Safety and Effectiveness of Intravenous Artesunate for Treatment of Severe Malaria in the United States-April 2019 Through December 2020

Artesunate: A Review of Its Potential Therapeutic Effects and Mechanisms in Digestive Diseases

Artesunate (ART), an artemisinin-derived semi-synthetic sesquiterpene lactone distinguished by its unique endoperoxide group, has become a cornerstone of clinical antimalarial therapy. Recent research has demonstrated its broad pharmacological profile, including its potent antimalarial, anti-inflammatory, anti-tumor, antidiabetic, immunomodulatory, and anti-fibrotic properties. These discoveries have significantly broadened the therapeutic scope of ART and offer new perspectives for its potential use in treating gastrointestinal disorders. Mechanistically, ART exerts significant therapeutic effects against diverse gastrointestinal pathologies-such as gastric ulcers, ulcerative colitis (UC), hepatic fibrosis (HF), gastric cancer, hepatocellular carcinoma, and colorectal cancer-via multimodal mechanisms, including cell cycle modulation, apoptosis induction, the suppression of tumor cell invasion and migration, proliferation inhibition, ferroptosis activation, and immune regulation. This review evaluates existing evidence on ART's therapeutic applications and molecular mechanisms in digestive diseases, intending to elucidate its clinical translation potential. ART emerges as a promising multi-target agent with significant prospects for improving the management of gastrointestinal disorders.

Artesunate promotes cervical cancer cell apoptosis by regulating Bcl2 family molecules and reducing the mitochondrial membrane potential

Artesunate (ART), an antimalarial drug, has a broad spectrum of antitumour effects in cancer types such as esophageal and gastric cancer. However, evidence demonstrating the role of ART in cervical cancer cells is limited. In the present study, the inhibitory effect of ART on the growth of cervical cancer cells through the modulation of the cell cycle and apoptosis was investigated. The growth-inhibitory effect of ART on a cervical cancer cell line (SiHa) was detected using a Cell Counting Kit-8 assay after treatment with ART for 24 h, after which the half-maximal inhibitory concentration (IC50) was calculated. Using flow cytometry assays, apoptosis, the cell cycle, the levels of reactive oxygen species (ROS) and calcium (Ca2+) ions, as well as the mitochondrial membrane potential were evaluated in SiHa cells following treatment with ART for 24 and 48 h. The mRNA expression levels of Bcl2, Bcl-xl, (myeloid cell leukaemia 1) Mcl-1, Bcl2-like protein 11 (BIM), (Bcl2-related ovarian killer protein) Bok, Bax and (Bcl2 homologous antagonist/killer) Bak in SiHa cells were detected using reverse transcription-quantitative PCR. ART inhibited the growth of SiHa cells in a dose-dependent manner. The IC50 of ART in SiHa cells was 26.32 µg/ml. According to the IC50 value, 15, 30 and 100 µg/ml ART were selected for further experiments, and normal saline (0 µg/ml ART) was used as the control group. The results indicated that treatment with 15, 30 and 100 µg/ml ART for 24 and 48 h induced apoptosis, increased the levels of ROS, the levels of Ca2+ and the mRNA expression levels of BIM, Bok, Bax and Bak, but decreased the cell proliferation indices, the mitochondrial membrane potential and the mRNA expression levels of Bcl2, Bcl-xl and Mcl-1 in a dose- and time-dependent manner. In conclusion, ART inhibited the growth of SiHa cells and induced apoptosis via a mechanism associated with the regulation of Bcl2 family member expression, which was associated with the increase of the levels of ROS and Ca2+ and the reduction of the mitochondrial membrane potential.

