Scutellaria
Scutellaria is a genus of flowering plants in the mint family, Lamiaceae. They are known commonly as skullcaps. The generic name is derived from the Latin "scutella", meaning "a small dish, tray or platter", or "little dish", referring to the shape of the calyx. The common name alludes to the resemblance of the same structure to "miniature medieval helmets". The genus has a subcosmopolitan distribution, with species occurring nearly worldwide, mainly in temperate regions. Description. Most are annual or perennial herbaceous plants from tall, but a few are subshrubs; some are aquatic. They have four-angled stems and opposite  leaves. The flowers have upper and lower lips. The genus is most easily recognized by the typical shield on the calyx that has also prompted its common name. Traditional use. Skullcaps are common herbal remedies in systems of traditional medicine. In traditional Chinese medicine they are utilized to "clear away the heat-evil and expel superficial evils". "Scutellaria baicalensis" in particular is a common component of many preparations. Its root, known as "Radix Scutellariae", is the source of the Chinese medicine "Huang Qin". It is still in demand today, and marketed in volumes that have led to the overexploitation of  the wild plant. Its rarity has led to an increase in price, and encouraged the adulteration of the product with other species of "Scutellaria". In North America, "Scutellaria lateriflora" became a common treatment in America for rabies. Today it is still a popular medicinal herb. It is widely available as a commercial product used in western herbalism to treat anxiety and muscle tension. The plant reportedly commands prices of $16 to $64 per pound dry weight. Constituents and pharmacology. The main compounds responsible for the biological activity of skullcap are flavonoids. Baicalein, one of the important "Scutellaria" flavonoids , was shown to have cardiovascular effects in "in vitro". Research also shows that "Scutellaria" root modulates inflammatory activity "in vitro" to inhibit nitric oxide (NO), cytokine, chemokine and growth factor production in macrophages. Isolated chemical compounds including wogonin, wogonoside, and 3,5,7,2',6'-pentahydroxyl flavanone found in "Scutellaria" have been shown to inhibit histamine and leukotriene release. Other active constituents include baicalin, apigenin, oroxylin A, scutellarein, and skullcapflavone. Some "Scutellaria" species, including "S. baicalensis" and "S. lateriflora", have demonstrated anxiolytic activity in both animals and humans. A variety of flavonoids in "Scutellaria" species have been found to bind to the benzodiazepine site and/or  a non-benzodiazepine site of the GABA receptor, including baicalin, baicalein, wogonin, apigenin, oroxylin A, scutellarein, and skullcapflavone II. Baicalin and baicalein, wogonin, and apigenin have been confirmed to act as positive allosteric modulators and produce anxiolytic effects in animals, whereas oroxylin A acts as a negative allosteric modulator (and also, notably, as a dopamine reuptake inhibitor). As such, these compounds and actions, save oroxylin A, are likely to underlie the anxiolytic effects of "Scutellaria" species. "Scutellaria" also contains rosmarinic acid which inhibits GABA transaminase which breaks GABA down, thus making it available longer. Selected species. Estimates of the number  of species in the genus range from around 300 to about 350 or 360 to 470. Selected species include: