Recent studies reveal the anti-cancer and liver-protective effects of Prunella vulgaris, or self-heal, through key molecular mechanisms including MEK/ERK and TGF-β1/Smad pathways.
Prunella vulgaris, also known as self-heal, has long been used in traditional medicine for its cooling and detoxifying properties. With the growing global interest in herbal therapeutics, recent studies have uncovered a wide range of pharmacological activities of this herb. This article highlights the latest findings regarding its anti-cancer and liver-protective mechanisms, with a special focus on molecular pathway analysis.
1. Anti-Tumor Activity
Various extracts of Prunella vulgaris exhibit significant inhibitory effects on multiple cancer cell lines:
- 85% ethanol extract (0.5–2 mg/mL) inhibited HT-29 colon cancer cells by downregulating Bcl-2 and upregulating Bax mRNA expression, increasing Caspase-3 activity in a dose- and time-dependent manner.
- In HCT-8 colon cancer cells, the extract reduced CDK2 and CCND1 expression while increasing Caspase-8/9 and Bax levels.
- Suppressed proliferation, migration, and tube formation of HUVECs by downregulating VEGF and its receptors.
- Induced cell cycle arrest at G0/G1 or G2/M phase in A549 lung cancer cells.
- Aqueous-alcoholic extract inhibited proliferation and metastasis in esophageal cancer Eca-109 cells.
Key compounds such as ursolic acid, 2α-hydroxyursolic acid, and betulinic acid have demonstrated strong anti-cancer effects on breast cancer cells. Sulfated polysaccharides from the herb reduced microvascular density in liver cancer tissues.
2. Hepatoprotective Properties
- Aqueous extracts (0.5–2 g/kg) significantly lowered ALT and AST in CCl₄-induced liver injury in mice, while increasing hepatic SOD and CAT activity.
- Total triterpenes (62.5–250 mg/kg) improved acute liver failure by inhibiting the MEK/ERK signaling pathway.
- In vitro, the extract suppressed hepatic stellate cell proliferation by blocking the TGF-β1/Smad signaling pathway.
3. Blood Pressure and Glucose Regulation
- Aqueous and ethanol supernatant extracts (2.5–10 g/kg) effectively reduced systolic blood pressure in spontaneously hypertensive rats.
- Oral administration (5.5–22 g/kg) lowered postprandial blood glucose levels by enhancing hepatic glycogen synthesis.
- In vitro, the extract inhibited α-amylase and α-glucosidase activity, delaying glucose absorption.
4. Antibacterial and Antiviral Potential
- Aqueous extract showed strong inhibitory effects against Staphylococcus aureus and Propionibacterium acnes.
- Flavonoid-rich ethanol extract demonstrated antimicrobial activity against S. aureus and E. coli.
- A decoction (5–20 g/kg) was effective in treating bacterial vaginitis in rat models.
5. Additional Pharmacological Effects
- Total triterpenes inhibited the release of PGE2, TNF-α, and IL-6 in RAW264.7 macrophages.
- Polysaccharide fractions enhanced macrophage phagocytic activity in immunocompromised mice.
These multifaceted benefits, backed by molecular insights, suggest that Prunella vulgaris holds great potential as a natural therapeutic agent. Future research may further validate its efficacy and lead to broader clinical applications.
