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

Frankincense can promote blood circulation. Acetyl-11-keto-β-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.

Acetyl-11-keto-β-boswellic acid inhibits proliferation and induces apoptosis of gastric cancer cells through the phosphatase and tensin homolog/Akt/cyclooxygenase-2 signaling pathway

BACKGROUND Gastric cancer is one of the most common malignant tumors of the digestive system worldwide,posing a serious danger to human health.Cyclooxygenase(COX)-2 plays an important role in the carcinogenesis and progression of gastric cancer.Acetyl-11-keto-β-boswellic acid(AKBA)is a promising drug for cancer therapy,but its effects and mechanism of action on human gastric cancer remain unclear.AIM To evaluate whether the phosphatase and tensin homolog(PTEN)/Akt/COX-2 signaling pathway is involved in the anti-tumor effect of AKBA in gastric cancer.METHODS Human poorly differentiated BGC823 and moderately differentiated SGC7901 gastric cancer cells were routinely cultured in Roswell Park Memorial Institute 1640 medium supplemented with 10%fetal bovine serum and 1%penicillin/streptomycin.Gastric cancer cell proliferation was determined by methyl thiazolyl tetrazolium colorimetric assay.Apoptosis was measured by flow cytometry.Cell migration was assessed using the wound-healing assay.Expression of Bcl-2,Bax,proliferating cell nuclear antigen,PTEN,p-Akt,and COX-2 were detected by Western blot analysis.A xenograft nude mouse model of human gastric cancer was established to evaluate the anti-cancer effect of AKBA RESULTS AKBA significantly inhibited the proliferation of gastric cancer cells in a dose-and time-dependent manner,inhibited migration in a time-dependent manner,and induced apoptosis in a dose-dependent manner in vitro;it also inhibited tumor growth in vivo.AKBA up-regulated the expression of PTEN and Bax,and downregulated the expression of proliferating cell nuclear antigen,Bcl-2,p-Akt,and COX-2 in a dose-dependent manner.The PTEN inhibitor bpv(Hopic)reversed the high expression of PTEN and low expression of p-Akt and COX-2 that were induced by AKBA.The Akt inhibitor MK2206 combined with AKBA downregulated the expression of p-Akt and COX-2,and the combined effect was better than that of AKBA alone.CONCLUSION AKBA inhibits the proliferation and migration and promotes the apoptosis of gastric cancer cells through the PTEN/Akt/COX-2 signaling pathway.