Comparison of the efficacy of low-level laser therapy and photodynamic therapy on oral mucositis in rats

Treatment of aphthous ulcers with photodynamic therapy: A randomized controlled clinical study

BACKGROUND

This study aims to assess whether photodynamic therapy (PDT) offers a clinically effective alternative for treating oral aphthous ulcers, contributing to the ongoing quest for methods to expedite their treatment process amidst the limited understanding of their etiology.

MATERIALS AND METHOD

The study involved thirty volunteers with aphthous ulcers, split equally between a control group and a PDT group. Patients in the PDT group received laser treatment using Indocyanine green upon admission, while the control group received no intervention. Lesion diameter was measured at presentation and on the 3rd, 5th, and 7th days for all patients, with wound healing assessed on the 7th day. Additionally, pain levels were evaluated using the Visual Analog Scale (VAS) preoperatively and on the 1st, 3rd, 5th, and 7th days for the PDT group, and on the corresponding days for the control group.

RESULTS

Lesion diameters in the PDT group showed a significant reduction over time (p = 0.001), particularly from preoperative to final measurements. The control group also exhibited a decrease, albeit slower (p = 0.001). The 7th-day healing scores favored the PDT group significantly (p = 0.012). VAS scores in the PDT group decreased significantly over time (p = 0.001), indicating pain reduction. A similar trend was observed in the control group, albeit slower. Between-group differences in healing data and pain data were statistically significant.

CONCLUSION

PDT proves effective in reducing aphthous ulcer diameters and pain intensity, facilitating faster healing than the control group. These results advocate for PDT as a viable treatment option for aphthous lesions.

Efficacy of photodynamic therapy on candida colonization and clinical symptoms in denture stomatitis: a systematic review and meta-analysis

BACKGROUND

Photodynamic therapy (PDT) has been recently proposed as a promising alternative therapy for Denture Stomatitis (DS). The present systematic review and meta-analysis investigated the current available evidence regarding the efficacy of PDT in the management of DS.

MATERIALS AND METHODS

PubMed, Scopus, Web of Science, Google Scholar, and ProQuest were searched up to June 7, 2023. All relevant clinical trials were included. RevMan software was used for the statistical analyses.

RESULTS

Elven randomized clinical trials (460 DS patients) were included. Eight studies assessed the efficacy of PDT vs. topical antifungal therapy, while three studies assessed the adjunctive use of PDT (PDT + antifungal therapy) vs. topical antifungal therapy alone. The results revealed comparable efficacy of PDT and conventional antifungal therapy on candida colonization at 15 days (MD: 0.95, 95% CI: -0.28, 2.19, p = 0.13) and at the end of follow-up (MD: -0.17, 95% CI: -1.33, 0.98, p = 0.77). The pooled two studies revealed relatively better efficacy of adjunctive use of PDT with antifungal therapy on candida colonization compared to antifungal therapy alone at 15 days (MD: -6.67, 95% CI: -15.15, 1.82, p = 0.12), and at the end of follow-up (MD: -7.14, 95% CI: -19.78, 5.50, p = 0.27). Additionally, the results revealed comparable efficacy of PDT and topical antifungal therapy on the clinical outcomes.

CONCLUSIONS

PDT might be considered a viable option for DS either as an adjunct or as an alternative to the topical antifungal medications. Further studies with adequate sample sizes and standardized PDT parameters are warranted.

The therapeutic effect of bovine colostrum on 5-Fluorouracil-Induced oral mucositis in rats

OBJECTIVE

The purpose of this study is to determine the effect of bovine colostrum on 5-fluorouracil-induced oral mucositis in rats.

MATERIAL AND METHOD

Twenty-four male Wistar albino rats were randomly divided into three groups as the Preoperative, Postoperative and Control groups. All rats were administered 100 mg/kg 5-fluorouracil on the first day and 65 mg/kg 5-FU on the third day intraperitoneally. On the third and fifth days, a superficial incision was created on the mucosa of the right cheek pouch. The oral mucositis protocol was applied in the control group. The preoperative group was given bovine colostrum by gavage from the 1st day of the 5-FU procedure to the 5th day, while the postoperative group was given bovine colostrum by gavage from the 5th day to the 10th day.

RESULTS

According to the scoring made in terms of secondary infections, two cases in the control group had moderate infections, and two cases in each of the preoperative and postoperative groups had severe infections. The difference between the control group and the preoperative and postoperative groups was significant (p=0.020). There was no significant difference between the preoperative and postoperative groups. While the degree of wound healing in the postoperative group was higher than the other groups, the difference was not statistically significant.

