Evaluation of Anti-Inflammatory Properties of Isoorientin Isolated from Tubers of Pueraria tuberosa

Inflammation is the major causative factor of different diseases such as cardiovascular disease, diabetes, obesity, osteoporosis, rheumatoid arthritis, inflammatory bowel disease, and cancer. Anti-inflammatory drugs are often the first step of treatment in many of these diseases. The present study is aimed at evaluating the anti-inflammatory properties of isoorientin, a selective cyclooxygenase-2 (COX-2) inhibitor isolated from the tubers of Pueraria tuberosa, in vitro on mouse macrophage cell line (RAW 264.7) and in vivo on mouse paw edema and air pouch models of inflammation. Isoorientin reduced inflammation in RAW 264.7 cell line in vitro and carrageenan induced inflammatory animal model systems in vivo. Cellular infiltration into pouch tissue was reduced in isoorientin treated mice compared to carrageenan treated mice. Isoorientin treated RAW 264.7 cells and animals showed reduced expression of inflammatory proteins like COX-2, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), 5-lipoxygenase (5-LOX), and interleukin 1-β (IL-1-β) both in vitro and in vivo. The antioxidant enzyme levels of catalase and GST were markedly increased in isoorientin treated mice compared to carrageenan treated mice. These results suggest that isoorientin, a selective inhibitor of COX-2, not only exerts anti-inflammatory effects in LPS induced RAW cells and carrageenan induced inflammatory model systems but also exhibits potent antioxidant properties

Mannose Receptor-Dependent Delay in Phagosome Maturation by Mycobacterium avium Glycopeptidolipids▿

The ability of pathogenic mycobacteria to block phagosome-lysosome fusion is critical for its pathogenesis. The molecules expressed by mycobacteria that inhibit phagosome maturation and the mechanism of this inhibition have been extensively studied. Recent work has indicated that mannosylated lipoarabinomannan (ManLAM) isolated from Mycobacterium tuberculosis can function to delay phagosome-lysosome fusion and that this delay requires the interaction of ManLAM with the mannose receptor (MR). However, the molecules expressed by other pathogenic mycobacteria that function to inhibit phagosome maturation have not been well described. In the present study, we show that phagosomes containing silica beads coated with glycopeptidolipids (GPLs), a major surface component of Mycobacterium avium, showed limited acidification and delayed recruitment of late endosomal/lysosomal markers compared to those of phosphatidylcholine-coated beads. The carbohydrate component of the GPLs was required, as beads coated only with the lipopeptide core failed to delay phagosome-lysosome fusion. Moreover, the ability of GPLs to delay phagosome maturation was dependent on the macrophage expression of the MR. Using CHO cells expressing the MR, we confirmed that the GPLs bind this receptor. Finally, human monocyte-derived macrophages knocked down for MR expression showed increased M. avium phagosome-lysosome fusion relative to control cells. Together, the data indicate that GPLs can function to delay phagosome-lysosome fusion and suggest that GPLs, like ManLAM, work through the MR to mediate this activity

M. tuberculosis-Initiated Human Mannose Receptor Signaling Regulates Macrophage Recognition and Vesicle Trafficking by FcRγ-Chain, Grb2, and SHP-1

Despite its prominent role as a C-type lectin (CTL) pattern recognition receptor, mannose receptor (MR, CD206)-specific signaling molecules and pathways are unknown. The MR is highly expressed on human macrophages, regulating endocytosis, phagocytosis, and immune responses and mediating Mycobacterium tuberculosis (M.tb) phagocytosis by human macrophages, thereby limiting phagosome-lysosome (P-L) fusion. We identified human MR-associated proteins using phosphorylated and non-phosphorylated MR cytoplasmic tail peptides. We found that MR binds FcRγ-chain, which is required for MR plasma membrane localization and M.tb cell association. Additionally, we discovered that MR-mediated M.tb association triggers immediate MR tyrosine residue phosphorylation and Grb2 recruitment, activating the Rac/Pak/Cdc-42 signaling cascade important for M.tb uptake. MR activation subsequently recruits SHP-1 to the M.tb-containing phagosome, where its activity limits PI(3)P generation at the phagosome and M.tb P-L fusion and promotes M.tb growth. In sum, we identify human MR signaling pathways that temporally regulate phagocytosis and P-L fusion during M.tb infection

Anti-inflammatory profile of Aegle marmelos (L) Correa (Bilva) with special reference to young roots grown in different parts of India

Background: Aegle marmelos (Bilva) is being used in Ayurveda for the treatment of several inflammatory disorders. The plant is a member of a fixed dose combination of Dashamoola in Ayurveda. However, the usage of roots/root bark or stems is associated with sustainability concerns. Objectives: The present study is aimed to compare the anti-inflammatory properties of different extracts of young roots (year wise) and mature parts of Bilva plants collected from different geographical locations in India, so as to identify a sustainable source for Ayurvedic formulation. Materials and methods: A total of 191 extracts (petroleum ether, ethyl acetate, ethanol and aqueous) of roots, stems and leaves of A. marmelos (collected from Gujarat, Maharashtra, Odisha, Chhattisgarh, Karnataka and Andhra Pradesh region) were tested for anti-inflammatory effects in vitro on isolated target enzymes cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX), lymphocyte proliferation assay (LPA), cytokine profiling in LPS induced mouse macrophage (RAW 264.7) cell line and in vivo carrageenan induced paw edema in mice. Results: Of 191 extracts, 44 extracts showed COX-2 inhibition and 38 extracts showed COX-1 inhibition, while none showed 5-LOX inhibition. Cytokine analysis of the 44 extracts showing inhibition of COX-2 suggested that only 17 extracts modulated the cytokines by increasing the anti-inflammatory cytokine IL-2 and reducing the pro-inflammatory cytokines like IL-1β, MIP1-α and IL-6. The young (2 and 3 years) roots of Bilva plants from Gujarat and young (1 yr) roots from Odisha showed the most potent anti-inflammatory activity by suppressing the pro-inflammatory cytokines and inducing anti-inflammatory cytokines. These three extracts have also shown in vivo anti-inflammatory activity comparable to that in adult stem and root barks. Conclusion: The present study reveals that young roots of Bilva plants from Gujarat and Odisha region could form a sustainable source for use in Ayurvedic formulations with anti-inflammatory activities. The present study also indicates that the region in which the plants are grown and the age of the plants play an important role in exhibiting the anti-inflammatory effect. Keywords: Aegle marmelos, Inflammation, Ayurveda, Cyclooxygenase-1 & 2, 5-Lipoxygenase, Immunomodulatio