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Forskolin, which is the active ingredient found from the roots and stems of Coleus forskohlii  has been widely used in many studies; particularly in its role in lean body mass . In addition, forskolin has been attributed to treating heart diseases, glaucoma, asthma and some cancers . Other reports have suggested forskolin can treat cardiovascular disorders and even lower blood pressure .
Mechanisms of action
Forskolin works induces the enzyme adenylate cyclase, along with marked increases in cyclic adenosine monophosphate (cAMP) concentrations [3; 4]. cAMP is an extremely important signal necessary for the proper response of cells to other molecules such as hormones . Downstream effects of an increased cAMP concentration in cells involve a broad range of biochemical and physiological outcomes. What forskolin does is re-sensitize cell receptors via the activation of adenylyl cyclase, increasing intracellular cAMP levels . Adding to this, cAMP is suggested to be involved in the regulation of memory; with forskolin even be considered as a good candidate for Alzheimer’s Disease (AD) .
Structure and function
Forskolin is a labdane diterpene which these types of diterpenes make up a class of natural products, all with a unique biological activity that works to provide algal, bacterial, fungal, anti-inflammatory, modulating immune cell functions and anti-tumour functioning [5; 9]. Forskolin cAMP production is linked to PDE4. PDE4 inhibitors increase the levels of cAMP, exhibiting anti-inflammatory effects . Selective inhibitors of PDE4 have been reported as important in controlling depression and cognitive function . The expression of PDEs (phosphodiesterases) play a role in regulating cAMP-mediated signalling .
Benefits and Effects
Along with its ability to treat cardiovascular disorders and blood pressure , forskolin can also be used for health benefits to those suffering from hypertension, asthma, and Alzheimer’s Disease . What’s more, forskolin can treat mood disorders, promote lean body mass, along with possessing anti-cancer properties . Recently, a pure forskolin has been shown to exhibit neuroprotective and positive behavioural effects in mice with cerebral amyloidosis . This pure forskolin treatment was orally given to mice over 10 days . Forskolin also possess the ability to kill multiple myeloma (MM) cells in vitro and in vivo . Multiple myeloma (MM) cells is considered a cell malignancy, which is characterised by the presence of malignant cells in the bone marrow – leading to bone pain, fractures and infections .
Forskolin and hair loss
Forskolin induces the production of cAMP , and this promotion of cAMP has been investigated as an activator of hair follicle activity , in the context of age-related hair loss. Additonally, forskolin has been suggested to be used in conjunction with other medicines to prevent hair greying, to the restoration of normal hair colour .
Forskolin and asthma
In a single-blind clinical study evaluating the efficacy of forskolin on preventing asthma attacks , a 10mg capsule forskolin dose, delivered orally over 6 months showed effectiveness in preventing asthma attacks .
Forskolin and weight loss
The ability of forskolin to increase intracellular levels of cAMP leads to the stimulation of lipolysis, which promotes the breakdown of stored fats . Moreover, cAMP increases the use of stored body fat; along with increases metabolic rate and regulating the body’s temperatures in response to food [18; 19]. Obese individuals have lower cAMP production, so, theoretically, forskolin could be trigger weight loss . Forskolin induces weight loss and fat loss through its interaction with producing lipolysis [17; 20]. A 250mg dose of forskolin extract was shown to induce weight loss – fat percentage and mass – over a 12-week period in obese males . Other work has suggested that forskolin does not promote weight loss; however, in fact mitigates weight gain in overweight women with no clinical side effects . This work used a forskolin extract dose of 500mg per day over 12 weeks . Pure forskolin extract – fed to male mice for 2-3 weeks – showed little increase in relative liver weight; along with increasing hepatic cytochrome P450 and glutathione S-transferase activity . It has been suggested that differences in response to forskolin extract in men and women requires further investigation . It is currently unclear whether forskolin works for weight loss.
