Abstract:
Medicinal plants are the most valuable source of
biomedicine used in traditional systems of
medicine and they also it supplies the chemical
entities for the synthetic drugs [1]. Plant
secondary metabolites are various chemical
compounds produced by the plant cell through
primary metabolic pathways. At present,
traditional medicine, which comprises mostly of
herbal components is preferred globally [2].
There are some secondary metabolites
abundantly used in traditional medicine. Among
these, tannins which are phenolic compounds
possessing high molecular weight ranging from
500-3000 Dalton are abundant in vacuole
tissues of leaves, wood, roots, fruit, and bark of
plants [3]. Up to the present, exceeding 4500
varying flavonoids have been found. They are a
larger category of phenolic compounds.
Flavonoids have been discovered in a lot of
plant tissues including plant cell vacuoles.
Flavonoids are available as monomers and
dimers of oligomers [4]. Antioxidants are
important phytoconstituents in medicinal plants.
An antioxidant is “any substance that, when
present at low concentrations compared with
those of an oxidizable substrate, significantly
delays or prevents oxidation of that substrate”
[5, 6]. Free radicals denote the highly reactive
species capable of widespread, indiscriminate
oxidation and peroxidation of proteins, lipids
, and DNA [7]. Rapid production of free radicals
leads to oxidative damage to biomolecules and
causes serious diseases like degenerative
disorders, cancer, diabetes, neural disorders, and
aging. Hence antioxidants play a vital role to
block free radical production [8, 9].
Antioxidants are known to fulfill their task
through several mechanisms including
retarding, avoiding, or eliminating the oxidative
damage to the susceptible molecules [10]. Many
research has investigated almost all the fresh
herbal medicinal plants and different parts of
them to test their phytochemical content,
antioxidant potential etc., but the above qualities
of commercially available medicinal plants are
not that much touched by researchers although
it is important. Therefore, the current study was
conducted to investigate the secondary
metabolite content and in vitro antioxidant
activities of six selected commercially available
dried medicinal plant parts namely stems of
Coscinium fenestratum, flowers of Aegle
Marmelos, roots of Vetiveria Zizanioides, stems
of Tinospora cordifolia , rhizomes of Acorus
calamus and fruits of Terminalia Chebula which
are commonly employed in herbal medicine to
treat digestive system associated ailments, apart
from their medicinal value in the treatment of
many other diseases. The plant parts were
assessed qualitatively and quantitatively during
the current experiment. These plants are widely
used in the traditional medicine system of Sri
Lanka, due to their vast medicinal properties
that immensely contribute to treating diseases.
