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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

An example of utilizing CI model to determine synergy for the combination of agent AB in certain fixed ratio. (A) Dose-effect curves for A, B, and AB, respectively. (B) CI value-Fa (Fa: fraction affected level) curve for AB generated from CalcuSyn based on the dose-response curves shown in (A). It demonstrated that synergistic effect is starting from 60% effective level (Fa = 0.6) and this synergistic effect continues to increase (CI < 1) at higher effect levels in AB.
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Figure 1: An example of utilizing CI model to determine synergy for the combination of agent AB in certain fixed ratio. (A) Dose-effect curves for A, B, and AB, respectively. (B) CI value-Fa (Fa: fraction affected level) curve for AB generated from CalcuSyn based on the dose-response curves shown in (A). It demonstrated that synergistic effect is starting from 60% effective level (Fa = 0.6) and this synergistic effect continues to increase (CI < 1) at higher effect levels in AB.

Mentions: In addition, computer software including “CalcuSyn” and its third-generation “CompuSyn” have been developed, which greatly facilitates the CI analysis (Patrick Reynolds and Maurer, 2005; Chou, 2006). By inputting the dose-effect data of agents 1 and 2 and their combination, the software can generate a Fa (effect level)–CI curve, which demonstrates a complete dataset of CI values (represent antagonistic/additive/synergistic interactions) at all tested doses. Also, a CI-Fa (effect levels) can be generated (an example is shown in Figure 1). This model can also be applied for the determination of interactions among multiple agents in a mixture. The calculation is based on Equation (2), which demonstrates n-drug combination at x% inhibition. Examples using CI model for the determination of synergistic interaction in CHM are discussed in Section Synergistic Interactions within Single Herb Analyzed by CI or Isobologram Method.(1)CI =D1d1+D2d2    (1)(2)(CI)nx=∑j = 1n(D)j(d)j    (2)n(CI)x = combination index for n drugs at x% inhibition


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)

An example of utilizing CI model to determine synergy for the combination of agent AB in certain fixed ratio. (A) Dose-effect curves for A, B, and AB, respectively. (B) CI value-Fa (Fa: fraction affected level) curve for AB generated from CalcuSyn based on the dose-response curves shown in (A). It demonstrated that synergistic effect is starting from 60% effective level (Fa = 0.6) and this synergistic effect continues to increase (CI < 1) at higher effect levels in AB.
© Copyright Policy
Related In: Results  -  Collection

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

Figure 1: An example of utilizing CI model to determine synergy for the combination of agent AB in certain fixed ratio. (A) Dose-effect curves for A, B, and AB, respectively. (B) CI value-Fa (Fa: fraction affected level) curve for AB generated from CalcuSyn based on the dose-response curves shown in (A). It demonstrated that synergistic effect is starting from 60% effective level (Fa = 0.6) and this synergistic effect continues to increase (CI < 1) at higher effect levels in AB.
Mentions: In addition, computer software including “CalcuSyn” and its third-generation “CompuSyn” have been developed, which greatly facilitates the CI analysis (Patrick Reynolds and Maurer, 2005; Chou, 2006). By inputting the dose-effect data of agents 1 and 2 and their combination, the software can generate a Fa (effect level)–CI curve, which demonstrates a complete dataset of CI values (represent antagonistic/additive/synergistic interactions) at all tested doses. Also, a CI-Fa (effect levels) can be generated (an example is shown in Figure 1). This model can also be applied for the determination of interactions among multiple agents in a mixture. The calculation is based on Equation (2), which demonstrates n-drug combination at x% inhibition. Examples using CI model for the determination of synergistic interaction in CHM are discussed in Section Synergistic Interactions within Single Herb Analyzed by CI or Isobologram Method.(1)CI =D1d1+D2d2    (1)(2)(CI)nx=∑j = 1n(D)j(d)j    (2)n(CI)x = combination index for n drugs at x% inhibition

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