The present study suggests that IGOB131, a seed extract of Irvingia gabonensis, safely and significantly reduces body weight in overweight and/or obese subjects, and has a favorable impact upon a variety of other metabolic parameters. The current clinical study shows IGOB131 administration is associated with increases in plasma adiponectin levels and decreases in leptin and CRP levels in comparison with the placebo group. These observations support the results of a recent in vitro study  which suggests a favorable impact upon adipogenesis associated with IGOB131.
Insulin resistance is the hallmark of the metabolic syndrome and is strongly associated with excess adiposity . A variety of adipocyte-derived biologically active molecules have been identified, including leptin, resistin, TNF-α, and IL-6, that may contribute to obesity-linked metabolic abnormalities . Since plasma leptin levels are closely correlated with the level of adipose tissue , the decreases in plasma leptin level associated with IGOB131 treatment may be attributable to the decrease of adipose tissue induced as a consequence of weight loss.
According to McTernan et al. , adipose tissue plays a prominent role in the clinical expression of metabolic syndrome, most likely mediated by the increased release and peripheral tissue action of non-esterified fatty acids and by the dysregulated production of adipocyte-secreted proteins, including leptin, adiponectin, resistin, TNF-α, and IL-6. Adiponectin, known to correlate with endothelial function and vascular health, is exclusively expressed in adipose tissue and abundant in human plasma, and appears to be decreased in individuals with obesity and type 2 diabetes, risk factors for atherosclerosis.
The observation of a significant weight loss, as well as an increase in adiponectin is consistent with earlier reports in the literature observing an association between weight loss and an increase in adiponectin levels .
IGOB131 is relatively rich in plant-derived protein and antioxidants. A study by Baum et al,  had earlier shown a reduction of both total cholesterol and triglycerides levels in a hypercholesterolemic man who was fed a plant protein diet. Other studies have shown metabolic syndrome-preventive activity of antioxidant components (e.g. vitamin C, polyphenols). A number of polyphenols such as epigallocatechin gallate have anti-obesity activity and may improve metabolic disorders via modulation of adipokines and growth factors, including metabolic improvement of leptin function [22–24]. Although the active principles of IGOB131 have not yet been fully identified, it is possible that it contains some of the above mentioned compounds.
In conclusion, Irvingia gabonensis extract administered twice a day to healthy, overweight and obese individuals resulted in both weight reduction (body weight, body fat, waist size) and an improvement in metabolic parameters associated with insulin resistance. The current results suggest that IGOB131 may be a helpful adjunct in the management of overweight and/or obesity, supporting previous suggestions from our laboratory .