CONCLUSION

No significant effect of bovine colostrum on the healing of oral mucositis was observed. Additional studies are needed to shed light on the pathogenic inflammatory mechanisms in mucositis and the prophylactic and therapeutic roles of antioxidants.

Nattokinase crude extract enhances oral mucositis healing

Background

Nattokinase (NK) is a promising alternative in the prevention and treatment of cardiovascular diseases due to its potent fibrinolytic activity. In this study, we investigated the effect of crude nattokinase extract on the healing of acetic acid-induced oral mucositis in mice.

Methods

Bacillus subtilis culture media (BSCM) was isolated into the supernatant, named nattokinase crude extract (NCE), and the pellet was named Bacillus subtilis mass (BSM). An oral mucositis model was established in mice by applying 50% glacial acetic acid to the buccal mucosa. According to the treatment conditions, the mice were divided into BSCM, NCE, BSM and phosphate buffered saline (PBS) groups. The weight of the mice, oral mucositis healing score and histopathological examination were used to evaluate the treatment.

Results

Fibrinolytic activities of BSCM, NCE and BSM were approximately 8069, 10,800 and 80 U/ml, respectively. The weight gain of mice in the NCE group was significantly different from the PBS group after three days’ treatment (p < 0.05). The oral mucositis score of NCE group was significantly higher than other groups (p < 0.05). The differences in histopathology scores between the NCE and other groups were statistically significant (p < 0.01).

Conclusions

NCE could possess remarkable potential to reduce pain and promote oral mucositis healing with minimal safety concerns. In this study, we first report that NCE from the supernatant of Bacillus subtilis can promote the healing of oral mucositis, which extends the application scope of NK.

Treatment Parameters of Photobiomodulation in the Prevention of Non-surgical Cancer Treatment-Induced Oral Mucositis: A Review of Preclinical Studies

Introduction: The most important side effect after non-surgery cancer treatment (NSCT) is oral mucositis (OM) which degrades the quality of life. Using photobiomodulation (PBM), formerly known as low-level laser therapy (LLLT), in the prevention of NSCT-induced OM was widely studied. Hence, this review evaluates the efficacy of optical treatment parameters behind the working process of PBM in preventing NSCT-induced OM in preclinical studies. Methods: Using the PubMed, Scopus and Embase databases, the present study systematically reviewed existing preclinical studies for optical treatment parameters of PBM in preventing NSCT-induced OM in experimental models without restriction on the year of publication. Results: In total, 51 articles were recognized during the search of the literature, and only 16 research papers were included in this review, taking into consideration the inclusion as well as exclusion benchmarks. The reviewed studies showed that a consensus has yet to be reached on the optimal PBM treatment parameters in preventing NSCT-induced OM. However, a wavelength of 660 nm, a power density of 40 mW as well as fluence which ranged between 2 and 6 J/cm2 were mostly utilized in the included studies. Furthermore, the severity of NSCT-induced OM was reduced following PBM application with no reported severe side effects. Conclusion: The efficacy of PBM with the associated optical parameters is a promising strategy in preventing NSCT-induced OM. However, the optimal parameters of PBM need to be investigated.

A systematic review and meta-analysis of the effect of photodynamic therapy for the treatment of oral mucositis

BACKGROUND

Oral mucositis is a significant reaction to antineoplastic treatment characterized with pain, nutritional compromise, impact on the quality of life, interruption in cancer therapy and risk for infection. There is no effective standard protocol for the treatment of oral mucositis. This study aims to synthesize the scientific evidence available about the effects of photodynamic therapy on treatment of oral mucositis.

METHODS

PubMed, Scopus, Web of Science, Science Direct, Scielo, Embase and Cochrane libraries were searched. Two independent and calibrated researchers (kappa = 0.92) performed all systematic steps according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). To access the risk of bias, RoB 2 and Delphi list criteria for clinical trials were used. Meta-analysis was conducted using the R software with "META" package.

RESULTS

Clinical and randomized clinical trials were included with a total of five articles. Meta-analysis, level of evidence, and risk of bias assessment were performed showing that photodynamic therapy was effective in reducing healing time in association with low-power laser therapy when compared to low-power laser therapy alone (p = 0.0005).

CONCLUSION

Photodynamic therapy presents promising results for the treatment of oral mucositis. It may be an effective therapeutic option, contributing to the healing of injured tissues especially in the time needed for repair.

