Adipose tissue growth is angiogenesis-dependent, and angiogenesis inhibitors can regulate adipose tissue mass by cutting off the blood supply. We examined whether antiangiogenic herbal composition Ob-X can reduce fast-growing abdominal fat, especially visceral fat in humans by inhibiting angiogenesis. Eighty abdominally obese subjects (body mass index: 25-29.9 kg/m2, waist circumference: exceeding 90 cm for males and 85 cm for females) participated in a 12-week randomized, double-blind, placebo-controlled human study to evaluate the efficacy and safety of Ob-X. 690 mg of Ob-X was administered orally twice a day. The Ob-X group showed a noticeable reduction in visceral fat of 20.5% after the 12-week treatment as compared to baseline measured by computed tomography. The change in visceral fat in the Ob-X group was statistically significant as compared to the placebo group (p = 0.0495) and 1.9 times higher than in the placebo group. Therefore, angiogenesis inhibitor Ob-X has the potential to improve obesity-related metabolic syndrome by reducing dangerous visceral fat.
Obesity, particularly abdominal obesity, plays an important role in the pathogenesis of metabolic disorders and cardiovascular diseases, including type 2 diabetes [
Angiogenesis is the process of new blood vessel formation from preexisting vasculature. Similar to tumor tissue, adipose tissue growth is angiogenesis-dependent, and adipose tissue mass can be regulated by its vasculature [
We screened antiangiogenic and MMP-inhibitory activities from herbal extract libraries and found that three herbal extracts of
Melissa has been used as a medicinal plant to treat nervousness, insomnia, gastrointestinal disorders, herpes virus infection, and Alzheimer’s disease [
In animal studies, a mixture of three herbal extracts, called Ob-X, reduced adipose tissue mass in high fat diet-induced obese mice, providing evidence that adipose tissue growth can be inhibited by angiogenesis inhibitor [
Ob-X supplementation in high-fat diet-induced obese mice increased the hepatic mRNA levels of the PPAR
In genetically obese
In the present study, Ob-X was evaluated in humans to determine whether it reduces fast-growing abdominal fat, especially visceral fat, by inhibiting angiogenesis.
Healthy volunteers, 19-50 years of age, were recruited. Informed consent was obtained from all the subjects prior to enrolling in the study. A total of 80 volunteers, with a BMI of 25-29.9 kg/m2 and waist circumference exceeding 90 cm for males and 85 cm for females, met the inclusion criteria and enrolled. Exclusion criteria for the study included those on drug therapy, those on a special diet, those taking dietary substitutes for weight loss, and those involved in a diet program within 3 months prior to the start of the study. Hypertensive individuals whose SBP was higher than 160 mmHg or DBP higher than 100 mmHg, those taking diuretics, diabetics taking oral hypoglycemic agents or insulin, those with active thyroid disease or hyperlipidemia, those with a history of renal, liver, pancreatic, or chronic inflammatory/infectious diseases, allergic diseases, asthma, heart failure, or malignant tumors, pregnant or lactating women, and volunteers with suspected drug or alcohol abuse or with any clinical condition rendering them unfit to participate were also excluded from the study.
Ob-X was prepared using food grade aqueous extracts of
Ethical approval for this human study was obtained from the Institutional Review Board at the Inje University Seoul Paik hospital (SIT 240) in 2008 as being in compliance with the Helsinki II Declaration. It was a randomized, placebo-controlled, double-blind, 12-week study. Eighty subjects were enrolled in the study and randomized to receive placebo (1.38 g of dextrin) or 1.38 g of Ob-X per day for 12 weeks. The daily dose of Ob-X was determined by the preliminary human study (data not published). 1.38 g of Ob-X contains 0.9 g of active extracts and 0.48 g of dextrin as excipient. Subjects were instructed to take 3 capsules (230 mg/capsule) twice a day in the morning and afternoon, a total of 6 capsules per day (1.38 g). The placebo capsules and Ob-X capsules were identical in appearance.
All subjects were scheduled to visit the hospital every 4 weeks from the start of the study. During the study, all subjects were counseled on diet and exercise compliance at every visit from the nutritionist. All subjects were instructed to restrict their total energy intake to 500-kcal deficit of the recommended daily calorie intake and were advised to exercise corresponding to an energy expenditure of 250 kcal per day, three times a week. All subjects were educated to fill out a food diary, and the nutritionist analyzed the food intake of three major nutrients in terms of calorie content, using the nutrition analysis program (CAN pro) at baseline and at 12 weeks.
Baseline characteristics and demographic data were recorded by the medical staff as the subjects entered the study, to evaluate their eligibility. Body weight, height, waist and hip circumferences, BMI, and vital signs, such as systolic and diastolic blood pressure and heart rate measurements, were recorded.
