Worldwide, the greatest fear is that the malaria parasite might develop resistance to the drug of choice, Artemisinin Combination Therapy (ACT). In fact, health experts are worried that more people may become ill or die due to the rapid speed of these drug-resistant malaria parasites, especially in the season when malaria cases are on the rise.
Scientists have been working for years to target increasing partial resistance to the top anti-malaria drug, artemisinin. The focus has been on identifying herbs that can boost the effectiveness of artemisinin, as a treatment for malaria.
In a new study, scientists found bitter leaf as a partner drug of artemisinin for treating malaria. Its different extract in combination with artemisinin had a very strong antimalarial effect. The scientists tested the antimalarial effect of bitter leaf extract and its fractions in combination with artemisinin against malaria parasites under laboratory conditions.
This 2020 study aimed at exploring the interaction of Vernonia amygdalina (Delile) Leaf Extract with Artesunate and Amodiaquine for treating malaria was published in the Journal of Pharmaceutical Research International.
The advocacy for Artemisinin-Based Combination Therapies (ACTs) such as artesunate-amodiaquine as the standard practice in malaria chemotherapy has globally reduced estimates of malaria cases and related deaths.
However, recently, the detection of resistance of Plasmodium falciparum to artemisinin in Southeast Asia, is threatening the gains recorded in combating malaria
For the study, various doses of aqueous bitter leaf extract (100-500 mg/kg/day), Amodiaquine (2-10 mg/kg/day) and Artesunate (0.8-4 mg/kg/day) were administered orally to malaria-infected Swiss albino mice to determine their sub-therapeutic doses.
These doses were subsequently used to investigate the chemotherapeutic interactions of the bitter leaf with Amodiaquine and/or Artesunate in both early and established malaria infection test models.
The survival of animals with established infections that received different drug/herb treatments were determined.
The chemosuppressive effect of Amodiaquine or Artesunate was significantly increased when administered in combination with the bitter leaf extract. Similarly, a combination of bitter leaf extract with Amodiaquine or Artesunate resulted in significant parasite clearance when compared to the effects of the herb or the conventional drugs administered separately.
The average survival period of animals with established infection was also significantly enhanced by the bitter leaf alone or with Amodiaquine (or Artesunate) compared to placebo.
They wrote, “Overall, concurrent administrations of V.amygdalina with amodiaquine and/or Artesunate result in significant enhancement of the efficacies of these orthodox antimalarial drugs.
This may be an approach towards overcoming development of resistance to malaria parasites by these drugs.”
Moreover, scientists also found a combination of Gynostemma pentaphyllum (Asofeyeje in Yoruba), or Moringa oleifera (Ewe Igbale or drumstick tree)leaf extracts can also increase the antimalarial effect of artesunate, and as such a low dose of artesunate will be required in treating malaria.
In 2016, Thai scientists tested the effect of Gynostemma pentaphyllum or Moringa oleifera leaf extracts on the effectiveness of artesunate in treating malaria.
In animals under laboratory conditions, the combination with G. pentaphyllum leaf extract was more effective than the combination that had Moringa oleifera leaf extract.
Additionally, artesunate combined with these extracts had a higher antimalarial activity, compared to extract treated along with G. pentaphyllum leaf extract of M. oleifera leaf extract.
Written in the Journal of Tropical Medicine, the scientists concluded: “the addictive effect of these extracts with artesunate is important in the context that offers opportunities to further standardise new ACT as possible antimalarial combination.”
In addition, experts in 2016 in the Malaria Journal found that herbs such as Cryptolepis sanguinolenta (paran pupa in Yoruba) can also boost the effectiveness of artemisinin-based combination therapy.
The aqueous or water root extract of C. sanguinolenta is patronised in rural West Africa as a herbal extract in the treatment of malaria even for patients who are on prescribed artemisinin derivatives.
Its combination produced a significant reduction in the level of the malaria parasite in the blood from days one to six.
At all doses, it also ensured higher malaria organism suppression in the first three days compared to the herbal extract only.
According to them, “This indicates a possible rapid onset of antimalarial or antiplasmodial activity when Cryptolepis sanguinolenta extract is used in combination with ART compared to each of the drugs used alone.
“With the current three-day anti-malarial treatment, a combination of CPE, an extract from Cryptolepis sanguinolenta, with ART may offer a better choice for rapid clearance of parasites in the blood compared to any of the two agents used alone. Again, the long duration of action of this combination will ensure efficient parasite clearance. “
Previously in 2013, researchers at the Obafemi Awolowo University, Ile-Ife, Osun State also said that extracts of the stem bark of Khaya grandifoliola potentiated the antimalarial activity of Artemisinin. This was in the European Journal of Medicinal Plants.
