Bryophyllum pinnatum Compounds Inhibit Oxytocin-Induced Signaling Pathways in Human Myometrial Cells

Area of Science:

• Pharmacology
• Obstetrics
• Phytochemistry

Background:

• Bryophyllum pinnatum (Kalanchoe pinnata) is traditionally used for treating premature labor.
• Recent studies indicate its potential as an add-on therapy in conventional settings.
• In vitro studies show B. pinnatum inhibits oxytocin-induced intracellular calcium increase in myometrial cells.

Purpose of the Study:

• Identify active fractions/compounds in B. pinnatum press juice responsible for inhibiting oxytocin-induced effects.
• Investigate the impact of these fractions on the oxytocin-driven MAPK signaling cascade.
• Substantiate the therapeutic use of B. pinnatum for preterm labor.

Main Methods:

• Fractionation of B. pinnatum leaf press juice.
• Measurement of intracellular free calcium concentration in hTERT human myometrial cells.
• Assessment of MAPK pathway activation (SAPK/JNK, ERK1/2) following oxytocin stimulation.
• Comparison with atosiban, an oxytocin-receptor antagonist and tocolytic agent.

Main Results:

• Several fractions reduced oxytocin-induced calcium increase concentration-dependently, but less effectively than the whole press juice.
• A combination of bufadienolide and flavonoid-enriched fractions demonstrated synergistic effects, matching the efficacy of the whole B. pinnatum press juice.
• B. pinnatum press juice and its bufadienolide-enriched fraction inhibited oxytocin-induced activation of SAPK/JNK and ERK1/2 MAPKs.
• The inhibitory effects on oxytocin signaling pathways were comparable to those of atosiban.

Conclusions:

• The synergistic combination of bufadienolide and flavonoid fractions contributes significantly to the tocolytic effect of B. pinnatum press juice.
• B. pinnatum inhibits key signaling pathways involved in uterine contractions, supporting its role in preterm labor management.
• These findings provide a scientific basis for the established clinical use of B. pinnatum preparations in treating premature labor.