br Acknowledgements br Introduction Major research interests
Introduction Major research interests have been attributed to reactive oxygen species (ROS) and their likely involvement in human physiopathology from the health point over the last few decades. Oxidative stress, caused by an imbalance between antioxidant systems and the production of oxidants, including ROS, seems to be associated with many multifactorial diseases , especially cancers, cardiovascular diseases and inflammatory disorders . Chronic inflammation is widely recognized as a major underlying cause of various degenerative diseases. Accumulative effects of tissue destruction caused by ROS coupled with damage induced by proteolytic metalloproteinases lead to pathological conditions [3,4]. It has been reported that bioactive herb extracts with high levels of phenolic and flavonoid compounds exhibit strong anti-oxidant and anti-inflammatory activities . Therefore, fruits and vegetables which contain significant amounts of antioxidants are believed to have health beneficial effects by counteracting oxidative stress thus reducing the risk of chronic diseases [5,6]. These antioxidants mainly come from plants in the form of phenolic compounds such as flavonoid, phenolic acids, stilbenes, tocopherols, tocotrienols, ascorbic urat1 inhibitor and carotenoids. Recently, phenolic compounds have been received much attention on their effective antioxidant properties, and their beneficial effects are attributed to their donating electrons, scavenging free radicals, and reducing power [7,8]. In addition, natural antioxidants have the capacity to improve food quality and stability, and can also act as nutraceuticals to terminate free radical chain reactions in biological systems, and thus may provide additional health benefits to consumers . Chinese jujube (Zizyphus jujuba Miller) has been used as a crude drug in traditional Chinese medicine for the purpose of analeptic, palliative, antibechic for thousands of years in China . Recently, the high antioxidant activity of the extracts from different parts of jujube fruit such as peel, pulp and seeds has been reported. This antioxidant activity has been attributed to the high level of phenolic compounds. Jujube fruit is known to contain considerable amount of phenolic compounds, including chlorogenic acid, gallic acid, protocatechuic acid and caffeic acid . Currently, some literatures reported its in vitro antioxidant capacity of phenolic and flavonoids in several cultivars of Chinese jujube . However, little research is available about its details both in vitro and in vivo antioxidant capacity for this fruit. Based on antioxidant capacity and phenolic content, seven cultivars of Chinese jujube were classified for three groups. The objective of this study tries to explore the phenolic composition and antioxidants capacity in vitro and in vivo of the ethanol–water extracts from seven cultivars of Chinese jujube, to provide sufficient experimental evidence for antioxidant activity and potential for further development and utilization of Chinese jujube.
Materials and methods
Results and discussion
Acknowledgment This research was supported by the Ministry of Science and Technology in Agricultural Science and Technology Achievement Transformation Fund Project: (No. 2011CB23600017), the National Technology People\'s Republic of China.
Introduction Natural products are defined as natural sources-derived substances having biological activities. Natural products have long been implemented as alternative health care treatment and in discovery of modern drugs . A major focus of natural product chemistry has been toward drug design and discovery. Our literature tracking displayed that most research activity into natural products in Indonesia is still limited to the inventory of folkloric information and utilization of various plants and trees, meaning that obtaining scientific proof for their biological activity is still challenging [2,3].