Author: Lui, Siu-yan
Title: An in vitro study of the antioxidant activities and effect on DNA of a Chinese medicinal formulation, 'Bu Zhong Yi Qi Tang' (補中益氣湯), and its individual herbal components
Degree: M.Sc.
Year: 2005
Subject: Hong Kong Polytechnic University -- Dissertations
Antioxidants -- Therapeutic use
Medicine, Chinese -- Formulae, receipts, prescriptions
Department: School of Nursing
Pages: xiv, 92 leaves : col. ill. ; 30 cm
Language: English
Abstract: Traditional Chinese Medicine (TCM), with a long history of clinical practice, occupies an important place in 'alternative medicine', but with little scientific validation. TCM is mainly based on the use of medicinal formulations (combination of multiple herbs), rather than a single herb. One such Chinese medicinal formulation, Bu Zhong Yi Qi Tang (BZYQT), which is an ancient prescription with impressive health benefits reported for the improvement of gastroenteric circulation, the alleviation of fatigue and depressed vitality. This study was conducted to measure and compare the in vitro antioxidant activity, and to investigate possible synergistic or antagonistic effects of the individual herbal components of BZYQT, by testing the whole formulation (as a commercially available product) as well as each of the ten individual component herbs, and selected combinations as both 'staggered' mixtures of individual herbal decoctions, and 'staggered' decoctions of multiple herbs using the Ferric Reducing / Antioxidant Power (FRAP) assay (US patented). The in vitro genoprotective or genotoxic effect of BZYQT and its chief herb, huang qi, was also studied on human lymphocytic DNA with or without the induction of a standard oxidant challenge, and using the Comet assay. In vitro antioxidant activity (as the FRAP value) of the commercial BZYQT powder, was 77 +- 0.31 (mean +- SD of triplicate tests) umol/g. All component herbs of BZYQT also possessed in vitro antioxidant activity, with the FRAP values ranging from 11.1 +- 0.30 umol/g to 112.5 +- 2.64 umol/g. For the staggered mixtures of individual herbal decoctions, there was a good linear relationship between expected and observed (measured) FRAP values for equal quantity basis and weight ratio basis, with strong correlation (r2 = 0.9976 and 0.9342 respectively). For the decoctions of multiple herbs, the linearity between expected and observed FRAP values for equal quantity basis and weight ratio basis was less good, with r2 = 0.9204 and 0.7722 respectively. In all cases of staggered mixtures, there was a significant difference (p <0.05) between the means of the observed and expected FRAP values except the case of the mixtures of individual herbal decoctions in the basis of weight ratio of the BZYQT formula. The commercial BZYQT powder showed genoprotective effect with significantly lower DNA damage in cells found after a standard oxidant challenge (induced by 45 uM hydrogen peroxide) at BZYQT concentrations of 0.025 g/l (w/v), 0.05 g/l (w/v), 0.1 g/l (xv/v), 0.2 g/l (w/v) and 0.4 g/l (w/v). No evidence of genotoxicity of the formulation was seen. The chief herb, huang qi appeared to have a protective effect in cells exposed to a standard oxidant challenge, but the results were quite variable and did not reach a statistically significant level (p > 0.05). Results from this study indicate that BZYQT may serve a potential source of antioxidants. The commercial formulation and the individual herbal components of BZYQT showed in vitro antioxidant activity, but no clear additive, synergistic or antagonistic affects were seen in staggered mixtures. The findings also indicate that BZYQT may protect cellular DNA from oxidative damage in vitro, and this could account for some of its reported health benefits. Further study is needed to elucidate the genoprotective effect of BZYQT by investigating all its component herbs and in clinical trial.
Rights: All rights reserved
Access: restricted access

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