Rehmannia chinensis is a perennial herb closely related to Rehmannia glutinosa and widely used in Traditional Chinese Medicine (TCM) for its reputed therapeutic properties. It is known for its tuberous roots, which are used to improve kidney and liver health and support overall vitality. Though less known than R. glutinosa, R. chinensis has a similar chemical profile, making it suitable for many of the same therapeutic and cosmetic applications.
Botanical Classification
- Kingdom: Plantae
- Clade: Tracheophytes
- Class: Magnoliopsida
- Order: Lamiales
- Family: Orobanchaceae
- Genus: Rehmannia
- Species: Rehmannia chinensis
Plant Characteristics
Rehmannia chinensis is a small, hardy plant reaching about 20–30 cm in height. It has dark green, lanceolate or ovate leaves arranged in a basal rosette. Its flowers, similar to those of R. glutinosa, are bell-shaped, ranging in color from pink to purple, and bloom from late spring to summer. The roots are fleshy and elongated, with a dark, wrinkled surface that turns purplish-brown when dried.
Chemical Composition and Structure
Like R. glutinosa, Rehmannia chinensis contains numerous bioactive compounds that contribute to its therapeutic properties. Key constituents include:
Iridoid Glycosides: Catalpol and rehmannioside, responsible for its anti-inflammatory and neuroprotective properties, and widely studied for their effects on the nervous and immune systems.
Phenethyl Alcohol Glycosides: Acteoside and isoacteoside, which contribute to its antioxidant effects and support cellular regeneration.
Polysaccharides: Complex sugar molecules with immunomodulating effects, supporting immune response and protecting liver function.
Amino Acids: Contains amino acids like arginine and serine, which contribute to tissue health and nervous system support.
Stachyose: A prebiotic sugar that promotes gut health by supporting beneficial bacteria.
How to Cultivate Rehmannia chinensis
The cultivation of Rehmannia chinensis requires similar conditions to R. glutinosa:
Climate: Prefers a temperate climate with cool winters and mild summers. Avoid overly wet or cold areas.
Soil: Requires sandy or loamy, well-drained soil with high organic content and a pH between 6.0 and 7.5.
Propagation: Propagated from seeds or root cuttings. Seeds are sown indoors in spring, while root cuttings can be planted at any time during the growing season.
Watering and Maintenance: Needs regular watering without waterlogging. Mulching helps retain moisture and stabilize soil temperature.
Harvesting: Roots are harvested in autumn, typically after 2–3 years of growth, and are dried for medicinal use.
Uses and Benefits
In TCM, Rehmannia chinensis is employed for its effects similar to those of R. glutinosa:
Kidney and Adrenal Support: Used as a remedy to support kidney health and to treat “kidney yin deficiency,” which contributes to stress resilience.
Blood Tonic and Circulatory Support: Used as a blood tonic to enhance circulation and improve hemoglobin, supporting energy levels and reducing fatigue.
Antioxidant Properties: Thanks to its iridoid glycosides, it is thought to have antioxidant effects.
Immune System Modulation: The polysaccharides help support immune function, enhancing the body’s ability to fight infections.
Hormonal Balance: Traditionally used to regulate hormones and help women with menopausal symptoms.
Applications
Medical: Rehmannia chinensis extracts are used in formulations for kidney issues, liver disorders, and vitality enhancement. It is commonly combined with other herbs in TCM to boost efficacy.
Cosmetics: The extracts are used in skincare products for their hydrating, antioxidant, and anti-aging potential.
Other Applications: Found in wellness formulations, particularly in supplements for immunity and adrenal support. The stachyose content provides prebiotic benefits for gut health.
Environmental and Safety Considerations
Rehmannia chinensis is generally safe for traditional use, though, like all botanical products, caution is advised for individuals with sensitive skin or allergies. Sustainable cultivation practices are important to prevent over-harvesting and ensure consistent product quality.
References__________________________________________________________________________
Um, J. N., Min, J. W., Joo, K. S., & Kang, H. C. (2017). Antioxidant, anti-wrinkle activity and whitening effect of fermented mixture extracts of Angelica gigas, Paeonia lactiflora, Rehmannia chinensis and Cnidium officinale. Korean Journal of Medicinal Crop Science, 25(3), 152-159.
Abstract. Background: In this study, examined the effects of an extract of a mixture of Angelica gigas, Cnidium officinale, Paeonia lactiflora, and Rehmannia glutinosa fermented by Leuconostoc mesenteroides, with enhanced value and functionality. In oriental medicine, a mixture of these herbs is called Samultang. Methods and Results: In this study, we evaluated the effects of a fermented extract of Samultang on oxidative stress, procollagen type I expression, and melanin production. Samultang was extracted with 70% ethanol, followed by inoculation with Leuconostoc mesenteroides to obtain the fermented extract. The evaluation of viability of B16F10 cells and human foreskin fibroblast (HHF) revealed that both ethanol and fermented extracts of Samultang were non-toxic. The results of 1,1-diphenyl-2-picrylhydrazyl (DPPH) test showed that the fermented extract of Samultang ($SC_{50}value=100{\mu}g/m{\ell}$) was a more effective DPPH free radical scavenger than its ethanol extract. In addition, procollagen type I expression was higher in cells treated with the fermented extract of Samultang than in cells treated with ethanol. In the non-toxic concentration range, the fermented extract of Samultang showed strong inhibitory effect on melanin production in ${\alpha}-melanocyte$ stimulatin hormone-stimulated B16F10 cells ($IC_{50}=37.9{\mu}g/m{\ell}$). Conclusions: These results suggest that the fermented extract of Samultang has considerable protential as a cosmetic ingredient owing to its antioxidant, anti-wrinkle, and whitening effects.
Rehmannia Chinensis 
