Preparation, characterization, and anti-Helicobacter pylori activity of Bi3+-Hericium erinaceus polysaccharide complex

•HEPs were isolated by enzyme-assisted extraction and ethanol precipitation.•Two new BiHEP complexes with lower content of Bi3+ were prepared.•HEPs themselves have definite inhibition effects on Hp.•BiHEP with lower content of Bi3+ exhibited strong inhibition effects on Hp.

Two new Bi3+-Hericium erinaceus polysaccharide (BiHEP) complexes were prepared using Bi3+ and two purified polysaccharides from H. erinaceus (HEPs), respectively. The complexes were characterized by elemental analysis, FT-IR, CD, SEM, AFM, XRD, and TG. The anti-Helicobacter pylori (Hp) activities in vitro by agar dilution assay of the complexes were evaluated. The molecular weights of HEPs were 197 and 20 kDa, respectively. All the analyses confirmed the formation of new BiHEP complexes with lower content of Bi3+ compared with colloidal bismuth subcitrate (CBS), the most utilized bismuth preparation clinically. Furthermore, HEPs themselves have definite inhibition effects on Hp, and BiHEP complexes have lower content of Bi exhibited strong inhibition effects on Hp (MIC = 20 μg/mL), similar to that of CBS with higher content of Bi. The study provides a basis for further development of multiple treatments of Hp infection or new medicines.