The impact of photobiomodulation therapy on the biology and behavior of head and neck squamous cell carcinomas cell lines.

Photobiomodulation therapy (PBMT) is an emerging therapeutic modality designed to prevent and treat chemotherapy-driven oral mucositis (OM). However, the response of tumor cells to the effects of PBMT remains poorly understood. Our study explores the effects of PBMT in head and neck squamous cell carcinoma (HNSCC) based on cellular proliferation, migration, and survival of tumor cells and its population of cancer stem cells (CSC). We explored the behavior of two HNSCC cell lines (HN6 and HN13) under two distinct conditions, a physiological growing condition (10% FBS), and under stress growing condition (2% FBS) prior to irradiation using diode laser (InGaAlP; MM Optics, São Carlos, SP, Brazil). Diode laser (660 nm) was applied with a power of 100 mW delivering a total energy per point of 0.24 J. MTT and wound healing test (scratch assay) were performed to evaluate, respectively, proliferation and migration of tumor cells. Clonogenic and spheres formation assays were also performed to evaluate the survival and percentage of CSC upon irradiation. Overall, we observed that PBMT does not exacerbate the behavior of HNSCC. We could only observe a decrease in cellular proliferation of one cell line (HN6) when cultured under nutritional stress conditions (p < .05). There were no significant differences between the control and the PBMT groups regarding cell migration, survival and the percentage of CSC. Collectively, our results suggest that in vitro administration of PBMT to HNSCC does not modify the behavior of tumor cells.

Effects of a mucoadhesive formulation containing Curcuma longa L. on oral wound healing

Introduction: The aim of this study was to investigate the effects of a topical mucoadhesive formulation with Curcuma longa L. extract (MFC) on oral wound healing. Methods: Seventy-two Wistar rats were randomly assigned to 3 groups: Control, Vehicle, and MFC. Traumatic ulcers were made on the dorsum of the tongue with a 3-mm diameter punch. Vehicle and MFC groups received application of the products twice a day, while animals in the control group were cared for in identical conditions but received no product application. Six rats in each group were euthanized at days 3, 5, 10, and 14. Percentage of repair was calculated based on wound area. HE-stained histological sections were obtained for semi-quantitative analysis of re-epithelization and inflammation. Results: Clinical findings revealed that at days 3 and 5, animals from the MFC group exhibited a significantly higher percentage of wound repair. At day 5, animals from this group also demonstrated a significant increase in the degree of re-epithelization and inflammation. Conclusions: MFC is capable of accelerating oral wound repair in an in vivo model by modulating the inflammatory process and stimulating epithelial proliferation. (AU)

Photobiomodulation therapy modulates epigenetic events and NF-κB expression in oral epithelial wound healing.

The aim of this study was to evaluate the effect of photobiomodulation therapy (PBMT) on histone 3 acetylation (acH3) and NF-κB expression during oral ulcer healing. A total of 48 male Wistar rats were divided into control group (CG) and PBMT group (n = 24 each). Traumatic ulcers were created in the dorsum of the rats' tongue with a punch tool. Irradiation with InGaAlP laser, 660 nm, 40 mW, 0.04 cm2 spot size, 4 J/cm2, 4 s, and 0.16 J per spot was performed once a day in close contact for 10 consecutive days. CG received only daily handling. Rats were euthanized on days 3, 5, and 10 (n = 8) and were monitored daily to assess wound status. Immunohistochemical analysis for acH3 and NF-κB detection was performed. One thousand epithelial cells were counted, and mean acH3- and NF-κB-positive cells were calculated and compared between the groups. PBMT accelerated the repair of oral ulcers. On day 3, PBMT showed significantly higher means for acH3- and NF-κB-positive cells than CG. On day 5, no difference was observed between the groups concerning both markers. On day 10, PBMT presented lower acH3 and NF-κB means than the control group. We concluded that PBMT stimulates keratinocyte migration in the early stage of oral wound healing and keratinocyte differentiation at the final stage by modulating histone acetylation and NF-κB expression.

Copaiba oil-resin (Copaifera reticulata Ducke) modulates the inflammation in a model of injury to rats' tongues.

