Assessing the photodynamic therapeutic effects of 5‑aminolevulinic acid on human colon cancer cells using light‑emitting diodes

Abstract

The minimal invasiveness and high selectivity of 5-aminolevulinic acid (5-ALA)-based photodynamic therapy (PDT; 5-ALA-PDT) renders it a viable therapeutic option for the treatment of various types of cancer. Compared with conventional lasers, light-emitting diodes (LEDs) are an inexpensive and convenient low-energy light source option. Nevertheless, the scope of LEDs in the 5-ALA-PDT of colorectal cancer (CRC) has yet to be fully determined. Thus, the aim of the present study was to assess the efficacy of LEDs in the 5-ALA-PDT of colon cancer in vitro by evaluating cytotoxic activity. 5-ALA-treated human CRC cells (SW480) were irradiated with LEDs of varying wavelengths: Red (630 nm), green (515 nm), blue (456 nm) and violet (399 nm). An MTS assay was conducted to determine cell viability. Additionally, a concentration-response experiment was conducted with the most therapeutic wavelength (violet) to examine the 5-ALA pharmacodynamics in vitro. The results revealed that only violet light in 5-ALA-PDT produced antitumour activity; this combination alone produced a drug concentration-and energy-related decrease in cell viability. The decrease in viability was partially reversed by 3-methyladenine, but not by Z-VAD(OMe)-FMK, suggesting that 5-ALA induced the autophagy, but not the apoptosis of SW480 cells. The nature of the multi-well plates used markedly affected the effectiveness of PDT. Black-walled plates appeared to protect approximately 25% of cells from the effects of PDT. By contrast, clear plates permitted light access to the wells, even when protected from direct PDT treatment. On the whole, the findings of the present study indicate that the use of LEDs in 5-ALA-PDT in vitro induce the fluence-dependent tumour cell death of SW480 cells. The choice of multi-well plates greatly affects the results obtained in vitro. The antitumour effect was high with violet light. Hence, the use of LEDs in 5-ALA-PDT may prove to be an effective potential treatment for CRC.

Photodynamic Therapy Directed to Melanoma Skin Cancer by Thermosensitive Hydrogel Containing Chlorophyll A

“…Et when comparing the two types of treatments, PDT and dark. This low reduction in cell viability is not related to exposure to LED, considering that cell viability is higher when cells were exposed to PDT (Figure 5A), which was also observed in studies by Shah et al [31], in which they evaluated the photodynamic activity of four types of LEDs when cancer cells were exposed to them. Furthermore, it was observed that LEDs at wavelengths of 630 nm (red), 515 nm (green), and 410-456 nm (blue) did not influence the reduction in cell viability.…”

5-Aminolevulinic Acid-Mediated Photodynamic Therapy Potentiates the Effectiveness of Doxorubicin in Ewing Sarcomas

“…Thus, there is an unmet need for new therapeutic approaches to augment and improve the current standard of care for ES. Although 5-ALA-mediated PDT has been shown to be a viable therapeutic option for the treatment of various types of cancer [ 18 , 30 , 36 ], its use with soft tissue sarcomas such as ES is not well documented. The goal of this study was to investigate the therapeutic effects of 5-ALA PDT and DOX on ES cell lines, both individually and in combination.…”

Fluorescence lifetime imaging unravels the pathway of glioma cell death upon hypericin-induced photodynamic therapy

“…As 5-ALA and thus PPIX are specifically enriched in brain tumors, their application in PDT was expected to be a promising approach. Several studies were performed to investigate the potential of 5-ALA-PDT for PDT applications (17)(18)(19). Eskiler et al demonstrated the effectiveness of 5-ALA-PDT in the treatment of breast cancer (20), whereas its photodamaging capabilities on rhabdomyosarcoma were shown by Atif et al (21).…”