O. sanctum L. (O. tenuiflorum) is an important sacred medicinal plant of India known as Holy Basil or Tulsi. The chemical composition of
volatile oil is highly complex and comprises high ratio of phenylpropanoids and
terpenes, and some phenolic compound or
flavonoids such as
orientin and
vicenin. These minor
flavonoids are known to be
antioxidant and anticancer in nature.
Orientin reported as potential
anticancer agent due to anti-proliferative activity on human
liver cancer cell line HepG2, but its mechanism of action is not fully explored. In the present work an in-silico structure-activity relationship study on
orientin was performed and built a pharmacophore mapping and QSAR model to screen out the potential structurally similar analogues from chemical database of Discovery Studio (DSv3.5, Accelrys, USA) as potential
anticancer agent. Analogue fenofibryl
glucuronide was selected for in vitro cytotoxic/anticancer activity evaluation through MTT assay. Binding affinity and mode of action of
orientin and its analogue were explored through molecular docking studies on
quinone oxidoreductase, a potential target of
flavonoids. Contrary to the assumption, in vitro results showed only 41% cell death at 202.389 μM concentration (at 96 hrs). Therefore, we concluded that the selected
orientin analogue fenofibryl
glucuronide was non-cytotoxic/non-anti-carcinogenic up to 100 μg/ml (202.389 μM) concentrations for a long term exposure i.e., till 96 hrs in human
cancer cells of HepG2. We concluded that
orientin and its analogue fenofibryl
glucuronide as pure compound showed no activity or less cytotoxicity activity on
liver cancer cell line HepG2.