Hemolytic, antitumor, and antifungal activity of Eugenia gracillima Kiaersk. essential oil against Candida glabrata: In vitro and in vivo evaluation.

Eugenia gracillima Kiaersk. is traditionally used in the treatment of urinary tract infections, respiratory disorders, and skin conditions, and its essential oil (EgEO) from leaves has shown antioxidant, anti-protozoal, analgesic, and anti-inflammatory effects, although its pharmacological potential remains insufficiently studied. This work aimed to evaluate the hemolytic, cytotoxic, toxicological, and antifungal properties of EgEO. The oil was extracted by hydrodistillation and chemically characterized by GC/MS, revealing 39 sesquiterpenes representing 97.02 % of the total composition. Hemolytic activity was assessed via spectrophotometric quantification of hemoglobin released from human erythrocytes, while cytotoxicity was evaluated using the MTT assay in HL-60, MCF-7, and HT-29 cell lines, showing significant cytotoxicity, particularly against HL-60 (IC₅₀ = 10.8 μg/mL). Contact toxicity was tested on Tenebrio molitor larvae, pupae, and adults, with pupae being the most susceptible (LD₅₀ = 4.55 mg/mL), followed by adults and larvae. Sublethal doses (2.3 and 4.6 mg/mL) injected into larvae caused no morphological abnormalities. Antifungal activity against standard and multidrug-resistant strains of Candida glabrata was evaluated through broth microdilution, with MICs ranging from 0.11 to 3.69 mg/mL and MFCs from 0.92 to 3.69 mg/mL. Time-kill assays indicated that EgEO at MIC had fungistatic activity, while at 2 × MIC it was fungicidal. In vivo efficacy, assessed using T. molitor as an infection model, demonstrated that EgEO at a sublethal dose (2.302 mg/mL) was effective against the standard C. glabrata strain. Overall, EgEO showed low hemolytic activity, significant antitumor effects, and notable antifungal efficacy, with low toxicity in vivo, particularly at sublethal concentrations. These results support the therapeutic potential of E. gracillima essential oil as a natural agent with antifungal and anticancer properties.