BACKGROUND:Chlorophyll-a is a novel photosensitizer recently tested for the treatment of acne vulgaris.

OBJECTIVE:We sought to evaluate the clinical efficacy and safety of chlorophyll-a photodynamic therapy used for acne treatment.

METHODS:Subjects with acne on both sides of the face were included. Eight treatment sessions were performed over a 4-week duration. Half of the face was irradiated using a blue and red light-emitting diode after topical application of chlorophyll-lipoid complex. The other half underwent only light-emitting diode phototherapy. The lesion counts and acne severity were assessed by a blinded examiner. Sebum secretion, safety, and histologic changes were also evaluated.

RESULTS:In total, 24 subjects completed the study. Facial acne improved on both treated sides. On the chlorophyll-a photodynamic therapy-treated side, there were significant reductions in acne lesion counts, acne severity grades, and sebum levels compared with the side treated with light-emitting diode phototherapy alone. The side effects were tolerable in all the cases.

LIMITATIONS:All the subjects were of Asian descent with darker skin types, which may limit the generalizability of the study. A chlorophyll-a arm alone is absent, as is a no-treatment arm.

CONCLUSIONS:We suggest that chlorophyll-a photodynamic therapy for the treatment of acne vulgaris can be effective and safe with minimal side effects.

BACKGROUND AND OBJECTIVES:Our group recently synthesized a new, low-cost photosensitizer, chlorophyllin f. In this study, the effects of chlorophyllin f-mediated photodynamic therapy (PDT) and its potential mechanisms were examined in human bladder cancer cells.

MATERIALS AND METHODS:MitoTracker® Green probe and LysoTracker® Green probe were used to label mitochondria and lysosomes, revealing the intracellular localization of chlorophyllin f in 5637 and T24 cells by confocal laser scanning microscopy (CLSM). The cells were treated with chlorophyllin f-mediated PDT; the photo-cytotoxicityof chlorophyllin f was monitored using the Cell Counting Kit-8 assay, and apoptosis was measured by Annexin V-FITC/PI dual staining. Western blotting, transmission electron microscopy (TEM), and staining with Cyto-ID® Autophagy Detection dye, monodansylcadaverine (MDC) and acridine orange were performed to assess autophagy. The role of autophagy was examined by measuring cell viability and apoptosis in both cell lines pretreated with the autophagy inhibitor 3-methyladenine (3-MA).

RESULTS:Chlorophyllin f showed affinity for mitochondria and lysosomes. It exhibited significant photocytotoxicity, resulting in a maximum of 86.51% and 84.88% cell death in 5637 and T24 cells, respectively. Additionally, chlorophyllin f-mediated PDT (f-PDT) also induced a significantly higher percentage of apoptosis in treated cells compared to the control groups (P < 0.05). Moreover, the expression of Beclin1 protein and the proportion of LC3-II:LC3-I in both cell lines significantly increased after f-PDT. Autophagy, characterized by an increase in the formation of Cyto-ID® Autophagy Detection dye-labeled autophagosomes, MDC fluorescent dye-labeled autophagic vacuoles and acridine orange-labeled acidic vesicular organelles (AVOs), was observed in f-PDT-treated cells. TEM also revealed double-membrane autophagosome structures 1 hour after f-PDT. Most importantly, when pretreated with 3-MA, the two cell lines showed more significant photo-cytotoxicityand apoptotic cell death compared to those exposed to f-PDT alone (P < 0.05).

CONCLUSION:Chlorophyllin f-mediated PDT exerts anti-tumor activity by inducing apoptosis and autophagy, and most importantly, autophagy inhibition enhances f-PDT-mediated apoptotic cell death. These results suggest that chlorophyllin f is a new, effective photosensitizer and that the combination of f-PDT with autophagy inhibitors may be an attractive therapeutic strategy against human non-muscle invasive bladder cancer.

BACKGROUND:Various studies have shown that phototherapy promotes the healing of cutaneous wounds.

OBJECTIVE:To investigate the effect of phototherapy on healing of cutaneous wounds in nourished and undernourished rats.

