Antibacterial, anti-inflammatory and antioxidant activities of Mahanintangtong and its constituent herbs, a formula used in Thai traditional medicine for treating pharyngitis.

BACKGROUND: Mahanintangtong is listed in the Thailand's National List of Essential Medicines (NLEM). It is used to treat non-specific fevers and illnesses such as pharyngitis and chickenpox. In this study, we investigated the biological activities of the different medicinal plants used in the Mahanintangtong formula. METHODS: The plant materials were extracted by maceration and decoction. Antimicrobial activity, assessed by disc diffusion method, the minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) were compared with commercially available standard antibiotics. To elucidate the anti-inflammatory mechanisms, inhibition of nitric oxide (NO), tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6) production was tested by Griess and ELISA techniques. Antioxidant activity was measured by ABTS and DPPH scavenging assays. RESULTS: The extracts with the best antimicrobial activities were carbonized Tectona grandis showing against Streptococcus pyogenes, Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. The ethanol extract of Dracaena loureiroi wood exhibited the highest NO and IL-6 inhibitory activity with IC50 values of 9.42 ± 1.81 and 12.02 ± 0.30 µg/mL, respectively. The ethanol extract of Pogostemon cablin had the highest TNF-α inhibitory with IC50 values of 10.68 ± 0.02 µg/mL. In anti-free radical testing, the ethanol extract of D. loureiroi displayed high antioxidant activity by both ABTS and DPPH assays. CONCLUSION: The ethanol extracts from carbonized T. grandis and Mahanintangtong showed good antimicrobial activity, especially against S. pyogenes, and good anti-inflammatory activity. These findings are relevant to the pathogenesis of pharyngitis and justify additional studies to see if Mahanintangtong could have clinical utility.

Ligand-competent fractalkine receptor is expressed on exosomes.

Expression of chemokine receptor CX3CR1 is reportedly restricted to several cell types including natural killer cells, cytotoxic T cells, monocytes, and macrophages. However, its expression and function on exosomes, which are nanosized extracellular vesicles known to act as mediators of intercellular communications, remain unclear. Here, we investigated CX3CR1 expression on exosomes isolated from various cell types. Although we found that all the exosomes tested in our study highly expressed CX3CR1, this chemokine receptor was expressed only inside, but barely on, their source cells. Moreover, exosomal CX3CR1 was capable of binding soluble CX3CL1. Therefore, our study suggests that CX3CR1 is a novel and ligand-competent exosome receptor.

Anti-Helicobacter pylori, Anti-Inflammatory, Cytotoxic, and Antioxidant Activities of Mace Extracts from Myristica fragrans.

The aril (mace) of Myristica fragrans, known as Dok-Chan, is a spice that has long been used for treating stomach discomfort, peptic ulcer, and nausea. It is an ingredient in many remedies in Thai traditional medicine, e.g., Ya-Hom-Thep-Bha-Jit, Ya-Hom-Nao-Wa-Kot, and Ya-That-Bun-Job, which are used to treat dyspepsia and other gastrointestinal tract symptoms. The aqueous and ethanolic extracts of mace were used for all tests. Anti-H. pylori activities were determined by the disc diffusion method and agar dilution. Anti-inflammatory activity was determined by the LPS-induced nitric oxide (NO) inhibition in a RAW264.7 cell line, and cytotoxicity was determined against gastric cancer cell lines (Kato III) using the sulphorhodamine B (SRB) assay. The DPPH radical scavenging and ABTS radical cation decolorization assays were used to determine the antioxidant activities. The result found that the ethanolic extract of mace exhibited antimicrobial activity against H. pylori ATCC 43504 and six clinical strains with MIC values of 125-250 µg/ml. The aqueous extract MICs against H. pylori ATCC reference strain and six clinical strains were 500 µg/ml compared with 0.5 µg/ml for the positive control, clarithromycin. The inhibitory effect of LPS-induced NO release and cytotoxic activity of the ethanolic extract had IC50 values of 82.19 µg/ml and 26.06 µg/ml, respectively, and the EC50 values for the DPPH and ABTS antioxidant assays were 13.41 µg/ml and 12.44 µg/ml, respectively. The mace extract also had anticancer properties. In conclusion, the ethanolic mace extract had anti-H. pylori, anti-inflammatory, antioxidant, and anticancer activities. These data support further preclinical and clinical investigation to see if the mace extract could have a role in treating patients with dyspepsia, peptic ulcers, and possibly gastric cancer.

Talin-2 regulates integrin functions in exosomes.

