The Coleus plant (Coleus forskohlii), a tropical perennial herb in the mint family, is traditionally utilized in Ayurvedic medicine, particularly the root. It is native to the mountainous regions of Nepal, India, and Thailand. Its medicinal properties are attributed to a specific compound isolated from its tuberous roots: forskolin, a labdane diterpenoid. Forskolin acts by directly activating the enzyme adenylate cyclase, which significantly increases the intracellular levels of cyclic adenosine monophosphate (cAMP). This fundamental biochemical action on cAMP is the mechanism behind its diverse biological effects.
Forms of Medicinal Preparation
The most common method for medicinal consumption is through standardized extracts, which ensures a consistent concentration of the active compound, forskolin. These commercial extracts are typically standardized to contain 10% to 20% forskolin. The active components are extracted from the dried root material and then encapsulated into tablets or capsules for oral use.
Another form of preparation is the fluid extract, a concentrated liquid consumed by the drop. Traditional preparations, especially in Ayurvedic practices, involve using the raw or dried root as a tea or powder. However, the forskolin content in raw root preparations can vary greatly, making the standardized extract a more predictable option. For specific conditions, the active compound is sometimes prepared in specialized formats, such as a sterile fluid extract for direct application to the eye or a powdered form for inhalation.
Specific Therapeutic Applications
The therapeutic use of Coleus centers on conditions that benefit from increased cyclic AMP (cAMP) levels, which acts as a second messenger in many biological processes. One primary application is in the management of glaucoma, where forskolin reduces intraocular pressure (IOP). This effect is achieved through the relaxation of smooth muscle tissue and the regulation of fluid dynamics within the eye. Sterile ophthalmic preparations of forskolin have demonstrated pressure-lowering effects in clinical settings.
Forskolin’s bronchodilating properties support respiratory function, particularly in conditions like asthma. By increasing cAMP in the smooth muscle cells lining the airways, the compound promotes muscle relaxation, leading to the dilation of the bronchial tubes and improved airflow. This action is similar to some conventional asthma medications. Historically, the plant was used in Asian medicine for respiratory issues like asthma and bronchitis.
The cardiovascular system responds to forskolin due to its ability to stimulate adenylate cyclase in heart and vascular cells. This stimulation results in vasodilation, the widening of blood vessels, which helps to lower blood pressure. Intravenous forskolin has been shown to improve the forcefulness of heart contractions in people with conditions like cardiomyopathy. The plant’s historical use in Ayurvedic medicine for angina and high blood pressure aligns with these modern observations.
Safety Profile and Usage Warnings
While generally tolerated, Coleus extract requires careful consideration of its effects on blood pressure and coagulation. Common side effects at higher oral doses include gastrointestinal disturbances such as nausea, diarrhea, or vomiting. Due to its vasodilatory action, it may cause a drop in blood pressure, which can manifest as flushing or lightheadedness.
The compound should be avoided by individuals who already have low blood pressure (hypotension), as it may cause a further, unsafe reduction. Forskolin inhibits platelet aggregation, increasing the risk of bleeding. Therefore, people with existing bleeding disorders or those taking blood-thinning medications should not use this supplement.
Discontinue use at least two weeks before any scheduled surgical or dental procedure to mitigate the risk of excessive bleeding. Pregnant or breastfeeding women should also avoid this supplement due to insufficient safety data. A general guideline for a standardized extract is 100 to 250 milligrams, standardized to 10% forskolin, taken once or twice daily. Consulting a healthcare provider for personalized guidance is strongly recommended.