BACKGROUND: The regeneration of integrity and tissue homeostasis after injury is a fundamental property and involves complex biological processes fully dynamic and interconnected. Although there are medications prescribed to accelerate the process of wound healing by reducing the exaggerated inflammatory response, comes the need to search for different compounds of Amazonian biodiversity that can contribute to the acceleration of the healing process. Among these products, the copaiba oil-resin is one of the most prominent feature in this scenario, as they have been reported its medicinal properties. METHODS: Aiming to evaluate the anti-inflammatory and healing effect of copaiba oil-resin (Copaifera reticulata Ducke) in transfixing injury of rats' tongues first proceeded up the copaiba oil-resin oral toxicity test in 5 male mice to stipulate the therapeutic dose which was established at 200 mg/kg/day. Then it was induced transfixing injury in a total of 15 Wistar rats. The animals were randomly divided into three groups based on the treatment: control group, dexamethasone group and copaiba oil-resin group. After 7 days of treatment, histological slides stained with hematoxylin and eosin was prepared. Immunohistochemistry for CD68 (macrophage marker) was performed and analyzed by the cell counter Image J. RESULTS: The acute toxicity test showed that the oil-resin copal has low toxicity. Furthermore, copaiba oil-resin therapy modulates the inflammatory response by decreasing the chronic inflammatory infiltrate, edema and specifically the number of macrophages. CONCLUSIONS: The results indicate the potential of the Amazon region and showed up relevant because therapy with this extract modulates the inflammatory process.

Effects of Copaiba Oil Topical Administration on Oral Wound Healing.

The effects of topical copaiba oil extract and topical corticosteroid were assessed on oral wound healing in an in vivo model using 96 male Wistar rats. Traumatic ulcers were caused in the dorsum of the tongue using a 3-mm punch tool. The animals were divided into: Control; Corticosteroid; Placebo and Copaiba oil Group. The animals received two daily applications of the products. The control group received only daily handling. Six rats in each group were euthanized at days 3, 5, 10 and 14. The animals were monitored daily to determine wound status. The weigh was assessed at day 0 and euthanasia day. The percentage of repair was calculated, and histopathological aspects were analyzed. The Kruskal-Wallis test was used to compare the results between groups and times of evaluation. Closing time was assessed through the log-rank test. The corticosteroid group lost more weight at days 10 and 14 than the control group (p < 0.05). Moreover, the healing time of corticosteroid group was longer than the control group (p = 0.007). No differences were observed between the copaiba oil group and the control group. We concluded that topical copaiba oil, in spite of being safe, did not accelerate the process of oral wound healing. Copyright © 2017 John Wiley & Sons, Ltd.

Photobiomodulation regulates cytokine release and new blood vessel formation during oral wound healing in rats.

The aim of the present study was to evaluate the effects of photobiomodulation (PBM) on cytokine levels and angiogenesis during oral wound healing. Ulcers were made on the dorsum of the tongue in 48 Wistar rats. Irradiation with an indium-gallium-aluminum-phosphide (InGaAlP) laser (660 nm; output power, 40 mW; spot size, 0.04 cm(2)) was performed once a day on two points of the ulcer for 14 days. Two different energy densities were used: 4 J/cm(2) (energy per point 0.16 J, total energy 0.32 J) and 20 J/cm(2) (energy per point 0.8 J, total energy 1.6 J). Tissue levels of interleukin (IL)-1ß and tumor necrosis factor (TNF)-α were investigated by enzyme-linked immunosorbent assay (ELISA). Image analysis of CD31-immunostained sections was used to investigate microvessel density (MVD). PBM increased the tissue levels of IL-1ß at the early stage of oral wound healing (p < 0.01) and increased the tissue levels of TNF-α during all stages of oral wound healing (p < 0.05). PBM at a dose of 4 J/cm(2) produced more significant results regarding cytokine modulation and was associated with higher MVD at day 5. Collectively, these findings indicate that cytokine modulation and increased angiogenesis are among the basic mechanisms whereby PBM improves oral wound repair.