There are nearly 1300 plants used to treat malaria (Plasmodium falciparum) around the world, and they are often used in combinations. Researchers have long debated over whether it is best to use whole plant treatments or isolated extracted chemicals. Whole plant extracts are more effective than using a single extracted chemical as treatment against malaria. This article is a review of the interaction between whole plant components and herbal combinations in malaria treatment.
Synergy is the term used to describe how various chemicals interact in therapy. Synergy “means that the effect of the combination is greater than the sum of the individual effects.” The activity of a combination of plant chemicals is often eight times as high as the activity of the components used separately. The synergy of plant chemicals is believed to be the result of evolution.
Cinchona bark chemicals work in combination with other plants to enhance treatment of malaria. Quinine is one component of cinchona which has been shown to be much more effective when used in combination with other components of cinchona. “Whole cinchona bark extracts were shown to be clinically safe and effective for the treatment of uncomplicated falciparum and vivax malaria in extensive clinical trials in the 1930s.”
Artemisinin in Artemisia annua tea absorbs faster than pure artemisinin alone. Artemisia contains flavonoids, phenols and a very high antioxidant capacity. Plant extracts may contain natural multidrug resistance inhibitors, which reduces the chance that malaria will become resistant to plants containing such inhibitors. Some plants are added to a combination because they reduce some side effect, such as nausea.
Curcumin extract from turmeric (Curcuma longa) has anti-malarial activity and is used in combinations with such herbs as Andrographis paniculata for synergy. Piperine from black pepper (Piper nigrum) improves the bioavailability of curcumin in the intestine by 2000%. (Piperine increases the bioavailability of epigallocatechin gallate or EGCG also.)
Pure chemicals extracted from plants lack synergy. They “rarely have the same degree of activity as the unrefined extract at a similar dose of the active component and are expensive.” Herbal plant medicines can be grown by people who need them. Plants produce chemicals which fit into the enzymes of parasites, disabling them.
Some plants have multiple actions so that, in addition to treating malaria, they stimulate the immune system. On the other hand, plants with little activity against malaria may be important in certain combinations. Some plants have mechanisms for preventing the development of multi-drug resistance MDR and have been used for thousands of years without the development of resistance in malaria. (This is not true for isolated chemicals and synthetic malarial treatments.) EGCG from green tea is a MDR inhibitor which works well with artemisinin.
CONCLUSION: Combinations of herbs and combinations of plant chemicals work by synergy. The whole is better than the sum of its parts. Artemisia works well as an anti-malarial, but works even better when combined with turmeric, black pepper extract and green tea catechins. Cinchona bark works well in combinations; there are advantages to whole plant extracts.
NOTE: Cinchona officinalis is one cinchona species.