Lithospermum erythrorhizon, commonly known as purple gromwell, red gromwell, or redroot lithospermum, is a plant species recognized for its deep purple roots. This perennial herb can grow to about 0.7 meters in height and 0.3 meters in spread, featuring green leaves and white flowers typically 2 to 6 cm in size. It is native to East Asia, particularly found across Eastern China, Japan, and Korea.
Traditional Uses and Historical Significance
Lithospermum erythrorhizon, or Zicao in Chinese, has a rich history in traditional East Asian medicine, including Traditional Chinese Medicine (TCM) and Kampo. For centuries, the dried root was applied to various skin conditions like burns, rashes, measles, chickenpox, boils, carbuncles, and eczema.
Traditional uses also included treating inflammatory conditions, promoting wound healing, and addressing internal issues like hepatitis. Its root was also cultivated in Japan since the Nara period as a vibrant purple dye for luxury textiles like kimonos.
Key Compounds and Their Effects
The primary bioactive compounds in Lithospermum erythrorhizon are shikonins and their derivatives, such as acetylshikonin and isobutyrylshikonin. These lipophilic red pigments, found in the plant’s roots, are responsible for its biological activities.
These compounds demonstrate anti-inflammatory, antioxidant, and antimicrobial effects. Shikonin, for instance, inhibits inflammatory pathways and acts as a free radical scavenger. Its derivatives also exhibit antibacterial and antifungal properties against various pathogens.
Modern Applications and Research
Modern research explores Lithospermum erythrorhizon’s potential. In dermatology, studies indicate its wound healing potential by promoting dermal fibroblast proliferation and reducing inflammation. Root extracts improve skin barrier function by reducing trans-epidermal water loss and offer soothing effects.
Research also highlights its anti-inflammatory properties for conditions like eczema and psoriasis. Traditional Chinese medicine formulas containing Lithospermum erythrorhizon reduce psoriatic lesions. Shikonin and β,β-dimethylacryloyl alkannin, active components, alleviate psoriatic lesions and decrease epidermal thickness. Investigation into its anti-cancer properties shows shikonin and its derivatives have antiproliferation and antimetastasis activities in various cancer types.
Safety and Precautions
While Lithospermum erythrorhizon has a long history of use, precautions are important. Do not self-prescribe without professional consultation. Pregnant individuals should avoid its use.
Individuals with pre-existing liver conditions should exercise caution, as some traditional herbs can impact liver function. While generally having minimal side effects in traditional formulas, some studies note increased diarrhea. Always consult a healthcare professional before incorporating Lithospermum erythrorhizon into any health regimen, especially due to potential interactions with other medications.