Integrins on exosomes have been shown to mediate binding to recipient cells, potentially playing important roles in controlling exosomal internalization and organ distributions. Although the ability of cellular integrins to mediate cell adhesion is known to be regulated by the cytoplasmic adaptor protein talin, whether the activity of exosomal integrins is similarly regulated by talin remains to be elucidated. Here we have studied this question in T-cell exosomes that surface express the integrins αLß2 and α4ß7. T-cells and T-cell exosomes engineered to lack talin-2 showed reduced binding to the integrin ligand ICAM-1 and MAdCAM-1 compared with control T-cells and exosomes, despite the fact that those T cells and exosomes express intact levels of the other isoform talin-1. In addition, talin-2-deficient T-cell exosomes were less efficiently internalized by endothelial cells, compared with control exosomes. These results suggest that the mechanisms of talin-mediated integrin regulation operate similarly in cells and exosomes.

Anti-adhesive effects of human soluble thrombomodulin and its domains.

We reported previously that leukocyte ß2 integrins (LFA-1 and Mac-1) bind to the serine/threonine-rich domain of thrombomodulin (TM) expressed on vascular endothelial cells (VECs). Recombinant human soluble TM (rhsTM, TMD123) has been approved as a therapeutic drug for septic disseminated intravascular coagulation. However, the roles of TMD123 on the adhesion of leukocyte integrins to VECs remain unclear. In the current study, we have revealed that an integrin-dependent binding between human peripheral blood mononuclear cells (PBMCs) and VECs was inhibited by TMD123. Next, using mutant proteins composed of isolated TM extracellular domains, we examined the structural characteristics responsible for the anti-adhesion properties of TMD123. Namely, we investigated whether the effects of the binding of TM and leukocytes was inhibited by the administration of TMD123. In fact, we confirmed that TMD123, TMD1, and TMD3 inhibited the binding of PBMCs to the immobilized recombinant proteins TMD123 and TMD3. These results indicate that TMD123 inhibited the adhesion of leukocytes to endothelial cells via ß2 integrins and endothelial TM. Moreover, since TMD1 might bind to leukocytes via other adhesion receptors than integrins, TMD1 and TMD3 appear to inhibit leukocyte binding to TM on VECs via different mechanisms. In summary, TMD123 (rhsTM), TMD1 or TMD3 is a promising treatment option for sepsis that attenuates integrin-dependent binding of leukocytes to VECs, and may inhibit the undesirable adhesion and migration of leukocytes to VECs in sepsis.

Integrin and PD-1 Ligand Expression on Circulating Extracellular Vesicles in Systemic Inflammatory Response Syndrome and Sepsis.

Extracellular vesicles (EVs) in the plasma mediate important intercellular communications in the pathogenesis of cancer and inflammatory diseases. EVs express integrins that regulate target specificities and programmed cell death ligand 1 and 2 (PD-L1 and 2) that suppress lymphocyte activation. However, the roles of these molecules on EVs in systemic inflammatory response syndrome (SIRS) and sepsis remain little understood. This study aimed to investigate how the EV expression of integrins and PD-1 ligands might differ in SIRS and sepsis, compared with healthy controls, and to correlate their expression with the clinical parameters reflecting pathogenesis. Twenty-seven SIRS patients without sepsis, 27 sepsis patients, and 18 healthy volunteers were included. EVs were isolated from plasma samples. The expression of three major integrins (ß1, ß2, ß3 integrins) and PD-L1 and 2 were measured. The EV expression of ß2 integrin and PD-L2 was significantly increased in sepsis patients compared with healthy controls. EV expression of PD-L1 was not elevated in sepsis and SIRS; however, circulating soluble PD-L1 levels were significantly higher in sepsis. Furthermore, EV expression of ß2 integrin in sepsis patients correlated with hypotension and reduced kidney function. In addition, soluble PD-L1 levels correlated with sepsis severity, impaired kidney function, and impaired central nervous system function. These results suggest the potential involvements of the EV ß2 integrin, as well as EV PD-L2 and soluble PD-L1, in the septic pathogenesis that occurs with the systemic immune activation leading to multiple organ dysfunctions.

Exosomal regulation of lymphocyte homing to the gut.

