• Parasites, Hosts and Diseases
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• v.60 no.5
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• pp.339-344
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• 2022

The development of drug resistance is one of the most severe concerns of malaria control because it increases the risk of malaria morbidity and death. A new candidate drug with antiplasmodial activity is urgently needed. This study evaluated the efficacy of different dosages of aqueous extract of Strychnos ligustrina combined with dihydroartemisinin and piperaquine phosphate (DHP) against murine Plasmodium berghei infection. The BALB/c mice aged 6-8 weeks were divided into 6 groups, each consisting of 10 mice. The growth inhibition of compounds against P. berghei was monitored by calculating the percentage of parasitemia. The results showed that the mice receiving aqueous extract and combination treatment showed growth inhibition of P. berghei in 74% and 94%, respectively. S. ligustrina extract, which consisted of brucine and strychnine, effectively inhibited the multiplication of P. berghei. The treated mice showed improved hematology profiles, body weight, and temperature, as compared to control mice. Co-treatment with S. ligustrina extract and DHP revealed significant antimalarial and antipyretic effects. Our results provide prospects for further discovery of antimalarial drugs that may show more successful chemotherapeutic treatment.

• Parasites, Hosts and Diseases
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• v.53 no.1
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• pp.35-41
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• 2015

Pyronaridine and artesunate have been shown to be effective in falciparum malaria treatment. However, pyronaridine is rarely used in Hainan Island clinically, and artesunate is not widely used as a therapeutic agent. Instead, conventional antimalarial drugs, chloroquine and piperaquine, are used, explaining the emergence of chloroquine-resistant Plasmodium falciparum. In this article, we investigated the sensitivity of P. falciparum to antimalarial drugs used in Hainan Island for rational drug therapy. We performed in vivo (28 days) and in vitro tests to determine the sensitivity of P. falciparum to antimalarial drugs. Total 46 patients with falciparum malaria were treated with dihydroartemisinin/piperaquine phosphate (DUO-COTECXIN) and followed up for 28 day. The cure rate was 97.8%. The mean fever clearance time ($22.5{\pm}10.6hr$) and the mean parasite clearance time ($27.3{\pm}12.2hr$) showed no statistical significance with different genders, ages, temperatures, or parasite density (P>0.05). The resistance rates of chloroquine, piperaquine, pyronarididine, and artesunate detected in vitro were 71.9%, 40.6%, 12.5%, and 0%, respectively (P<0.0001). The resistance intensities decreased as follows: chloroquine>piperaquine>pyronarididine>artesunate. The inhibitory dose 50 ($IC_{50}$) was $3.77{\times}10^{-6}mol/L$, $2.09{\times}10^{-6}mol/L$, $0.09{\times}10^{-6}mol/L$, and $0.05{\times}10^{-6}mol/L$, and the mean concentrations for complete inhibition (CIMC) of schizont formation were $5.60{\times}10^{-6}mol/L$, $9.26{\times}10^{-6}mol/L$, $0.55{\times}10^{-6}mol/L$, and $0.07{\times}10^{-6}mol/L$, respectively. Dihydroartemisinin showed a strong therapeutic effect against falciparum malaria with a low toxicity.