Sophora flavescens, known in traditional Chinese medicine as Ku Shen, is a deciduous perennial herb that belongs to the Fabaceae family. Originating from Asia, particularly China, Korea, and Japan, this plant has been a staple in medicinal practices for centuries, renowned for its potent pharmacological properties. The plant's common name, shrubby sophora, highlights its typical growth form.

Botanical Classification

Kingdom: Plantae
Clade: Angiosperms
Class: Eudicots
Order: Fabales
Family: Fabaceae
Genus: Sophora
Species: S. flavescens

Plant Characteristics

Sophora flavescens typically reaches up to 1.5 meters in height. Its growth habit includes a woody stem that supports pinnate leaves composed of 9-15 small, lanceolate leaflets, giving it a lush, green appearance. During summer, the plant produces attractive yellow flowers arranged in racemes, which later develop into leguminous pods. These pods carry several seeds, characteristic of the Fabaceae family. The root system is robust, woody, and dark, containing the plant's most potent medicinal attributes.

Chemical Composition and Structure

The chemical profile of Sophora flavescens is rich and diverse, primarily recognized for its high concentration of alkaloids such as matrine and oxymatrine. These alkaloids exhibit strong anti-inflammatory, antiviral, and anticancer activities. Additionally, the roots contain flavonoids and triterpene glycosides, enhancing their therapeutic efficacy. Quinolizidine alkaloids also present in the plant contribute to its pharmacological diversity, supporting its use in traditional medicine for their therapeutic effects.

How to Cultivate It

Cultivating Sophora flavescens requires attention to several key horticultural practices:

1. Soil: The plant favors well-drained, sandy loam soils that are neutral to slightly alkaline in pH. It is adaptable but thrives in nutrient-rich substrates.
2. Light: It performs best in full sun but can tolerate partial shade, which may influence the density of the foliage and flowering patterns.
3. Water: While drought-tolerant once established, regular watering during dry spells promotes optimal growth and flowering.
4. Temperature: Sophora flavescens is suited to temperate climates and can withstand light frost, but young plants are particularly sensitive to extreme cold.

Uses and Benefits

Traditionally, the roots of Sophora flavescens are used to treat a variety of ailments. Its applications in cooling blood, promoting diuresis, and clearing damp-heat underline its importance in managing fevers, skin diseases, and gastrointestinal issues. Modern pharmacological research has explored its role in cancer therapy, primarily due to its ability to induce apoptosis in cancer cells without significant toxicity to normal cells.

Applications

• Medicinal: Utilized in traditional Chinese medicine in various forms, including extracts, powders, and decoctions, often for its benefits against inflammatory diseases and as a natural treatment for skin conditions like eczema and psoriasis.
• Research: The plant’s bioactive compounds are currently being studied for their potential in treating chronic diseases and in immune system modulation.
• Ornamental: Apart from its medicinal uses, Sophora flavescens can be grown as an ornamental plant, adding aesthetic value to gardens with its bright yellow flowers.

Environmental and Safety Considerations

While Sophora flavescens is not typically invasive, careful management in non-native environments is necessary to prevent unintended spread. It is considered safe for medicinal use under professional guidance. However, its potent bioactive ingredients mean that it should be used with caution, observing appropriate dosages to avoid potential side effects. It is not recommended for pregnant or breastfeeding women due to a lack of safety data.

References__________________________________________________________________________

Yang YF, Liu TT, Li GX, Chen XQ, Li RT, Zhang ZJ. Flavonoids from the Roots of Sophora flavescens and Their Potential Anti-Inflammatory and Antiproliferative Activities. Molecules. 2023 Feb 22;28(5):2048. doi: 10.3390/molecules28052048. 

Abstract. The phytochemical investigation of the roots of the traditional Chinese medicinal plant Sophora flavescens led to the isolation of two novel prenylflavonoids with an unusual cyclohexyl substituent instead of the common aromatic ring B, named 4',4'-dimethoxy-sophvein (17) and sophvein-4'-one (18), and 34 known compounds (1-16, 19-36). The structures of these chemical compounds were determined by spectroscopic techniques, including 1D-, 2D-NMR, and HRESIMS data. Furthermore, evaluations of nitric oxide (NO) production inhibitory activity against lipopolysaccharide (LPS)-treated RAW264.7 cells indicated that some compounds exhibited obvious inhibition effects, with IC50 ranged from 4.6 ± 1.1 to 14.4 ± 0.4 μM. Moreover, additional research demonstrated that some compounds inhibited the growth of HepG2 cells, with an IC50 ranging from 0.46 ± 0.1 to 48.6 ± 0.8 μM. These results suggest that flavonoid derivatives from the roots of S. flavescens can be used as a latent source of antiproliferative or anti-inflammatory agents.

