Ancient Chinese Methods Are Remarkably Effective for the Preparation of Artemisinin-Rich Extracts of Qing Hao with Potent Antimalarial Activity

Abstract

Ancient Chinese herbal texts as far back as the 4th Century Zhou hou bei ji fang describe methods for the use of Qing Hao (Artemisia annua) for the treatment of intermittent fevers. Today, the A. annua constituent artemisinin is an important antimalarial drug and the herb itself is being grown and used locally for malaria treatment although this practice is controversial. Here we show that the ancient Chinese methods that involved either soaking, (followed by wringing) or pounding, (followed by squeezing) the fresh herb are more effective in producing artemisinin-rich extracts than the usual current method of preparing herbal teas from the dried herb. The concentrations of artemisinin in the extracts was up to 20-fold higher than that in a herbal tea prepared from the dried herb, but the amount of total artemisinin extracted by the Chinese methods was much less than that removed in the herbal tea. While both extracts exhibited potent in vitro activities against Plasmodium falciparum, only the pounded juice contained sufficient artemisinin to suppress parasitaemia in P. berghei infected mice. The implications of these results are discussed in the context of malaria treatment using A. annua infusions.

In vitro antiplasmodial activity of Withania frutescens —Solanaceae

“…Pure drugs that are industrially produced or isolated from plants against a humans disease have not always the same degree of activity as the unrefined extract or fraction at comparable concentraction of the active component, and in many cases there is evidence of synergistic or multifactorial effects between compounds present in the extracts [28,29]. In a recent study, it was found that the antiplasmodial IC 50 values of Artemisia annua extracts were 6 to 18 fold lower than was expected in terms of their artemisinin content, suggesting that the activity of the extracts could not be accounted entirely by their artemisinin content [29]. In another study, the flavone casticin enhanced the in vitro activity of artemisinin by 3-5 fold [30].…”

The complexity of medicinal plants: The traditional Artemisia annua formulation, current status and future perspectives

“…It is therefore possible that the compounds responsible for the enhanced aqueous solubility of artemisinin only occur in the stems and not in the leaves. Wright et al (2010) found that soaking the leaves and stems in water for 12 h followed by squeezing gave the most effective extraction yield of 72.6 mg/L, compared to 45.9 mg/L after 2 h and 14.5 mg/L for the dried herb infusion. They suggested that squeezing may cause the artemisinin concentration to increase, due to rupturing of the glandular trichomes containing most of the artemisinin.…”

Antimicrobial resistance and synergy in herbal medicine

“…Niemeyer, et al (2013) and others have suggested that the findings of reductionist approaches using processed plant parts and isolated constituents may not be generalisable to herbal medicine practice. All the research reviewed used dried plant extracts although there are researchers (Wright et al, 2010) and herbal medicine practitioners finding that traditional, fresh preparations have the best antimicrobial results (Buhner, 2013).…”