Forskolin Vs Garcinia cambogia
In a study evaluating the efficacy of Garcinia cambogia in body weight and fat mass loss in obese humans, results showed that G. cambogia failed to produce significant weight loss compared to the placebo control . This study involved 135 subjects, in which a 1500mg dose of hydroxycitric acid – the active herbal compound – was administered over a 12-wek period . In comparison, a double-blind placebo-controlled clinical trial showed that a 10% forskolin extract – given to 15 obese men at 500mg per day – significantly decreased their body fat and increased lean body mass . Another study assessing garcinia cambogia’ effects on body weight and weight loss failed to produce any significant results . Overall, there have been inconsistent results from the assessment of garcinia cambogia and weight loss . In particular, experiments have found the active ingredient of G. cambogia, hydroxycitric acid, to elicit adverse effects such as hepatotoxicity. There is still little evidence to conclude a long-term benefit of taking G. cambogia, and its role in weight loss .
Forskolin in depressed patients
In a study that aimed to determine the before and after effects of forskolin in depressed and schizophrenic patients, forskolin – administered intravenously at a dose between 0.5 – 2 micrograms per kg – results demonstrated that forskolin had a positive impact . Interestingly, some patients showed improvement in mood anxiety, fatigue and confusion, after forskolin had been given. Other work has documented forskolin’s antidepressant activity in a forced swimming test in mice .
Forskolin is generally extracted using a range of organic solvents and purified using a series of separation techniques . One particular study used an extract of forskolin to assess the skin diffusion properties of forskolin . These results found that the forskolin extract could be effectively delivered through the outermost layer of the skin . Forskolin extraction from the Coleus roots involves extraction using alcohol and a range of different solvents followed by the use of laboratory-based chromatography equipment .
Forskolin and testosterone
In the investigation of how forskolin might impact testosterone and other physiological parameters in obese men results found that a 250mg forskolin extract raised serum free testosterone levels . One particular research looking to assess the effects of forskolin on a steroid-producing cell line found that a low dose of forskolin could induce higher hormone production . In addition, forskolin was able to increase gene expression in this cell line, and induce steroidogenesis . The importance of having steroid-producing machinery within a cell is crucial for the synthesis of testosterone . An increase in steroidogenesis indicates the presence of the required machinery necessary to producing testosterone.
Forskolin has been documented as being well tolerated at doses of 50-100mg/kg body weight . Other academic sources report that oral administration of 50mg per day does not produce significant side effects in patients .
Side effects and safety
Side effects and dangers associated with forskolin have yet to be fully evaluated . In addition, a safe forskolin dose has yet to be determined; however, no adverse effects from been reported from its use . Forskolin’s safety has also been assessed in a 3-month topical, cream, treatment in animals [Spry et al., 2008]. Researchers of this study found that forskolin topically administered to animal skin in a low dose caused no toxic reactions . Other cosmetically relevant applications of forskolin-based cream are, apparently, currently in laboratory testing stages . Clinical trials that investigate the effectiveness of forskolin as a therapy is currently limited . Although forskolin might be considered safe, there is potential for herb-drug interactions in patients who might be on combination therapy .
Forskolin and artichoke extract
Artichoke leaf extract (ALE) has been noted as being able to increase bile flow, exert hepatoprotective and antioxidant effects . Artichoke (Cynara scolymus) showed significant inhibition activity on PDE activity . The weight loss potential of artichoke is initiated via the constituent cynarin (artichoke extract) has been investigated through the assessment of artichoke on non-alcoholic fatty acid liver disease (NAFLD) . 60 patients suffering a form of NAFLD, after given a 2700mg artichoke extract showed improvement in liver enzymes .
The stacking of artichoke with forskolin has gained recent attention. Although scientific literature has not confirmed the safety profile, dosing or side effects of stacking artichoke with forskolin, reviews have spoken of the CILTEP stack – a stack used to improve mental performance and induce Long-term potentiation (LTP). Long-term potentiation is important in the formation and retrieval of some forms of memory ; the long-lasting increase in strengthening synapses .