Antioxidant activity of different extracts of lotus (Nelumbo nuficera Gaertn) rhizome by gradient solvent extraction
Lotus (Nelumbo nucifera Gaertn) is both an ornamental plant and a dietary staple in Eastern Asia, particularly in China (Hu & Skibsted, 2002). All parts of lotus are used for various medicinal purposes in oriental medicine (Kashiwada et al., 2005). The seed of lotus is used in folk remedies as diuretic, cooling agent, antiemetic and antidote in the treatment of tissue inflammation, cancer, skin disease, leprosy and poisoning (Chopra et al., 1956; Liu et al., 2004). The leaf of lotus is considered best for “over-coming body heat”, and stopping bleeding (Bensky et al., 2004). It is used as a drug for hematemesis, epistaxis, hemoptysis, hematuria and metrorrhagia (Ono et al., 2006) in traditional Chinese medicine. Lotus rhizome can be cooked into different dishes or eaten raw as a common vegetable. Especially, it has been applied in Chinese herbal prescriptions to alleviate tissue inflammation, cancer, and liver cirrhosis for a long time (Mukherjee et al., 1997).