Effects of obesity in rats on prostate histology and expression of leptin receptor, prolactin receptor, IL-6, and NF-κB

BACKGROUND

Hypercaloric intake can lead to obesity, which is a major risk factor associated with chronic subclinical inflammation and many types of cancer. It can increase the serum levels of leptin, prolactin, nuclear factor kappa B (NF-кB) and interleukin (IL)-6, implicated in cell proliferation, differentiation and survival.

AIM

To explore the effects of obesity induced by chronic hypercaloric diet in rats on the long-term expression of leptin receptor (OB-R), prolactin receptor, NF-кB, and IL-6, and the changes of histology in rat prostate.

MATERIALS AND METHODS

From postnatal day 21, experimental males were fed with normal chow or chow plus enriched hypercaloric liquid diet. On the postnatal day 90 (13 week old), the animals were euthanized for prostate histology (hematoxylin and eosin staining) and hormone receptors analysis by Western blot.

RESULTS

Hypercaloric diet resulted in obesity (32% higher body weight). The prostates of the obese males showed epithelium anisocytosis and compressed interstice. There was also greater volume of lipidic content, anisokaryosis, alterations of the nucleus-cytoplasm ratio, and apparent proplasia. Measures in the ventral prostate (VP) showed that alveoli area increased, but epithelium height and nucleus area were reduced. In the dorsolateral prostate, there was only reduction of nucleus area and presence of mononuclear cells in the lumen. Hypercaloric males also expressed a trend for more OB-R 130 kD in the VP, but no changes were observed with regard to prolactin receptor, NF-кB and IL-6.

CONCLUSION

The obesity due to chronic consumption of hypercaloric diet affects both prostatic regions, but VP is possibly more sensitive via OB-R. We suggest that longer periods of obesity are needed to alter other receptors or the molecular markers of inflammation.

Structure-Based Virtual Screening of Sterols and Triterpenoids Isolated from Ganoderma (Agaricomycetes) Medicinal Mushrooms Shows Differences in Their Affinity for Human Glucocorticoid and Mineralocorticoid Receptors

An extensive database of sterols and triterpenoids isolated from Ganoderma mushrooms was evaluated by in silico structure-based virtual screening to determine their respective ligand affinities for the glucocorticoid or mineralocorticoid receptor (GCR or MNR). The main ligands for GCR in our database were ergosta-7,22-dien-3-one (compound 1) and ganodermaside B (compound 2), while the best ligands for MNR were 2β,3α,9α-trihydroxyergosta-7,22-diene (compound 8) and 5α-ergosta-7,22-dien-3β-ol (compound 3). The binding free energy (BFE) values calculated for such metabolites were similar to those of the natural ligands for each receptor (i.e., dexamethasone for GCR and aldosterone for MNR). Moreover, the differences between mean BFE values calculated for both receptors suggest that ergosta-7,22-dien-3-one (compound 1), ganodermaside B (compound 2), fungisterol (compound 5), ganoderic acid Ma (compound 9), and cerevisterol (compound 10) might be used as specific ligands for GCR, with a significantly lower affinity for MNR. Finally, it is worth noting that even though this work is exclusively theoretical, the reported bioactivities (either pro- or anti-inflammatory) for those metabolites that were previously studied are consistent with our findings, suggesting that the well-known immunomodulatory effect of Ganoderma triterpenoids and sterols might be attributed, at least partially, to their ability to act as specific GCR ligands.

Ergosterol exerts a differential effect on AR-dependent LNCaP and AR-independent DU-145 cancer cells

Androgen-dependent LNCaP and androgen-independent DU-145 cells, were treated with different concentrations of ergosterol (15 µM and 25 µM) and its respective cell viability was measured by MTT bioassay. While ergosterol showed an antiproliferative effect on LNCaP, on DU-145 promoted cell proliferation. This differential effect suggests that the effect of ergosterol might be related to its ability to act as an Androgen Receptor ligand. In silico Molecular Dynamics simulations were performed to analyze the interaction mechanism between androgen receptor and ergosterol, in comparison with natural ligands, 5α-dihydrotestosterone and testosterone. Our model suggests that the binding of androgen receptor with ergosterol is thermodinamically feasible, which is concordant with our experimental results.

