Phytochemicals in cancer therapy
28 June 2023
OVERVIEW
Cancer is one of the leading causes of death worldwide. Considering the high incidence of the adverse effects of current chemotherapeutics, discovering molecules with strong anti-cancer potential and low toxicity is imperative in the search for more effective cancer treatments. One promising avenue of cancer research is the application of phytochemicals in cancer therapy.
WHAT ARE PHYTOCHEMICALS?
Phytochemicals are plant-based bioactive compounds that are notable for their health benefits. These compounds are commonly found in:
- fruits,
- vegetables,
- beans,
- nuts,
- herbs, and
- grains.
The main groups of phytochemicals include carotenoids, polyphenols, terpenes, isoprenoids, phytosterols, alkaloids, saponins, dietary fibres, flavonoids and isoflavones. Many of these compounds are present in various parts of plants, such as seeds, flowers, bark, fruit, leaves, or rhizomes.
THERAPEUTIC POTENTIAL OF PHYTOCHEMICALS
Plants have been used in traditional medicine for centuries. Nearly 80 % of the global population traditionally use natural compounds in medicinal plants. The therapeutic potential of these compounds in the prevention and treatment of cancer (including inflammatory, cardiovascular and neurodegenerative diseases) is attributed to their strong anti-oxidant, anti-inflammatory, cell-cycle arrest- and apoptotic-inducing properties.
Interestingly, many phytochemical-based studies involving cancer cell lines or animal models indicate that these compounds could have anti-cancer or chemo-preventative properties. Several of these studies have shown that phytochemicals are able to target certain cell-signaling pathways that affect the regulation of proliferation, differentiation and the progression of cancer cells, while displaying no or minimal toxicity in normal cells.
It is also notable that various pre-clinical studies have shown that combination therapies involving phytochemicals and conventional anticancer drugs are more effective than individual treatment, with many reports alluding to the potential of phytochemicals as strong adjuvants in cancer therapy.
Plant-derived chemotherapeutics that are currently used include:
- vinca alkaloids (vinblastine, vincristine, vindesine, and vinorelbine),
- taxane diterpenoids (paclitaxel, docetaxel),
- camptothecin derivatives (irinotecan, topotecan), and
- epipodophyllotoxins (etoposide, teniposide)
Considering that only 15 per cent of the approximately 300,000 described terrestrial plant species have been systematically studied for their biological activities and/or phytochemical profiles; it is evident that an enormous field of exploration exists for research on phytochemicals.
LIMITATIONS ASSOCIATED WITH THE THERAPEUTIC APPLICATION OF PHYTOCHEMICALS
The application of phytochemicals in cancer therapy is limited due to their poor bioavailability (which accounts for the proportion of the absorption, digestion and metabolism of these compounds after entering the circulation system). Also, the physico-chemical properties and the potential of some phytochemicals to induce systemic toxicity if administered in excess, could lead to adverse effects.
Nevertheless, numerous epidemiological and experimental studies allude to the protective role of phytochemicals in various types of diseases. To this end, more research is needed to clarify the potential of phytochemical-based treatments against cancer.
REFERENCES
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Terms of Use
The content provided is for educational purposes and is not intended to offer personal medical advice. You should seek the advice of your physician or other qualified health provider with any questions you may have relating to a medical condition.
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