GUAVA AND CANCER: EXPLORING THE ANTI-CARCINOGENIC POTENTIAL OF GUAVA EXTRACT
According to the WHO (World Health Organization), cancer is the second leading cause of death worldwide and has now become a global burden to the healthcare system. As we all know, cancer treatment is expensive, making it difficult to afford in developing countries with low income. Therefore, it is high time to find economical anticancer treatments that can be used either as a sole agent or as adjuvant therapy with minimal side effects.
For this purpose, many plants have been explored for their anticarcinogenic potential. Among them, Psidium guajava commonly known as the guava plant has shown promising anti-carcinogenic potential. Interestingly, different parts of the plant, such as fruits, leaves, bark, roots, and branches, have been studied for cancer treatment. So far, fewer than 50 in vitro and some in vivo studies indicate the anticancer potential of guava extract.
WHAT IS CANCER?
Before diving into how guava may help, let’s first understand what cancer actually is.
Cancer is simply the abnormal growth of cells that do not follow signaling or instructions as normal body cells do. In simple words, we can say there is an imbalance between increased cell proliferation and decreased cell death.
REASONS FOR ABNORMAL GROWTH OF CANCER CELLS
To better understand the role of guava, we must know why cancerous cells behave abnormally:
1. Cancerous cells do not undergo apoptosis (programmed cell death), while normal cells do.
2. Cancerous cells exhibit metastasis, a process in which tumor cells migrate from their point of origin to other parts of the body.
3. Cancerous cells exhibit angiogenesis, a process in which new blood vessels are formed to supply nutrients and oxygen to tumor cells, supporting their growth and spread.
4. Cancerous cells modulate the immune system, preventing the body from recognizing them, which allows them to spread easily within the host body.
BIOACTIVE COMPONENTS OF GUAVA
Now, what makes guava so special? The answer lies in its rich chemical profile. Guava contains phytochemicals, polyphenols, essential oils, carotenoids, vitamin C, quercetin, kaempferol, lycopene, flavonoids, saponins, tannins, calcium, phosphorus, iron, vitamin A, vitamin B, beta-sitosterol, alkaloids, triterpenoids, guajonoic acid, uvoal, oleanolic acid, ursolic acid, apigenin, and resveratrol.
ENZYMES, PROTEINS, AND SIGNALING PATHWAYS INVOLVED IN CARCINOGENESIS
To understand how guava exerts its effects, we also need to look at the biological targets involved in cancer progression. Several enzymes, proteins, and signaling pathways play a key role in carcinogenesis, including
• COX-2: Promotes tumorigenesis by producing prostaglandin E2 (PGE-2), which induces inflammation, proliferation, angiogenesis, metastasis, chemotherapy resistance, and immune evasion.
• Cyclin-D: Regulates the cell cycle. Its overexpression promotes carcinogenesis.
• VEGF (Vascular Endothelial Growth Factor): Secreted by tumor cells; binding to VEGF receptors initiates angiogenesis.
• MMP (Matrix Metalloproteinases):
Promote carcinogenesis by enhancing metastasis and angiogenesis.
• MMP-2: Stimulates angiogenic factors.
• MMP-9: Breaks down extracellular matrix (ECM) barriers, promoting metastasis and angiogenesis.
• IL-6: Overexpression induces proliferation, angiogenesis, metastasis, and prevents apoptosis.
• IL-8: Promotes proliferation, angiogenesis, metastasis, and immune evasion.
• PGHS (Cyclooxygenase/COX-1, COX-2): Overexpression promotes carcinogenesis and inflammation.
• Androgen Receptor Binding (Prostate Cancer): Abnormal androgen receptor signaling in mutated genes promotes uncontrolled prostate cell growth.
• MAPK (Mitogen-Activated Protein Kinase): Overactivity regulates abnormal cell growth.
• Akt (Protein Kinase B): Overexpression promotes tumorigenesis.
• mTOR (Mammalian Target of Rapamycin): Mutation promotes uncontrollable cell growth.
