Protective anti-inflammatory activity of tovophyllin A against acute lung injury and its potential cytotoxicity to epithelial lung and breast carcinomas

Tovophyllin A (TA) is a xanthone isolated from Garcinia mangostana L. (GM, Guttiferae) pericarps that possesses various beneficial bioactivities. However, its protective effects on acute lung injury (ALI) and lung carcinoma have not yet been explored. The current work was designed to investigate the protective potential of TA against ALI and explore the possible mechanism of action. Two different doses of TA were tested against lipopolysaccharide (LPS)-induced ALI in mice. Moreover, the cytotoxic potential of TA was assessed in epithelial lung (A549 cells) and breast (MCF7 cells) carcinomas utilizing a sulforhodamine B (SRB) assay. The results revealed that TA possessed the ability to protect against LPS-induced acute lung damage. TA attenuated LPS-induced pulmonary edema, as it lowered the protein content in the bronchoalveolar lavage fluid (BALF) and the lung W/D ratio. In addition, TA counteracted inflammatory cell infiltration into the lung tissue, as shown by the total and differential cell counts in the BALF and histopathological examination of the lungs. The oxidative burden in the pulmonary tissue was ameliorated in TA-treated animals as there were reductions in the malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) levels in the lung tissue. TA increased the levels of antioxidants such as reduced glutathione (GSH) and superoxide dismutase (SOD) in the lungs. Furthermore, TA inhibited the activation of nuclear factor-κB (NF-κB). In addition, TA had potent anti-inflammatory activity as it reduced the immunoexpression and levels of the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6. Furthermore, TA showed significantly enhanced cytotoxic activity against the MCF-7 and A549 cell lines with IC₅₀s of 6.1 and 2.2 µM, respectively, compared to doxorubicin (IC₅₀s of 0.41 and 0.74 µM, respectively). In conclusion, TA ameliorates LPS-induced ALI through the suppression of oxidative stress and inflammation. These findings suggest the potential use of this compound as a future treatment for ALI.