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Personalized Medicine Universe 2 (2013) 25e27

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Personalized Medicine Universe

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Original article

A Coleus forskohlii extract improves body composition in healthyvolunteers: An open-label trial

Seika Kamohara a,b,*, Somboon Noparatanawong b

aHealth Science University, Fujikawaguchiko-machi, Yamanashi, JapanbDHC Corporation, Minami-azabu 2-7-1, Minato-ku, Tokyo, Japan

a r t i c l e i n f o

Article history:Received 8 January 2013Accepted 22 March 2013

Keywords:Coleus forskohliiPhytotherapyForskolinObesityAyurveda

Abbreviations: CF, Coleus forskohlii; BMI, body maosine monophosphate; GI, gastrointestinal.* Corresponding author. Health Science University, M

bldg. 11fl. DHC, Tokyo 106-0047, Japan. Tel.: þ81 33947.

E-mail address: kamohara-seika@umin.ac.jp (S. Ka

2186-4950/$ e see front matter Copyright � 2013, Inhttp://dx.doi.org/10.1016/j.pmu.2013.04.003

a b s t r a c t

Purpose: Coleus forskohlii (CF) is a south Asian herb that has been historically used in Ayurvedic medicine.The root of CF contains forskolin, a biologically active compound that has been demonstrated to improvewell-being in some individuals by promoting lean body mass and supporting healthy metabolic function.We conducted an open-label study to evaluate the efficacy of CF root extract for weight management.Methods: After obtaining informed consent, 15 healthy volunteers participated in an 8-week open-labelstudy. The subjects received 500 mg of CF extract (10% forskolin) twice a day with their meals. Bodycomposition measurements were conducted using a bioelectric impedance analyzer once each week.Body weight (kg), fat content (kg), lean body mass (kg), and basal metabolic rate (kcal/day) were alsomeasured and documented.Results: Of the 15 subjects, 12 (mean age 32.2 � 2.3 years) completed the study. Significant decreasescompared with baseline were observed after 8 weeks for body mass index (BMI) (24.92 � 0.87 to23.99 � 0.86 kg/m2, p ¼ 0.0038), body weight (66.33 � 3.00 to 63.96 � 3.10 kg, p ¼ 0.0038), fat content(29.64 � 2.19 to 27.77 � 2.27 kg, p ¼ 0.0038), lean body mass (44.34 � 2.98 to 43.93 � 3.01 kg,p ¼ 0.0044) and basal metabolic rate (1379.1 � 74.4 to 1363.9 � 77.5 kcal, p ¼ 0.0254).Conclusion: These findings suggest that CF root extract has potential as an adjunct therapy for thetreatment of obesity. Further studies using double-blind, randomized, placebo-controlled designs arewarranted to conclusively demonstrate the effectiveness of CF root extract in personalized supplementsand/or pharmacological interventions.Copyright � 2013, International Society of Personalized Medicine. Published by Elsevier B.V. All rights

reserved.

1. Introduction

Obesity has become one of the major challenges for generalpublic health worldwide. The scarcity of effective therapeutics forobesity demands the development of tailor-made approaches fromthe viewpoint of personalized medicine. Although there arecurrently few effective pharmacological treatments for obesity,there is a growing body of literature showing the potential efficacyof botanical medicine and phototherapy as complementary ther-apy. Several botanicals, including Coleus forskohlii (CF), have been

ss index; cAMP, cyclic aden-

inami-azabu 2-8-12, Nissei-5442 3945; fax: þ81 3 5442

mohara).

ternational Society of Personalized

considered and tested for the treatment of obesity and for thepromotion of healthy weight management.

CF is an Indian plant that has been used in traditional Indianmedicine, Ayurveda [1,2]. CF belongs to the family Labiatae, alsoknown as the mint family (Fig. 1). The plant is rich in various kindsof alkaloids. The root portion of CF contains forskolin, a biologicallyactive compound [1,2]. Forskolin is a diterpene that acts as anadenylate cyclase activator [3]. Adenylate cyclase is involved in theproduction of cyclic adenosine monophosphate (cAMP), a signifi-cant biochemical agent in metabolic processes. cAMP inducesbiochemical events that trigger metabolic processes and diet-induced thermogenesis, increase lean body mass, and stimulatethe loss of body fat. Consequently, the use of CF extract may bebeneficial for maintaining healthy body composition and lean bodymass levels.

