is observed in the principal PGB-indicated conditions which share the alteration in IL-6, TNF-α, IL-2 and IL-1β cytokines level. Yet, reports on PGB immunomodulatory and anti-inflammatory effects are a few and focused mainly on in vitro assays, local inflammatory changes within the nervous system, and attenuation of the secretion of only IL-1β and TNF-α cytokines 18-20. In addition, PGB effects on cytokines secretion in immune cells, such as isolated splenocytes and peritoneal macrophages (PMs), and its effect on lymphoid organs, were not examined before. Therefore, there is a need to perform a simultaneous assessment of the effect of PGB on the secretion of the cytokines that were commonly elevated in the aforementioned PGB-indicated conditions (IL-6, TNF-α, IL-1β and IL-2) and to expand the investigation to its effect on lymphoid organs and cytokine secretion in immune cells. As peripheral inflammation and elevated systemic cytokines levels were demonstrated in the above-mentioned PGB-indicated conditions, we investigated in this study the effect of PGB on murine models of peripheral inflammation. In this study, we used for the first time, LPS and ConA-induced murine models of inflammation to examine the effect of PGB on peripheral proinflammatory cytokine secretion (IL-6, TNF-α, IL-1β and IL-2) in vitro and in vivo in BALB/c mice. LPS-model of inflammation has been employed before to study neuroinflammatory conditions, seizure and anxiety disorders in mice 21-25 , while ConA was used to investigate T-cell function in patients with fibromyalgia 26. Additionally, in this study, the effect of PGB on mitogen-induced inflammatory changes in the spleen, as a lymphoid organ, was also examined for the first time. Regarding in vitro investigation, the lack of reports that examined the effect of PGB on the secretion of cytokines in immune cells prompted us to investigate such effects of PGB on basal and mitogen-induced proinflammatory cytokines secretion in splenocytes and peritoneal macrophages (PMs).

Prostate cancer is one of the most common malignant tumors around the world. Hyperlipidemia is considered as one of the most important risk factors for the development of prostate cancer. Simvastatin is widely used for the treatment of hyperlipidemia and was previously shown to induce apoptosis in several cancer types including lung, colon, pancreas, breast, and prostate cancer. In this study we aimed to explore the potential role of simvastatin in enhancing irinotecan-induced apoptosis in prostate cancer cells. In addition, the underlying molecular mechanisms driving this potential effect of simvastatin were also explored. PC3 cells were treated with simvastatin, irinotecan or combination. Cell viability was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) colorimetric assay. Flow cytometry technique was used to analyze apoptosis and cell cycle progression. Western blot was used for detection of protein expression. Results showed that simvastatin has a significant anti-proliferative activity on PC3 cells. Combined treatment of simvastatin with irinotecan exhibited a significant inhibition of PC3 cell growth compared to each treatment alone. Flow cytometry analysis showed that PC3 cell treatment with simvastatin and irinotecan combination demonstrated a remarkable increase in the percentage of apoptotic cells and those accumulated at G0/G1 phase when compared to each treatment alone. Moreover, induction of apoptosis was caspase-independent. Western blot showed that apoptosis was accompanied by upregulation of GRP-78 level and downregulation of Mcl-1 levels in a time-dependent manner. The results of this study demonstrated that combined treatment of simvastatin with chemotherapeutic agents such as irinotecan resulted in enhancement of growth inhibition and induction of prostate cancer cell apoptosis.