Artesunate treats obesity in male mice and non-human primates through GDF15/GFRAL signalling axis

Obesity, a global health challenge, is a major risk factor for multiple life-threatening diseases, including diabetes, fatty liver, and cancer. There is an ongoing need to identify safe and tolerable therapeutics for obesity management. Herein, we show that treatment with artesunate, an artemisinin derivative approved by the FDA for the treatment of severe malaria, effectively reduces body weight and improves metabolic profiles in preclinical models of obesity, including male mice with overnutrition-induced obesity and male cynomolgus macaques with spontaneous obesity, without inducing nausea and malaise. Artesunate promotes weight loss and reduces food intake in obese mice and cynomolgus macaques by increasing circulating levels of Growth Differentiation Factor 15 (GDF15), an appetite-regulating hormone with a brainstem-restricted receptor, the GDNF family receptor α-like (GFRAL). Mechanistically, artesunate induces the expression of GDF15 in multiple organs, especially the liver, in mice through a C/EBP homologous protein (CHOP)-directed integrated stress response. Inhibition of GDF15/GFRAL signalling by genetic ablation of GFRAL or tissue-specific knockdown of GDF15 abrogates the anti-obesity effect of artesunate in mice with diet-induced obesity, suggesting that artesunate controls bodyweight and appetite in a GDF15/GFRAL signalling-dependent manner. These data highlight the therapeutic benefits of artesunate in the treatment of obesity and related comorbidities.

Drug-Induced Acute Pancreatitis in Adults: Focus on Antimicrobial and Antiviral Drugs, a Narrative Review

Acute pancreatitis (AP) is an acute inflammation of the pancreas caused by the activation of digestive enzymes in the pancreatic tissue. The main causes of AP are cholelithiasis and alcohol abuse; less commonly, it can be caused by drugs, with a prevalence of up to 5%. Causal associations between drugs and pancreatitis are largely based on case reports or case series with limited evidence. We reviewed the available data on drug-induced AP, focusing on antimicrobial drugs and antivirals, and discussed the current evidence in relation to the classification systems available in the literature. We found 51 suspected associations between antimicrobial and antiviral drugs and AP. The drugs with the most evidence of correlation are didanosine, protease inhibitors, and metronidazole. In addition, other drugs have been described in case reports demonstrating positive rechallenge. However, there are major differences between the various classifications available, where the same drug being assigned to different probability classes. It is likely that the presence in multiple case reports of an association between acute pancreatitis and a drug should serve as a basis for conducting prospective randomized controlled trials to improve the quality of the evidence.

Post-artesunate Delayed Hemolysis in Patients With Severe Malaria in the United States-April 2019 Through July 2021

BACKGROUND

Studies have demonstrated the safety and efficacy of intravenous artesunate (IVAS) for treatment of severe malaria in endemic and nonendemic countries. However, post-artesunate delayed hemolysis (PADH) is an increasingly recognized phenomenon after its administration. This study describes the prevalence and outcomes of PADH events among severe malaria cases treated with IVAS in the United States.

METHODS

Patients diagnosed with severe malaria and treated with IVAS from April 2019 to July 2021 were included. Demographic, clinical, laboratory, therapeutic, and outcome measures were described using proportions, medians, and interquartile range. Patients reported to experience PADH were compared with those not reported to have PADH, and tests of significance were performed.

RESULTS

Of 332 patients included in our analysis, 9 (2.7%) experienced PADH. The majority of infections in both groups were in non-Hispanic Black individuals. Parasite density (11.0% vs 8.0%), admission hemoglobin (11.0 g/dL vs 11.8 g/dL) were similar in the 2 groups. Total bilirubin levels at admission (4.7 mg/dL vs 2.2 mg/dL) and within 8 hours after completion of IVAS (2.6 mg/dL vs 1.2 mg/dL) were notably higher in PADH patients. Cumulative IVAS dose of >9.5 mg/kg and >3 doses of IVAS were risk factors for PADH. The majority (7 of 9) of PADH cases were diagnosed within 2 weeks after initiation of IVAS. Five patients (56%) required blood transfusions, and all recovered without sequelae.

CONCLUSIONS

PADH is an uncommon and self-limiting adverse event in many cases; weekly monitoring of hemoglobin and hemolytic markers may identify cases requiring intervention in a timely manner.

Diagnosis, Treatment, and Prevention of Malaria in the US: A Review

IMPORTANCE

Malaria is caused by protozoa parasites of the genus Plasmodium and is diagnosed in approximately 2000 people in the US each year who have returned from visiting regions with endemic malaria. The mortality rate from malaria is approximately 0.3% in the US and 0.26% worldwide.