White blood cell (WBC), red blood cell (RBC), hematocrit, hemoglobin, and platelet were determined as hematological studies. Creatinine, blood urea nitrogen (BUN), uric acid, calcium (Ca), potassium (P), sodium (Na), potassium (K), chloride (Cl), insulin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), albumin, protein, alkaline phosphatase(ALP), total cholesterol, LDL-cholesterol, HDL-cholesterol, triglyceride, glucose, and C-reactive protein (CRP) were determined as laboratory test items for safety analysis.
The primary outcome measure of this study was the reduction of abdominal fat at week 12 as compared to baseline. Computed tomography was used, on a Siemens CT scanner (Erlangen, Germany), to determine total abdominal fat, visceral fat, and subcutaneous fat areas at baseline and at week 12. An image of the cross section at the L4/L5 intervertebral disc level was obtained and was analyzed using Siemens’ software.
Body composition was measured by bioelectric impedance analysis (BIA, BC-418, Tanita, Japan) at baseline and at week 12.
Subjects were asked to return all unused capsules in the original bottles every 4 weeks. The returned capsules were counted and the compliance was calculated as the number of capsules actually consumed divided by the number of capsules that should have been used by the end of 12 weeks of treatment. Each subject was considered compliant when taking at least 70% of Ob-X or placebo given.
The effect of Ob-X was assessed by analyzing the Ob-X treated group compared with the placebo group. The results are given as mean and standard deviation. The data were processed using the SPSS statistical program, and the significance of the difference in mean value between the placebo and the Ob-X treated group was submitted to Student’s t-test. ANCOVA analysis was also conducted. If the p value was smaller than 0.05, the value was regarded as statistically significant. Correlations between initial values and changes in total abdominal, visceral, and subcutaneous fat areas were assessed using Pearson’s correlation coefficient.
As shown in Figure
CONSORT (Consolidated Standards of Reporting Trials) flow diagram of the recruitment, enrollment, and randomization process.
Of the 58 subjects who completed the study, 5 had compliance lower than 70% as described in the protocol. Therefore, 53 subjects completed the study according to the study protocol, and the results of these 53 subjects were analyzed, except for the safety analysis.
There were no significant differences between the characteristics of the groups at baseline, as shown in Table
Characteristics of the subjects at baseline.
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Sex, n (%) | Male (%) | 2 (8.7%) | 6 (20%) |
Female (%) | 21 (91.3%) | 24 (80%) | |
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Age (y) | 33.61 ± 9.47 | 32.30 ± 7.11 | |
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Height (cm) | 159.90 ± 5.62 | 162.70 ± 7.74 | |
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Weight (kg) | 69.99 ± 6.27 | 72.65 ± 8.22 | |
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BMI (kg/m2) | 27.33 ± 1.27 | 27.78 ± 2.98 | |
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Waist circumference (cm) | 91.04 ± 3.72 | 90.53 ± 3.95 | |
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Hip circumference (cm) | 101.58 ± 3.85 | 102.14 ± 4.29 | |
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Waist to hip ratio | 0.897 ± 0.033 | 0.887 ± 0.038 | |
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Systolic BP (mmHg) | 115.65 ± 10.37 | 119.53 ± 11.31 | |
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Diastolic BP (mmHg) | 74.70 ± 10.61 | 75.77 ± 8.69 | |
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Pulse (beats/min) | 66.52 ± 10.92 | 68.10 ± 10.99 |
Values represent the mean ± SD.
To determine whether Ob-X reduces fast-growing abdominal fat, visceral fat, and subcutaneous fat were assessed by computed tomography at baseline and at week 12.
When we analyzed the change in abdominal fat by Ob-X at week 12 compared to the placebo group, the Ob-X group reduced subcutaneous fat (-8.33 ± 51.63 cm2 versus 1.56 ± 39.88 cm2, respectively), visceral fat (-30.23 ± 27.28 cm2 versus -15.22 ± 24.61 cm2 respectively), total abdominal fat (-38.56 ± 64.24 cm2 versus -13.67 ± 51.13 cm2 respectively), and visceral/subcutaneous fat ratio (-0.14 ± 0.17 versus -0.09 ± 0.15) as shown in Table
Changes in abdominal fat analyzed by computed tomography.
| | | | |
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Subcutaneous fat (cm2) | Placebo | 243.15 ± 53.36 | 244.71 ± 55.18 | 1.56 ± 39.88 |
Ob-X | 238.72 ± 61.15 | 230.38 ± 57.67 | -8.33 ± 51.63 | |
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Visceral fat (cm2) | Placebo | 141.68 ± 47.60 | 126.46 ± 47.58 | -15.22 ± 24.61 |
Ob-X | 147.50 ± 38.90 | 117.27 ± 26.42 | -30.23 ± 27.28 | |
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Total abdominal fat (cm2) | Placebo | 384.83 ± 55.79 | 371.16 ± 70.18 | -13.67 ± 51.13 |
Ob-X | 386.21 ± 70.94 | 347.65 ± 63.67 | -38.56 ± 64.24 | |
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Visc.fat / Subc. fat ratio | Placebo | 0.64 ± 0.36 | 0.55 ± 0.30 | -0.09 ± 0.15 |
Ob-X | 0.68 ± 0.27 | 0.54 ± 0.18 | -0.14 ± 0.17 |
Values represent the mean ± SD.