Insights into Ergosterol Peroxide's Trypanocidal Activity

Trypanosoma cruzi, which causes Chagas disease, is a significant health threat in many countries and affects millions of people. Given the magnitude of this disease, a broader understanding of trypanocidal mechanisms is needed to prevent and treat infection. Natural endoperoxides, such as ergosterol peroxide, have been shown to be toxic to parasites without causing harm to human cells or tissues. Although prior studies have demonstrated the trypanocidal activity of ergosterol peroxide, the cellular and molecular mechanisms remain unknown. The results of this study indicate that a free-radical reaction occurs in T. cruzi following ergosterol peroxide exposure, leading to cell death. Using a combination of biochemical, microscopic and in silico experimental approaches, we have identified, for the first time, the cellular and molecular cytotoxic mechanism of an ergosterol peroxide obtained from Pleurotus ostreatus (Jacq) P. Kumm. f. sp. Florida.

Molecular Dynamics and Virtual Screening Analysis of Lanosterol Derivatives from Ganoderma Medicinal Mushrooms (Agaricomycetes) as Selective Ligands of Human Androgen Receptor

Male sex hormones such as testosterone and dihydrotestosterone play important roles in several physiological and pathological processes. The biological activities of the aforementioned metabolites are mediated by the multidomain androgen receptor (AR), which is therefore a well-studied drug target. Ganoderma mushroom lanostanoid extracts have previously been shown to exert antiandrogenic activity; therefore, this work aims to identify which lanostane derivatives might act as selective ligands for AR. Because protein flexibility is of paramount importance for ligand binding, different conformations of AR were sampled to account for binding modes within a ligand binding site, then subjected to virtual screening against a metabolite library. Fifteen Ganoderma lanostanoids were selected as AR ligands, according to their calculated binding affinity to this nuclear receptor. The results show the relevance of certain structural and chemical aspects of our ligands, such as the presence of a ketonic group on C-3, which influences the process through which they bind to AR.

The Amoebicidal Effect of Ergosterol Peroxide Isolated from Pleurotus ostreatus

Dysentery is an inflammation of the intestine caused by the protozoan parasite Entamoeba histolytica and is a recurrent health problem affecting millions of people worldwide. Because of the magnitude of this disease, finding novel strategies for treatment that does not affect human cells is necessary. Ergosterol peroxide is a sterol particularly known as a major cytotoxic agent with a wide spectrum of biological activities produced by edible and medicinal mushrooms. The aim of this report is to evaluate the amoebicidal activity of ergosterol peroxide (5α, 8α-epidioxy-22E-ergosta-6,22-dien-3β-ol isolated from 5α, 8α-epidioxy-22E-ergosta-6,22-dien-3β-ol) (Jacq.) P. Kumm. f. sp. Florida. Our results show that ergosterol peroxide produced a strong cytotoxic effect against amoebic growth. The inhibitory concentration IC50 of ergosterol peroxide was evaluated. The interaction between E. histolytica and ergosterol peroxide in vitro resulted in strong amoebicidal activity (IC50  = 4.23 nM) that may be due to the oxidatory effect on the parasitic membrane. We also tested selective toxicity of ergosterol peroxide using a cell line CCL-241, a human epithelial cell line isolated from normal human fetal intestinal tissue. To the best of our knowledge, this is the first report on the cytotoxicity of ergosterol peroxide against E. histolytica, which uncovers a new biological property of the lipidic compound isolated from Pleurotus ostreatus (Jacq.) P. Kumm. f. sp. Florida.

Isolation and Characterization of Bioactive Metabolites from Fruiting Bodies and Mycelial Culture of Ganoderma oerstedii (Higher Basidiomycetes) from Mexico

Various species of the genus Ganoderma have been used for centuries according to oriental tradition as a source of medicines and nutrients. A chemical study of the fruiting bodies and mycelial culture of G. oerstedii was carried out with the idea of isolating and characterizing active natural components present to make use of their potential pharmaceutical application in Mexico. The fruiting bodies and mycelial culture of G. oesrtedii were lyophylized and extracted one after the other with hexane, chloroform, and methanol. Following this process, each substance was extracted separately by using column chromatography. From fruiting bodies eight metabolites, five sterols (ergosta-7,22-dien-3β-ol, ergosterol peroxide, ergosterol, cerevisterol, and ergosta-7,22-dien-3-one) as well as three terpene compounds (ganodermanondiol, ganoderic acid Sz, and ganoderitriol M) were obtained from fruiting bodies. From the mycelial culture three metabolites, two sterols (ergosterol and cerevisterol), and a new terpene compound (ganoderic acetate from the acid) were obtained. These structures were established based on a spectroscopic analysis mainly using nuclear magnetic resonance and a comparison with data already established.