Antioxidant and angiotensin I converting enzyme inhibitory activity of Bambusae caulis in Liquamen

Bambusae caulis in Liquamen (BCL) is a nutritious liquid that can be extracted from heat-treated bamboo stems. It is also an important herbal medicine in Asia. In this study, antioxidant and angiotensin I converting enzyme (ACE) inhibitory activity of BCL were investigated. BCL significantly quenched DPPH and peroxyl radicals measured by electron spin resonance (ESR) spectroscopy, while IC₅₀ values were 79.85 and 28.85 μg/ml, respectively. The ability of BCL to inhibit the oxidative damage of DNA was assessed in vitro by measuring the conversion of supercoiled pBR322 plasmid DNA to the open circular form. It was found that BCL significantly protected hydroxyl radical-induced DNA damage in a dose-dependant manner, while also inhibiting apoptosis in hydrogen peroxide-induced PC-12 cells and angiotensin I converting enzyme (ACE) activity. These findings suggest that BCL may be a beneficial ingredient in functional foods and/or pharmaceuticals.