Interactive relationship between Trp metabolites and gut microbiota: The impact on human pathology of disease

Tryptophan (Trp), an α-amino acid, is the precursor of serotonin (5-hydroxytryptamine, 5-HT), which is involved in a variety of features of metabolic function and human nutrition. Evidence highlights the role of Trp metabolites (exclusively 5-HT) in the gastrointestinal (GI) tract; however, the mechanisms of action involved in the release of 5-HT in the GI tract are still unknown. Considering the fact that variations of 5-HT may facilitate the growth of certain GI disorders, gaining a better understanding of the function and release of 5-HT in the GI tract would be beneficial. Additionally, investigating Trp metabolism may clarify the relationship between Trp and gut microbiota. It is believed that other metabolites of Trp (mostly that of the kynurenine pathway) may play a significant role in controlling gut microbiota function. In this review, we have attempted to summarize the current research investigating the relationship of gut microbiota, Trp and 5-HT metabolism (with particular attention paid to their metabolite type, as well as a discussion of the research methods used in each study). Taking together, regarding the role that Trp/5-HT plays in a range of physical and mental diseases, the gut bacterial types, as well as the related disorders, have been exclusively considered.     

Nicotine improves morphine-induced impairment of memory: possible involvement of N-methyl-D-aspartate receptors in the nucleus accumbens

The possible involvement of N-methyl-D-aspartate (NMDA) receptors in the nucleus accumbens (NAc) in nicotine's effect on impairment of memory by morphine was investigated. A passive avoidance task was used for memory assessment in male Wistar rats. Subcutaneous (s.c.) administration of morphine (5 and 10 mg/kg) after training impaired memory performance in the animals when tested 24 h later. Pretest administration of the same doses of morphine reversed impairment of memory because of post-training administration of the opioid. Moreover, administration of nicotine (0.2 and 0.4 mg/kg, s.c.) before the test prevented impairment of memory by morphine (5 mg/kg) given after training. Impairment of memory performance in the animals because of post-training administration of morphine (5 mg/kg) was also prevented by pretest administration of a noncompetitive NMDA receptor antagonist, MK-801 (0.75 and 1 microg/rat). Interestingly, an ineffective dose of MK-801 (0.5 microg/rat) in combination with low doses (0.075 and 0.1 mg/kg) of nicotine, which had no effects alone, synergistically improved memory performance impaired by morphine given after training. On the other hand, pretest administration of NMDA (0.1 and 0.5 microg/rat), which had no effect alone, in combination with an effective dose (0.4 mg/kg, s.c.) of nicotine prevented the improving effect of nicotine on memory impaired by pretreatment morphine. The results suggest a possible role for NMDA receptors of the NAc in the improving effect of nicotine on the morphine-induced amnesia.     

The Effects of Soy Milk Enriched with Lactobacillus casei and Omega-3 on the Tibia and L5 Vertebra in Diabetic Rats: a Stereological Study

Bone fragility, despite relatively high BMD values, is an important complication related to insulin resistance and oxidative stress in diabetes mellitus type 1. The present study aimed to compare the effects of soy milk (SM), soy milk containing Lactobacillus casei (PSM), and soy milk enriched with Lactobacillus casei and omega-3 (OPSM) on the stereology of the tibia and vertebra, and antioxidant activity in type 1 diabetic rats. Sixty-five male Sprague Dawley rats were randomly assigned into 5 groups of 13 animals each. Diabetes was induced by a single injection of STZ (60 mg/kg); two control groups (non-diabetic: CN and diabetic: CD) were selected and then fed with 1 mL of distilled water. Three treatment groups were fed 1 ml of SM, PSM, and OPSM via intragastric gavage for 60 days. Treatment with SM, PSM, and OPSM significantly decreased (P < 0.05) the number of the osteoclasts in both tibia and L5 vertebra, and plasma alkaline phosphatase level. Also, the osteoblast number, calcium level, catalase activity, and total antioxidant capacity were increased in the SM, PSM, and OPSM groups compared to the STZ group. OPSM had the greatest effects on the stereological and biochemical parameters compared to the SM and PSM groups. Soy milk combination with Lactobacillus casei and omega-3 can ameliorate the stereological changes in the tibia and vertebra. In addition, this combination increased the antioxidant activity and improved the redox homeostasis in diabetic rats. These results suggest the potential role of soy milk containing Lactobacillus casei enriched with omega-3 in preventing and delaying osteoporosis in diabetic patients.

