Despite the great development in human medicine, cancer is still a serious threat to public health and consequently, research on new anticancer agents should be continued. Natural products from medicinal plants (e.g., Plectranthus species) continue to be a substantial resource to treat different diseases, particularly in developing countries. Plectranthus species are rich in diterpenoids, which are reported to be responsible for various pharmacological activities such as cytotoxic activity. P. mutabilis Codd. is a perennial succulent herb containing Nepetoidins A and Nepetoidins B in its essential oils and have limited information available in the literature.
In this study, we performed an ultrasound-assisted acetone extraction of air-dried P. mutabilis whole plant followed by a bio-guided fractionation using the Artemia salina general toxicity assay that resulted in the identification of four compounds: Coleon U quinone (1), 8α,9α-Epoxycoleon U quinone (2), Coleon U (3, maor) and 7-hydro,14-deoxycoleon U (4). The cytotoxicity of the isolated compounds and P. mutabilis extract was evaluated using a model system of sensitive (NCI-H460) and MDR (NCI-H460/R) cells, along with normal human embryonal bronchial epithelial cells (MRC-5). Studies of modulation of P-gp activity are ongoing to unveil the interaction of these compounds and extract with P-gp.
1. Where the researchers only interested in identification of diterpenes?
2. What informed the choice of the topic?
I think more polar constituents from the plant such as flavonoids would have exhibited more effect compared to diterpenes. Expanding the scope could have helped.
Thank you
We study Plectranthus species because they are used traditionally for the treatment of different ailment including cancer. Cytotoxicity screenings have identified Plectranthus plants as potential sources of antitumor lead compounds. Specifically, they are known to contain diterpenoids with abietane skeleton known for their cytotoxic activity. Hence the isolation of diterpenes from Pleactranthus mutabilis is therefore in agreement with other studies identifying Plectranthus species as a source of abietane diterpenoids.
Thank you
