Acetyl-11-keto-ß-boswellic acid extracted from Boswellia serrata promotes Schwann cell proliferation and sciatic nerve function recovery.

Frankincense can promote blood circulation. Acetyl-11-keto-ß-boswellic acid (AKBA) is a small molecule with anti-inflammatory properties that is derived from Boswellia serrata. Here, we hypothesized that it may promote regeneration of injured sciatic nerve. To address this hypothesis, we established a rat model of sciatic nerve injury using a nerve clamping method. Rats were administered AKBA once every 2 days at doses of 1.5, 3, and 6 mg/kg by intraperitoneal injection for 30 days from the 1st day after injury. Sciatic nerve function was evaluated using the sciatic functional index. Degree of muscle atrophy was measured using the triceps surae muscle Cuadros index. Neuropathological changes were observed by hematoxylin-eosin staining. Western blot analysis was used to detect expression of phospho-extracellular signal-regulated kinase 1 and 2 (p-ERK1/2) in injured nerve. S100 immunoreactivity in injured nerve was detected by immunohistochemistry. In vivo experiments showed that 3 and 6 mg/kg AKBA significantly increased sciatic nerve index, Cuadros index of triceps muscle, p-ERK1/2 expression, and S100 immunoreactivity in injured sciatic nerve of sciatic nerve injury model rats. Furthermore, for in vitro experiments, Schwann cells were treated with AKBA at 0-20 µg/mL. Proliferation of Schwann cells was detected by Cell Counting Kit-8 colorimetry assay. The results showed that 2 µg/mL AKBA is the optimal therapeutic concentration. In addition, ERK phosphorylation levels increased following 2 µg/mL AKBA treatment. In the presence of the ERK1/2 inhibitor, PD98059 (2.5 µL/mL), the AKBA-induced increase in p-ERK1/2 protein expression was partially abrogated. In conclusion, our study shows that AKBA promotes peripheral nerve regeneration with ERK protein phosphorylation playing a key role in this process.

Dracorhodin Perchlorate Accelerates Cutaneous Wound Healing in Wistar Rats.

Dracorhodin perchlorate (DP) is extracted from Dragon's blood, which is widely used in traditional Chinese medicine, especially in wound healing. The aim of this paper is to investigate the influence of DP ointment, which contained DP dissolved in DMSO and mixed with Vaseline, on cutaneous wound healing in Wistar rats. Forty Wistar rats were divided into two groups: control and DP groups. The skin on the back of each rat was punched with two full-thickness wounds and then treated with the corresponding drug. After 3, 7, 10, 14, and 21 days, four rats were sacrificed for immunological, biochemical, and histological analyses. Compared with the control treatment, DP could significantly promote wound closure. Histological and biochemical analyses of the skin biopsies also showed that DP regulated the expression of inflammatory responses by TNF-α and IL-ß and by supporting wound tissue growth and collagen deposition. Western blot revealed that DP could also facilitate the expression of EGF and VEGF proteins. In conclusion, DP promotes wound healing.