Changes in abdominal fat at week 12 of treatment with Ob-X. (a) Changes in subcutaneous fat, (b) visceral fat, (c) total abdominal fat, and (d) visceral fat/subcutaneous fat ratio (
Reduction in visceral fat after 12-week treatment of Ob-X. (a) Visceral fat area was analyzed by computed tomography (
This result indicates that the angiogenesis inhibitor, Ob-X, specifically reduces visceral fat, as angiogenesis occurs actively in fast-growing visceral fat.
We examined the correlation between the initial visceral fat area and the change in visceral fat area induced by Ob-X treatment. As shown in Figure
The fat reducing effect of placebo and Ob-X treatment in relation to the initial abdominal fat area. Correlation between the induced change in visceral fat and initial visceral fat before intervention of placebo (a) or Ob-X (b). Correlation between the induced change in subcutaneous fat and initial subcutaneous fat before intervention of placebo (c) or Ob-X (c). Correlation between the induced change in total abdominal fat and initial total abdominal fat before intervention of placebo (e) or Ob-X (f).
Looking at the analysis data for other secondary outcome measurements, i.e., body weight, BMI, body fat composition, body fat mass, waist circumference, and WHR, there were no statistically significant differences on these variables between the placebo group and the Ob-X-treated group (Table
Changes from week 0 to week 12 between placebo and Ob-X treated group.
| | | | |
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Body weight | Placebo | 69.99 ± 6.27 | 66.83 ± 6.61 | -3.17 ± 2.49 |
Ob-X | 72.65 ± 8.22 | 70.07 ± 7.75 | -2.58 ± 2.97 | |
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BMI (kg/m2) | Placebo | 27.33 ± 1.27 | 26.08 ± 1.31 | -1.25 ± 1.01 |
Ob-X | 27.78 ± 2.98 | 26.43 ± 1.82 | -1.34 ± 2.35 | |
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Body fat (%) | Placebo | 39.01 ± 4.19 | 36.93 ± 1.15 | -2.08 ± 2.24 |
Ob-X | 37.24 ± 5.68 | 35.44 ± 6.10 | -1.80 ± 2.90 | |
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Body fat mass | Placebo | 27.30 ± 3.88 | 24.68 ± 3.75 | -2.63 ± 2.39 |
Ob-X | 26.91 ± 4.29 | 24.65 ± 4.24 | -2.26 ± 2.94 | |
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Waist circumference | Placebo | 91.04 ± 3.72 | 87.07 ± 5.86 | -3.97 ± 5.17 |
Ob-X | 90.53 ± 3.95 | 86.29 ± 5.84 | -4.24 ± 4.29 | |
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Hip circumference | Placebo | 101.58 ± 3.85 | 98.43 ± 4.55 | -3.14 ± 2.96 |
Ob-X | 102.14 ± 4.29 | 99.56 ± 4.05 | -2.58 ± 3.13 | |
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Waist / Hip | Placebo | 0.90 ± 0.03 | 0.88 ± 0.05 | -0.01 ± 0.04 |
Ob-X | 0.89 ± 0.04 | 0.87 ± 0.05 | -0.02 ± 0.04 |
Values represent the mean ± SD. BMI, body mass index.
In the serum analysis, there were no statistically significant changes between the placebo group and the Ob-X-treated group at baseline and at week 12, in terms of total cholesterol, LDL-cholesterol, HDL-cholesterol, triglyceride, glucose, and CRP, which were all in the normal ranges in both groups (data not shown).
Adverse events were observed during the study period in the Ob-X group and placebo group, as shown in Table
Self-reported adverse events during 12 weeks of treatment.