OBSERVATIONS

In the US, most malaria is diagnosed in people who traveled to an endemic region. More than 80% of people diagnosed with malaria in the US acquired the infection in Africa. Of the approximately 2000 people diagnosed with malaria in the US in 2017, an estimated 82.4% were adults and about 78.6% were Black or African American. Among US residents diagnosed with malaria, 71.7% had not taken malaria chemoprophylaxis during travel. In 2017 in the US, P falciparum was the species diagnosed in approximately 79% of patients, whereas P vivax was diagnosed in an estimated 11.2% of patients. In 2017 in the US, severe malaria, defined as vital organ involvement including shock, pulmonary edema, significant bleeding, seizures, impaired consciousness, and laboratory abnormalities such as kidney impairment, acidosis, anemia, or high parasitemia, occurred in approximately 14% of patients, and an estimated 0.3% of those receiving a diagnosis of malaria in the US died. P falciparum has developed resistance to chloroquine in most regions of the world, including Africa. First-line therapy for P falciparum malaria in the US is combination therapy that includes artemisinin. If P falciparum was acquired in a known chloroquine-sensitive region such as Haiti, chloroquine remains an alternative option. When artemisinin-based combination therapies are not available, atovaquone-proguanil or quinine plus clindamycin is used for chloroquine-resistant malaria. P vivax, P ovale, P malariae, and P knowlesi are typically chloroquine sensitive, and treatment with either artemisinin-based combination therapy or chloroquine for regions with chloroquine-susceptible infections for uncomplicated malaria is recommended. For severe malaria, intravenous artesunate is first-line therapy. Treatment of mild malaria due to a chloroquine-resistant parasite consists of a combination therapy that includes artemisinin or chloroquine for chloroquine-sensitive malaria. P vivax and P ovale require additional therapy with an 8-aminoquinoline to eradicate the liver stage. Several options exist for chemoprophylaxis and selection should be based on patient characteristics and preferences.

CONCLUSIONS AND RELEVANCE

Approximately 2000 cases of malaria are diagnosed each year in the US, most commonly in travelers returning from visiting endemic areas. Prevention and treatment of malaria depend on the species and the drug sensitivity of parasites from the region of acquisition. Intravenous artesunate is first-line therapy for severe malaria.

Artesunate monotherapy versus artesunate plus quinine combination therapy for treatment of imported severe malaria: a TropNet retrospective cohort study

Background

The addition of intravenous quinine (IVQ) to intravenous artesunate (IVA) has been recently suggested by World Health Organization  in areas where artemisinin resistance is highly prevalent. Since IVA is not yet widely available as “Good Manufacturing Practices” product, for several years combination treatment with IVA and IVQ was used in some Italian centers to mitigate the legal risks in using an unlicensed drug.

Methods

A retrospective cohort study was designed to compare IVA + IVQ and IVA treatment for imported severe malaria. We collected data from three Italian centers. Adult and pediatric cohorts were analyzed separately.

Results

Forty-nine patients treated with IVA and 44 with IVA + IVQ were enrolled, 45 were adults and 48 children. All acquired malaria in Sub-Saharan Africa. In the adult cohort, median of fever clearance time (FCT) was similar in both groups (48 h vs 48 h, p = 0.19) but number of patients who reached apyrexia within 48 h (FCT48) was higher in IVA group (20/24, 83.3% vs 8/17, 47%, p = 0.002). The parasite clearance time (PCT) measure did not differ (median 48 h vs 48 h, p = 0.669). In the pediatric cohort, FCT did not differ in the two groups (median 30 vs 48 h, p = 0.50) while PCT was longer in IVA + IVQ group (median 72 vs 48 h, p = 0.002). Adverse events (AEs) in adults were more common in the combination treatment group (6/19, 31.58% vs 2/26, 7.69%, p = 0.055).

Conclusion

IVA + IVQ treatment did not show better outcome with respect to IVA monotherapy. AEs were more frequent in the IVA + IVQ group compared to the monotherapy. Further studies are necessary to investigate whether IVA + IVQ could be an efficient strategy to treat severe malaria cases in areas at high risk of artemisinin resistance.

Supplementary Information

The online version contains supplementary material available at 10.1007/s15010-022-01771-5.