Background: Since centuries plant-based compounds are known for the treatment of cancer in
both traditional and contemporary medicine. The problems like target non-specificity and toxicity are
well-known regarding anticancer drugs. Therefore, target specific search of novel entities is constant. Isothymusin
is a dimethoxy, trihydroxy flavone present in plants like Ocimum sanctum, and Limnophilla
geoffrayi. There are limited reports available on the anticancer potential of isothymusin.
Objectives: The effects of isothymusin on redox status, cell cytotoxicity, and targets involved in the promotion
and progression of the cancer cells have been investigated.
Methods: Antiproliferative efficacy was evaluated by MTT, Neutral Red Uptake, and Sulforhodamine-B
assays. The spectrophotometric methods were adopted to study the effect against selected targets. Redox
activity was assessed by in vitro antioxidant assays and the interaction study, ADMET profiling, and toxicity
assessments were done in silico.
Results: Isothymusin scavenges the radicals, i.e., DPPH and nitric oxide with moderate ferric reducing
potential. It affected the proliferation of leukemia, colon, skin, and breast cancer cell lines by more than
50% but moderately affected prostate, kidney, lung, hepatic, and breast adenocarcinoma (up to 48%). Isothymusin
inhibited the enzymes associated with the promotion stage of cancer, including cycloxygenase-
2 and lipoxygenase-5. Additionally, it also inhibited the activity of proliferation markers like cathepsin-
D, dihydrofolate reductase, hyaluronidase, and ornithine-decarboxylase. Besides, in silico studies supported
the in vitro enzyme inhibition assays outcome. Toxicity studies showed promising results of
chemical descriptors and non-skin-irritant, moderate ocular-irritancy, and in vitro Ames test confirmed
Conclusion: Isothymusin showed radical scavenging and anti-proliferative activities, which may be
taken up as a phytochemical lead for the synthesis of analogues possessing enhanced anticancer potential.