In vivo anti-ulcer, anti-stress, anti-allergic, and functional properties of gymnemic acid isolated from Gymnema sylvestre R Br.

BACKGROUND: Gymnema sylvestre is a highly valued ethno pharmacologically important medicinal plant used currently in many poly-herbal formulations due to its potential antidiabetic activity and other health benefits. The present study was carried out to analyze the anti-stress, anti-allergic, and antiulcer activity of the bioactive compounds present in Gymnema sylvestre leaves.

METHODS: The preliminary phytochemical screening for bioactive compounds from aqueous extracts revealed the presence of alkaloids, triterpenes, flavonoids, steroids, and saponins. The antioxidant activities were investigated using DPPH radical scavenging method. The characterization of the extract was carried out using standard compound by High Performance Thin Layer Chromatography (HPTLC) and phytochemical analysis in terms of total phenol, total flavonoids, reducing power and antioxidant potentials, etc. The in vivo studies on albino mice proved the purified fraction has anti-stress/anti-allergic activity against milk induced leucocytosis/eosinophilia and able to inhibit the aspirin induced gastric ulcers.

RESULTS: The quantitative estimation for aqueous extract exhibited total antioxidant (9.13 ± 0.04 μg/g), flavonoids (125.62 ± 26.84 μg/g), tannin (111.53 ± 15.13 μg/g), total phenol content (285.23 ± 1.11 μg/g) and free radical scavenging (52.14 ± 0.32%). Further the aqueous extract was consecutively purified by TLC and silica column chromatography. The purified fractions were characterized by HPTLC and GC-MS and the component was identified as gymnemic acid. The potency of the antimicrobial activity of the extract was studied with bacteria. Pharmacological experiments clearly demonstrated that the extracts of all plants given orally showed significant gastric protection against the asprin-induced gastric ulcer model in mice. Furthermore, healing effects were also confirmed through histopathological examination.

CONCLUSIONS: The aqueous extracts of the leaves of Gymnema sylvestre possess anti ulcerogenic, Anti allergic, Anti stress, properties that may be due to cytoprotective mechanism. These results support the ethno medical uses of the plant in the treatment of gastric ulcer.