans 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 in vitro antioxidant and in vivo anti-aging together with stress resistance properties, which could provide the theoretical basis for its production and popularization in China.

芍药（Paeonia lactiflora Pall.）是一类以根部入药的传统中药材，但其花部结构尤其是雄蕊尚未得到开发利用。本研究对芍药雄蕊（Paeonia lactiflora stamens，以下简称PLS）的主要活性成分进行了鉴定，并以秀丽隐杆线虫（Caenorhabditis elegans）为模型，检测了其体外抗氧化活性与体内抗衰老、抗胁迫能力。
研究结果表明，PLS共含有350种活性成分，涵盖黄酮类、酚酸类、萜类、生物碱类等多类化合物。当PLS提取物浓度处于0.2~1.2 mg·mL⁻¹区间时，其体外抗氧化活性较强，且抗氧化能力随浓度升高呈线性增长趋势。在1.2 mg·mL⁻¹浓度下，PLS提取物的吸光度值、羟自由基（·OH）、DPPH自由基及ABTS自由基清除率分别可达0.84、31.55%、84.67%与99.49%。
此外，该浓度范围内的PLS提取物对秀丽隐杆线虫无毒性作用；1.2 mg·mL⁻¹的PLS提取物可显著延长线虫寿命，且该延寿效果并未以降低线虫繁殖能力及大肠杆菌OP50（Escherichia coli OP50）生长为代价。同时，该处理组线虫的运动行为得到显著增强，且衰老过程中的肠道自身荧光水平显著降低。
进一步实验显示，1.2 mg·mL⁻¹的PLS提取物可显著提升秀丽隐杆线虫在热应激与氧化应激条件下的抗胁迫能力。综上，本研究结果证实PLS提取物兼具体外抗氧化活性与体内抗衰老、抗胁迫功效，可为其在中国的产业化生产与推广应用提供理论依据。