Anti-Malaria Drug Hydroquinine May Effectively Treat Drug-Resistant Bacteria

Antibiotic resistance is making it increasingly difficult for clinicians to treat infections, becoming a public health threat throughout the world. Researchers from the University of Portsmouth and Naresuan and Pibulsongkram Rajabhat Universities in Thailand suggest the compound hydroquinine, found in the bark of certain trees, can kill drug-resistant bacteria.¹

“One of the main mechanisms used by these bacteria to escape killing activity of the drug was upregulated with treatment—indicating a robust response from the bacteria,” Baldock said in the press release. "By studying this compound further, our hope is that it may in future offer another line of treatment in combatting bacterial infections."¹

More than 35,000 people die each year from drug-resistant bacterial infection. These superbugs—bacteria, viruses, fungi, and parasites that stop responding to medicine over time—can cause severe ailments such as sepsis, urinary tract infections, and pneumonia, among other diseases.¹

Robert Baldock of the School of Pharmacy and Biomedical Sciences at the University of Portsmouth, said in a press release that hydroquinine successfully killed the common multidrug-resistant (MDR) pathogen pseudomonas aeruginosa (P. aeruginosa), a glucose fermentative Gram-negative bacterium that can cause infections in patients with burn wounds, cystic fibrosis, skin infections, and pneumonia, according to the study authors.²

P. aeruginosa is also associated with high mortality.¹ Statistically, bloodstream infections can cause death between 30% and 50% of patients, potentially having a 70% mortality rate among P. aeruginosa-caused pneumonia in hospital patients.²

Using a broth microdilution method, investigators studied hydroquinine and its ability to stop anti-resistant bacterial growth. At minimum inhibitory concentrations (MIC) between 650 and 2500 micrograms, hydroquinine effectively killed the bacterium Escherichia coli (E. Coli) and Pseudomonas aeruginosa (P. aeruginosa) at minimum bactericidal concentrations of 1250 to 5000 micrograms.²

“The results of this study indicate that hydroquinine is likely to be a good candidate for development with better antibacterial activity than the quinine-derivative, quinine dihydrochloride (which has an MIC of 125 grams/mL),” the investigators said in the press release.²

Hydroquinine is currently used as an anti-malaria drug. It is an organic compound that is closely related to quinine and rich with antibacterial extracts.² The new research, published in the journal Tropical Medicine and Infectious Disease,opens doors for further investigation in future clinical trials, according to the authors.¹

"Our future research aims to uncover the molecular target of hydroquinine,” said Jirapas Jongjitwimol, of the Department of Medical Technology at Naresuan University, in a press release. “This would help our understanding of how the compound works against pathogenic bacteria and how it could potentially be used in a clinical setting."¹

References

1. University of Portsmouth. Scientists discover compound found in trees has potential to kill drug-resistant bacteria. Science Daily. August 31, 2022. Accessed on September 1, 2022. https://www.sciencedaily.com/releases/2022/08/220831210014.htm
2. Antimalarial Tree Bark Compound Kills Multidrug-Resistant Bacteria in the Lab. Genetic Engineering & Biotechnology News. September 1, 2022. Accessed on September 1, 2022. https://www.genengnews.com/topics/drug-discovery/antimalarial-tree-bark-compound-kills-multidrug-resistant-bacteria-in-the-lab/