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Placebo | 15 | Esophagitis(1), Headache(1), Edema(1), Nausea(1), Low back pain(1), Enteritis(2), Menstrual irregularity(1), Cold/flu(7) |
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Ob-X | 10 | Heartburn(1), Constipation(1), Dry mouth(1), Cold/flu(3) |
The safety analysis for clinical laboratory test items (WBC, RBC, hematocrit, hemoglobin, platelet, creatinine, insulin, BUN, uric acid, Ca, P, Na, K, Cl, AST, ALT, albumin, protein, and ALP) and vital signs was conducted for 58 subjects (placebo: 25, Ob-X: 33), who were randomized and completed this study. There were no problematic abnormalities or findings. The mean values for all the clinical laboratory test items and vital signs from baseline to week 12 were in the normal range, and the changes were similar between the groups (data not shown). There was no statistical difference between the placebo and Ob-X groups, from baseline to week 12. Based on these results, the safety of Ob-X is similar to placebo, and it is considered that Ob-X has a good safety profile.
Angiogenesis has been shown to play a crucial role in the modulation of adipogenesis and obesity [
The present study demonstrated, for the first time, that the angiogenesis inhibitor Ob-X can reduce abdominal fat, especially visceral fat, in humans. Ob-X, which is composed of three herbal extracts, has synergistic effect on inhibition of angiogenesis when combined with three extracts comparing to a higher dose of a single extract [data not shown].
It is reported that vascular endothelial growth factor (VEGF) and its system account for most of the angiogenic activity in adipose tissue, making it an attractive target to reduce obesity [
MMPs play major roles in the extracellular matrix remodeling events associated with angiogenesis [
The Ob-X reduced adipose tissue mass in nutritionally obese mice and the size of adipocytes in Ob-X treated mice were markedly smaller than those in control mice. The size of visceral adipocytes was decreased by 63%, while the size of subcutaneous adipocytes was decreased by 32% in Ob-X-treated mice relative to control mice. In addition, in Ob-X-treated mice, the blood vessel density in visceral adipose tissue was lower than that of the controls, which shows that the decrease in visceral adipose tissue mass by Ob-X is the result of inhibition of angiogenesis [
Adipose tissue is one of the few adult tissues that can grow and regress throughout adulthood. This characteristic relies heavily on active angiogenesis, since the expansion of capillary beds is necessary for tissue growth. Accordingly, adipose tissue contains extensive capillary networks surrounding the adipocytes, which are probably induced by adipocyte-secreted growth factors and hormones [
In a randomized placebo-controlled double-blind human study, Ob-X reduced total abdominal fat, subcutaneous fat, and visceral fat. However, a statistically significant reduction was shown only in visceral fat compared to placebo. The percentage of reduction in visceral fat by Ob-X was 20.5% as compared to baseline (10.7%), which was 1.9 times as much as placebo group. The selective effect of Ob-X in reducing visceral fat may be attributed to the different properties of visceral fat and subcutaneous fat. Specifically, visceral fat is more sensitive to angiogenesis inhibitor, which is consistent with animal studies of Ob-X [
The effects of Ob-X treatment in reducing visceral fat, subcutaneous fat, and total abdominal fat were negatively correlated with the initial areas of fat before intervention. The significantly negative correlation was the strongest in visceral fat. This implies that Ob-X may have a strong effect in reducing visceral fat in individuals with high visceral fat.
Although Ob-X reduced visceral fat in a statistically significant manner compared to the placebo group, we observed no effect on the other measurements related to visceral fat loss. The reduction in body fat mass and percentage body fat measured by BIA were not statistically significant compared to placebo. This may because the percentage of visceral fat in the total body fat is small, and 85% of the subjects were women, who have a larger proportion of fat in their body mass than men and are more likely to deposit fat subcutaneously [
No side effects were observed during the study period, and there were no statistically significant differences between the two groups. The adverse events reported in the Ob-X group were common cold, heartburn, constipation, dry mouth, stomachache, menstrual irregularity, and meningitis, which were considered not to be related to Ob-X. The results for the safety analysis showed no significant differences between the placebo and Ob-X-treated groups in the clinical laboratory blood test, biochemical test, blood pressure, and pulse. All the results were within normal ranges. The safety analysis suggested that Ob-X is safe. Moreover, the good compliance and low dropout rates in the Ob-X group indicate that Ob-X can be administered for long-term use.
Many studies indicate that visceral adipose tissue, independent of obesity, is a major determinant of insulin resistance and contributes to variations in insulin sensitivity, even in healthy nonobese subjects [
Metabolic syndrome is a group of metabolic risk factors, including abdominal obesity, high blood pressure, high triglyceride levels, low levels of high density lipoprotein (HDL) cholesterol, and high levels of fasting plasma glucose [
Hayashi et al. showed that visceral adiposity increases the odds of hypertension in Japanese Americans, independent of other adipose depots and fasting plasma insulin [
The results of the present human study demonstrate that the angiogenesis inhibitor Ob-X reduces visceral fat safely in humans. Therefore, it is expected that Ob-X would reduce the risk of metabolic syndrome by reducing dangerous visceral fat.
The authors declare that they have no conflicts of interest.
This research was supported by the Small and Medium Business Administration (S1017496).