Ulcerative colitis (UC) is a nonspecific, chronic, and recurrent inflammatory bowel disease. Alpinia plants (Zingiberaceae family) are treated as the ideal materials for finding therapeutics agents against UC. Alpinia hainanensis is an important food spice and ethnic medicine in Southwest China. However, there have been few reports about chemical and anti-inflammatory investigations of A. hainanensis rhizomes.

In a study published in Journal of Agricultural and Food Chemistry, researchers from the Xishuangbanna Tropical Botanical Garden (XTBG) and the Shanghai Institute of Materia Medica of the Chinese Academy of Sciences found that the EtOAc-soluble fraction (AHE) of the A. hainanensis rhizome ethanol extract could ameliorate dextran sulfate sodium-induced UC.

By nuclear magnetic resonance, chiral high-performance liquid chromatography separation, and electronic circular dichroism calculation, the researchers isolated and structurally characterized 19 compounds (1-14), including five pairs of previously unreported enantiomers (1-5).

The results showed that compounds (-)-1, (-)-3, 6, 9, 11, and 12 exhibited inhibitory effects on the nuclear factor-κB (a widely expressed nuclear transcription factor) signaling pathway, and the two most active compounds (-)-3 and 6 exhibited significant inhibition of inflammation expression in lipopolysaccharide-induced RAW264.7 cells (mouse macrophage cell line).

The study reports not only the anti-colitis effects of the active fraction from the A. hainanensis rhizome ethanol extract but also active ingredient isolation, structural elucidation, putative biosynthetic pathway analysis, and evaluation of anti-inflammatory effects.

"We suggest that the major active fraction AHE of the A. hainanensis rhizome ethanol extract could be developed as a nutritional and dietary supplement for treating UC," said JI Kailong of XTBG.

Alpinia hainanensis. (Image by JI Kailong)

Alpinia hainanensis. (Image by JI Kailong)