Phycocyanin in Spirulina Shown Effective Against Many Types of Cancer

PHYCOCYANIN FROM SPIRULINA

C-Phycocyanin (C-PC) - a major component of spirulina - has been shown to be promising in cancer treatment; however, although several articles detailing this have been published, its main mechanisms of action and its cellular targets have not yet been defined, nor has a detailed exploration been conducted of its role in the resistance of cancer cells to chemotherapy, rendering clinical use impossible.

From an extensive examination of the literature, it was determined that C-PC has no one specific target, but rather acts on the membrane, cytoplasm, and nucleus with diverse mechanisms of action.

We highlight the cell targets with which C-PC interacts (the MDR1 gene, cytoskeleton proteins, and COX-2 enzyme) that make it capable of killing cells resistant to chemotherapy.

The drugs currently available for cancer treatment, such as vinca alkaloids and taxanes, are not satisfactory in their effectiveness, because of the resistance developed by cancer cells, a major factor in the failure of treatment.

NATURAL ALTERNATIVE CANCER TREATMENT

Natural products have been the basis of cancer chemotherapy for the last 30 years and cyanobacteria like spirulina are a rich source of natural products.

Among these natural compounds, the use of C-phycocyanin (C-PC), a phycobiliprotein (PBP), has led to interesting results in the fight against cancer in several studies.

CANCER AND MULTIDRUG RESISTANCE

Cancer is characterized by the uncontrolled growth and spread of abnormal cells.

It can be caused by external factors (tobacco, infectious organisms, inadequate nutrition, chemical agents, and radiation) and internal factors (hereditary mutations).

However, cancer is essentially a genetic disease, arising from non-lethal changes in DNA that can occur in specific genes, namely, proto-oncogenes and tumor-suppressor genes, which cause uncontrolled cell proliferation when mutated.

A main cause of failures in current chemotherapy treatment is the acquisition of resistance. The MDR phenotype is defined as the resistance of cancer cells to a specific chemotherapeutic drug, accompanied by resistance to other chemotherapeutic drugs that may have different mechanisms of action and structures. 

C-PHYCOCYANIN

C-phycocyanin (C-PC) is a water-soluble protein that was first reported in 1928 and is the main PBP found in Spirulina.

It can constitute up to 20% of the dry weight of Spirulina.

TUMOR-SPECIFICITY OF C-PC

The nonspecificity of numerous chemotherapies induces toxicity in healthy tissues, impairing the quality of life, weakening the immune system, and sometimes generating irreversible damage to the recovery power of the patient.

C-PC specificity has been verified to have significant effects on the multiplication of uterine cervix carcinoma cells (HeLa) without such an effect on non-cancer cells.

The recombinant b-subunit of C-PC has a smaller effect on proliferation in non-cancer cells as well as greater toxicity in metastatic cells.

Hence, C-PC could be an agent for the prevention of metastasis.

CELLULAR TARGETS OF C-PHYCOCYANIN 

Several authors have reported the antiproliferative and cytotoxic capacity of C-PC both in vitro and in vivo.

C-PC has been studied in-vitro (in labs with living cells) for its anti-tumor effects against: 

• Histiocytic Sarcoma - a tumor that can appear can appear in the thyroid and also in the brain
• Acute Myeloid Leukemia (AML) - a cancer of the blood and bone marrow common in adults
• Adenocarcinoma - a type of cancer that develops in the glands that line your organs. Common forms of adenocarcinoma include breast, stomach, prostate, lung, pancreatic and colorectal cancers.
• Squamous carcinoma of the head and neck - including tumors in the throat, mouth, sinuses and nose. Squamous cell carcinoma makes up about 90 percent of all head and neck cancers.
• Colorectal Adenocarcinoma - tumors in the colon and rectum
• Estrogen-responsive breast cancer
• Hepatocellular Cancer/HepG2 - liver cancer
• Lung adenocarcinoma/A549 - lung cancer
• Ovary Adenocarcinoma/SKOV-3 - ovarian cancer

C-PC has been studied in-vivo (in the living) for its anti-tumor effects against:

• MCF-7 - a human breast cancer cell line with estrogen, progesterone and glucocorticoid receptors
• TPA-Induced Skin Tumorigenesis - skin cancer
• Lung Cancer

MECHANISMS OF ACTION

Unlike other natural substances with antitumoral potential, C-PC does not have a known mechanism of action.

Nevertheless, based on existing evidence, we hypothesize that C-PC has more than one specific target; therefore, it has a diversity of effects.

Thus, due to its several targets, the mechanisms by which C-PC generates its antitumor effects would be as follows:

• Cell cycle arrest in specific phases
• Modification of the cellular redox state through the modulation of enzymatic and non-enzymatic antioxidants COX-2
• Induction of apoptosis and necrosis
• Intracellular accumulation and potentialization of the effects of doxorubicin (a traditional anticancer drug).

C-PHYCOCYANIN AND MULTIDRUG RESISTANCE

C-PC is a strong candidate for overcoming chemoresistance.

Some previously cited mechanisms of action of C-PC may also be related to its anti-MDR potential.

The mechanisms for the chemo-resistance of tumor cells are not fully understood, but some studies have shown that the increased expression and/or activity of certain proteins may contribute to this phenotype.

CONCLUSION

The studies in this paper have undeniably shown the chemotherapeutic potential of C-PC.

In addition to its inhibition of cell proliferation, which is a basic requirement, it has the important ability to circumvent multi drug resistance and the lack of specificity of current anticancer drugs.

C-PC demonstrates interesting effects when isolated; however, its interaction with traditional drugs could potentiate the effects of C-PC, mainly by decreasing the extrusion of drugs via the ABC transporter family and/or increasing the specificity of standard drugs. 

 

Comment from SpiruLiving Institute

1. This study illustrates the pharmaceutical / medical sector recognizing that phycocyanins from spirulina have enormous anti-cancer potential. 

2. The research studies on which this paper is based used extracts of dried spirulina.

3. The richest source of unprocessed pure phycocyanin is fresh, or freshly frozen spirulina - never heated never dried - that is recently becoming available in many countries.

4. There are many other phytonutrients in spirulina that also show powerful anti-cancer effects - including beta-carotene, chlorophyl, zeaxanthin, ascorbic acid, 22 different phenols and 11 flavonoids. 

LEARN MORE

C- Phycocyanin: Cellular targets, mechanisms of action and multi-drug resistance in cancer

Pharmacological Reports 2017

 SLI-CA12

Curated by Spiruliving Institute

Spiruliving Institute is a non-profit dedicated to building awareness of the benefits of fresh and fresh-frozen (never dried) spirulina for cancer prevention, as an alternative and/or complementary treatment, and as a functional treatment for cancer survivors to boost health and prevent cancer recurrence. We curate independent research and make it available to the public.