Institute of Chinese Materia Medica, Academy of Chinese Medical Sciences, Beijing 100700, China.
Z Naturforsch C J Biosci. 2012 Jan-Feb;67(1-2):77-85. doi: 10.1515/znc-2012-1-210.
The active compounds in the roots of Scutellaria baicalensis Georgi, a traditional Chinese medicinal plant, are mainly flavonoids which have anti-inflammatory, antitumour, and anti-HIV activity, respectively. The increasing annual average temperature has rendered the S. baicalensis plants grown in some ancient producing regions no longer suitable for their medicinal usage. Hydrogen peroxide plays an important role in root responses to abnormal temperature in S. baicalensis. Baicalin and baicalein and antioxidative enzymes were anticipated to detoxify H2O2 in S. baicalensis. Here, we show that abnormal temperatures (10 and 40 degrees C) decreased the content of flavonoids as compared with the normal temperature (30 degrees C), and the transcripts of UDP-glucuronate:baicalein 7-O-glucuronosyltransferase and beta-glucuronidase involved in the interconversion between baicalin and baicalein were affected by the 40-degrees C treatment. High temperature also increased the activities of catalase and peroxidase. Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that the transcript levels of peroxidase 2, peroxidase 3, monodehydroascorbate reductase 2, and dehydroascorbate reductase were significantly increased under high-temperature conditions. The respective genes would be candidates for improvement of the adaptation of S. baicalensis plants to abnormal temperatures and for regulation of the contents of the active compounds.
黄芩根中的活性化合物主要为黄酮类化合物，分别具有抗炎、抗肿瘤和抗 HIV 活性。中国传统药用植物黄芩的年平均温度升高，使得一些古老产区的黄芩植物不再适合药用。过氧化氢在黄芩根对异常温度的反应中起着重要作用。预计黄芩中的黄芩苷和黄芩素以及抗氧化酶将解毒 H2O2。在这里，我们表明异常温度（10 和 40°C）与正常温度（30°C）相比，降低了类黄酮的含量，而涉及黄芩苷和黄芩素相互转化的 UDP-葡萄糖醛酸：黄芩素 7-O-葡萄糖醛酸基转移酶和β-葡萄糖醛酸酶的转录物受到 40°C 处理的影响。高温还增加了过氧化氢酶和过氧化物酶的活性。逆转录-聚合酶链反应（RT-PCR）分析显示，在高温条件下，过氧化物酶 2、过氧化物酶 3、单脱氢抗坏血酸还原酶 2 和脱氢抗坏血酸还原酶的转录水平显著增加。这些基因可能是改善黄芩植物适应异常温度和调节活性化合物含量的候选基因。
