探究色素玉米“紫糯8号”玉米须原花青素最佳提取条件并验证其抗肿瘤活性。设计四因素四水平正交实验，探索pH，提取剂浓度，提取温度及提取时间对原花青素提取得率的影响，通过自由基清除实验验证玉米须原花青素的抗氧化活性，不同浓度的玉米须原花青素处理Hela细胞，MTT法测定细胞存活率，进一步测定Bax/Bcl-2表达情况和Caspase-3活性，评价玉米须原花青素抗肿瘤活性并初步阐明机制。玉米须原花青素最佳提取条件为pH=6，50 ℃条件下，通过70%的乙醇，提取3 h。玉米须原花青素对DPPH自由基具有较强的清除活性，4 mg/mL即可达到86.09%的清除率。细胞实验证实，100 μg/mL玉米须原花青素可以显著抑制Hela细胞增殖，细胞活性为88.83%，且抑制活性具有剂量依赖关系。此外，玉米须原花青素能够提高Bax/Bcl-2比例，启动凋亡并提高凋亡执行者Caspase-3活性。因此，玉米须可作为一种具有抗氧化、抗肿瘤活性的保健品加以开发利用。

The optimal conditions for the extraction of proanthocyanidins from the corn silk of the pigmented corn cultivar “Zinuo 8” (PCZ) were investigated and the antitumor activity of the extracted PCZ was measured. An orthogonal experiment with four factors and levels was designed to investigate the influences of pH, extractant concentration, extraction temperature, and extraction time on PCZ yield. A free radical scavenging experiment was performed to measure the antioxidant activity of PCZ. HeLa cells were treated with different concentrations of PCZ, and cell viability was determined using the MTT assay. Subsequently, Bax/Bcl-2 expression and Caspase-3 activity were measured to evaluate the anti-tumor activity of PCZ and elucidation of relevant mechanisms. The optimum conditions for the extraction of PCZ were as follows: pH 6; temperature 50°C; extractant concentration 70%; ethanol; time 3 h. Results indicated that PCZ had high scavenging activity towards DPPH, with a clearance rate of 86.09% achieved with 4 mg/mL of PCZ. The cell experiment showed that 100 μg/mL of PCZ significantly inhibited HeLa cell proliferation in a dose-dependent manner, resulting in 88.83% cell viability. In addition, it was found that PCZ enabled an increase in the Bax/Bcl-2 ratio, initiation of apoptosis, and enhancement of the activity of the apoptosis executioner Caspase-3. Therefore, corn silk can be used in the development of health products with antioxidant and antitumor activities.

四川省科技计划项目（2017GZ0277）；四川省科协青年人才托举工程（2018QNRC007）