Abstract

PHARMACOGNISTIC AND PHYTOCHEMICAL STUDY OF THE STEM BARK OF A FOLK DRUG VISHAGNA- Alstonia venenata R. Br.

Anusha P. R., Chandrakanth Bhat, Hariprasad Shetty and Rejukrishnan

Abstract

Back ground and objective: With enormously diversified ethnic groups and rich biological resources, India represents one of the great emporia of ethno botanical wealth. These plants are under threat due to deforestation, overgrazing and their reckless utilization. It indicates the urgent need of their conservation. Alstonia venenata R. Br is a small tree belonging to Apocynaceae family. Its stem bark is used by tribes in fever, epilepsy and as anti-venom in snake bites. This study is to describe the pharmacognistic and phytochemical characters of the stem bark of Alstonia venenata R. Br. Materials and methods: The test drug was collected from the natural habitat. The pharmacognistic and phytochemical analysis of the stem of Alstonia venenata R. Br. Was done using the standard procedures. Result: Microscopic study of bark shows brownish coloured cork with sclerae’s, and thickly packed cells. Cortex is present with starch grains and prismatic crystals. Secondary cortex shows presence of tannin. Phloem is seen next to a layer of pericycle. Physicochemical analysis shows loss on drying: 10.73 %, Values of total ash, acid insoluble ash and water soluble ash are 5.83%, 0.34% w/w, 30% w/w respectively. The value of water soluble extract and alcohol soluble extract of the drug is 31.6%w/v and 30%w/v respectively. Qualitative analysis shows presence of Alkaloids, Carbohydrate, Steroids, Tannin, Flavonoids, Phenols, Glycosides and Proteins.

Keywords: ethno botanical, pharmacognistic, phytochemical, Alstonia venenata R. Br.