Enhancement of the functionality of attenuating acute lung injury by a microemulsion formulation with volatile oil of Angelicae Sinensis Radix and Ligusticum Chuanxiong Rhizoma encapsulated

Acute lung injury (ALI), a clinical syndrome of acute respiratory failure due to acute lung inflammation, remains a substantial public health problem in the worldwide. Ligusticum Chuanxiong Rhizoma and Angelicae Sinensis Radix was herb-pair of the traditional Chinese medicine. Modern pharmacological studies have shown that volatile oil extracted from Chuanxiong Rhizome and Angelicae Sinensis Radix is identified as an important active ingredient, which has good antipyretic, analgesic and anti-inflammatory effects. However, whether their volatile oil combination (CA-VO), has effects on the prevention and treatment of ALI has not been reported yet. Due to poor water solubility and low oral bioavailability of CA-VO, CA -VO-loaded microemulsion (CA-VO-ME) was formulated to enhance its oral bioavailability. The physical properties of CA-VO-ME were characterized. The pharmacokinetic parameters and the effect on ALI were evaluated. The particle size, polydispersity index, zeta potential, and encapsulation efficiency of CA-VO-ME were 20.19 ± 0.08 nm, 0.091 ± 0.01, 36.33 ± 4.29%, and 93.75%, respectively. CA-VO-ME had a greater bioavailability (214%) than CA-VO. CA-VO-ME reduced the lipopolysaccharide (LPS)-induced increase in levels of nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) in vitro and/or in vivo. Moreover, CA-VO-ME treatment notably decreased the lung index, ameliorated histopathological changes and prolonged the survival of ALI mice. By comparison, CA-VO-ME exerted a better effect on ALI than CA-VO, suggesting that CA-VO-ME is a promising drug for the treatment of ALI.