A novel phenol-bound pectic polysaccharide from Decalepis hamiltonii with multi-step ulcer preventive activity

AIM: To investigate H+, K+-ATPase inhibition,
anti-H pylori , antioxidant, and the in vivo antiulcer
potential of a pectic polysaccharide from Swallow root
(Decalepis hamiltonii ; SRPP).
METHODS: SRPP, with known sugar composition
[rhamnose: arabinose: xylose: galactose in the ratio of
16:50:2:32 (w/w), with 141 mg/g of uronic acid] was
examined for anti-ulcer potency in vivo against swim/
ethanol stress-induction in animal models. Ulcer index,
antioxidant/antioxidant enzymes, H+, K+-ATPase and
gastric mucin levels were determined to assess the antiulcer
potency. Anti-H pylori activity was also determined
by viable colony count and electron microscopic studies.
RESULTS: SRPP, containing phenolics at 0.12 g GAE/g,
prevented stress-induced gastric ulcers in animal models
by 80%-85%. Down regulation of gastric mucin 2-3
fold, antioxidant/antioxidant enzymes and upregulation
of 3 fold of H+, K+-ATPase in ulcerous animals were
normalized upon treatment with SRPP. Histopathological
analysis revealed protection to the disrupted gastric
mucosal layer and epithelial glands. SRPP also inhibited
H+, K+-ATPase in vitro , at an IC50 of 77 μg/mL as opposed
to that of 19.3 μg/mL of Lansoprazole and H pylori
growth at Minimum Inhibitory Concentration (MIC) of
150 μg/mL. In addition, free radical scavenging (IC50-40
μg/mL) and reducing power (3200 U/g) activities were
also observed.
CONCLUSION: SRPP, with defined sugar composition
and phenolics, exhibited multi-potent free radical
scavenging, antioxidant, anti-H pylori , inhibition of H+,
K+-ATPase and gastric mucosal protective activities. In
addition, SRPP is non-toxic as opposed to other known
anti-ulcer drugs, and therefore may be employed as a
potential alternative for ulcer management.