The effect of indocyanine green-mediated photodynamic therapy in healing of experimentally induced oral mucosal traumatic ulcer in rat

Photodynamic therapy (PDT) is a promising approach for the healing of ulcerative lesions. This study aimed to investigate the effect of PDT using indocyanine green (ICG) in the healing of the experimentally induced oral mucosal traumatic ulcer in rat. Sixty adult male Sprague-Dawley rats were recruited in this experimental study. The ulceration was surgically made in the left cheek mucosa, and the rats were randomly assigned into four equal groups (n = 15). Oral ulcers in groups 1 and 2 were treated with the sterile saline solution (0.9%) and ICG (1 mg/ml). In group 3, laser irradiation was applied using the 810 nm diode laser in the continuous-wave mode for 30 s (light dose: 55 J/cm2, power: 300 mW, spot size: 4.5 mm). Following the topical application of ICG (1 mg/ml) in group 4, laser irradiation was performed in the same way as the previous group. After 24 h, treatments were repeated once more in all groups. The healing process was histopathologically assessed at the 3rd, 7th, and 14th days after ulceration. Wound healing was significantly accelerated in the ICG-mediated PDT group in comparison to the control group at all sampling time points (p < 0.005). However, the other groups displayed a similar healing rate (p > 0.05). Data suggest that ICG-mediated PDT has the potential to accelerate wound healing and prevent clinical infection in oral mucosal traumatic ulcers. However, further studies are required to confirm whether our results can be generalized to other wounds.

The Effects of Early Nutritional Intervention on Oral Mucositis and Nutritional Status of Patients With Head and Neck Cancer Treated With Radiotherapy

Radiation-induced oral mucositis (RIOM) is a common side effect after radiotherapy (RT) in head and neck cancer (HNC) patients. RIOM patients with severe pain have difficulty in eating, which increases the incidence of malnutrition and affects patients' quality of life and the process of RT. The mechanism of RIOM is not fully understood, and inflammatory response and oxidative stress appear to be important for RIOM occurrence and development. The nutritional status of patients is very important for their RT tolerance and recovery. Malnutrition, which can lead to anemia, low protein, decreased immunity and other problems, is an important clinical factor affecting tumor progression and treatment. Recent studies have shown that early nutritional intervention can ameliorate oral mucositis and nutritional status of patients with HNC. However, in clinical practice, early nutritional intervention for patients with HNC is not a conventional intervention strategy. Therefore, this review summarized the possible pathogenesis of RIOM, commonly used assessment tools for malnutrition in patients, and recent studies on the effects of early nutritional interventions on RIOM and nutritional status of patients with HNC. We hope to provide the basis and reference for the clinical application of early nutritional intervention models.

Photodynamic antimicrobial chemotherapy using indocyanine green in experimentally induced intraoral ulcers in rats

BACKGROUND

Photodynamic antimicrobial chemotherapy (PACT) is a promising modality for eradication of microorganisms from the wound. This study aimed to investigate the effectiveness of PACT using indocyanine green (ICG) for reduction of bacterial load of oral ulcers in rats and its impact on the healing process.

METHODS

In this experimental study, 50 adult male Sprague Dawley rats were recruited. Oral ulcers were surgically made on the left cheek mucosa, and animals were randomly assigned into five groups (n = 10). Wound site in groups 1, 2, and 3 was irrigated with the sterile saline (0.9%), chlorhexidine (CHX; 0.2%), and ICG solutions (1 mg/mL), respectively. Group 4 was exposed to laser irradiation using 810 nm diode laser on continuous-wave mode for 30 seconds (fluence: 55 J/cm² , power: 300 mW, spot size: 4.5 mm). In group 5, PACT was performed using topical application of ICG followed by laser irradiation in the same way as the previous group. Bacterial load of oral ulcers was assessed before and after each treatment modality. Besides, rats were sacrificed on the 5th day post ulceration and histological features of healing were evaluated.

RESULTS

Bacterial load was significantly reduced merely in the PACT-ICG-treated group by one log (P < .0001). Animals in the PACT-ICG-treated group also showed an accelerated healing in comparison with others on the 5th day of an experiment.

CONCLUSION

Photodynamic antimicrobial chemotherapy using topical application of ICG has a potential to reduce the bacterial load of oral ulcers and accelerate wound repair. Therefore, it can be considered as an alternative to currently available modalities for wound management.

