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Synergistic Effects of Chinese Herbal Medicine: A Comprehensive Review of Methodology and Current Research.

Zhou X, Seto SW, Chang D, Kiat H, Razmovski-Naumovski V, Chan K, Bensoussan A - Front Pharmacol (2016)

Bottom Line: However, evidence to support these synergistic effects remains weak and controversial due to several reasons, including the very complex nature of CHM, misconceptions about synergy and methodological challenges to study design.Despite the availability of some scientific data to support the synergistic effects of multi-herbal and/or herb-drug combinations, the level of evidence remains low, and the clinical relevancy of most of these findings is undetermined.There remain significant challenges in the development of suitable methods for synergistic studies of complex herbal combinations.

View Article: PubMed Central - PubMed

Affiliation: School of Science and Health, National Institute of Complementary Medicine, Western Sydney University Penrith, NSW, Australia.

ABSTRACT
Traditional Chinese medicine (TCM) is an important part of primary health care in Asian countries that has utilized complex herbal formulations (consisting 2 or more medicinal herbs) for treating diseases over thousands of years. There seems to be a general assumption that the synergistic therapeutic effects of Chinese herbal medicine (CHM) derive from the complex interactions between the multiple bioactive components within the herbs and/or herbal formulations. However, evidence to support these synergistic effects remains weak and controversial due to several reasons, including the very complex nature of CHM, misconceptions about synergy and methodological challenges to study design. In this review, we clarify the definition of synergy, identify common errors in synergy research and describe current methodological approaches to test for synergistic interaction. We discuss the strengths and weaknesses of these models in the context of CHM and summarize the current status of synergy research in CHM. Despite the availability of some scientific data to support the synergistic effects of multi-herbal and/or herb-drug combinations, the level of evidence remains low, and the clinical relevancy of most of these findings is undetermined. There remain significant challenges in the development of suitable methods for synergistic studies of complex herbal combinations.

No MeSH data available.


Related in: MedlinePlus

The lsobole method for synergy study. Dose A and Dose B are the individual concentrations of Components A and B; Dose AB are the concentrations of A and B in the combination. The dashed line shows zero interaction between A and B, which represents a simple additive effect. The effect of the combination equals the sum of the effects from individual components. (A) Effect of synergy: the dot is underneath the dashed line. (B) Effect of antagonism: The dot is above the dashed line; Addition: The dot is on the dashed line.
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Figure 2: The lsobole method for synergy study. Dose A and Dose B are the individual concentrations of Components A and B; Dose AB are the concentrations of A and B in the combination. The dashed line shows zero interaction between A and B, which represents a simple additive effect. The effect of the combination equals the sum of the effects from individual components. (A) Effect of synergy: the dot is underneath the dashed line. (B) Effect of antagonism: The dot is above the dashed line; Addition: The dot is on the dashed line.

Mentions: Isobologram, was first introduced by Fraser in 1870 based on Loewe additivity (Fraser, 1872). This method has been widely accepted as one of the most practical models in terms of experimental design and effectiveness to illustrate the synergistic/additive/antagonistic interactions. Similar to the CI model, the isobole method requires the determination of dose-response relationship of the combination and its individual components independently to assess if synergism exists. This is expressed as a dose response curve on an isobole graph as shown in Figure 2. The isobole is an “iso-effect” curve, in which a combination of components (A or B) at different dose levels is represented on the graph, the axes of which are the dose-axes of the individual constituent (A and B). The dashed line joining the points (i.e. ED50 of A and B) which represent the same dosage required from the combination as the sum of the individual component to reach the same effect. If the dots of the combination falls on this dashed line, it represents an additive effect, i.e., no interactions between components A and B. If synergy occurs the curve becomes “concave.” The opposite applies for antagonism representing by a “convex” isobole (Figure 2). It is also possible to have synergy at one dose combination and antagonism at another, with the same substances and this would give a complicated isobole with a wave-like or even elliptical appearance.


