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INNOSC Theranostics and
Pharmacological Sciences Anticancer activity of cyanobacteria

3.11. Metabolites from other chemical families bartolosides, caylobolide, bisebromoamides, carmaphycins,

3.11.1. Iezoside anaenamides, cocosamides, aurilides, wenchangamides,
coibamide A, largazole, almiramides, dolastatins,
A new compound called iezoside (Figure 6) is isolated from microcolins, hectochlorins, lyngbyabellins, patellamides,
marine cyanobacterium Leptochromothrix valpauliae. It is majusculamides, aplysiatoxins, caldorazole, laxaphycins,
a polyketide peptide with a unique structure that includes a iezoside, and caldoramide. These compounds can be found
2,3-O-dimethyl-α-l-rhamnose branch, a conjugated diene in various cyanobacteria species and have been shown to
group, and an α,β,γ,δ-unsaturated-amide group. Iezoside possess anticancer properties against a range of cancer cell
has been found to exhibit potent anticancer properties lines, such as human colon carcinoma, osteosarcoma, breast
against HeLa cells with an IC value of 6.7 nM, causing cancer, lung cancer, cervical cancer, and fibrosarcoma cells.
50
a delay in the cell cycle, inducing morphological changes However, further research is needed to determine the safety
(spindle-like), and activating the apoptosis-induction and effectiveness of these compounds in animal models and
pathways . clinical applications. It is of utmost importance to find the
[62]
3.11.2. Caldoramide right balance between drug safety and effectiveness for these
compounds in the treatment of cancer. Although the general
Caldoramide (Figure 6) is a pentapeptide compound rule of thumb is to discontinue any further investigations
derived from the marine cyanobacterium Caldora on the slightly effective compounds that elicit severe side
penicillata. This compound exhibits potent cytotoxic effects, there are still no clear guidelines on whether effective
activity against HCT116, HT-29, and MCF-7, with IC 50 compounds that can cause significant side effects should
values of 43.8 ± 3.7, 77.5 ± 1.3, and 33.9 ± 1.3, respectively. be approved for further studies. This uncertainty poses a
However, its cytotoxicity is lower than that of belamide A challenge for drug developers in selecting the appropriate
and dolastatin 10 . drugs that have the highest potential to maximize the overall
[63]
Based on reviews in the literature, several compounds patient outcome in cancer treatment.
have been isolated from different cyanobacteria strains
which may be due to the ability of cyanobacteria to Acknowledgments
produce these metabolites as a chemical defense technique None.
against predators and compete for space and nutrients or
to produce these metabolites when growing in extreme Funding
environment and/or cultivation under different cultivation None.
condition or stress condition (such as high or low pH,
temperature, and salinity). Conflict of interest
Some metabolites have been found to exhibit The authors declare that they have no competing interests.
cytotoxicity against different cancer cell lines, with varying
cellular responses depending on the type of cancer cell. The Author contributions
mechanisms underpinning their cytotoxic effects include Conceptualization: Hanaa Ali Hussein, Fatin L. Khaphi
cell cycle arrest, caspase activation, impairment of the actin Writing – original draft: Hanaa Ali Hussein
cytoskeleton, histone deacetylase inhibition, inhibition Writing – review & editing: All authors
of the trimeric Sec61 translocon, depolymerization of
microtubules, 20S proteasome inhibition, mitochondrial Ethics approval and consent to participate
fragmentation, and prevention of multidrug resistance.
Several other compounds are not reviewed in this paper Not applicable.
due to a lack of information concerning their cytotoxicity Consent for publication
or their selectivity toward normal cells rather than
cancer cells. Therefore, modifying the structure of these Not applicable.
compounds is necessary to create analogs that exhibit high
cytotoxicity and are more selective against cancer cells Availability of data
than the original metabolite. Not applicable.
4. Conclusions References

Cyanobacteria are known to contain various bioactive 1. IARC, 2021, Global Cancer Observatory. France:
compounds, including apratoxin, symplostatin 1, International Agency for Research on Cancer.

Volume 7 Issue 1 (2024) 9 https://doi.org/10.36922/itps.1388