In the Dai minority region of China, the Aspidopterys obcordata (Hei Gai Guan) has been used a fork medicine for treating urinary tract infection, cystitis and urinary tract stones. Previous studies showed that the Aspidopterys obcordata fructo oligosaccharide (AOFOS) from Hei Gai Guan had inhibitory effects on the growth of calcium oxalate crystals of the kidney stones (also known as urolithiasis). However, the effects of plant polysaccharides on kidney stone prevention and treatment are poorly understood.
In a study published in Journal of Ethnopharmacology, researchers from Xishuangbanna Tropical Botanical Garden (XTBG) investigated the effect of inulin-type AOFOS from Aspidopterys obcordata on urinary calcium oxalate crystals to explore its effectiveness and mechanism in treating renal calculi in rats.
The researchers firstly developed a renal stone rat model and examined the transport kinetics and effectiveness of AOFOS in living rats. By combining crystallization experiments with density functional theory calculations, they then investigated the relationship between polysaccharides and calcium oxalate crystals.
They found that the inulin-type AOFOS extracted from Aspidopterys obcordata had inhibitory effects on kidney stones in rat models.The polysaccharide was transported to the urinary system. Low dose of AOFOS had a good therapeutic effect on kidney stones in rats, but the therapeutic effect of medium and high dose of polysaccharide was weak.
They then examined the anti-stone ability of rat urine and polysaccharide content under different treatment conditions. Under acidic conditions, calcium oxalate crystal formation was slower and tended toward monohydrate crystal formation. However, with increasing pH, the crystal formation rate increased, resulting in crystals with various shapes and larger volumes, including calcium oxalate dihydrate (COD) crystal formation.
The researchers further found that the accumulation of polysaccharide was inhibited by controlling their crystallization and modulating calcium ion and oxalate properties in the urine. Thus, the kidney stone formation was effectively prevented in the rats.
"Our study provides valuable insights into the potential therapeutic use of the polysaccharide AOFOS extracted from Aspidopterys obcordata in managing kidney stone formation,” said XU Youkai of XTBG.
Contact
XU Youkai
Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, Yunnan, China
E-mail: xyk@xtbg.org.cn
F-First published: 3 April 2024
