Sigesbeckia is a genus of annual plants in the aster family. St. Paul's wort is a common name for some of the species. Sigesbeckia is widely distributed and has been traditionally used for the management of chronic diseases, including arthritis. Based on phytochemical studies, the main chemicals in Sigesbeckia include flavonoids, sesquiterpenoids, diterpenoids, triterpenoids, and sterols. Kaurane-type and pimarane-type diterpenoids, including siegeskaurolic acid, kirenol, and sesquiterpene lactone are the main bio-active molecules in Sigesbeckia.
Origin
Sigesbeckia is named for a botanist Johann Georg Siegesbeck, who was a strong critic of Carl Linnaeus's botanic classification system. He was known to refer to it as "Loathsome Harlotry" because of the focus of the system upon the presence of sex organs in plants and their locations and groupings. Siegesbeck tried to refute Linnaeus' sexual classification system, but was unable to provide sound scholastic arguments to support his arguments. In Linnaeus' work, Critica Botanica, he proposed that there should be a link between the plant and the botanist after whom it was named. Considering the feud between Sigesbeck and Linnaeus, it is not unsurprising that in the classification book Hortus Cliffortianus, Linnaeus named a pungent weed Siegesbeckia.
Classification
Sigesbeckia is related to a group of South American plants variously known as subtribe Espeletiinae or the Espeletia complex, which include genera such as Axiniphyllum, Espeletia, Polymnia, Smallanthus, Rumfordia, Trigonospermum, and Unxia. Some African Sigesbeckia species were transferred, at least by some authors, to Guizotia. ; Species
Traditional medicine
Three species of Sigesbeckia are used in traditional medicine: Sigesbeckia orientalis, Sigesbeckia pubescens, and Sigesbeckia glabracens, although the Royal Botanical Gardens, Kew, only recognizes two species, with Sigesbeckia pubescens considered a subspecies of Sigesbeckia orientalis. In traditional medicine, the aerial parts of the plant are used to treat rheumatic conditions such as arthritis, joint pain, muscle pain, sciatica. It is also used to treat hypertension. Use of Sigesbeckia as a traditional medicine dates back to 659 AD, when it was first reference in Chinese materia medica. The traditional Chinese medicine is called xi xian cao, and is used to "dispel wind-dampness, to strengthen sinews, and for wind-heat-damp pain obstructions".
Research
Analgesic
Oral administration of Sigesbeckia has been shown to have mild effect at reducing pain when taken orally. Topical application of Sigesbeckia extract has also been shown to have an analgesic effect.
Anti-inflammatory
Sigesbeckia extracts have been shown to have anti-inflammatory properties, and reduces phase 2oedema, by inhibiting nitric oxide, prostaglandin E2, and tumor necrosis factor alpha. Sigesbeckia has been shown to act on the NF-κB pathway of inflammation. The transcription factorNF-κB regulates multiple aspects of immune function and is a pivotal mediator of the inflammatory response. Activation of the NF-κB pathway induces the expression of pro-inflammatory genes, including those that encode cytokines and chemokines that propagate the inflammatory response. Sigesbeckia extracts have been shown to inhibit NF-κB in macrophages, white blood cells that are involved in inflammation. In lipopolysaccharide -stimulated macrophages, Sigesbeckia significantly inhibits nitric oxide, MCP-1, IL-6, iNOS, TNF-α and COX-2 expression.
Antioxidant
Sigesbeckia extracts have been shown to have a range of antioxidant activities. Butanolic and aqueous extracts have been shown to inhibit the superoxide radical, hydroxyl radical, and inhibit lipid peroxidation.
Cartilage protection
Oral administration of Sigesbeckia extract has been shown to significantly protect joint cartilage in osteoarthritis. Daily use for four weeks showed a dose-dependant improvement in joint stiffness and histological parameters. Sigesbeckia increased the expression of proteoglycan, aggrecan and type-2 collagen, important structural proteins used in the synthesis of articular cartilage. Sigesbeckia also decreased the expression of protease enzymes that are responsible for the degradation of aggrecan and cartilage. Four weeks of use of Sigesbeckia extract was shown to significantly decrease levels of inflammatory cytokines IL-1B and TNF-α in joint fluid, and was able to protect cartilage cells from damage and degradation.
