Bamboo leaves have a long history as both food and medicine in China, which is recognized by Chinese authority. Researches shows that, bamboo leaves contain many effective ingredients such as flavone, phenolic acid, anthracene quinone, lactone, amylose, amino acid and trace elements, which have effects on anti-free-radicals, anti-oxidation, anti-aging, anti-fatigue, and anti-cancer, preventing cardio-cerebro-vascular diseases, protecting the liver, widening capillary vessels, smoothing micro-circulation, vitalizing the brain, improving memory and sleep, and improving the texture of skin. It is reported that at the Second International Natural Antioxidants Conference many experts from home and abroad reported on the effects of natural and biological flavone on controlling the toxicity brought by anti-cancer medicine to the marrow and inhibition to the immune system, improving micro-circulation and platelet's function and preventing cardiac muscles of people with coronary heart diseases from bleeding.

Bamboo leaf flavone is of great significance to health and longevity. Japanese scientific academia thinks that the structure of bamboo leaf flavone is similar to that of human hemoglobin. Therefore, it can be directly injected into the vein to achieve a high performance.

Bamboo leaf flavone is non-hazardous and toxin-free. As known to all, gingko leaves contain certain amounts of gingko acid, which is harmful to the body. However, in the research of effective ingredients of bamboo leaves, no poisonous or harmful ingredient has been found so far. The safety level of bamboo leaf ingredients is much higher than that of gingko extracts. The toxicity experiments made by the China Zhejiang Medical and Scientific Academy show that bamboo leaf extracts are not poisonous to small mice which have orally taken LD50 with average dosage over 10g/kg body weight and that the results of microkernel experiment, sperm deformity experiment and mouse typhoid salmonella/mammal microsome (AMES) experiment are all negative. The experiment on big mouse concerning acute toxicity shows that bamboo leaf extracts are actually toxin-free.

Flavonoids, also named bioflavonoids, widely exist in every part of plants, especially in their flowers and leaves. According to documents, around 20% of traditional Chinese herbs have flavonoids. Much research has shown that flavonoids possess a lot of biological vitalities, having obvious effect on antibiosis, diminishing inflammation, anti-mutation, reducing blood pressure, detoxicification, sedation, diuresis, anti-oxidation, and anti-cancer, preventing cancer and containing lipase. Flavonoids can be obtained directly from food such as beans, oranges, onions and also be extracted from plants containing rich flavonoids, and made into various health foods and snacks.

 Ⅱ. Bamboo leaf flavone and its effective ingredients

Bamboo leaf flavone is a botanic flavonoid preparation newly developed in the 1990s based on wild alpine bamboo leaves as raw materials. Its functional part is flavone glycoside, especially carbo-glycoside flavone. Flavone glycoside is a compound formed when some part of flavone's parent nucleus is bonded to the sugar group. There are two types flavone glycoside: carbo-glycoside flavone and oxo-glycoside flavone. Carbo-glycoside flavone's sugar group is connected with flavone's parent nucleus through –C–C–bond. And oxo-glycoside flavone's sugar group is connected with flavone's parent nucleus through –O–C–bond. Compared with oxo-glycoside flavone, carbo-glycoside flavone has the following advantages. a. Its structure is very stable and does not easily degrade. b. It enters the defective tissue deeply and have direct curative effects. c. Its strong hydrophilicity enables it to be used in the development of medicine, food and cosmetics. The international academic community has started focusing on carbo-glycoside flavone since the 1990s. This opens a new scientific field. Carbo-glycoside flavone in bamboo leaves consists of polygonum orientale glucoside, iso-polygonum orientale glucoside, vitexin and iso-vitexin. Bamboo leaf flavone is a botanic flavone with unique Chinese flavor. Bamboo leaf flavone produced with patent technology is a synergetic bio-antioxidant of multi-components. These ingredients, besides flavonoids, are phenolic acid, anthracene quinine compound, biological active amylose, coumarins lactone, special amino acid and fragrance, manganese, zinc, stannum and other trace elements. They have jointly laid the foundation for the medical and phamacological functions of bamboo leaf flavone.

