Homogenous amniotic membrane as a biological dressing for oral mucositis in rats: histomorphometric analysis

Micronuclei and nuclear buds in amniotic tissue of rats treated with cyclophosphamide

Fetal development can be altered by DNA damage caused by maternal exposure to chemical, physical, or biological agents during gestation. One method of assessing genotoxicity is to detect micronuclei (MNs) and/or nuclear abnormalities. This can be performed in vivo and requires only frequently dividing tissues, such as amniotic tissue (AT), which is in contact with the fetal environment and is composed of very thin layers of cells. This study evaluated the presence of MNs, nucleoplasmic bridges, and nuclear buds (NBs) in the fetal AT following maternal exposure to cyclophosphamide (CP) during pregnancy. Pregnant Wistar rats were divided into a negative control group and an experimental group that was orally administered CP (10 mg/kg). Daily blood smears were obtained from pregnant rats on days 14-19 of gestation. The rats were dissected, and fetal ATs were obtained on the 19th day of gestation. The MN and NB frequencies in AT cells were analyzed using a fluorescence microscope (100 ×). Micronucleated erythrocytes in the peripheral blood of the control rats were also assessed. Micronucleated polychromatic erythrocyte frequencies were significantly higher than those in the controls. Polychromatic erythrocyte frequencies were lower in CP-treated rats than in controls at 48-120 h. Fetuses in the CP-treated group also showed a significant increase in MNs and NBs in AT cells. In conclusion, AT could be used for analyzing MNs and NBs in rats following maternal exposure to a genotoxic agent and as a viable alternative for analyzing the integrity of fetal DNA during gestation.

Effects of Topical Hangeshashinto (TJ-14) on Chemotherapy-Induced Oral Mucositis

Purpose

Hangeshashinto (TJ-14), a Kampo medicine comprising seven types of herbs, has been used in Japan to alleviate the side effects associated with anticancer drug treatments. However, the pharmacological effects of this medicine currently remain unclear. The present study aimed to demonstrate the efficacy of TJ-14 against anticancer drug-induced stomatitis, the pain associated with which may have a negative impact on mastication and swallowing.

Methods

Mucositis was induced in Sprague-Dawley rats by cancer chemotherapy. Changes in body weight, stomatitis grades, histopathological scores, and oral bacterial counts were examined among TJ-14-treated, saline-treated, and Control (no treatment) rats. In vitro studies, including cell proliferation and wound healing assays, using epidermal keratinocyte and fibroblast cell lines were conducted.

Results

The local application of TJ-14 exerted strong antibacterial effects and attenuated oral chemotherapy-induced stomatitis in rats. TJ-14 also increased the viability and invasion of epidermal keratinocytes and fibroblasts.

Conclusion

The present results demonstrated the potential of TJ-14 to attenuate chemotherapy-induced stomatitis.

Effects of ozone nano-bubble water on mucositis induced by cancer chemotherapy

No effective, reliable treatment for stomatitis associated with cancer therapy has been established. This study focused on the its effectiveness of ozone nano-bubble water (ONBW) for the treatment of chemotherapy-induced stomatitis. Oral mucositis was induced in 14-week-old male Sprague-Dawley rats (N = 21). The animals were randomly divided into 3 groups: 7 without treatment (control); 7 treated with physiological salt solution (saline); and 7 treated with ONBW. Animals were weighed on Days 7, 9, 11, and 16. Stomatitis grade evaluation and bacterial count measurements were performed before rinsing in all animals 3, 5, and 10 days after acetic acid irritation (Days 9, 11, and 17 respectively). Weight loss after stomatitis creation was observed in all groups, with significant differences between the control and ONBW groups and between the saline and ONBW groups on Day 16. The stomatitis grade did not worsen during the experimental period in any group, with the lowest grades in the ONBW group on Days 11 and 16. Significant differences were identified between the control and ONBW groups and between the saline and ONBW groups on Days 11 and 16. Oral bacterial counts tended to decrease over time in all three groups, with the greatest decrease in the ONBW group, followed by the saline group. The decrease in the bacterial count was steepest in the ONBW group. Rinsing out the oral cavity with ONBW decreased bacterial counts and encouraged the healing of oral chemotherapy-induced stomatitis. ONBW may be an effective treatment for chemotherapy-induced stomatitis.

Pain mechanism of oral ulcerative mucositis and the therapeutic traditional herbal medicine hangeshashinto

BACKGROUND

Oral ulcerative mucositis causes severe pain during eating and speaking, resulting in poor quality of life for patients with cancer undergoing chemoradiotherapy. Recently, some basic and clinical studies demonstrated that hangeshashinto, a traditional Japanese herbal medicine, alleviated oral ulcerative mucositis-induced pain. Here, we review a recently revealed pain mechanism underlying oral ulcerative mucositis in a preclinical rat model and the pharmacological analgesic effect of hangeshashinto.

HIGHLIGHT

In a rat model of experimentally induced oral ulcerative mucositis, the mucosal surface of the ulcerative region is damaged, which increases oral bacterial loading in the mucosa and prostanoid production. Chemotherapeutic drugs exaggerate the pathological condition and cause severe pain. The pain-related TRP channels, TRPV1, TRPA1, and/or TRPV4, mediate spontaneous and mechanical pain in oral ulcerative mucositis models. Swab application of hangeshashinto had a prolonged localized analgesic effect on oral ulcerative mucositis, even in a chemotherapy-treated oral ulcer model. Two ingredients of hangeshashinto, gingerol and shogaol, strongly inhibit voltage-activated sodium channels (though they have agonistic effects on TRPV1 and TRPA1), which confers hyposensitivity to the oral mucosa. Their analgesic effects on oral ulcerative mucositis are accompanied by accelerated delivery of drugs (other saponin-containing herbal extracts) into the ulcerative region.