METHODS:Forty rats, 20 nourished plus 20 others rendered marasmus with undernourishment, were assigned to four equal groups: nourished sham, nourished Light Emitting Diode treated, undernourished sham and undernourished Light Emitting Diode treated. In the two treated groups, two 8-mm punch wounds made on the dorsum of each rat were irradiated three times per week with 3 J/cm2 sq cm of combined 660 and 890 nm light; wounds in the other groups were not irradiated. Wounds were evaluated with digital photography and image analysis, either on day 7 or day 14, with biopsies obtained on day 14 for histological studies.

RESULTS:Undernourishment retarded the mean healing rate of the undernourished sham wounds (p<0.01), but not the undernourished Light emission diode treated wounds, which healed significantly faster (p<0.001) and as fast as the two nourished groups. Histological analysis showed a smaller percentage of collagen in the undernourished sham group compared with the three other groups, thus confirming our photographic image analysis data.

CONCLUSION:Phototherapy reverses the adverse healing effects of undernourishment. Similar beneficial effects may be achieved in patients with poor nutritional status.

BACKGROUND:Various studies have shown that phototherapy promotes the healing of cutaneous wounds.

OBJECTIVE:To investigate the effect of phototherapy on healing of cutaneous wounds in nourished and undernourished rats.

METHODS:Forty rats, 20 nourished plus 20 others rendered marasmus with undernourishment, were assigned to four equal groups: nourished sham, nourished Light Emitting Diode treated, undernourished sham and undernourished Light Emitting Diode treated. In the two treated groups, two 8-mm punch wounds made on the dorsum of each rat were irradiated three times per week with 3 J/cm2 sq cm of combined 660 and 890 nm light; wounds in the other groups were not irradiated. Wounds were evaluated with digital photography and image analysis, either on day 7 or day 14, with biopsies obtained on day 14 for histological studies.

RESULTS:Undernourishment retarded the mean healing rate of the undernourished sham wounds (p<0.01), but not the undernourished Light emission diode treated wounds, which healed significantly faster (p<0.001) and as fast as the two nourished groups. Histological analysis showed a smaller percentage of collagen in the undernourished sham group compared with the three other groups, thus confirming our photographic image analysis data.

CONCLUSION:Phototherapy reverses the adverse healing effects of undernourishment. Similar beneficial effects may be achieved in patients with poor nutritional status.

OBJECTIVE:Phototherapy using blue light-emitting diodes (LED) is effective against neonatal jaundice. However, green light phototherapy also reduces unconjugated jaundice. We aimed to determine whether mixed blue and green light can relieve jaundice with minimal oxidative stress as effectively as either blue or green light alone in a rat model.

METHODS:Gunn rats were exposed to phototherapy with blue (420-520 nm), filtered blue (FB; 440-520 nm without<440-nm wavelengths, FB50 (half the irradiance of filtered blue), mixed (filtered 50% blue and 50% green), and green (490-590 nm) LED irradiation for 24h. The effects of phototherapy are expressed as ratios of serum total (TB) and unbound (UB) bilirubin before and after exposure to each LED. Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) was measured by HPLC before and after exposure to each LED to determine photo-oxidative stress.

RESULTS:Values<1.00 indicate effective phototherapy. The ratios of TB and UB were decreased to 0.85, 0.89, 1.07, 0.90, and 1.04, and 0.85, 0.94, 0.93, 0.89, and 1.09 after exposure to blue, filtered blue, FB50, and filtered blue mixed with green LED, respectively. In contrast, urinary 8-OHdG increased to 2.03, 1.25, 0.96, 1.36, 1.31, and 1.23 after exposure to blue, filtered blue, FB50, mixed, green LED, and control, indicating side-effects (>1.00), respectively.

CONCLUSIONS:Blue plus green phototherapy is as effective as blue phototherapy and it attenuates irradiation-induced oxidative stress.

PRACTICE IMPLICATIONS:Combined blue and green spectra might be effective against neonatal hyperbilirubinemia.

