Analysis Of Bamboo Extracts And Their Calcium Antagonistic Effects

The overload of Ca²⁺ in intracellular places will lead to many diseases, such as coronary heart disease and other diseases in cardiac or brain blood vessels. If Ca²⁺ channels in cell membranes can be blocked or the superfluous Ca²⁺ in intracellular fluid can be induced to efflux by medicines or other substances, these diseases might be cured or controlled.Bamboo, a kind of traditional drug in China, is important floral natural resources for foodstuff (bamboo shoot), papermaking, package material, building, intertexture and others. Moreover, it can make our environment beautiful and balance our ecological system. Bamboos possess not only many advantageous biological activities and contain cellulose, hemicellulose, amino acid, flavones, polysaccharose as well as several minerals. Of which, flavonoids and polysaccharose are ubiquitous compounds in plants and have shown a variety of biological activities at nontoxic concentrations in organisms. Structure diversity of flavonoids and polysaccharose allow them to exhibit antineoplastic, antihepatites, antibacterial, anti-inflammatory, antimutagenic, antiallergic, anti-thrombotic, antiviral, and vasodilatory activities. Recently, the investigation of flavonoids and polysaccharose is causing comprehensive attention increasingly. Some researches show that there are some close relationship between flavonoids, polysaccharose and human's healthiness.In this paper, the folia bambosae, the branch and culm of two bamboos, sinocalamus affinis and Bambusa Rigida, are extracted by distilled water, lye (saturated lime water), acid water (1mol/L HCl), 70% ethanol and 95% ethanol, respectively. The flavonoid contents in sinocalamus affinis. and Bambusa Rigida extracts were measured by using rutin as the reference in a spectrophotometer at 510nm using rutin as the reference, while the polysaccharose contents in sinocalamus affinis and Bambusa Rigida extracts were measured by using glucose as the reference compound in a spectrophotometer at 620nm. The influences of several extracts of bamboo on Ca²⁺ influx and efflux in the isolated aortas and hearts of rats were investigated by using ⁴⁵Ca as a radioactive tracer and their calcium antagonistic effects were evaluated. Additionally, their protective effects on myocardial ischemia were investigated in live rats.The results show that the highest contents of flavonoids and polysaccharose in folia bambosae of sinocalamus affinis and Bambusa Rigida extracts are the 70% ethanol extracts. Nevertheless, the alkali extracts of sinocalamus affinis and Bambusa Rigida have a prominent influence on Ca²⁺ influx and efflux in the isolated rat aorta and heart, in that they can markedly block ⁴⁵Ca entering into cell and can stimulate efflux of intracellular Ca²⁺. Among these extracts, the alkali extracts have the most significant effect in calcium channels, even the alkali extract is diluted in 2 or 4 times. However, no statistically significant effect of the ethanol, chlorhydric acid or water extracts on the Ca²⁺ influx and efflux is observed. Moreover, the sinocalamus affinis and Bambusa Rigida alkali extract has favorable protective effect on myocardial ischemia induced either by isoproterenol injection (ISO) or by the ligation of coronary artery. All of these implied that the sinocalamus affinis and Bambusa Rigida has attractive potential for the treatment for heart, cerebrovascular and other diseases, and should be further explored. However, it is very difficult to conclude that whether the flavonoid and polysaccharose in sinocalamus affinis and Bambusa Rigida is involved in the calcium antagonistic effects and Ca²⁺ channels or not, just based on the results until now.