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Background and Objectives: Colorectal cancer (CRC) is the fourth most commonly diagnosed cancer and the third most deadly cancer in the world. According to recent experimental reports, probiotics and their derivatives protect CRC patients from treatment-related side effects. Therefore, the present study aimed to investigate the cytotoxic impact of the cell-free supernatant (CFS) of Lentilactobacillus buchneri on the HT-29 cancer cell line. Materials and Methods: In the current study, we used the L. buchneri CFS, which was well isolated and identified in our previous investigation from traditional yogurt in the Arak region of Iran. The apoptosis induction in HT-29 cancer cells was assessed by cell cytotoxicity, flow cytometry, and qRT-PCR. Results: L. buchneri CFS inhibited the proliferation of HT-29 cancer cells in a time- and dose-dependent manner. The apoptotic effect of CFS was further supported by the flow cytometry data, which showed that the maximum incidence of apoptosis was observed in HT-29 cancer cells treated with the IC50 concentration of CFS after 72 hours. CFS of L. buchneri also exerted the up-regulating effect on the expression of pro-apoptotic genes including BAX, CASP9, and CASP3. L. buchneri CFS at an IC50 dose induced cell cycle arrest in the G0/G1 phase in HT-29 cells. Conclusion: This study indicates that L. buchneri CFS can prevent colorectal cancer (CRC) development in patients by inducing cancer cell apoptosis. This finding suggests that the CFS of L. buchneri could be used as a therapeutic agent for the control of CRC.

Background and Objectives: Plant growth-promoting bacteria (PGPB) may reduce the negative effects of salinity stress. The aim of this study was to optimize Bacillus megaterium RTS1 and characterize the effect of the PGPB on the physiological characteristics of tomato (Lycopersicon esculentum). Materials and Methods: The Central composite design (CCD) of response surface methodology (RSM) was used to optimize Bacillus megaterium RTS1 to produce maximum cell biomass and spores. Then the effect of the PGPB on the physiological characteristics of tomato (Lycopersicon esculentum), including membrane stability, leaf relative water content percentage, anthocyanin and carotenoids content, chlorophyll photosynthetic parameters, sugar and starch level, superoxide anion and antioxidant activity under salt stress conditions. The NFB medium was inoculated with 5% bacterial culture and the fermentation was carried out in a 10-lit fermenter. Results: After optimization, the amount of cell biomass by the model was 9.45 log10 CFUs/mL, which showed a 1.2-fold increase compared to the non-optimized medium. Usage of bacteria under the optimal conditions of the culture medium may increase the stability of the membrane and improve the relative water content. Bacteria were able to prevent the excessive increase of anthocyanins. Oxidative stress led to an increase in the content of chlorophyll a, while causing the degradation of chlorophyll b. Bacterial inoculation led to an increase in the level of sugar and starch compared to the control. PGPB showed an increasing effect on the amount of superoxide anion production and caused a significant increase in the antioxidant activity under salinity stress conditions. Conclusion: The PGPB can be a promising way to boost physiological characteristics of tomato plant under salinity stress. Also, sporulation capacity of Bacillus megaterium with high bacterial cell density in fermenter produce a sustainable product for tomato plants.

Background and Objectives: Peptic ulcer disease is a multifactorial disease that affects up to 10% of people. The use of natural product remedies has received much attention for its treatment. In this research, the healing effect of metabiotic extracted from Bifidobacterium bifidum was investigated. Materials and Methods: 45 male wistar rats were divided into 3 groups (Ctrl-, drug, and metabiotic), and stomach ulcers were induced by ethanol administration and treated by drug and metabiotic. The healing process was investigated on different days by histological analysis and qRT-PCR. Results: The metabiotic increased IL-8 and PDGF expression and stimulated the recruitment of polymorphonuclear cells to the wound site. It caused a faster onset of the inflammation phase followed by the proliferation phase. The metabiotic increased the expression of SOD and GPx genes and the antioxidant capacity of the wound. The increase in EGF expression led to faster re-epithelization, which was evident in the wound closure process. Conclusion: Metabiotic extracted from B. bifidum is a promising candidate for the treatment of PUD. It causes a faster onset of the inflammation phase. Improving the antioxidant status of the wound, causes a faster resolution of inflammation, which leads to the acceleration of the wound-healing process.

