Beneficial Effect of Bee Venom and Its Major Components on Facial Nerve Injury Induced in Mice.

Peripheral nerve injury (PNI) is a health problem that affects many people worldwide. This study is the first to evaluate the potential effect of bee venom (BV) and its major components in a model of PNI in the mouse. For that, the BV used in this study was analyzed using UHPLC. All animals underwent a distal section-suture of facial nerve branches, and they were randomly divided into five groups. Group 1: injured facial nerve branches without any treatment. Group 2: the facial nerve branches were injured, and the normal saline was injected similarly as in the BV-treated group. Group 3: injured facial nerve branches with local injections of BV solution. Group 4: injured facial nerve branches with local injections of a mixture of PLA2 and melittin. Group 5: injured facial nerve branches with local injection of betamethasone. The treatment was performed three times a week for 4 weeks. The animals were submitted to functional analysis (observation of whisker movement and quantification of nasal deviation). The vibrissae muscle re-innervation was evaluated by retrograde labeling of facial motoneurons in all experimental groups. UHPLC data showed 76.90 ± 0.13%, 11.73 ± 0.13%, and 2.01 ± 0.01%, respectively, for melittin, phospholipase A2, and apamin in the studied BV sample. The obtained results showed that BV treatment was more potent than the mixture of PLA2 and melittin or betamethasone in behavioral recovery. The whisker movement occurred faster in BV-treated mice than in the other groups, with a complete disappearance of nasal deviation two weeks after surgery. Morphologically, a normal fluorogold labeling of the facial motoneurons was restored 4 weeks after surgery in the BV-treated group, but no such restoration was ever observed in other groups. Our findings indicate the potential of the use of BV injections to enhance appropriate functional and neuronal outcomes after PNI.

Efficacy of LED Photobiomodulation for Functional and Axonal Regeneration After Facial Nerve Section-Suture.

Facial nerve damage can lead to partial or total facial nerve palsy. Photobiomodulation has been reported to improve and accelerate functional recovery following peripheral nerve lesion, depending on the type of lesion and the light exposure parameters used. The aim of this study was to investigate the effects of infrared exposure on functional and axonal regeneration after section-suture of the distal branches of the facial nerve: the buccal and marginal mandibular branches and the distal pes. The animals underwent surgery and were irradiated with infrared light at 850 nm twice daily from day 1 to day 16. The recovery of facial function was then studied at both the behavioral and morphological levels. Behavioral analyses were performed by videoscoring with a high-speed camera and using various devices to assess the recovery of whisker movement on the lesioned side from day 1 to day 30. We also assessed nasal deviation toward the intact side and the ability to close the ipsilateral eyelid completely from day 1 to day 38 and from day 1 to day 50, respectively. For morphological analyses, we assessed the re-establishment of facial motoneuron labeling with Fluorogold®, an immunofluorescent retrograde marker of axonal transport injected into the vibrissae, on D10, D14 and D30. We found that whisker movements recovery was significantly faster in treated than in control mice. A complete disappearance of nasal deviation was observed at 2 weeks in infrared-treated lesioned mice and at 5 weeks in controls. Complete eyelid closure was observed 3 weeks after surgery in treated animals and 6 weeks after surgery in controls. Finally, normal fluorogold labeling of the facial nuclei complex was restored 30 days after surgery in the treated animals, but no such restoration was ever observed in control animals. In conclusion, our data show that IR treatment at a distal site has a significant positive effect on facial nerve recovery. These findings pave the way for the clinical use of infrared photobiomodulation in patients with nerve lesions.