 Ⅲ.  Medical research on the pharmacological activity of bamboo leaf flavone on cardio-cerebro-vascular diseases

Cardio-cerebro-vascular diseases such as high blood pressure, cerebral stroke and coronary heart disease have become the top killer of humans and seriously weakened the health of the mankind. Therefore, medicines for curing these diseases have taken up a large proportion of the medicine market. As more and more people are aware of the disadvantages of chemical medicine and the advantages of traditional medicine in curing multi-target spot diseases, the demand for high-efficient and low-poisonous natural medicines and foods are rising. Thus, the natural medicines extracted and segregated from plants to cure cardio-cerebro-vascular diseases have become the focus of attention.

 Ⅳ. Research on the effects of bamboo leaf flavone in regulating blood lipids

Blood lipids mainly consist of cholesterol, triglyceride (TG) and phospholipid. Cholesterol includes cholesterol esters and dissociative cholesterol, and they together are called total cholesterol (TC). Cholesterol has a close relation with artery sclerosis (AS). Total cholesterol and low-density lipoprotein cholesterol (LDL-C) are the main cause to arterial sclerosis. Therefore, it has been a focus in research to reduce total cholesterol and low-density lipoprotein cholesterol.

The Medical Nutrition Department of Zhejiang University took SD big male mice (weight ranging from 160g to 180g) as experimental objects, fed them with high-lipid feedstuff, then divided them into groups and fed them with different dosages of bamboo leaf flavone. Besides, the department compared the experiment with groups fed with high-lipid feedstuff and groups fed with gingko extracts (Egb). In the process, the mice were weighed at certain times and the contents of TG, TC, HDL-c and LDL-c were measured, respectively. The ideal result of reducing blood lipids is to succeed in reducing the contents of TG, TC and LDL-c and maintaining or raising the content of HDL-c. It is found in the experiment that bamboo leaf flavone reduces the contents of TG, TC and LDL-c in the mice's blood by a large percentage. Bamboo leaf flavone raises the content of HDL-c by a large margin in the groups where the mice are fed with medium and high dosages of bamboo leaf flavone. Besides, the effect of the flavone is the same with gingko extracts of the same dosage. The AS index is the most important indicator for examining the function of reducing blood lipids, indicating the ratio between AS index and LDL-c/HDL-c. This experiment found that the AS index of those mice taking none of bamboo leaf flavone went obviously higher due to high-lipid feedstuff, showing the increase of having AS risk. Low dosage of bamboo leaf flavone reduced the absolute density of TG, TC, LDL-c in the blood, but it did not bring the AS index down. High dosage of bamboo leaf flavone succeeded in bringing down the AS index and showed a positive correlation with the dosage: LDL-C's relative density in the blood was lower and HDL-c's relative density in blood was higher. So the risk of having AS was lowered.

Applying the method of abnormal lipid metabolism of big mouse, the Nutrition and Food Scientific Technology Institute of Nanjing Medical University has discovered that bamboo leaf flavone has the function of regulating big mouse's blood lipid (Table 7-1). When giving the mice high-lipid feedstuff, the research group filled the mice with low (0.1g/kg), medium (0.2g/kg) and high (0.6g/kg) dosages of bamboo leaf flavone. The mice were weighed every week and 28 days later, TG, TC and HDL-c were measured. The results showed that the TG of the mice fed with high dosage of bamboo leaf flavone was much lower than that of the mice fed with high-lipid feedstuff (P<0.01). TG content was lowered by 42.3% and 40.8%, respectively. HDL-c content of the mice fed with high dosage of bamboo leaf flavone was higher by 9mg/dl than that of the mice fed with high-lipid feedstuff. TC was not obviously different in each group, showing that bamboo leaf flavone has the function of regulating blood lipid.

Table 7-1 Bamboo leaf flavone's function of regulating blood lipid of big mouse

* Significance of statistics: * P<0.05 (obvious difference); ** P<0.01 (extremely obvious difference)
Judging from Table 7-1, bamboo leaf flavone's function of regulating blood lipids was obviously shown in the animal experiments.