Isoforskolin from Native Plant Coleus forskohlii of Yunnan, China Plays Multiple Biological Roles

Isoforskolin (ISOF) was isolated from Coleus forskohlii native to Yunnan in China. It is identified as one analog of diterpene forskolin (FSK) which comes from the Indian plant Coleus forskohlii. Researches found that the Yunnan native plant Coleus forskohlii contained rich ISOF but not FSK. ISOF was reported to activate adenylyl cyclase (AC) isoforms. The ophthalmologic and cardiovascular effects of ISOF were firstly reported in the 1990s. The researchers in Kunming, China, found ISOF could lower blood pressure and intraocular pressure. Recent researches found the respiratory tract effects of ISOF, and showed that ISOF significantly elevated cyclic adenosine monophosphate (cAMP) levels in rat lung homogenate, and relaxed the histamine-induced contraction of isolated guinea pig trachea and lung smooth muscle, isoforskolin pretreatment attenuates acute lung injury induced by lipopolysaccharide (LPS) in several models, lowered LPS-induced secretion of the inflammatory cytokine in human monocytes.