Gu Sui Bu
StarDrynaria fortunei (Kunze) J. Sm.
☯ TCM Properties
Treats Traumatic Injuries; Benefits the Kidneys and Strengthens the Bones; Invigorates Blood and Dispels Stasis; Strengthens the Sinews and Bones; Dispels Wind-Heat from the Skin
Traditional Chinese Uses
Gu Sui Bu (drynaria rhizome, "mend the broken bones" rhizome) is a warm herb named for its famous application in Chinese medicine as a bone-healing and fracture-knitting herb. It tonifies the Kidney Yang and Blood to strengthen bones and sinew, promotes Blood circulation to speed fracture healing, and expels Wind-Cold-Damp for joint pain and stiffness. It is also used topically for hair loss and tinnitus associated with Kidney deficiency. As both a tonic and circulation-promoting herb, it addresses both deficiency and obstruction in musculoskeletal conditions.
Western Herbalism Properties
Botanical Description
Drynaria fortunei (syn. Drynaria roosii, Polypodiaceae), the oak-leaf fern or Gu Sui Bu, is an epiphytic or lithophytic perennial fern with a stout, long-creeping, densely scaly rhizome 1-2 cm thick covered in lustrous golden-brown ovate-lanceolate scales 1-1.5 cm long. Two distinct leaf types arise from the rhizome: sterile, sessile, oak-leaf-like nest leaves 5-9 cm long that turn brown and persist to trap leaf litter and humus, and large, deeply pinnatifid green foliage fronds 20-60 cm long borne on petioles, with sori arranged in two rows along each pinna lobe. Native to rocks, tree trunks, and old walls across southern China, Taiwan, Vietnam, Laos, and northern Thailand. The fleshy rhizome is harvested year-round and the golden scales scorched off before drying. (Sources: POWO; Wikipedia; Bensky)
Active Constituents
Naringin
Flavanone-7-O-glycosideConcentration: Major flavonoid; a Pharmacopoeia marker
The principal bioactive and quality-control marker of the rhizome. Naringin stimulates osteoblast proliferation and alkaline phosphatase activity, promotes bone morphogenetic protein signalling and mineralisation, and inhibits osteoclast-mediated resorption, underpinning the herb's fracture-healing and anti-osteoporotic reputation.
Neoeriocitrin
Flavanone glycosideConcentration: Major (co-dominant with naringin)
One of the two highest-concentration flavonoids in Drynariae Rhizoma; promotes osteoblastic differentiation and mineralisation and contributes antioxidant activity.
Naringenin
Flavanone (aglycone)Concentration: Minor
The aglycone released from naringin; exerts oestrogen-receptor-dependent, bone-protective and anti-inflammatory effects.
Kaempferol and flavan glycosides (e.g., drynarin)
Flavonol / flavan glycosidesConcentration: Minor
Contribute to the total-flavonoid fraction shown to prevent bone loss and stimulate osteoblasts in vivo and in vitro.
Caffeic acid and chlorogenic acid
Phenolic acidsConcentration: Minor
Antioxidant phenolics that support the herb's anti-inflammatory activity and protect osteoblasts from oxidative stress.
Astilbin
Dihydroflavonol glycosideConcentration: Minor
A flavanonol glycoside with anti-inflammatory and antioxidant properties reported among Drynaria constituents.
Polysaccharides
PolysaccharideConcentration: Variable
Contribute immunomodulatory activity and are proposed to support the herb's bone- and cartilage-protective effects.
⚠ Drug Interactions
CYP3A4 substrates (e.g., felodipine, some statins, ciclosporin)
Naringin, the herb's major flavonoid, is the aglycone-precursor of the grapefruit constituent associated with intestinal CYP3A4 inhibition. At high intakes this raises a theoretical potential to raise blood levels of CYP3A4-metabolised drugs, though clinical data for Drynaria itself are lacking.
Clinical note: Interaction is theoretical and unquantified for the whole herb; exercise general caution with narrow-therapeutic-index CYP3A4 substrates.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 6-15g | Daily | — | — | — |
Preparation Methods
Decoction
Parts: rhizome
Typical adult dose 3-9 g (up to 15 g) of the sliced rhizome, decocted in water. The hairy scales are usually singed or scraped off before use.
Sand-fried (tang zhi) / stir-fried processing
Parts: rhizome
The rhizome is commonly stir-fried in hot sand until it puffs, then the scales are removed; this processing is held to strengthen its kidney-tonifying and bone-knitting action and improve palatability.
External application / medicated wine
Parts: rhizome
For traumatic injury the powdered rhizome may be applied externally or soaked in wine (jiu) for internal use, exploiting its blood-invigorating, stasis-dispelling action on bruises and fractures.
Clinical Studies
Drynaria fortunei Promoted Angiogenesis Associated With Modified MMP-2/TIMP-2 Balance and Activation of VEGF Ligand/Receptors Expression
Drynaria fortunei water extract promoted endothelial-cell angiogenesis by rebalancing MMP-2/TIMP-2 and up-regulating VEGF ligand and receptor expression, offering a mechanistic basis for the herb's traditional use in wound and fracture healing.
Total Flavonoids of Drynariae Rhizoma Improve Glucocorticoid-Induced Osteoporosis of Rats: UHPLC-MS-Based Qualitative Analysis, Network Pharmacology Strategy and Pharmacodynamic Validation
Total flavonoids of Drynariae Rhizoma improved bone mineral density and microarchitecture in a rat model of glucocorticoid-induced osteoporosis, with UHPLC-MS characterisation and network-pharmacology analysis supporting flavonoid-driven osteogenic mechanisms.
Water Extract of Rhizoma Drynaria Selectively Exerts Estrogenic Activities in Ovariectomized Rats and Estrogen Receptor-Positive Cells
Rhizoma Drynaria water extract produced selective oestrogenic, bone-sparing effects in ovariectomized rats and oestrogen-receptor-positive cells without stimulating uterine tissue, supporting a favourable profile for post-menopausal bone loss.
Historical Texts
Yao Xing Lun (Treatise on the Nature of Medicinal Herbs)
Tang (7th century)Kai Bao Ben Cao (Kaibao Materia Medica)
Northern Song (973 CE)Ben Cao Gang Mu (Compendium of Materia Medica), Li Shizhen
Ming (1596)References
- Huang ST, Chang CC, Pang JHS, et al.. Drynaria fortunei Promoted Angiogenesis Associated With Modified MMP-2/TIMP-2 Balance and Activation of VEGF Ligand/Receptors Expression . Frontiers in Pharmacology (2018) [DOI]
- Zhou L, Wong KY, Poon CCW, et al.. Water Extract of Rhizoma Drynaria Selectively Exerts Estrogenic Activities in Ovariectomized Rats and Estrogen Receptor-Positive Cells . Frontiers in Endocrinology (2022) [DOI]
- Zhang F, Li Q, Wu J, et al.. Total Flavonoids of Drynariae Rhizoma Improve Glucocorticoid-Induced Osteoporosis of Rats . Frontiers in Endocrinology (2022) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
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