Introduction
Breast and ovarian cancers remain devastating diseases, particularly in regions like Sri Lanka where they rank among the leading causes of cancer-related deaths in women 1 3 . While conventional treatments like chemotherapy exist, their severe side effects drive the search for gentler, nature-derived alternatives.
Enter the humble mango—specifically, the bark of two Sri Lankan varieties, Rata Amba (RA) and Karthakolomban (KA). New research reveals these culturally revered trees harbor potent compounds that selectively kill cancer cells while sparing healthy ones, merging ancient wisdom with cutting-edge oncology 3 5 .
The Mango Medicine Legacy
Botanical Background
Mangifera indica (common mango) and the endemic Mangifera zeylanica are staples in Sri Lankan traditional medicine. For generations, healers have used bark decoctions to treat cancers, uterine ailments, and infections 1 5 . M. zeylanica, classified as "vulnerable," is especially prized but understudied—until now.
Key Insight
The vulnerable M. zeylanica species contains unique resorcinolic lipids not found in common mango varieties, making conservation efforts crucial for future drug development 1 .
Key Anti-Cancer Compounds
Research identifies several bioactive agents in mango bark:
2. Resorcinolic lipids
Phenolic compounds isolated from M. zeylanica bark. These penetrate cancer cell membranes, inducing oxidative stress and apoptosis 1 .
3. Gallic acid derivatives
Work synergistically with mangiferin to block multiple cancer growth pathways, including MEK1 and JNK1/2 8 .
Traditional Knowledge Validation
Modern research is now confirming what Sri Lankan traditional healers have known for centuries—that mango bark contains powerful medicinal compounds. This intersection of ethnobotany and modern pharmacology could lead to breakthrough cancer treatments 5 .
Inside the Lab: Decoding Mango Bark's Cancer Fight
The Pivotal Experiment
A landmark 2016 study led by Ediriweera et al. investigated bark extracts from RA and KA mango varieties against breast (MCF-7, MDA-MB-231) and ovarian (SKOV-3) cancer cells, while testing safety on normal breast cells (MCF-10A) 3 .
1. Extraction
Bark samples were dried, powdered, and processed using solvents (hexane, chloroform, ethyl acetate, methanol) to isolate different phytochemical fractions.
2. Cytotoxicity Screening
Treated cancer and normal cells with extracts for 48 hours. Viability was measured via the Sulforhodamine B (SRB) assay, which stains live proteins.
3. Apoptosis Detection
Active extracts underwent further testing:
- Caspase 3/7 activation (enzymes that execute cell death)
- DNA fragmentation (a hallmark of apoptosis)
- Microscopy (Hoechst staining for condensed DNA)
4. Antioxidant Activity
Free radical scavenging capacity was assessed using the DPPH assay.
Results That Stood Out
- Methanol extracts showed the highest cancer-specific toxicity. RA extract was particularly potent against ovarian cancer (IC₅₀: 71.5 µg/mL), outperforming KA (IC₅₀: 137.2 µg/mL) 3 .
- Selective toxicity: Both extracts spared normal cells (IC₅₀ >255 µg/mL) (Table 1).
- Apoptosis Confirmed: Extracts activated caspases 3/7 and fragmented DNA in >60% of MCF-7 cells.
| Cell Line | RA Methanol Extract | KA Methanol Extract |
|---|---|---|
| MCF-7 (Breast ER+) | 81.1 | 123.9 |
| MDA-MB-231 (Breast TN) | 91.5 | 111.2 |
| SKOV-3 (Ovarian) | 71.5 | 137.2 |
| MCF-10A (Normal) | 255.6 | 615.6 |
| Marker | Result |
|---|---|
| Caspase 3/7 Activation | 4.2-fold increase vs. control |
| DNA Fragmentation | 68% of cells affected |
| ROS Production | Significant increase (p<0.01) |
Research Significance
The study demonstrated that mango bark extracts can selectively target cancer cells while showing minimal toxicity to normal cells—a crucial advantage over conventional chemotherapy that often damages healthy tissue 3 . The RA variety showed particular promise against ovarian cancer cells, suggesting it may contain unique compounds worth further investigation.
The Scientist's Toolkit: Key Reagents in Mango Cancer Research
| Reagent/Technique | Role in Discovery |
|---|---|
| Sulforhodamine B (SRB) Assay | Measures cell viability via protein content; confirmed dose-dependent cancer cell death 3 . |
| DPPH Radical Scavenging Assay | Quantified antioxidant capacity of extracts, linked to anti-cancer efficacy 3 . |
| High-Performance Liquid Chromatography (HPLC) | Isolated and purified resorcinolic lipids from M. zeylanica 1 . |
| Nuclear Magnetic Resonance (NMR) | Elucidated the structure of new compounds (e.g., resorcinolic lipid C42H72Oâ‚‚) 1 . |
SRB Assay Process
- Cells treated with extracts for 48 hours
- Fixed with trichloroacetic acid
- Stained with Sulforhodamine B dye
- Protein-bound dye measured spectrophotometrically
This method provided reliable quantification of cell viability across different extract concentrations 3 .
Compound Identification
Advanced techniques like HPLC and NMR were crucial for:
- Isolating active fractions
- Determining molecular structures
- Identifying novel compounds like unique resorcinolic lipids 1
Beyond the Bark: Implications and Future Horizons
Synergy in Mango's Arsenal
- Other parts (kernels, peel) also show promise. Kernel extracts inhibit triple-negative breast cancer cells (IC₅₀: 30 µg/mL) 4 .
- M. zeylanica's unique resorcinolic lipids target oxidative stress pathways, a vulnerability in cancer cells 1 .
Conservation Meets Innovation
With M. zeylanica vulnerable, sustainable cultivation is urgent. Projects like China-FAO-Sri Lanka's tropical fruit initiative boost yields using advanced agricultural techniques, ensuring supply for future drugs .
Global Collaboration Potential
The intersection of Sri Lanka's rich biodiversity, traditional knowledge, and international research capabilities creates exciting opportunities for developing novel cancer therapies. Partnerships between local researchers and global institutions could accelerate progress while ensuring equitable benefit-sharing .
Conclusion: Nature's Pharmacy, Reinvented
Sri Lanka's mango trees embody a powerful convergence of tradition and translational science. Their bark, once a folk remedy, now stands validated as a source of precise anti-cancer agents. While challenges remain—standardizing extracts, conserving species, advancing to clinical trials—the groundwork is laid. As global collaborations flourish , these "miracle trees" may well yield the next generation of targeted, tolerable cancer therapies.
Further Reading: Explore the full studies in [Biomedicine & Pharmacotherapy (2017)] 1 and [Journal of Pharmaceutical Research International (2016)] 3 .