CONCLUSION

Elucidation of the pain mechanism of oral ulcerative mucositis and analgesic mechanism of hangeshashinto will allow identification of novel therapeutic approaches against oral ulcerative mucositis-induced pain in patients. The traditional Japanese herbal medicine hangeshashinto is a reliable drug with supporting scientific evidence.

Distinct TRPV1- and TRPA1-based mechanisms underlying enhancement of oral ulcerative mucositis-induced pain by 5-fluorouracil

In many patients with cancer, chemotherapy-induced severe oral ulcerative mucositis causes intractable pain, leading to delays and interruptions in therapy. However, the pain mechanism in oral ulcerative mucositis after chemotherapy has not been extensively studied. In this study, we investigated spontaneous pain and mechanical allodynia in a preclinical model of oral ulcerative mucositis after systemic administration of the chemotherapy drug 5-fluorouracil, using our proprietary pain assay system for conscious rats. 5-Fluorouracil caused leukopenia but did not induce pain-related behaviors. After 5-fluorouracil administration, oral ulcers were developed with topical acetic acid treatment. Compared with saline-treated rats, 5-fluorouracil-exposed rats showed more severe mucositis with excessive bacterial loading due to a lack of leukocyte infiltration, as well as enhancements of spontaneous pain and mechanical allodynia. Antibacterial drugs, the lipid A inhibitor polymyxin B and the TRPV1/TRPA1 channel pore-passing anesthetic QX-314, suppressed both the spontaneous pain and the mechanical allodynia. The cyclooxygenase inhibitor indomethacin and the TRPV1 antagonist SB-366791 inhibited the spontaneous pain, but not the mechanical allodynia. In contrast, the TRPA1 antagonist HC-030031 and the N-formylmethionine receptor FPR1 antagonist Boc MLF primarily suppressed the mechanical allodynia. These results suggest that 5-fluorouracil-associated leukopenia allows excessive oral bacterial infection in the oral ulcerative region, resulting in the enhancement of spontaneous pain through continuous TRPV1 activation and cyclooxygenase pathway, and mechanical allodynia through mechanical sensitization of TRPA1 caused by neuronal effects of bacterial toxins. These distinct pain mechanisms explain the difficulties encountered with general treatments for oral ulcerative mucositis-induced pain in patients with cancer and suggest more effective approaches.

The therapeutic effects of apigenin and dexamethasone on 5-fluorouracil-induced oral mucositis - a pilot study using a Syrian hamster model

OBJECTIVE

Oral mucositis (OM) is a common complication of chemotherapy and radiotherapy. The aim of this study was to evaluate the effects of treating 5-fluorouracil-induced OM with apigenin and dexamethasone.

METHODS

Thirty-six male Syrian hamsters were randomly assigned to one of three groups: control (50% acetic acid + 5-FU), 50% acetic acid + 5-FU + potassium Apigenin (KA), and 50% acetic acid + 5-FU + dexamethasone. The animals from each group were sacrificed 5, 7, 10, and 14 days after inducing the mucositis, and two samples collected from each animal, accounting a total of 72 samples. Macroscopic changes were assessed by histomorphometric analysis, with ulcers being assessed by imaging analysis and the number of inflammatory cells in the ulcerated region quantified in all periods through histomorphometric analysis (H&E). Furthermore, immunohistochemical changes were evaluated by proliferating cell nuclear antigen.

RESULTS

All groups presented an increased inflammatory infiltrate after 7 days, compared to other evaluation times (P ≥ 0.05). There was significant difference between apigenin and control group in the 10-days period. Lower quantity of inflammatory cells in the apigenin-treated group in comparison with control group in the 7- and 10-days periods was observed (P < 0.05). No statistically significant difference was verified among the groups in 5- and 14-days periods. The healing process of the control group was slower than that of apigenin and dexamethasone-treated groups, with an overall significant difference between apigenin and the control group in the 10-days period.

CONCLUSIONS

Apigenin treatment may enhance healing of OM induced by 5-fluorouracil, thus suggesting that more extensive research in this area may be useful to assess the role of agents of natural origin capable of preventing OM. Hence, further studies involving broader samples are need to confirm the therapeutic potential shown by this study.

Amnion and Chorion Membranes: Potential Stem Cell Reservoir with Wide Applications in Periodontics

The periodontal therapy usually aims at elimination of disease causing bacteria and resolution of inflammation. It involves either resective or regenerative surgery to resolve the inflammation associated defects. Over the years, several methods have been used for achievement of periodontal regeneration. One of the oldest biomaterials used for scaffolds is the fetal membrane. The amniotic membranes of developing embryo, that is, amnion (innermost lining) and chorion (a layer next to it), have the properties with significant potential uses in dentistry. This paper reviews the properties, mechanism of action, and various applications of these placental membranes in general and specifically in Periodontics.

Review of preclinical studies on treatment of mucositis and associated pain

Oral mucositis is a significant problem in cancer patients treated with radiation or chemotherapy, often hindering definitive cancer treatment. For patients with oral mucositis, pain is the most distressing symptom, leading to loss of orofacial function and poor quality of life. While oral mucositis has been well-described, its pathophysiology is poorly understood. Oral health professionals treating patients with mucositis have almost no effective therapies to treat or prevent oral mucositis. The purpose of this review is to (1) describe the current preclinical models of oral mucositis and their contribution to the understanding of mucositis pathophysiology, (2) explore preclinical studies on therapies targeting mucositis and discuss the clinical trials that have resulted from these preclinical studies, and (3) describe the proposed pathophysiology of oral mucositis pain and preclinical modeling of oral mucositis pain.