In a recent study published in Nutrients, researchers conducted in vitro analyses on saffron-treated prostate cancer (PCa) cells to assess its impact on intermediates in prostate carcinogenesis.
Study: Mechanism of Antitumor Effects of Saffron in Human Prostate Cancer Cells. Image Credit: New Africa/Shutterstock.com
Background
In the United States, prostate tumors cause considerable mortality in males. Androgen receptor (AR) antagonists are critical in treating advanced prostate cancer, although some individuals develop castration-resistant disease, emphasizing the need for alternate therapies.
The spice and flavoring ingredient, saffron, has demonstrated anticancer activity in several malignancies. Studies have reported on the anticancer effects of saffron on aggressive PCa cell-derived xenografts in mice.
About the study
The researchers of the present study explored the impact of saffron therapy on deoxyribonucleic acid (DNA) repair, epigenetic pathways, and inflammatory signaling in prostate cancer cells in vitro.
The team examined the anticancer properties of powdered crude saffron extracts on the LNCaP and PC3 prostate tumor cells. They created saffron metabolites by dissolving 20.0 mg per mL of saffron in ultra-pure-type water and mixing it for an hour with an orbital shaker in the dark. The saffron extracts contained 5.0 mM of safranal, crocin, and crocetin.
The cells could adhere for 24 hours before treatment with saffron metabolites in varying concentrations (0.50 mg per mL, 2.0 mg per mL, and 4.0 mg per mL) of water-soluble-type saffron with 1.0 mL of medium. The team evaluated the impact of saffron therapy on LNCaP survival using direct cell counters using the trypan blue stain.
The researchers obtained total ribonucleic acid (RNA) from cultivated cells to perform real-time quantitative polymerase chain reaction (RT-PCR) of genes associated with epigenetic pathways and DNA repair in prostate cancer LNCaP cells following saffron therapy.
They also investigated B cell lymphoma 2 (Bcl-2) messenger ribonucleic acid (mRNA) expression and the inflammation-related interleukin-2 (IL-2) levels following treatment.
The team used inverted microscopes to assess the morphological alterations in PCa cells following saffron treatment (4.0 mg/mL).
They performed Western blot analysis to evaluate the expression of epigenetic regulatory genes, including DNA methyltransferase 1 (DNMT1), methyl-CpG-binding domain protein 2 (MBD2), and DNMT3b, in saffron-treated LNCaP cells compared to controls.
Results
Saffron suppressed cell growth in androgen-sensitive PCa cells via apoptotic mechanisms. In saffron-treated PCa cells, DNA methyltransferases [euchromatic histone lysine methyltransferase 2 (EHMT2), catechol-O-methyltransferase (COMT), methylguanine-DNA methyltransferase (MGMT), and sirtuin deacetylase] were likewise significantly down-regulated.
Furthermore, saffron-treated prostate cancer cells showed a considerable time-dependent dysregulation of deoxyribonucleic acid repair intermediates (p53, WRN, RECQ5, WDR70, and MST1R).
Saffron decreased cell proliferation dose-dependently, with considerable suppression observed at a 4.0 mg/mL dosage compared to untreated control cells.
The therapy also altered other relevant genes [cluster of differentiation 44 (CD44), histone deacetylase 3 (HDAC3), cellular myelocytomatosis oncogene (c-Myc), nuclear factor kappa B (NF-kB), tumor necrosis factor (TNF), neuroblastoma RAS viral oncogene homolog (N-RAS), phosphatase and TENsin homolog deleted on chromosome 10 (PTEN), DNMT1, DNMT3b, MBD2, and AR] in PCa cells.
After a day of treatment, LNCaP cells showed morphological alterations, including a decrease in live cells. After two days of treatment, cytotoxic impacts were evident, with virtually all cells granulating, cell proliferation halted, and considerable cellular separation.
Saffron therapy reduced Bcl-2 expression while increasing IL-2 expression, indicating that the saffron treatment triggers cell death.
This rise in interleukin-2 levels may result from the stimulation of immunological response and enhanced generation of natural killer lymphocytes and macrophages, both associated with programmed cellular death, inflammatory response control, and anticancer activity.
Saffron inhibited the expression of EHMT2, MGMT, COMT, and the NAD-dependent sirtuin 1 (SIRT1) transcript.
In silico ribonucleic acid sequencing analysis of prostate adenocarcinoma research revealed that DNMT1, DNMT3B, and MBD2 were upregulated in tumors relative to disease-free samples, indicating a worldwide rise in deoxyribonucleic acid methylation.
Western blot densitometry data demonstrated a drop in MBD2, DNMT1, and DNMT3B in treated PCa cells compared to untreated cells, indicating a general reduction in deoxyribonucleic acid methylation.
Conclusion
Overall, the study findings demonstrated that saffron has strong antineoplastic properties in PCa cells, indicating its potential use alongside traditional treatments. It inhibited cell proliferation more effectively in androgen-sensitive PCa cells than in androgen-insensitive PCa cells.
Saffron's antiproliferative action on LNCaP cells may depend on AR levels, similar to vitamin D's chemopreventive effect. It reduced epigenetic enzyme expression and increased DNA repair gene expression, but after 48 hours, these genes fell drastically.
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