     

Validation of delay‐multiply‐and‐standard‐deviation weighting factor for improved photoacoustic imaging of sentinel lymph node

Delay‐and‐sum (DAS) is one of the most common algorithms used to construct the photoacoustic images due to its low complexity. However, it results in images with high sidelobes and low resolution. Delay‐and‐standard‐deviation (DASD) weighting factor can improve the contrast of the images compared to DAS. However, it still suffers from high sidelobes. In this work, a new weighting factor, named delay‐multiply‐and‐standard‐deviation (DMASD) is introduced to enhance the contrast of the reconstructed images compared to other mentioned methods. In the proposed method, the SD of the mutual multiplied delayed signals are calculated, normalized and multiplied to DAS beamformed data. The results show that DMASD improves the signal‐to‐noise‐ratio about 19.29 and 7.3 dB compared to DAS and DASD, respectively, for in vivo imaging of the sentinel lymph node. Moreover, the contrast ratio is improved by the DMASD about 23.61 and 10.81 dB compared to DAS and DASD, respectively.      

The Effects of Probiotics or Synbiotics Supplementation in Women with Polycystic Ovarian Syndrome: a Systematic Review and Meta-Analysis of Randomized Clinical Trials

Probiotics and Antimicrobial Proteins - We searched bibliographic databases from inception through May 2018 to evaluate the effect of probiotics (or synbiotics) supplementation in women suffering...     

More Protection of Lactobacillus acidophilus Than Bifidobacterium bifidum Probiotics on Azoxymethane-Induced Mouse Colon Cancer

Based on the ability of the probiotics in the gut microflora modification, they can have the beneficial effects on diseases in the short and/or the long term. In previous study, we revealed that unlike Bifidobacterium bifidum, the amount of Lactobacillus acidophilus remained almost unchanged in mice gut microflora in the long term, indicating more stability of L. acidophilus than B. bifidum which can be used to prevent some incurable diseases such as cancer. Thirty-eight male BALB/c mice were divided into four groups, control, azoxymethane (AOM), L. acidophilus, and B. bifidum probiotics, to evaluate the protective effects of the probiotics on AOM-induced mouse colon cancer. Except for the control group, the rest of the animals were weekly given AOM (15 mg/kg, s.c) in three consecutive weeks. Colon lesion incidence was 74% in the AOM group in comparison with the control (0%) (P < 0.05). The lesions were varied from mild to severe dysplasia and colonic adenocarcinoma. Administration of the probiotics inhibited the incidence of colonic lesions by about 57% in L. acidophilus (P < 0.05) and 27% in B. bifidum (P > 0.05) compared to the AOM group. The serum levels of CEA and CA19-9 tumor markers were significantly decreased in L. acidophilus in comparison with the AOM group (P < 0.05). Moreover, the serum levels of IFN-γ and IL-10 and the number of CD4⁺ and CD8⁺ cells were significantly increased in L. acidophilus compared to AOM (P < 0.05). Our study highlighted the more potential effects of L. acidophilus probiotic than B. bifidum on mouse colon cancer.

     

Performance of Cryptolaemus montrouzieri feeding on Pulvinaria aurantii ovisacs on citrus plants

We studied the performance of the coccinellid Cryptolaemus montrouzieri on citrus plant species infested with orange pulvinaria scale, Pulvinaria aurantii, under controlled conditions in the laboratory. The experimental host plants were blood orange, grapefruit, lemon, pummelo and kumquat. All life history parameters indicated best performance of C. montrouzieri, when reared on P. aurantii ovisacs on the leaves of grapefruit. Pummelo, blood orange, lemon or kumquat were less suitable.     

EW-7197 prevents ulcerative colitis-associated fibrosis and inflammation

EW-7197 is a transforming growth factor-β type I receptor kinase inhibitor with potential anti-inflammatory and antifibrotic properties. Here, we investigate the potential therapeutic effects of EW-7197 in a murine model of ulcerative colitis. EW-7197 attenuated the colitis disease activity index by improving rectal bleeding, body weight, and degree of stool consistency. EW-7197 also reduced colorectal tissue damage and the colon histopathological score by reducing crypt loss, mucosal damage, and tissue inflammation. Moreover, EW-7197 appeared to ameliorate the inflammatory and fibrotic responses by reducing oxidative stress, reducing submucosal edema and inflammatory cell infiltration, downregulating proinflammatory and pro-fibrotic genes, and inhibiting excessive collagen deposition in inflamed and fibrotic ulcerative colitis tissues. These results suggest that EW-7197 has potentially useful therapeutic properties against colitis, with clinically translational potential of inhibiting key pathological responses of inflammation and fibrosis in patients with colitis.     

Tumor-derived exosomal microRNAs and proteins as modulators of macrophage function

Tumor cells are able to modify their surrounding microenvironment by transmitting bioactive molecules via exosomes. In exosomes, proteins and nucleic acids that can be taken up by surrounding cells have been identified and modulate their functions. Tumor microenvironment consists of different cells such as macrophages. Tumors-associated macrophages (TAMs) express M2 phenotype and affect many processes including tumor initiation, angiogenesis, and metastasis. It has been demonstrated that a high number of TAMs is associated with poor prognosis of cancers. The contents of tumor-derived exosomes such as microRNAs and proteins induce macrophages to M2-like polarization to support tumor growth. Herein, we review the most recent studies on the effect of tumor-derived exosomes on macrophage polarization and function in different types of cancers.