Background and Objectives: Breast cancer is the second leading cause of death and one of the most common malignancies among women in the world. The aim of this study was to investigate the preventive effects of postbiotic consisting of sonicated Bifidobacterium bifidum cells on triple negative breast cancer. Materials and Methods: Thirty-six female BALB/c mice aged 5-7 weeks were randomly divided into 3 groups (n=12): Ctrl-, healthy mice; Ctrl+, mice with breast cancer with no treatment; and Postbiotic, mice with orally gavage postbiotic before and after 4T1 cell line transplantation. Cancer progress and the effects of postbiotic were assayed by histological, immunohistochemical and gene expression quantification. Results: The histological results showed that administration postbiotic consisting of B. bifidum significantly decreased carcinogenesis in terms of tumor incidence, multiplicity and volume. The tumor progress was suppressed by oral intake of B. bifidum as showed by p53 and Ki-67 expression. Furthermore, Oral intake of postbiotic resulted in extended survival of mice and inhibited sever weigh loss. Conclusion: Pretreatment with sonication killed B. bifidum, as a postbiotic, inhibited breast cancer progress and malignancy.

Background and Objectives: Plant Growth-promoting Bacteria (PGPB) can replace the dangerous chemical fertilizers and pesticides. The aim of this study was to isolate the PGPBs for Lycopersicon esculentum plant and to determine the appropriate volume for inoculation. Materials and Methods: Plants samples were collected from tomato fields. Nitrogen fixing-PGPBs were isolated from rhizoplane and rhizosphere. Five isolates were screened based on their growth abilities and examined for PGPB traits including phosphate solubilization, and IAA, ammonia and HCN production. After high cell density cultivation, the cells were separated by centrifugation and freeze dried after resuspension in cryoprotectant. The powders were inoculated into sterile soil with a dose of 106, 107 and 108 CFUs/g. Tomato (Lycopersicon esculentum) seeds were sown in soil and after 42 days the shoot length was measured. Results: Most of the potent PGPBs with high growth capacity were isolated from rhizoplane. Maximum phosphate solubilization was 289.7 µg/ml by NFB12 which isolated from rhizoplane. This strain produced the maximum level of IAA. NFB12 produced ammonia without the ability of production of HCN. This strain enhanced shoot length in dosed dependent manner. Surprisingly, inoculation of soil with 108 CFUs/g dramatically decreased the shoot length by 21%. Based on molecular approach NFB12 was identified as Bacillus megaterium. Conclusion: Isolation of specific PGPBS is recommended for sustainable plant production. Our results showed that NBF12 improves tomato plant growth and its effect on tomato plant growth is does dependent. Maximum growth rate of tomato was observed with 107 CFUs/g soil inoculation of NFB12 while higher inoculation showed negative effect.

Background and Objectives: Secondary metabolites in the supernatants of probiotic microorganisms have shown anticancer effects. The present study was aimed to investigate the cytotoxicity of Bacillus coagulans supernatants and their role in apoptosis induction in MCF7 cancer cells. Materials and Methods: The inhibition of MCF7 cancer cells by Bacillus coagulans supernatants was assessed by MTT assay at three exposure times of 24, 48, and 72 h. Apoptosis induction was explored by flow cytometry while the expression levels of bax, caspase 3, caspase 9, and bcl2 were examined by real-time PCR and compared with normal HFF cells. Results: Bacillus coagulans supernatants exhibited inhibitory effects on MCF7 cells in a concentration-dependent and time-dependent manner; while lower cytotoxic effects were observed in normal HFF cells. The increase in the expression of bax, caspase 3, and caspase 9 genes and the decrease in the anti-apoptotic gene of bcl2, along with the flow cytometry results, confirmed the induction of apoptosis in the cancer cells. Conclusion: Regarding the cytotoxic influence of Bacillus coagulans supernatants against breast cancer cells, this bacterium can be considered as a potential candidate for a novel therapeutic strategy with lower side effects which of course requires further investigations.