Fractions of Boswellia Serrata Suppress LTA4, LTC4, Cyclooxygenase-2 Activities and mRNA in HL-60 Cells and Reduce Lung Inflammation in BALB/c Mice

Abstract

Background: Purified fractions from a Boswellia serrata Roxb. Ex. Colebr. (Burseraceae) extract (ETOH and DCM) contain biologically active compounds that are well known for having inflammation inhibitory properties. In this work, the purified fractions were tested in-vitro for LTC4, LTA4 and COX-2 activities using ELISA and qPCR was performed to determine gene regulation in human leukemia (HL-60) Cells. Two D-imaging tomography was performed to determine the anti-inflammatory activities of the fractions in BALB/c mouse model of lung inflammation. Objective: To evaluate anti-inflammatory activities of bioactive compounds of Boswellia serrata purified fractions. Methods: In-vitro MTT assay was performed in HL-60 cell lines for measuring the toxicity/ viability of the cells. ELISA tests were performed for evaluating LTA4, LTC4 and COX-2 activities. qPCR was performed to evaluate the expression of mRNA in HL-60 cells. In-vivo experiments were performed in OVA sensitized and challenged BALB/c mice at two doses of Boswellia serrata purified fraction containing 6% Boswellic acid of 50 and 100mg/kg body weight were given orally and the standard drug dexamethasone (DXA, 4 mg/kg body weight) and reduction in lung inflammation was assessed by using an IVIS Xenogen in-vivo fluorescence imaging system. Results: A purified fraction of Boswellia serrata ETOH extracts reduced leukotriene-C4-synthase activity by 52%, leuktotriene-A4-hydrolase activity by 22% and COX-2 activity by 99% with an IC50 of 12.5μg/ml. Intragastric administration of the purified fraction of Boswellia serrata at two doses of 50mg/kg b.w. and 100mg/kg b.w., respectively along with 2-3% HPMC resulted in a ~51% (P value <0.01) reduction in OVA induced lung inflammation in BALB/c mice as observed by imaging tomography. Treatment of the OVA challenged mice with standard drug dexamethasone (DXA) reduced inflammation by ~66% with significant value (P<0.0001). Conclusion: The present study describes that Boswellia serrata ethanolic extracts purified fraction (ETOH-BS) possess significant anti-inflammatory activities in HL-60 and in BALB/c and further supports for its use as Ayurvedic medicines traditionally in the treatment of lung disorders including allergy and asthma.