Activity detection of noni leaf (Morinda citrifolia L.) chlorophyll extract through the photoinactivation to reducing Streptococcus mutans cells using XTT assay method

Noni plant (Morinda citrifolia) has proven to contain antimicrobial substances, and inside their leaves have chlorophyll pigment. Today, Chlorophyll compound is a new candidate as a photosensitizer agent that is applied in the field of photodynamic inactivation (PDI) based on its natural properties, chemical purity, and quantum yield which has a long lifetime at the triplet excitation level. In this study, the PDT mechanism used a red laser (634 nm) and a blue laser (415 nm) in vitro which was applied to the planktonic Streptococcus mutans microbe culture with cell reduction analysis by comparing the XTT assay and CFU/mL test methods. The variations in the duration of the irradiation selected were 60, 120, 180, 240, and 300 seconds. The results showed that the aPDT-red laser-noni treatment was optimum with an exposure duration of 300 seconds (51%), while the aPDT-blue laser-noni treatment with an exposure duration of 300 seconds (62%). This indicates that the effectiveness of PACT against Streptococcus mutans with noni leaf extract as a photosensitizer is more effective when irradiated by a 415 nm laser than by a 634 nm laser