Mangosteen Extract Shows a Potent Insulin Sensitizing Effect in Obese Female Patients: A Prospective Randomized Controlled Pilot Study

Abstract

There is a widely acknowledged association between insulin resistance and obesity/type 2 diabetes (T2DM), and insulin sensitizing treatments have proved effective in preventing diabetes and inducing weight loss. Obesity and T2DM are also associated with increased inflammation. Mangosteen is a tropical tree, whose fruits—known for their antioxidant properties—have been recently suggested having a possible further role in the treatment of obesity and T2DM. The objective of this pilot study has been to evaluate safety and efficacy of treatment with mangosteen extract on insulin resistance, weight management, and inflammatory status in obese female patients with insulin resistance. Twenty-two patients were randomized 1:1 to behavioral therapy alone or behavioral therapy and mangosteen and 20 completed the 26-week study. The mangosteen group reported a significant improvement in insulin sensitivity (homeostatic model assessment-insulin resistance, HOMA-IR −53.22% vs. −15.23%, p = 0.004), and no side effect attributable to treatment was reported. Given the positive preliminary results we report and the excellent safety profile, we suggest a possible supplementary role of mangosteen extracts in the treatment of obesity, insulin resistance, and inflammation.

Keywords: Garcinia mangostana; diabetes; dietary supplements; inflammation; insulin resistance; mangostin; metabolic syndrome; phytotherapy; xanthones.

Figure 1

Glucose metabolism markers. (A) Insulin levels decreased significantly in the treatment group compared to control at 26 weeks; (B) HOMA IR % change went in the same direction in favor of the mangosteen group that showed a frank improvement in insulin resistance; (C) glucose levels did not significantly change in any of the studied arms.

Figure 2

Anthropometric parameters: (A) the mangosteen arm experienced weight loss (−4.5 ± 6.2%, p = 0.048) that the control failed to do, however groupwise comparison was not significant; (B) no statistically significant difference was seen regarding waist circumference in any of the groups; (C) no statistically significant difference was seen regarding body fat percentage in any of the groups.

Figure 3

Inflammation markers: (A) HsCRP was significantly reduced in the mangosteen group, with a mean decrease of 0.41 ± 0.34 mg/L (p = 0.004, −35.7 ± 22.51%). Comparison with the control group failed to show any significant groupwise difference (p = 0.13); (B) Fibrinogen levels had a trend decrease in the mangosteen group (−57 ± 93 mg/L, −9.9 ± 19.0%, p = 0.100) but failed to be significantly different when compared to control (p = 0.225).