OBJECTIVE:Phototherapy using blue light-emitting diodes (LED) is effective against neonatal jaundice. However, green light phototherapy also reduces unconjugated jaundice. We aimed to determine whether mixed blue and green light can relieve jaundice with minimal oxidative stress as effectively as either blue or green light alone in a rat model.

METHODS:Gunn rats were exposed to phototherapy with blue (420-520 nm), filtered blue (FB; 440-520 nm without<440-nm wavelengths, FB50 (half the irradiance of filtered blue), mixed (filtered 50% blue and 50% green), and green (490-590 nm) LED irradiation for 24h. The effects of phototherapy are expressed as ratios of serum total (TB) and unbound (UB) bilirubin before and after exposure to each LED. Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) was measured by HPLC before and after exposure to each LED to determine photo-oxidative stress.

RESULTS:Values<1.00 indicate effective phototherapy. The ratios of TB and UB were decreased to 0.85, 0.89, 1.07, 0.90, and 1.04, and 0.85, 0.94, 0.93, 0.89, and 1.09 after exposure to blue, filtered blue, FB50, and filtered blue mixed with green LED, respectively. In contrast, urinary 8-OHdG increased to 2.03, 1.25, 0.96, 1.36, 1.31, and 1.23 after exposure to blue, filtered blue, FB50, mixed, green LED, and control, indicating side-effects (>1.00), respectively.

CONCLUSIONS:Blue plus green phototherapy is as effective as blue phototherapy and it attenuates irradiation-induced oxidative stress.

PRACTICE IMPLICATIONS:Combined blue and green spectra might be effective against neonatal hyperbilirubinemia.

Pseudomonas aeruginosa (P. aeruginosa) is a major cause of infectious keratitis, which itself is a major cause of blindness worldwide. We have now evaluated the time-dependent effectiveness of photodynamic antimicrobial chemotherapy (PACT) with the chlorin derivative TONS 504 and a light-emitting diode (LED) on P. aeruginosa in vitro. PACT with TONS 504 (10 mg/L) and irradiation (30 J/m) by an LED device that delivers light centered on a wavelength of 660 nm was applied to 1 × 10colony-forming units of P. aeruginosa in liquid medium. The bacteria were then cultured at 37 °C for various times before assay of viability by determination of colony formation on agar plates. The effect of a second irradiation at 3 h after the initial LED exposure was also examined. Bacterial growth was markedly inhibited between 3 and 9 h after PACT with TONS 504, with the maximal effect being apparent at 3 h. Furthermore, a second exposure to LED irradiation at 3 h after the first treatment enhanced the inhibitory effect on bacterial growth. PACT with TONS 504 thus inhibited the growth of P. aeruginosa in a time-dependent manner, and an additional irradiation exposure applied 3 h after the first LED treatment greatly increased the effectiveness of PACT. This antibacterial system thus warrants further evaluation with regard to its potential effectiveness for the treatment of infectious keratitis.

Norovirus (NoV) is one of the most important seafood- and water-borne viruses, and is a major cause of acute gastroenteritis outbreaks. In the present study we investigated the effect of curcumin as a sensitizer to photodynamic treatment both in buffer and in oysters against murine norovirus 1 (MNV-1), a surrogate of NoV. MNV-1 cultured in buffer and MNV-1 bio-accumulated in oysters were irradiated with a novel LED light source with a wavelength of 470nm and an energy of 3.6J/cm(2). Inactivation of MNV-1 was investigated by plaque assays. After virus was extracted from the gut of oysters treated over a range of curcumin concentrations, the ultrastructural morphology of the virus was observed using electron microscopy, and the integrity of viral nucleic acids and stability of viral capsid proteins were also determined. Results showed that the infectivity of MNV-1 was significantly inhibited by 1-3 log PFU/ml, with significant damage to viral nucleic acids in a curcumin dose-dependent manner after photodynamic activation. Virus morphology was altered after the photodynamic treatment with curcumin, presumably due to the change of the viral capsid protein structures. The data suggests that treatment of oysters with photodynamic activation of curcumin is a potentially efficacious and cost-effective method to inactivate food-borne NoV. Further studies are necessary to evaluate the toxicology of this approach in detail and perform sensory evaluation of the treated product.