(Natural News) Lung moss (Lobaria pulmonaria) contains plant-based compounds with antibiotic and anti-fungal properties. A study from the Shandong University (SDU) tested their efficacy on drug-resistant Candida albicans to identify the most active molecules. The researchers received funding from the National Natural Science Foundation and the SDU’s Young Scholars Program. They published their findings in the Chinese Journal of Natural Medicines.

• Drug-resistant organisms and antibiotic-susceptible counterparts often share the same infectious niche. Similarly, a subset of the susceptible population may mutate into drug-resistant versions in response to antibiotic treatment. Eventually, the mutants take over.
• Researchers simulated in vivo conditions with a co-culture assay that contained both a drug-resistant C. albicans strain and a susceptible strain. They applied molecules from lung moss to test their anti-fungal potential and compared the results with the anti-fungal pharmaceutical drug fluconazole.
• Five natural molecules in lung moss displayed anti-fungal activity against both susceptible and drug-resistant C. albicans strains. Of these compounds, retigeric acid B and riccardin D preferred to target the drug-resistant fungi.
• The selectivity of retigeric acid B and riccardin D seemed related to the higher intracellular quantity of drugs in the resistant strains. The resistant fungi possessed activated efflux pump MDR1 that protected them against anti-fungal drugs.
• Analyses of the drug-resistant strains found changes in their lipid and sterol compositions. The changes might make their cells more vulnerable to the plant-based anti-fungal compounds.
• Further, retigeric acid B and riccardin D affected the sterol pathway. They hastened the reduction of ergosterol in the sterol synthesis pathway in the MDR1-activated fungal strains.