Whole plant extracts versus single compounds for malaria

[herbsandhelpers]

Whole plant extracts versus single compounds for the treatment of malaria: synergy and positive interactions.

Malar J. 2011 Mar 15;10 Suppl 1:S4. [Epub ahead of print], Madagascar. [email protected] 

BACKGROUND : In traditional medicine whole plants or mixtures of plants are used rather than isolated compounds. 

There is evidence that crude plant extracts often have greater in vitro or/and in vivo antiplasmodial activity than isolated constituents at an equivalent dose. 

The aim of this paper is to review positive interactions between components of whole plant extracts, which may explain this. 

METHODS : Narrative review. 

RESULTS : There is 
evidence for several different types of positive interactions between different components of 
medicinal plants used in the treatment of malaria. 

Pharmacodynamic synergy has been demonstrated between the Cinchona alkaloids and between various plant extracts 
traditionally combined. 

Pharmacokinetic interactions occur, for example between 
constituents of Artemisia annua tea so that its artemisinin is more rapidly absorbed than the 
pure drug. Some plant extracts may have an immunomodulatory effect as well as a direct antiplasmodial effect. Several extracts contain multidrug resistance inhibitors, although none of these has been tested clinically in malaria. Some plant constituents are added mainly to attenuate the side-effects of others, for example ginger to prevent nausea. 

CONCLUSIONS: More clinical research is needed on all types of interaction between plant constituents. This could include clinical trials of combinations of pure compounds (such as artemisinin + curcumin + piperine) and of combinations of herbal remedies (such as Artemisia annua leaves + Curcuma longa root + Piper nigum seeds). The former may enhance the activity of existing pharmaceutical preparations, and the latter may improve the effectiveness of existing herbal remedies for use in remote areas where modern drugs are unavailable. 

PMID: 21411015 [PubMed - as supplied by publisher]