Hydrastis: A plant genus of the family RANUNCULACEAE. Members contain BERBERINE.Ruta: A plant genus of the family RUTACEAE. Members contain quinoline alkaloids.Kava: Dried rhizome and roots of Piper methysticum, a shrub native to Oceania and known for its anti-anxiety and sedative properties. Heavy usage results in some adverse effects. It contains ALKALOIDS; LACTONES; kawain, methysticin, mucilage, STARCH, and yangonin. Kava is also the name of the pungent beverage prepared from the plant's roots.Herb-Drug Interactions: The effect of herbs, other PLANTS, or PLANT EXTRACTS on the activity, metabolism, or toxicity of drugs.