In ovariectomized rats, the administration of CF extract reducedbody weight, food intake, and fat accumulation [4]. Several clinicaltrials have reported an anti-obesity effect for CF extract [5,6].

Medicine. Published by Elsevier B.V. All rights reserved.

Fig. 1. Botanical aspects of Coleus forskohlii. A. C. forskohlii is an Indian herb, whichbelongs to the family Labiatae. B. Its root has been used in traditional Indian medicine,Ayurveda.

Table 1Effects of Coleus forskohlii extract on body composition.

Baseline 4 weeks 8 weeks p value

BMI 24.92 � 0.87 24.26 � 0.84 23.99 � 0.86 p ¼ 0.0038Body weight

(kg)66.33 � 3.00 64.61 � 2.99 63.96 � 3.10 p ¼ 0.0038

Fat content(kg)

29.64 � 2.19 28.75 � 2.20 27.77 � 2.27 p ¼ 0.0038

LBM (kg) 44.34 � 2.98 44.03 � 3.02 43.93 � 3.01 p ¼ 0.0044BMR (kcal) 1379.1 � 74.4 1367.6 � 76.0 1363.9 � 77.5 p ¼ 0.0254Systolic BP

(mmHg)116 � 5 116 � 5 114 � 5 p > 0.05 (n.s)

Diastolic BP(mmHg)

73 � 5 74 � 5 73 � 4 p > 0.05 (n.s)

N ¼ 12; BMI, body mass index; LBM, lean body mass; BMR, basal metabolic rate; BP,blood pressure; n.s., not significant.Values are represented as mean � standard error.The p values indicate the difference between values at baseline and at 8 weeks.

S. Kamohara, S. Noparatanawong / Personalized Medicine Universe 2 (2013) 25e2726

The purpose of this study was to investigate the efficacy of CFextract for weight-management in Japanese subjects.

2. Methods

2.1. Subjects and study protocol

Eligible volunteer participants were male and female subjectsaged 20 years or older without any organ dysfunction who hadnever experienced psychological and/or chronic diseases. Afterobtaining informed consent, 15 healthy volunteers participated inan 8-week open-label trial. Subjects received 500 mg of CF extract(10% forskolin) twice a day with their meals.

2.2. Body composition measurements

Body composition measurements were taken using a bioelectricimpedance analyzer (Tanita Corporation, Tokyo, Japan) on a weeklybasis. Body weight (kg), fat content (kg), lean body mass (kg), andbasal metabolic rate (kcal) were obtained. Obesity was defined interms of body mass index (BMI), calculated as body weight dividedby the square of height (kg/m2). Lean body mass was the mass ofthe body excluding fat mass. Adverse events were recorded on adaily basis.

2.3. Study drug

C. forskohlii (standardized powder extract formulation) wasprovided to the participants in a tablet form (Forskohlii, DHC Cor-poration, Tokyo, Japan). One tablet contained 250 mg of CF extract,including 10% forskolin.

2.4. Statistical analysis

For statistical analysis, values obtained after the 8-week sup-plementation period were compared to those at baseline using theWilcoxon t-test. A p value of less than 0.05 was considered to bestatistically significant.

3. Results

Twelve subjects (5 men and 7 women, mean age 32.0 � 2.3years) completed the study. Significant decreases compared tobaseline were detected after 8 weeks for BMI (24.92 � 0.87 to23.99 � 0.86 kg/m2, p ¼ 0.0038), body weight (66.33 � 3.00 to63.96 � 3.10 kg, p ¼ 0.0038), and fat content (29.64 � 2.19 to27.77 � 2.27 kg, p ¼ 0.0038) (Table 1). Lean body mass alsosignificantly decreased (44.34 � 2.98 to 43.93 � 3.01 kg,p ¼ 0.0044), as did basal metabolic rate (1379.1 � 74.4 to1363.9 � 77.5 kcal, p ¼ 0.0254). There were no significant differ-ences between baseline and week 8 in terms of systolic and dia-stolic blood pressure.

Three subjects reported abdominal discomfort, such asincreased bowel movements, soft stools, and/or diarrhea. No otherclinically significant adverse events were detected or noted.

