nov.: two new endophytic actinobacteria isolated from the roots of Barleria lupulina Lindl

Two endophytic actinobacteria, designated as strains 7R015^T and 7R016^T, were isolated from the roots of Barleria lupulina collected in Thailand. The morphological characteristics and results of chemotaxonomic studies and 16S rRNA gene analysis indicated that both strains represented members of the genus Streptomyces. They contained ll-diaminopimelic acid in the peptidoglycan. Ribose and glucose were detected as the whole-cell sugars. MK-9(H₄), MK-9(H₆) and MK-9(H₈), were found as the membrane menaquinone. The predominant cellular fatty acids detected were iso-C_16 : 0 and anteiso-C_15 : 0. The genomes of both strains harboured biosynthetic gene clusters for melanin, terpene, lanthipeptide, polyketides, non-ribosomal peptide synthetase, siderophore and ectoine. The 16S rRNA gene sequence of 7R015^T showed the highest similarity to that of Streptomyces pseudovenezuelae DSM 40212^T (98.6 %), Streptomyces cyaneus NRRL B2296^T (98.6 %) and Streptomyces curacoi DSM 40107^T (98.6 %). Strain 7R016^T showed the highest 16S rRNA gene sequence similarity to Streptomyces gilvifuscus NBRC 110904^T (98.2 %), which is lower than the threshold value for 16S rRNA gene sequence similarity for differentiation at the species level (98.65 %). Comparative genome analysis revealed that the genomes of 7R015^T, 7R016^T and the closely related type strains had an average nucleotide identity (ANI) of less than 95 % and a digital DNA-DNA hybridisation (dDDH) of less than 70 %, the thresholds for species demarcation. On the basis of the results of the polyphasic study, strains 7R015^T and 7R016^T represent novel species of the genus Streptomyces and are named herein as Streptomyces cylindrosporus sp. nov. (=NBRC 115200^T = TBRC 14542^T) for strain 7R015^T and Streptomyces spinosisporus sp. nov. (=NBRC 115201^T = TBRC 14543^T) for strain 7R016^T.

The anti-inflammatory properties of Acanthus Ebracteatus, Barleria Lupulina and Clinacanthus Nutans: a systematic review

This appraisal is comprised of the inflammatory studies that have been conducted on Clinacanthus nutans, Acanthus ebracteatus, and Barleria lupulina. The review aims to provide a comprehensive evaluation of the supporting and contradictory evidence on each plants' anti-inflammatory properties, whilst addressing the gaps in the current literature. The databases used to obtain relevant studies were Google Scholar, ResearchGate, PubMed and Nusearch (University of Nottingham). A total of 13 articles were selected for this review. A. ebracteatus was found to suppress neutrophil migration and weakly inhibits chronic inflammatory cytokines. Furthermore, B. lupulina and C. nutans were shown to possess very similar anti-inflammatory properties. The studies on C. nutans indicated that its anti-inflammatory effect is strongly related to the inhibition of toll-like receptor 4 (TLR4). Moreover, several phytoconstituents isolated from B. lupulina were shown to activate the anti-inflammatory Nrf2 pathway. Overall, all the studies have provided evidence to support the use of these plants as anti-inflammatory herbal remedies. However, their exact mechanism of action and the responsible phytoconstituents are yet to be established.

Antibacterial, antioxidant and Immuno-modulatory properties in extracts of Barleria lupulina Lindl

Background

Antibacterial, immunomodulatory and antioxidant properties of aerial parts of Barleria lupulina Lindl were investigated in the present communication.

Methods

The antibacterial, antioxidant and immunomodulatory properties of B. lupulina (methanol soluble leaf and stem extracts) was analyzed by minimum inhibitory concentration, total phenolic contents, DPPH radical scavenging activity, determination of toxicity, hemagglutination antibody titre, delayed type hypersensitivity and neutrophil adhesion test, respectively.