Li JC, Zhang ZJ, Liu D, Jiang MY, Li RT, Li HM. Quinolizidine alkaloids from the roots of Sophora flavescens. Nat Prod Res. 2022 Apr;36(7):1781-1788. doi: 10.1080/14786419.2020.1817011.

Abstract. Seventeen quinolizidine alkaloids, including a new matrine-type one, sophcence A (1), were isolated from the roots of Sophora flavescens Alt. The structure of compound 1 was elucidated by means of 1D and 2D NMR, as well as HR-ESI-MS spectroscopic data. The NMR data of (-)-Δ7-dehydrosophoramine (10) and oxy-N-methylcytisine (12) were reported for the first time. In addition, (+)-sophoranol (4) exhibited moderate inhibition on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 macrophages with IC50 value of 22.14 μM, while lupanine (17) was found to inhibit the growth of human glioma stem cells GSC-3# at 20 μg/mL.

Long GQ, Wang DD, Wang J, Jia JM, Wang AH. Chemical constituents of Sophora flavescens Ait. and cytotoxic activities of two new compounds. Nat Prod Res. 2022 Jan;36(1):108-113. doi: 10.1080/14786419.2020.1765340. 

Abstract. A chemical investigation of Sophora flavescens Ait. identified 6 compounds. On the basis of spectroscopic data, they were determined to be flavonoids and their analogues, among which were two previously undescribed compounds, sophoflavanone G (1) and sophoflavanone H (2). The inhibitory effects of new compounds against five human tumour cell lines were evaluated in vitro by MTT assays, which revealed potential inhibitory effects with IC50 values < 20 mM, in particular, compound 1 has shown significant cytotoxicity for several tumour cells with IC50 values around 20 mM, which was similar to cisplatin and potential to be used as tumour drugs.

Liu D, Chan BC, Cheng L, Tsang MS, Zhu J, Wong CW, Jiao D, Chan HY, Leung PC, Lam CW, Wong CK. Sophora flavescens protects against mycobacterial Trehalose Dimycolate-induced lung granuloma by inhibiting inflammation and infiltration of macrophages. Sci Rep. 2018 Mar 2;8(1):3903. doi: 10.1038/s41598-018-22286-w.

Abstract. The immune system responds to Mycobacterium tuberculosis (MTB) infection by forming granulomas to quarantine the bacteria from spreading. Granuloma-mediated inflammation is a cause of lung destruction and disease transmission. Sophora flavescens (SF) has been demonstrated to exhibit bactericidal activities against MTB. However, its immune modulatory activities on MTB-mediated granulomatous inflammation have not been reported. In the present study, we found that flavonoids from Sophora flavescens (FSF) significantly suppressed the pro-inflammatory mediators released from mouse lung alveolar macrophages (MH-S) upon stimulation by trehalose dimycolate (TDM), the most abundant lipoglycan on MTB surface. Moreover, FSF reduced adhesion molecule (LFA-1) expression on MH-S cells after TDM stimulation. Furthermore, FSF treatment on TDM-activated lung epithelial (MLE-12) cells significantly downregulated macrophage chemoattractant protein (MCP-1/CCL2) expression, which in turn reduced the in vitro migration of MH-S to MLE-12 cells. In addition, FSF increased the clearance of mycobacterium bacteria (Mycobacterium aurum) in macrophages. FSF mainly affected the Mincle-Syk-Erk signaling pathway in TDM-activated MH-S cells. In TDM-induced mouse granulomas model, oral administration with FSF significantly suppressed lung granulomas formation and inflammation. These findings collectively implicated an anti-inflammatory role of FSF on MTB-mediated granulomatous inflammation, thereby providing evidence of FSF as an efficacious adjunct treatment during mycobacterial infection.

Oh J, Kim SA, Kwon KW, Choi SR, Lee CH, Hossain MA, Kim ES, Kim C, Lee BH, Lee S, Kim JH, Cho JY. Sophora flavescens Aiton methanol extract exerts anti-inflammatory effects via reduction of Src kinase phosphorylation. J Ethnopharmacol. 2023 Apr 6;305:116015. doi: 10.1016/j.jep.2022.116015.

Xu Y, Wang X, Sa K, Li H, Chen L. Alkaloids from the roots of Sophora flavescens and their anti-tumor activity. Fitoterapia. 2023 Dec;171:105685. doi: 10.1016/j.fitote.2023.105685. 

Chen MH, Gu YY, Zhang AL, Sze DM, Mo SL, May BH. Biological effects and mechanisms of matrine and other constituents of Sophora flavescens in colorectal cancer. Pharmacol Res. 2021 Sep;171:105778. doi: 10.1016/j.phrs.2021.105778. 

Cao X, He Q. Anti-Tumor Activities of Bioactive Phytochemicals in Sophora flavescens for Breast Cancer. Cancer Manag Res. 2020 Feb 27;12:1457-1467. doi: 10.2147/CMAR.S243127.