Synergistic Effects of Chinese Herbal Medicine: A Comprehensive Review of Methodology and Current Research.

Zhou X, Seto SW, Chang D, Kiat H, Razmovski-Naumovski V, Chan K, Bensoussan A - Front Pharmacol (2016)

The lsobole method for synergy study. Dose A and Dose B are the individual concentrations of Components A and B; Dose AB are the concentrations of A and B in the combination. The dashed line shows zero interaction between A and B, which represents a simple additive effect. The effect of the combination equals the sum of the effects from individual components. (A) Effect of synergy: the dot is underneath the dashed line. (B) Effect of antagonism: The dot is above the dashed line; Addition: The dot is on the dashed line.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4940614&req=5

Figure 2: The lsobole method for synergy study. Dose A and Dose B are the individual concentrations of Components A and B; Dose AB are the concentrations of A and B in the combination. The dashed line shows zero interaction between A and B, which represents a simple additive effect. The effect of the combination equals the sum of the effects from individual components. (A) Effect of synergy: the dot is underneath the dashed line. (B) Effect of antagonism: The dot is above the dashed line; Addition: The dot is on the dashed line.
Mentions: Isobologram, was first introduced by Fraser in 1870 based on Loewe additivity (Fraser, 1872). This method has been widely accepted as one of the most practical models in terms of experimental design and effectiveness to illustrate the synergistic/additive/antagonistic interactions. Similar to the CI model, the isobole method requires the determination of dose-response relationship of the combination and its individual components independently to assess if synergism exists. This is expressed as a dose response curve on an isobole graph as shown in Figure 2. The isobole is an “iso-effect” curve, in which a combination of components (A or B) at different dose levels is represented on the graph, the axes of which are the dose-axes of the individual constituent (A and B). The dashed line joining the points (i.e. ED50 of A and B) which represent the same dosage required from the combination as the sum of the individual component to reach the same effect. If the dots of the combination falls on this dashed line, it represents an additive effect, i.e., no interactions between components A and B. If synergy occurs the curve becomes “concave.” The opposite applies for antagonism representing by a “convex” isobole (Figure 2). It is also possible to have synergy at one dose combination and antagonism at another, with the same substances and this would give a complicated isobole with a wave-like or even elliptical appearance.

Bottom Line: However, evidence to support these synergistic effects remains weak and controversial due to several reasons, including the very complex nature of CHM, misconceptions about synergy and methodological challenges to study design.Despite the availability of some scientific data to support the synergistic effects of multi-herbal and/or herb-drug combinations, the level of evidence remains low, and the clinical relevancy of most of these findings is undetermined.There remain significant challenges in the development of suitable methods for synergistic studies of complex herbal combinations.

View Article: PubMed Central - PubMed

Affiliation: School of Science and Health, National Institute of Complementary Medicine, Western Sydney University Penrith, NSW, Australia.

ABSTRACT
Traditional Chinese medicine (TCM) is an important part of primary health care in Asian countries that has utilized complex herbal formulations (consisting 2 or more medicinal herbs) for treating diseases over thousands of years. There seems to be a general assumption that the synergistic therapeutic effects of Chinese herbal medicine (CHM) derive from the complex interactions between the multiple bioactive components within the herbs and/or herbal formulations. However, evidence to support these synergistic effects remains weak and controversial due to several reasons, including the very complex nature of CHM, misconceptions about synergy and methodological challenges to study design. In this review, we clarify the definition of synergy, identify common errors in synergy research and describe current methodological approaches to test for synergistic interaction. We discuss the strengths and weaknesses of these models in the context of CHM and summarize the current status of synergy research in CHM. Despite the availability of some scientific data to support the synergistic effects of multi-herbal and/or herb-drug combinations, the level of evidence remains low, and the clinical relevancy of most of these findings is undetermined. There remain significant challenges in the development of suitable methods for synergistic studies of complex herbal combinations.

No MeSH data available.


Related in: MedlinePlus