In the present study, we showed that the intake of acerola juice decreased the level of inflammatory proteins (TNF-α) and increased lipolysis in mice fed a cafeteria diet.
The adipose tissue metabolism and plasticity are still complex topics. Numerous lipolytic and antilipolytic effectors, including hormones, cytokines, and adipokines, control the catabolism of stored fat in various tissues. Since 1992, the link between inflammation and lipolysis has been studied in regard to pro-inflammatory adipokine-induced lipolysis, principally focusing on IL-6 and TNF-α . We evaluated the phosphorylation levels of two serine residues, HSL (563 and 660), which we regarded as acting on β-adrenergic receptors. We observed that principally the phosphorylation of HSLSer660 and Perilipin A protein levels were reduced in the adipose tissues of mice who were submitted to a cafeteria diet, while mice receiving acerola juice had increased levels of phosphorylated HSLSer660 and Perilipin A. The results may be at least partially responsible for the minor adiposity index after treatment with acerola juice, in comparison with mice fed only a cafeteria diet.
Studies have shown that increased body fat can lead to low-grade inflammation (i.e., increased cytokines). As we observed reductions in the adiposity index, we hypothesized that the cytokine levels may also be reduced. With this in mind, we assayed the levels of TNF-α and IL-10 and calculated the IL-10/TNF-α ratio. We observed the increased phosphorylation of IκB-α, which can be explained by the reduction in TNF-α protein levels. This increase in the IL-10/TNF-α ratio and protein levels in the adipose tissue was observed in mice treated with acerola juice. Thus, the IkB-α levels must reflect the activity of the transcription factor NF-κB .
Our results showed that both acerola juice (industrial, unripe, ripe) and Vitamin C treatment lead to improved metabolic and inflammatory pathways. The effects of acerola juice observed in present study can be attributed to the polyphenol content, Vitamin C, quercetin and rutin .
Several studies have shown that high-fat diet-induced adiposity can be reduced by Vitamin C supplementation in rats [18, 19] and by modifications to adipocyte catecholamine-induced lipolysis . In addition, Garcia-Diaz et al.  demonstrated that Vitamin C supplementation can modulate an established inflammatory state in the interaction between adipocytes and macrophages. Moreover, resident macrophages produce catecholamines, which stimulate lipolysis in white adipose tissue . This pathway may be implicated in the central mechanisms of the increased lipolysis and anti-inflammatory effects of acerola juice, because IL-4, an anti-inflammatory cytokine, is necessary for the activation of lipolysis. The associated increase in catecholamine production in macrophages  may explain the increased level of IκB-α proteins and reduction in TNF-α protein levels.
However, others biocompounds exist in acerola juice that may be associated with the observed effects on metabolism and inflammation. Rivera et al.  related that the administration of quercetin reduced insulin resistance, dyslipidemia, and hypertension in rats. More recently, Overman et al.  reported that quercetin reduces inflammation in adipose tissue by lowering the infiltration of macrophages and suppressing NF-κB activation. We observed an increased level of phosphorylated Iκ-Bα proteins, which may indicate a suppression of NF-κB activation, confirming the observations of Overman and colleagues .
Hsu et al.  showed that the body, liver organ, and adipose tissue weights of the peritoneal and epididymal fat pads of mice on a high fat diet supplemented with rutin were significantly decreased, compared with those on a high fat diet without supplementation. In addition, the authors verified that the serum lipid profiles, insulin, and leptin were significantly decreased after treatment with rutin. Recently, Gao et al.  showed that rutin is able to block high fat diet-induced obesity, fatty liver and insulin resistance in mice. Further, these beneficial effects were correlated with a blockade of macrophage infiltration and chronic inflammation in the adipose tissues. In our study, we observed reduced TAG levels in accordance with the above cited studies.
Acerola juice suppresses glucose absorption and blood glucose elevation after feeding . This decrease in glucose disposition by the energetic metabolism can be responsible, due to the increased fatty acid utilization, for maintaining the energetic demand, ameliorating the vicious cycle of lipolysis-inflammation, and mobilizing the free fatty acids from lipolysis to be used as an energy source. However, recently, Leffa et al.  showed that acerola juice is not able to alter or reverse insulin resistance in mice fed a high-fat diet. More studies are needed to achieve a better understanding of the involved mechanisms.
Finally, to verify the area of the adipocytes, we evaluated the histology with hematoxylin and eosin (HE). The results demonstrated, at least in part, that all cafeteria diet groups had an increased area of adipocytes when compared with the STA group, regardless of the effects of the different treatments.
In conclusion, our results showed that acerola juice prevents weight gain (measured in terms of body weight and the adiposity index) and dyslipidemia (measured using TAG levels) and restores metabolic and inflammatory pathways to a normal range. Future studies are needed to better understand the mechanisms involved in the beneficial effects associated with acerola juice intake, especially in mice fed a cafeteria high-fat diet.