Adansonia Digitata Leaf Extract Nanoemulsions for Chlorophyll-Based Photodynamic Therapy: A Novel Green Approach for Combating Cancer and Microbial Infection

Abstract Purpose Photodynamic therapy (PDT) is an approach for cancer treatment and microbial infections that depends on the light excitation of a photosensitizer with a high yield of reactive oxygen species. Consistent with sustainable development goals, Adansonia digitata leaf extract (ADLE) loaded in nanoemulsions from natural components (ADLE-NE) was investigated as a promising natural photosensitizer. Methods The generation of singlet oxygen by ADLE was monitored via a 1,3-diphenylisobenzofuran assay. The in vitro cytotoxicity of ADLE and ADLE-NE was evaluated in normal HEK293 cells and cancerous A549 cells. The antimicrobial PDT of ADLE-NE was tested on methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa . Confocal Laser Scanning microscope (CLSM) and double fluorescent staining were performed to visualize bacterial uptake and the effect of aPDT. Results The absorption of 1,3-diphenylisobenzofuran decreased by 97.8% after 40 s of irradiation. The prepared ADLE-NE had a particle size of 289.37 ± 16.46 nm, a PDI of 0.37 ± 0.02 and a zeta potential of − 35.28 ± 2.51 mV. ADLE-NE exhibited significant phototoxicity to cancer cells, with significant early apoptosis. The PDT of 10 µg/ml ADLE or ADLE-NE on cancer cells showed 68.31 ± 14.53% and 48.71 ± 7.53% viability, respectively. The antimicrobial PDT of 10 µg/ml ADLE-NE on MRSA and Pseudomonas aeruginosa showed viabilities of 1.41 ± 0.84% and 32.61 ± 7.53%, respectively. CLSM revealed significant uptake from ADLE-NE with visible live/dead cells following aPDT. Conclusion These results suggest that ADLE is a promising photosensitizer for the photodynamic therapy of cancer and microbial infections, especially after loading in nanoemulsions.