Photodynamic therapy effect of morpholinium containing silicon (IV) phthalocyanine on HCT-116 cells

In this study, we investigated the in vitro potential of axially 1-morpholiniumpropan-2-ol disubstituted silicon (IV) phthalocyanine (SiPc) which was synthesized previously, on HCT-116 cells as a photodynamic therapy (PDT) agent. The singlet oxygen and photodegradation quantum yields of SiPc were calculated using UV-vis spectrophotometer. The cytotoxic and phototoxic effects of SiPc were evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. Annexin V-FITC/PI double staining kit, cell cycle kit, and mitochondria membrane potential (ΔΨm) assay kit with JC-1 were used to indicate the cell death pathway. Caspase-3 and β-catenin protein expressions were evaluated by western blotting. The singlet oxygen and photodegradation quantum yields of SiPc were calculated as 0.73 and 3.64 × 10^-4 in DMSO. The cell viability assays showed that IC₅₀ value of SiPc did not reach to 100 μM without irradiation. However, excellent phototoxicity was observed in the presence of SiPc upon light irradiation. The cells undergoing early/late apoptosis significantly increased in the presence SiPc at 5 μM upon light irradiation. Besides, the proportion of cells at S and G2/M phase increased. Moreover, mitochondria membrane potentials significantly decreased at 1 and 5 μM of SiPc with light irradiation. While caspase-3 expression increased, β-catenin expression significantly decreased on HCT-116 in the presence of SiPc (p < 0.01). The results indicated that the PDT could be related to apoptosis and Wnt/β-catenin signaling pathway. Based on our findings, SiPc exhibited a significant PDT effect on HCT-116 cells therefore, worthy of more detailed study.

Is low level laser therapy or ozone therapy more effective for bone healing? Understanding the mechanisms of HIF-1α, RANKL and OPG

Periodontitis is a common chronic infection of dental tissues. Ozone therapy (OT) and low level laser therapy (LLLT) are useful treatments for periodontitis. We investigated the effects of OT and LLLT on periodontal disease-induced bone destruction in rats with experimentally induced periodontitis (EP). We used 30 male Wistar rats divided into three groups: control, OT and LLLT. EP was induced by placing a 3.0 silk suture around the cervix of the left mandibular first molar tooth. OT was performed using an ozone generator at 80% concentration. LLLT was applied using a diode laser. Both OT and LLLT were performed for two weeks at two day intervals. Histomorphometric and immunohistochemical analyses also were performed. Alveolar bone loss was significantly less in the LLLT group compared to the control group. The number of HIF-1α positive cells was significantly less in the LLLT group compared to the control group. We found significantly fewer RANKL-positive cells in the OT group compared to the control group. The number of osteoprotegerin (OPG) positive cells was significantly greater for the LLLT group than for the control group. Although both treatments produced positive effects, LLLT appears to be more effective for increasing alveolar bone formation.

Anti-inflammatory effect of photodynamic therapy using guaiazulene and red lasers on peripheral blood mononuclear cells

INTRODUCTION

Photodynamic therapy improves oral mucositis treatment. The reactive oxygen species (ROS) generated from this reaction could contribute to an anti-inflammatory effect by suppressing inflammatory cells.

OBJECTIVE

To evaluate the anti-inflammatory effect of photodynamic therapy using guaiazulene and a red laser in peripheral blood mononuclear cells (PBMCs).

METHODS

Guaiazulene solutions (1, 2, 5, 25, 35, and 100 μM in 99.8 % methanol) were irradiated with red laser light (625 nm, 146.2 mW/cm²) in continuous mode at 0, 4, and 8 J/cm² in black 96-well plates. ROS were measured using spin trapping technique with electron spin resonance (ESR) spectroscopy and fluorescence. The two highest concentrations were tested using cell viability (PrestoBlue®) and anti-inflammation (RANTES and PGE₂ ELISA) assay kits. Kruskal-Wallis and Dunn Bonferroni tests were used for statistical analyses with significant differences at p-value < 0.05.

RESULTS

Guaiazulene solutions between 2 and 5 μM exposed to red laser light at 4-8 J/cm² generated significantly more singlet oxygen compared to the no guaiazulene group (p < 0.01) and reduced RANTES and PGE₂ levels in TNF-α-inflamed peripheral blood mononuclear cells without affecting cell viability.

CONCLUSION

Photodynamic activation of guaiazulene generated singlet oxygen and suppressed inflammatory markers in PBMCs.