INH₂BP (5-iodo-6-amino-1,2-benzopyrone), a poly-ADP ribose polymerase inhibitor, has been shown to possess anti-cancer, anti-viral, and anti-inflammation properties. The aim of this study was to investigate the protective effect of INH₂BP against oxidative stress-induced apoptosis in H9c2 cardiomyoblast cells. While the treatment of H9c2 cardiomyoblasts cells with hydrogen peroxide (H₂O₂) caused a loss of cell viability and an increase in the number of apoptotic cells, INH₂BP significantly protected the cells against H₂O₂-induced cell death without any cytotoxicity. Our data also shows that INH₂BP significantly scavenged intracellular reactive oxygen species (ROS), and markedly enhanced the expression of antioxidant enzymes such as Mn-SOD (superoxide) and Cu/Zn-SOD, and heme oxygenase-1, which was accompanied by the concomitant activation of extracellular regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK) phosphorylation in H9c2 cells. The effects of INH₂BP on ERK1/2 and p38 MAPK phosphorylation were abrogated by PD98059, an ERK1/2 inhibitor, and SB203580, a p38 inhibitor. In addition, inhibition of ERK1/2 and p38 MAPK by these inhibitors significantly attenuated INH₂BP-mediated H9c2 viability as well as cleaved caspases-3, Bax, and Bcl-2 activation. Taken together, these results demonstrate that INH₂BP prevents H₂O₂-induced apoptosis in H9c2 cells by reducing the production of intracellular ROS, regulating apoptotic-related proteins, and the activation of the ERK1/2 and p38 MAPK.

The rhizome of Atractylodes macrocephala Koidz (AM) is a constituent of various Qi booster compound prescriptions. We evaluated inflammatory responses in macrophages and T cells isolated from mice following oral administration of AM water extract (AME). Peritoneal exudate cells were isolated from thioglycollate-injected mice and alterations in scavenger receptors were examined. Peritoneal macrophages were stimulated with lipopolysaccharide (LPS). Serum cytokine responses to intraperitoneal LPS injection were also evaluated. Splenocytes were isolated and their composition and functional responses were measured. The content of atractylenolide I and atractylenolide III, known anti-inflammatory ingredients, in AME was 0.0338 mg/g extract and 0.565 mg/g extract, respectively. AME increased the number of SRA(+)CD11b(+) cells in response to thioglycollate. Peritoneal macrophages isolated from the AME group showed no changes in inflammatory markers such as tumor necrosis factor- (TNF-) α, interleukin- (IL-) 6, inducible nitric oxide synthase, and cyclooxygenase-2 but exhibited a decrease in CD86 expression. Interestingly, AME decreased the serum levels of TNF-α and IL-6 upon intraperitoneal injection of LPS. Regarding the adaptive immune system, AME increased the CD4(+) T cell population and major histocompatibility complex class II molecule expression in the spleen, and cultured splenocytes from the AME group showed increased production of IL-4 concurrent with decreased interferon-γ production during T cell activation. AME promoted the replenishment of peritoneal macrophages during the inflammatory response but its anti-inflammatory activity did not appear to be mediated by the modulation of macrophage activity. AME also altered the immune status of CD4 T cells, promoting the Th2 response.