Thermal Injuries Occurring to the Foot: A Review

Topical frankincense treatment for frostbite based on microcirculation improvements

ETHNOPHARMACOLOGICAL RELEVANCE

The Chinese traditional medicine frankincense, which can promote blood circulation, is often used to treat skin lesions, including frostbite.

AIM OF THE STUDY

To explore the properties of frankincense oil extract (FOE) and its active ingredients and their effect on frostbite wound recovery as an approach to understand the mechanism associated with microcirculation-improvement therapy.

MATERIALS AND METHODS

The microcirculation-improving effects of FOE and its active ingredients were evaluated using liquid nitrogen-induced frostbite animal models. The rewarming capacity of FOE on the skin was determined through infrared detection, and frostbite wound healing was evaluated following haematoxylin and eosin (H&E) staining and fibre analysis. Moreover, related factors were examined to determine the anti-apoptotic, anti-inflammatory, and microcirculatory properties of FOE and its active ingredients on affected tissue in the context of frostbite.

RESULTS

FOE and its active ingredients rapidly rewarmed wound tissue after frostbite by increasing the temperature. Moreover, these treatments improved wound healing and restored skin structure through collagen and elastin fibre remodelling. In addition, they exerted anti-apoptotic effects by decreasing the number of apoptotic cells, reducing caspase-3 expression, and eliciting anti-inflammatory effects by decreasing COX-2 and β-catenin expression. They also improved microcirculatory disorders by decreasing HIF-1α expression and increasing CD31 expression.

CONCLUSIONS

FOE and its active components can effectively treat frostbite by enhancing microcirculation, inhibiting the infiltration of inflammatory cells, decreasing cell apoptosis, and exerting antinociceptive effects. These findings highlight FOE as a new treatment option for frostbite, providing patients with an effective therapeutic strategy.

Development and validation of clinically Mimicable model of frostbite injury-induced chronic pain

Frostbite, a debilitating condition, significantly affects the well-being of military veterans and high-altitude residents, causing severe clinical complications such as chronic pain that markedly impacts overall quality of life. There has been a notable increase in the development of pre-clinical models for studying frostbite injury, but their suitability for pain evaluation remains limited. The major hurdle in the development of novel therapeutics for the treatment of frostbite-induced chronic pain is the unavailability of well-established preclinical models. In this study, we employed deep-frozen magnets to induce frostbite injury and conducted validation for chronic pain through assessments of face, predictive, and mechanistic validity. Behavioral assays demonstrated that frostbite injury exhibited significant mechanical, thermal & cold hypersensitivity in rats. Further, molecular analysis indicated that frostbite injury triggered the activation of TRP channels (TRPA1, TRPV1 and TRPM8), microgliosis, and neuroinflammation in the dorsal root ganglion (DRG) and spinal cord of rats. Notably, NR2B protein expressions were significantly upregulated in the DRG of injured rats, while no changes were observed in spinal NR2B expressions. Furthermore, the administration of ibuprofen (25, 50, and 100 mg/kg, i.p.) resulted in a significant improvement in behavioral, biochemical, and molecular alterations in frostbite-injured rats. Overall, results suggested that established frostbite model effectively recapitulates face, pharmacological, and mechanistic validity, highlighting its potential for screening future treatment modalities and exploring the intricate mechanisms associated with frostbite-induced chronic pain.