A spreading perennial herb up to 20–60 cm high. Stems erect, tetragonal, branching near base, glabrous or pubescent in the stem margins. Leaves opposite, simple, with short petioles 2 mm long; limb lanceolate, 1.5–4.0 cm long, 5 mm wide; tip obtuse, entire. Flowers blue to purple, in racemes.
Calyx campanulate, bilabiate, the superior lip with a crest at the back; corolla tube long, much longer than the calyx, enlarged towards the top, swelling at the base; limb bilabiate; stamens four, didymous, fertile, ascending under the superior lip; anthers ciliate; ovary superior. Fruits are collections of small tuberculate nutlets, nearly globular, leathery.
The major constituents are flavonoids, chiefl y baicalin (up to 14%), baicalein (up to 5%), wogonin (0.7%) and wogonin-7-Oglucuronide (wogonoside, 4.0%).
Contains not less than 9.0 per cent of baicalin (C21H18O11 ;Mr 446.4) (dried drug).
Intragastric administration of 400.0 mg/kg body weight (bw) of an aqueous extract of Radix Scutellariae to rats prevented increases in the activities of liver enzymes, such as alkaline phosphatase, lactate dehydrogenase and alanine aminotransferase, induced by carbon tetrachloride or galactosamine. Baicalein, 185.0 μmol/l, inhibited the proliferation of cultured hepatic stellate cells. Baicalein, 10.0 μmol/l, also signifi cantly (P < 0.001) decreased the incorporation of tritiated thymidine in cultured rat hepatic stellate cells stimulated with platelet-derived growth factor-B subunit homodimer or fetal calf serum.
Anti-infl ammatory activity
External application of 0.5 mg/ear of a 50% ethanol extract of the roots to the ears of mice with ear oedema induced by 12-O-etradecanoylphorbol-13-acetate or arachidonic acid signifi cantly reduced infl ammation (P < 0.01). The anti-infl ammatory effect of baicalein in treating chronic infl ammation in rats with adjuvant-induced arthritis (median effective dose (ED50) 120.6 mg/kg bw, intragastric route) was superior to that in carrageenan-induced footpad oedema (ED50 200.0 mg/kg bw, intragastric route). Baicalein also inhibited leukotriene C4 biosynthesis in vitro in rat resident peritoneal macrophages stimulated with calcium ionophore A23187, median inhibitory concentration (IC50) 9.5 μm. Three fl avonoids isolated from the roots, wogonin, baicalein and baicalin, 1.0 μg/ml, inhibited lipopolysaccharide-induced production of interleukin-1β in human gingival fi broblasts by 50%. The effects of nine fl avonoids, isolated from the roots, on adhesion molecule expression induced by interleukin-1β and tumour necrosis factor-α in cultured human umbilical vein endothelial cells were assessed. Baicalein only showed a dose-dependent inhibition of the induced expression of endothelial leukocyte
adhesion molecule-1 and intracellular adhesion molecule-1, with 50% inhibition observed at concentrations of 0.23 μmol/l and 0.4 μmol/l, respectively. These data suggest that Radix Scutellariae may exert its antiinflammatory effects through the inhibition of leukocyte adhesion to the endothelium. Baicalin has been shown to inhibit the binding of chemokines to human leukocytes and cells transfected with chemokine receptors. Coinjection of baicalin with CXC chemokine interleukin-8 into rat skin inhibited neutrophil infi ltration elicited by interleukin-8.
The free-radical scavenging and antioxidant activities of baicalein, baicalin, wogonin and wogonoside were tested in vitro. Electron spin resonance results showed that baicalein and baicalin scavenged hydroxyl radical and alkyl radical in a dose-dependent manner, while wogonin and wogonoside had no effect. Baicalein and baicalin, 10 μmol/l, inhibited lipid peroxidation of rat brain cortex mitochondria induced by Fe(2+)/ascorbic acid or NADPH, while wogonin and wogonoside had effects only on NADPH-induced lipid peroxidation. In a study on cultured human neuroblastoma SH-SY5Y, baicalein and baicalin, 10 μmol/l, protected cells against hydrogen peroxide-induced injury. An aqueous extract of the roots or baicalein, 25–100 μmol/l, signifi cantly (P < 0.001) attenuated ischaemia/reperfusion oxidative stress in cultured chick embryonic ventricular cardiomyocytes. Cell death due to ischaemia/reperfusion injury decreased from 47% to 26% in treated cells. After treatment of the cells with antimycin A, an extract of the roots decreased cell death to 23% in treated cells compared with 47% in untreated cells. Pretreatment with ganhuangenin, isolated from the roots, suppressed the formation of hosphatidylcholine hydroperoxide initiated by the peroxyl-generating oxidant, 2,2′-azobis-2-aminopropane hydrochloride. Baicalein, 5.0–25.0 μmol/l, and wogonin, 5.0–50.0 μmol/l, inhibited lipopolysaccharide-induced nitric oxide generation in a macrophagederived cell line, RAW 264.7 in a concentration-dependent manner. The same two compounds, 25.0 μmol/l, also inhibited protein expression of inducible nitric oxide synthase.
An aqueous or methanol extract of the roots, 200 μg/ml, elicited signifi – cant inhibition (> 90%) (P< 0.01) of the activity of human immunodefi ciency virus type-1 protease. Baicalein inhibited the growth of Fusarium oxysporum and Candida albicans in vitro, minimum inhibitory concentrations 0.112 g/l and 0.264 g/l, respectively. A hot aqueous extract of the roots inhibited the growth of Alcaligenes calcoaceticus, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus at concentrations of 200.0–400.0 μg/ml but was not active against Escherichia coli in vitro at concentrations of up to 1600.0 μg/ml.
A hot aqueous extract of the roots, 0.25–1.0 μg/ml, inhibited the growth of Actinomyces naeslundii, A. odontolyticus, Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum, Bacteroides gingivalis, B. melaninogenicus and Streptococcus sanguis.
The in vitro effects of baicalin on growth, viability, and induction of apoptosis in several human prostate cancer cell lines, including DU145, PC3, LNCaP and CA-HPV-10 were investigated. Baicalin inhibited the proliferation of prostate cancer cells but the responses were different in the different cell lines. DU145 cells were the most sensitive and LNCaP cells the most resistant. Baicalin caused a 50% inhibition of DU145 cells at concentrations of 150 μg/ml or higher. Inhibition of prostate cancer cell proliferation by baicalin was associated with induction of apoptosis. Baicalein inhibited the proliferation of estrogen receptor-positive human breast cancer MCF-7 cells in vitro, median effective concentration 5.3 μg/ml.
Keep it in isolation in a dry, well-ventilated and sheltered place. Protected from moisture. Recommended storage temperature is 18-20 ° С and humidity of air is 30-40%. Shelf life: 3 years.