Exosomes secreted from T cells have been shown to affect dendritic cells, cancer cells, and other T cells. However, little is known about how T-cell exosomes (T exosomes) modulate endothelial cell functions in the context of tissue-specific homing. Here, we study the roles of T exosomes in the regulation of gut-specific T-cell homing. The gut-tropic T cells induced by retinoic acid secrete the exosomes that upregulate integrin α4ß7 binding to the MAdCAM-1 expressed on high endothelial venules in the gut. T exosomes were preferentially distributed to the villi of the small intestine in an α4ß7-dependent manner. Exosomes from gut-tropic T cells suppressed the expression of MAdCAM-1 in the small intestine, thereby inhibiting T-cell homing to the gut. Moreover, microRNA (miRNA) profiling analysis has shown that exosomes from gut-tropic T cells were enriched with miRNAs targeting NKX2.3, a transcription factor critical to MAdCAM-1 expression. Taken together, our study proposes that α4ß7-expressing T exosomes distribute themselves to the small intestine and modify the expression of microenvironmental tissues such that any subsequent lymphocyte homing is precluded. This may represent a novel mechanism by which excessive lymphocyte homing to the intestinal tissues is downsized.

Cytotoxic, Anti-inflammatory and Antioxidant Activities of Heliotropium indicum Extracts.

Background: Heliotropium indicum Linn., or 'Indian heliotrope' is very common in India with a long history of traditional medicinal uses in many countries in the world. In Thailand, the plant has been traditionally use to cure various diseases such as fever, insect bites, stings, diarrhea, skin rashes, menstrual disorder and urticaria. In addition, the plant is commonly used by Thai folk doctors as a component in remedies for treatment of lung cancer. Objective: In the present study, we investigated cytotoxicity against two types of lung cancer cell lines (A549 and NCI-H226), anti-inflammatory effect and antioxidant activity of Heliotropium indicum extracts. Material and Method: The water and ethanolic extracts of Heliotropium indicum were tested. The cytotoxic activity against two types of human lung cancer cell lines (A549 and NCI-H226) was evaluated by sulforhodamine B (SRB) assay. The antiinflammatory effect was investigated on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. LPS-induced nitric oxide (NO) production was determined by Griess reagent. The antioxidant activity was performed by 1, 1-diphenyl-picrylhydrazyl (DPPH) radical scavenging method. Results: The ethanolic extract showed cytotoxic activity only against NCI-H226 (IC50 = 51.90±2.35 µg/ml) whereas the water extract had no cytotoxic activity against both A549 and NCI-H226 (IC50 >100 µg/ml). For anti-inflammatory effect, the results revealed that the ethanolic extract exhibited the most potent inhibitory activity on nitric oxide production (IC50 = 24.17±2.12 µg/ml), followed by Indomethacin (positive control) with an IC50 value of 34.67±6.23 µg/ml while water extract was apparently inactive (IC50 >100 µg/ml). For antioxidant activity, the ethanolic extract showed high antioxidant activity (EC50 = 28.91±4.26 µg/ml) but the water extract showed no antioxidant activity (EC50 >100 µg/ml). Conclusion: These results can support using Heliotropium indicum Linn. for component in lung cancer remedy by Thai folk doctors. However, more studies are required.

Antimicrobial activity of Thai medicinal preparation of Khampramong Temple used for cancer treatment and its plant components.

BACKGROUND: Thai medicinal preparation of Khampramong Temple has been used for cancer treatment more than ten years ago. It is composed of eleven herbs. Many anticancer drugs exhibited antimicrobial activity as antitumor antibiotics such as the anthracycline group [daunorubicin] and quinone group [mitomycin C]. OBJECTIVE: To determine antimicrobial activity of Thai medicinal plants used to treat cancer patients of Khampramong Temple by disc diffusion and agar dilution methods. MATERIAL AND METHOD: The extraction procedure was maceration method using 95% ethanol and drying by evaporator In the preliminary study, all extracts were evaluated for antimicrobial activity by disc diffusion method against two strains of Gram positive bacteria (Staphylococus aureus and Bacillus subtilis), one Gram negative bacteria (Escherichia coli) and one fungus (Candida albicans). The active plant extracts were diluted to determine the minimum inhibitory concentration (MIC) by agar dilution method. RESULTS: The preparation showed antimicrobial activity against S. aureus, B. subtilis and E. coli (MIC = 1.25, 0.625 and 5 mg/ml, respectively) but no inhibition against Candida albicans. Most extracts showed activity against B. subtilis and Rhinacanthus nasutus extract showed the highest antimicrobial activity (MIC = 0.156 mg/ml). Hydnophytum formicarum Jack, Tectona grandis L.f and Salacia chinensis L. exhibited good antibacterial activity against S. aureus (MIC = 1.25, 0.15625 and 0.3125 mg/ml respectively). CONCLUSION: These results supported the use of this preparation on chronic wound infection of cancer patients and the antimicrobial compounds of the preparation should be further studied to be used in cancer patients.