4. Discussion

C. forskohlii (CF) has been cultivated for the use of its root, andis commonly consumed as part of an ordinary diet in foodssuch as pickles [1,2]. Its root has also been used intraditional Indian medicine, Ayurveda, for the treatment of car-diovascular diseases, hypertension, abdominal pain, and con-stipation [2,5,7].

Recently, CF root extract has been widely included as an ingre-dient of functional foods and dietary supplements used for weightloss and weight management.

There were 2 key findings from this study. Firstly, 8 weeks of CFsupplementation (500 mg twice a day) promoted weight loss, and

S. Kamohara, S. Noparatanawong / Personalized Medicine Universe 2 (2013) 25e27 27

secondly, CF supplementation was associated with adversegastrointestinal (GI) events.

Several clinical trials have reported the effects of CF extract onweight loss. An 8-week open-label study in 6 overweight butotherwise healthy women (BMI > 25 kg/m2) who received oral CFextract (containing 50 mg per day of forskolin), found significantreductions in body weight and fat content [5]. In a randomized,double-blind, placebo-controlled 12-week trial, significant weightloss was observed in 30 overweight/obese men after taking CFextract (containing 250 mg per day of forskolin) [8]. A randomized,double-blind, 12-week clinical trial reported that overweight/obesewomen (BMI 25e35 kg/m2) taking CF extract (containing 50mg perday of forskolin) experienced weight loss, while the placebo groupexperienced weight gain. Heart rate, blood pressure, and bloodlipid levels were unaffected. No clinically significant side effectswere observed [6].

The results of this study were consistent with those of theseprevious reports, showing effects on weight loss and weightmanagement.

In Ayurvedic medicine, it has been reported that CF extractsupplementation can lead to mild improvements in systolic anddiastolic blood pressure in geriatric subjects with hypertension [7].Forskolin has also been shown to lower blood pressure in hyper-tensive rats [1,2]. However, in this study, CF extract had no signif-icant effect on blood pressure. The previous randomized, double-blind trial in mildly overweight women also found that CF had noeffect on blood pressure [6]. These data suggest that CF extract orforskolin may improve hypertension, but have no effect in patientswith normal blood pressure.

Forskolin, a major constituent of CF extract, activates adenylatecyclase and increases the production of cAMP [9,10]. Increasedlevels of cAMP induced by forskolin stimulate lipolysis in adiposetissue. Enhanced lipolysis increases fat degradation in the body andmay promote weight loss [4].

Traditionally, CF root has been used in Ayurvedic medicine forthe treatment of constipation. The contemporary use of CF extractin dietary supplements for weight loss has been anecdotally asso-ciated with the side effects of soft stool and diarrhea. In this study, 3subjects reported mild GI adverse events. We performed a doseescalation study of CF supplementation to assess the frequency andseverity of GI adverse events. This 4-week dose escalation studyshowed that the intake of CF extract was associated with mild GIadverse events, which appeared to be dose-related [11].

The mechanism by which GI events are induced is not fullyunderstood, but one possibility is that cAMP-induced efflux ofchloride ions from the intestinal membrane causes GI events suchas soft stool and diarrhea. We suggest that a cAMP-dependentchloride channel, known as the cystic fibrosis transmembraneconductance regulator (CFTR), is responsible for the secretion ofwater into the lumen [12]. Theoretically, increased levels of cAMP inthe intestine induced by the intake of CF extract could causesecretion of chloride ions into the lumen via the CFTR. This couldresult in secretion of water, which manifests as soft stool anddiarrhea in subjects who are more susceptible to these effects.

5. Conclusion

In summary, we showed that the intake of CF extract improvedbody composition in healthy volunteers. Our findings indicate thatCF extract has potential as a complementary therapy in the treat-ment of obesity. Further studies with double-blind, randomized,placebo-controlled designs are warranted to conclusively demon-strate the effectiveness of CF extract for weight loss and weightmanagement.

Funding

This work was supported by a research grant from the DHCCorporation.

Conflict of interest

Seika Kamohara is a research advisor for the DHC Corporationlaboratory. Somboon Noparatanawong is an employee of the DHCCorporation.

Acknowledgments

The authors are grateful to Dr. L. Todd Landreneau for preparingthis manuscript.

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