Selective cytotoxic activity of isolated compounds from Globimetula dinklagei and Phragmanthera capitata...

Area of Science:

• Natural Product Chemistry
• Pharmacology
• Cancer Biology

Background:

• Cancer remains a leading cause of mortality worldwide, necessitating the development of novel therapeutic agents.
• Natural products offer a rich source of diverse chemical structures with potential anticancer activities.
• Selective cytotoxicity, targeting cancer cells while sparing normal cells, is a crucial goal in cancer therapy.

Purpose of the Study:

• To evaluate the selective cytotoxicity of six natural compounds against a panel of human cancer cell lines (MCF-7, HeLa, Caco-2, A549) and normal cells (Hs1.Int, Wl-38).
• To investigate the structure-activity relationships (SAR) of these compounds.
• To elucidate the mechanism of action, specifically the induction of apoptosis, in treated cancer cells.

Main Methods:

• Cytotoxicity was assessed using 50% inhibitory concentration (IC50) assays.
• Selectivity Index (SI) was calculated to determine the ratio of toxicity to normal cells versus cancer cells.
• Apoptosis induction was evaluated using the Caspase-Glo® 3/7 assay kit.

Main Results:

• Globimetulin B (2) demonstrated significant cytotoxicity against cancer cells (IC50: 12.75–37.65 μM) with SI values ranging from 1.13 to 3.48.
• 3-O-β-d-glucopyranosyl-28-hydroxy-α-amyrin (5) exhibited potent activity against HeLa cells (IC50: 6.88 μM) and high SI values (5.20–8.71).
• A hydroxyl group at the C-3 position was implicated in enhancing cytotoxic activity. Both active compounds induced caspase-3 and -7 activity, indicating apoptosis.

Conclusions:

• Globimetulin B and 3-O-β-d-glucopyranosyl-28-hydroxy-α-amyrin are promising candidates for selective cancer therapy.
• These natural compounds induce apoptosis in cancer cells, offering a potential therapeutic mechanism.
• The selective killing of cancer cells by Globimetulin B suggests a favorable therapeutic profile compared to conventional doxorubicin.