Hamid Behrouj

Background: The Coronaviridae family is responsible for coronavirus disease 2019 (COVID-19), which has become a global health threat. In Iran, the first confirmed case of COVID-19 was reported in Qom on February 19, 2020. The rapid spread of the virus led to a significant number of fatalities, highlighting the need for a detailed ...

Background Osteoporosis is a bone disease leading to bone fracture and affects 200 million women worldwide. Autophagy and apoptosis are two fundamental mechanisms that are involved in the development of osteoporosis. In this study we aim to investigate the combined effects of quercetin and alendronate on the markers of osteoporosis, autophagy, and apoptosis in the bone of ovariectomized rats. Methods and results Fifty adult female Sprague–Dawley rats were ovariectomized and treated with alendronate alone (5 µg/kg/day) or alendronate (5 µg/kg/day) in combination with quercetin (15 mg/kg/day) for 12 weeks. Then, ELISA, stereological tests, Real-time PCR analysis, and immunofluorescence assay were used to measure the markers of osteoporosis, autophagy, and apoptosis in the serum and tibia of rats. The serum osteocalcin was significantly decreased in ovariectomized rats that received quercetin and alendronate compared with alendronate only. Stereological data showed that except for osteoclasts, the total trabecular volume, bone weight, bone volume, osteocyte, and osteoblast numbers were increased in an ovariectomized group that was treated with quercetin and alendronate compared with alendronate alone. Except for Bcl2, the autophagy markers (Beclin-1 and LC3B) and Caspase-3 were significantly downregulated in ovariectomized rats that received quercetin and alendronate compared with those treated with alendronate alone. Conclusion Our results show that quercetin enhances the anti-osteoporotic effects of alendronate, possibly through the regulation of autophagy and apoptosis mechanisms. These findings suggest that the combination of quercetin and alendronate could be a useful therapeutic strategy in the treatment of osteoporosis in postmenopausal women.

Background There is evidence that low doses or physiological concentrations of certain natural polyphenols enhance the activity of telomerase. However, the precise mechanism by which natural polyphenols regulate telomerase activity remains unclear. Recent research indicates that NF-E2 related factor 2 (Nrf2) and silent information regulator 1 (SIRT1) are involved in human telomerase reverse transcriptase (hTERT) regulation. Thus, in order to better comprehend the mechanism by which polyphenols regulate hTERT, the present study investigated the effects of the natural polyphenols Resveratrol, Gallic acid, and Kuromanin chloride on hTERT, Nrf2, and SIRT1 expression as well as oxidative stress in HepG2 hepatocellular carcinoma. Methods The trypan blue dye exclusion assay was used to assess cell viability. The level of mRNA for hTERT, Nrf2, and SIRT1 was then determined using real-time PCR. A spectrophotometric analysis was conducted to quantify oxidative stress markers. Results The results demonstrated that Resveratrol induces the expression of hTERT and the SIRT1/Nrf2 pathway in a dose-dependent manner. Gallic acid at concentrations of 10 and 20 μM also increased the expression of the hTERT and SIRT1/Nrf2 pathway. Furthermore, dose-dependent overexpression of hTERT and Nrf2 was induced by Kuromanin chloride at 10 and 20 µM. Moreover, we found that Resveratrol and Kuromanin chloride ameliorated oxidative stress, whereas Gallic acid exacerbated it. Conclusions This study demonstrates that low doses of polyphenols (Resveratrol, Gallic acid, and Kuromanin chloride) upregulate the expression of the hTERT gene in the HepG2 hepatocellular carcinoma cell line, possibly via induction of the SIRT1/Nrf2 signaling pathway. Therefore, by targeting this pathway or hTERT, the anti-cancer effect of polyphenols can be enhanced.

Ionizing radiation has various applications, including uses in medicine, industry, agriculture, and research. However, ionizing radiation is accompanied by side effects in normal radiosensitive tissues. Probiotics as natural radioprotective agents can protect normal tissues from ionizing radiation. In this regard, this study aimed to investigate the effect of Lactobacillus species on apoptosis-related genes BCL2, BAX, and caspase 3 (CASP3) in the testes of gamma-irradiated rats. A total of 30 male Wistar rats were involved in this study. The animals received the whole- body radiation with the dose rate of 2 Gy gamma-ray and were orally gavaged with 0.2 mL of 1×1010 Lactobacillus species in phosphate-buffered saline (PBS) for 4 weeks. Then, the relative gene expression levels of BCL2, BAX, and CASP3 in the testis were assessed by using the quantitative real-time polymerase chain reaction (qRT-PCR). Compared with the control group, radiation significantly downregulated the BCL2 and upregulated the BAX and CASP3 genes (p<0.0001). However, Lactobacillus species significantly reversed these effects. All in all, according to our results, employing Lactobacilli probiotics as a natural radioprotector may protect radiosensitive tissue from damage.