Results

Methanol soluble leaf extract (MLE) contains more soluble bioactive compounds inhibiting the growth of five bacterial pathogens viz., Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Salmonella typhi even at MICs of 1.25 and 2.5 mg/mL. Aqueous stem extract (ASE) was least effective while MLE was highly effective in inhibiting the growth and survival of bacterial pathogens. While testing the effect of these extracts in animal model, no mortality of albino rats was recorded by using MLE and MSE at the concentrations from 200 to 600 mg/kg of their body weight. The MLE showed significant result in agglutination reaction and induced paw edema volumes when compared with untreated group (control). Both MLE and MSE extracts significantly increased neutrophil adhesion with increase in doses of extracts. MLE was found to have more potent immune-stimulant properties than the MSE. High phenolic contents were found in MSE while lowest IC₅₀ values were found in MLE in term of DPPH radical scavenging activity.

Conclusions

Methanol soluble leaf and stem extract of Barleria lupulina contains antibacterial, antioxidants and immunomodulating phytochemical compounds that was effective for antibacterial, antioxidant and immunomodulatory properties. These may be used as synthetic drug.

Anti-inflammatory activity of Barleria lupulina: Identification of active compounds that activate the Nrf2 cell defense pathway, organize cortical actin, reduce stress fibers, and improve cell junctions in microvascular endothelial cells

ETHNOPHARMACOLOGICAL RELEVANCE

Hot aqueous extracts of the plant Barleria lupulina (BL) are used for treating inflammatory conditions and diabetic vascular complications.

AIM OF THE STUDY

The goal was to identify active compounds in hot aqueous extracts of BL (HAE-BL) that are consistent with a role in reducing inflammation and reducing the vascular pathology associated with diabetes. In particular, we examined activation of the Nrf2 cell defense pathway because our initial findings indicated that HAE-BL activates Nrf2, and because Nrf2 is known to suppress inflammation. Activation of Nrf2 by HAE-BL has not been described previously.

MATERIALS AND METHODS

Human endothelial cells, real-time PCR, western blotting, cytoskeletal analyses, and assay-guided fractionation with HPLC were used to identify specific compounds in HAE-BL that activate the Nrf2 cell defense pathway and reduce markers of inflammation in vitro.

RESULTS

HAE-BL potently activated the Nrf2 cell defense pathway in endothelial cells consistent with its traditional use and reported success in reducing inflammation. Assay guided fractionation with HPLC identified three alkyl catechols: 4-ethylcatechol, 4-vinylcatechol, and 4-methylcatechol, that are each potent Nrf2 activators. In addition to activating Nrf2, HAE-BL and akyl catechols each profoundly improved organization of the endothelial cell actin cytoskeleton, reduced actin stress fibers, organized cell-cell junctions, and induced expression of mRNA encoding claudin-5 that is important for formation of endothelial tight junctions and reducing vascular leak.

CONCLUSIONS

HAE-BL contains important alkyl catechols that potently activate the Nrf2 cell defense pathway, improve organization of the endothelial cell cytoskeleton, and organize tight cell junctions. All of these properties are consistent with a role in reducing inflammation and reducing vascular leak. Because activation of the Nrf2 cell defense pathway also prevents cancers, neuro-degeneration, age-related macular degeneration, and also reduces the severity of chronic obstructive pulmonary disorder and multiple sclerosis, HAE-BL warrants additional consideration for these other serious disorders.

Diabetic Wound Healing and Activation of Nrf2 by Herbal Medicine

Nrf2 defense is a very important cellular mechanism to control oxidative stress, which is implicated in wound healing. Nrf2 can induce many cytoprotective genes, including HO-1, NQO1 and G6PD. Among many natural products that have been reported as Nrf2 activators, sulforaphane and curcumin have been studied more widely than any others, and both are in clinical trials for non-cancerous disorders. Recently, we reported 4-ethyl catechol and 4-vinyl catechol as Nrf2 co-factors that can induce Nrf2 as potently as sulforaphane and curcumin. These new Nrf2 co-factors were identified in hot aqueous extract of an herbal medicine Barleria lupulina, and fermented Noni (Morinda citrifolia) juice, which are used traditionally for diabetic wound healing.

Chakyunglupulins A and B, two novel 4,8,8-trimethylcyclooct-2-enone derivatives from Barleria lupulina

Two novel 4,8,8-trimethylcyclooct-2-enone derivatives, chakyunglupulins A and B, together with six known lignans were isolated from the aerial part of Barleria lupulina. The structures of new compounds were established by extensive spectroscopic data and HR-MS, and their absolute configurations were determined by a combination of NOE experiment and application of the modified Mosher's method.