• S6K1 (Ribosomal S6 Kinase): Mutation induces proliferation and metastasis.
• NF-κB (Nuclear Factor Kappa B): Promotes inflammation and regulates cellular functions.
MECHANISM OF ACTION OF GUAVA FOR ANTI-CARCINOGENIC POTENTIAL
Now, let’s explore how guava works against cancer through different mechanisms:
1. High Antioxidant Activity
Guava is rich in antioxidants such as quercetin, vitamin C, and kaempferol. These reduce oxidative stress by scavenging free radicals and inflammation, subsequently lowering the risk of cancer.
What is oxidative stress?
Oxidative stress occurs when free radicals accumulate due to a deficiency of antioxidant nutrients in the body. These free radicals damage cells and tissues, potentially leading to diabetes, Alzheimer’s disease, arthritis, and cancer. Mutated cells resulting from oxidative stress can initiate carcinogenesis.
2. Antiproliferative Activity
Furthermore, compounds like quercetin, resveratrol, guajadiol, and guvainoside inhibit abnormal proliferation of cells, showing antiproliferative effects against cancer.
3. Induction of Apoptosis
In addition, guava’s potent antioxidants induce apoptosis by inhibiting pathways such as S6K1, mTOR, Akt, and MAPK, thereby suppressing tumor growth.
4. Anti-Metastasis
Moreover, apigenin, polyphenols, and flavonoids synergistically inhibit metastasis by reducing tumor cell migration.
5. Anti-Angiogenesis
Another important mechanism is guava’s ability to suppress angiogenesis by inhibiting COX-2, VEGF, MMP-2, MMP-9, Cyclin-D, IL-6, and IL-8.
6. Inhibition of Mutated Genes (Oncogenes)
Additionally, guava extract, rich in lycopene and antioxidants, inhibits oncogenes and suppresses carcinogenesis by blocking PGHS activity and androgen receptor binding.
7. Reduction of Inflammation
Guava also reduces prostaglandin secretion and blocks NF-κB and other inflammatory pathways involved in carcinogenesis.
8. Immune Response
Finally, guava boosts immune activity through T-helper cells, IL-2, and interferon-gamma, helping suppress tumors.
DOES GUAVA EXTRACT DAMAGE NORMAL BODY CELLS?
One major concern with anticancer agents is their toxicity to normal cells. Fortunately, guava is not cytotoxic to healthy cells but is effective against cancerous ones. This suggests it may help reduce chemotherapy-related hazards in the future.
CONCLUSION
In conclusion, future studies and research will help explore the full anticarcinogenic potential of guava. Nevertheless, it is an inexpensive, fiber rich dietary option that holds promise as an adjuvant therapy alongside chemotherapy.
FAQS ABOUT GUAVA AND HEALTH
1. Can eating guava prevent cancer?
Guava is rich in antioxidants like vitamin C, lycopene, and flavonoids, which may help reduce oxidative stress linked to cancer. However, guava or its extract should not be considered a cure. More human studies are needed.
2. Is guava safe for everyone to eat?
Yes, guava is generally safe for most people. However, individuals with irritable bowel syndrome (IBS) or sensitive digestion may experience bloating if they consume large amounts.
3. How much guava should I eat daily?
One to two medium-sized guavas a day can provide a good boost of fiber, vitamin C, and antioxidants. Balance is key.
4. Can guava supplements replace fresh fruit?
Guava extracts and supplements may offer concentrated benefits, but fresh fruit provides fiber and other phytonutrients not always present in supplements. Whole food is usually the better choice.
DISCLAIMER
This article is for educational purposes only and should not replace professional medical advice. Always consult your doctor or healthcare provider before making changes to your diet, especially if you have existing medical conditions or are on medication.
CALL TO ACTION to Action
Guava is more than just a tropical delight it’s a nutrient powerhouse with potential benefits for immunity, digestion, and even cancer prevention. Adding this fruit to your daily routine may support overall health in a natural way.
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