Historically, Calendula was used to treat various skin diseases, ranging from skin ulcerations to eczema, and the flowers were also believed to be useful in reducing inflammation, wound healing and as an antiseptic. Internally, the soothing effects of Calendula were used for stomach ulcers and inflammation. A sterile tea of this herb was also applied to the eyes in cases of conjunctivitis. Calendula is referred to as an antispasmodic, aperient, cholagogue, diaphoretic and vulnerary. The primary chemical constituents of this herb include saponins, carotenoids, flavonoids, mucilage, bitter principle, phytosterols, polysaccharides and resin. The flavonoids, found in high amounts in Calendula, account for much of its anti-inflammatory activity; triterpene saponins may also be important. There is evidence suggesting use of Calendula for some viral infections, and the constituents responsible for these actions are not entirely clear, but investigations continue to be conducted. As a cholagogue, this herb helps to relieve gallbladder problems and to aid digestion. As an emmenagogue, Calendula can be of benefit in the treatment of delayed menstruation. The hormonal influences are likely to stem from the sterol fraction. An infusion of the flowers can be used for such gastrointestinal problems as ulcers, stomach cramps, colitis and diarrhea. Calendula is also useful when taken internally for fever, boils, abscesses and to prevent recurrent vomiting. The fresh juice of the herb or flowers can substitute for the infusion. For external use, a good salve for wounds can be made from the dried flowers or leaves, or from the juice pressed out of the fresh flowers. There is an old saying: "Where Calendula is, no pus will form." The salve is also good for insect bites, bruises, sprains, pulled muscles, sores and boils. An infusion of Calendula can be used to soothe watery, irritated eyes and for relief in bronchial complaints. It is also used frequently in the treatment of liver disorders. Additionally, it is thought to induce perspiration in case of fever. Calendula has been shown to promote blood clotting and to reduce capillary effusion. Recent clinical studies have shown that Calendula flower extracts lower blood pressure and have sedative effects. In 1955, an Australian patent was issued for the use of Calendula in the treatment of burns in humans. Although it contains no tannins, Calendula is locally astringent, due to its resin component.