Triple artemisinin-based combination therapies for malaria: proceed with caution - Authors' reply

The problem of antimalarial resistance and its implications for drug discovery

INTRODUCTION

Malaria remains a devastating infectious disease with hundreds of thousands of casualties each year. Antimalarial drug resistance has been a threat to malaria control and elimination for many decades and is still of concern today. Despite the continued effectiveness of current first-line treatments, namely artemisinin-based combination therapies, the emergence of drug-resistant parasites in Southeast Asia and even more alarmingly the occurrence of resistance mutations in Africa is of great concern and requires immediate attention.

AREAS COVERED

A comprehensive overview of the mechanisms underlying the acquisition of drug resistance in Plasmodium falciparum is given. Understanding these processes provides valuable insights that can be harnessed for the development and selection of novel antimalarials with reduced resistance potential. Additionally, strategies to mitigate resistance to antimalarial compounds on the short term by using approved drugs are discussed.

EXPERT OPINION

While employing strategies that utilize already approved drugs may offer a prompt and cost-effective approach to counter antimalarial drug resistance, it is crucial to recognize that only continuous efforts into the development of novel antimalarial drugs can ensure the successful treatment of malaria in the future. Incorporating resistance propensity assessment during this developmental process will increase the likelihood of effective and enduring malaria treatments.

Establishment and evaluation of glucose-modified nanocomposite liposomes for the treatment of cerebral malaria

Cerebral malaria (CM) is a life-threatening neurological complication caused by Plasmodium falciparum. About 627,000 patients died of malaria in 2020. Currently, artemisinin and its derivatives are the front-line drugs used for the treatment of cerebral malaria. However, they cannot target the brain, which decreases their effectiveness. Therefore, increasing their ability to target the brain by the nano-delivery system with brain-targeted materials is of great significance for enhancing the effects of antimalarials and reducing CM mortality. This study used glucose transporter 1 (GLUT1) on the blood-brain barrier as a target for a synthesized cholesterol-undecanoic acid-glucose conjugate. The molecular dynamics simulation found that the structural fragment of glucose in the conjugate faced the outside the phospholipid bilayers, which was conducive to the recognition of brain-targeted liposomes by GLUT1. The fluorescence intensity of the brain-targeted liposomes (na-ATS/TMP@lipoBX) in the mouse brain was significantly higher than that of the non-targeted liposomes (na-ATS/TMP@lipo) in vivo (P < 0.001) after intranasal administration. The infection and recurrence rate of the mice receiving na-ATS/TMP@lipoBX treatment were significantly decreased, which had more advantages than those of other administration groups. The analysis of pharmacokinetic data showed that na-ATS/TMP@lipoBX could enter the brain in both systemic circulation and nasal-brain pathway to treat malaria. Taken together, these results in this study provide a new approach to the treatment of cerebral malaria.

Current and emerging strategies to combat antimalarial resistance

INTRODUCTION

Since the spread of chloroquine resistance in Plasmodium falciparum in the 1960s, recommendations have been made on how to respond to antimalarial resistance. Only with the advent of artemisinin partial resistance were large scale efforts made in the Greater Mekong Subregion to carry out recommendations in a coordinated and well-funded manner. Independent emergence of parasites partially resistant to artemisinins has now been reported in Rwanda.

AREAS COVERED

We reviewed past recommendations and activities to respond to resistance as well as the research ongoing into new ways to stop or delay the spread of resistant parasites.

EXPERT OPINION

Inadequate information limits the options and support for a strong, coordinated response to artemisinin partial resistance in Africa, making better phenotypic and genotypic surveillance a priority. A response to resistance needs to address factors that may have hastened the emergence and could speed the spread, including overuse of drugs and lack of access to quality treatment. New ways to use the existing treatments in the response to resistance such as multiple first-lines are currently impeded by the limited number of drugs available.