Isolation of endophytic bacteria from the medicinal, forestal and ornamental tree Handroanthus impetiginosus.

Plant interactions with endophytic bacteria produce mutual benefits and contribute to environmental sustainability. Handroanthus impetiginosus (Mart. ex DC.) Mattos 'pink lapacho' (syn. Tabebuia impetiginosa, Bignoniaceae) is a medicinal, ornamental and forestal native tree from South and Mesoamerica. Plant growth promoting bacteria (PGPB) isolated from pink lapacho are scarcely described. The aim of this work was to isolate and characterize native endophytic bacteria from pink lapacho. Ten bacterial strains were isolated from leaves and six from roots of naturally growing trees in Luján (Central-Eastern region of Argentina). Endophytes were identified as Bacillus, Paenibacillus, Pseudomonas, Rhizobium, Rummeliibacillus and Methylobacterium genera, according to 16S rRNA gene sequencing and phylogenetic analysis. In the present study, a strain of the Rummelibacillus genus (L14) has been first ever reported as endophyte. This strain was capable of growing in Nfb medium and exhibited zinc solubilization ability. A high percentage of strains showed PGPB traits; namely 88% fixed nitrogen, 63% solubilized zinc, 69% solubilized phosphate and 63% produced indole compounds such as IAA. Most strains were salt tolerant that confer them a potential competitive advantage to survive in saline conditions. To the best of our knowledge, this is the first study reporting an approach to assess the diversity of cultivable endophytic bacteria of H. impetiginosus tree and its plant growth promoting capacity. The knowledge about this kind of associations could contribute to environmental sustainability by developing effective biofertilizers that minimize the use of chemical fertilizers and pesticides.

Natural products for the management of hyperuricaemia and gout: a review.

Hyperuricaemia is characterised by a high level of urate in the blood. The crystallisation of urate is considered a critical risk factor for the development of gout. Allopurinol and febuxostat have been commonly used medications to decrease the circulating urate levels. However, the use of these drugs is associated with undesired side effects. Therefore, the development of a new active, safety anti-hyperuricaemic and anti-inflammatory drug could be useful in gout therapy and is highly justified. Natural products have become a source of new pharmaceuticals due to their strong efficacy with less side effects, which relies on the comprising of complex bioactive compounds. There are a growing number of studies purporting decreasing serum urate with traditional medicines. This article was aimed to review these studies and identify which extracts promote urate reduction, along with their different mechanisms.

Phytotoxic potential of Senna occidentalis (L.) Link extracts on seed germination and oxidative stress of Ipê seedlings.

Senna occidentalis is an invasive plant producing a series of allelochemicals that might inhibit the development of other plants. The objective of this study was to assess the phytotoxic effect of S. occidentalis extracts on the germination, development and antioxidant defence of the native species Tabebuia chrysotricha, T. pentaphylla, T. roseoalba and Handroanthus impetiginosus (Ipê species). We evaluated the effects of chemicals extracted from S. occidentalis on the germination rate, germination speed index (GSI) and biometric parameters of the test species under controlled conditions. The effect of the extracts on the pigment content, amount of H2 O2 and malondialdehyde (MDA), and the activity of the antioxidant enzymes in roots and leaves were also tested. Alkaloids, coumarins, phenols, saponins, free steroids and condensed tannins were present in all extracts of S. occidentalis, while catechins were present only in leaf and stem extracts. Stem and root extracts caused a growth reduction in all Ipê species and total inhibition of seed germination in T. chrysotricha and T. roseoalba. All target species showed an increase in H2 O2 and MDA in radicles and leaves. Oxidative stress contributed strongly to the morphological changes, such as seed blackening, thinning and darkening of radicle tips and reduction of biomass allocation in all Ipê species. Although there was activation of antioxidant defence mechanisms, such as an increase in activity of ascorbate peroxidase (APX) and peroxidase (POD) enzymes, the joint action of the allelochemicals caused phytotoxicity, leading to cell dysfunction in all Ipê species.

Antinociceptive Activity of Methanol Extract of Tabebuia hypoleuca (C. Wright ex Sauvalle) Urb. Stems.

OBJECTIVE: The aim of this study was to evaluate the antinociceptive activity of the methanol extract of Tabebuia hypoleuca stems (THME). MATERIALS AND METHODS: The animals were divided into 5 groups of 8 mice for each test (negative controls, positive controls, and 3 groups treated with THME at doses of 150, 300, and 500 mg/kg, p.o.). The antinociceptive effect of THME was evaluated using the writhing, formalin, tail flick, and hot plate models in mice. RESULTS: In the writhing test, THME (150, 300, and 500 mg/kg) produced significantly (p < 0.001) fewer writhes induced by acetic acid than in the control group. In the formalin test, the licking time for THME at doses of 300 and 500 mg/kg was significantly shorter (p < 0.001) compared to the control group in the first phase of the formalin test, whereas in the second phase only the dose of 500 mg/kg showed an antinociceptive effect. In addition, THME at doses of 300 and 500 mg/kg significantly increased the latency time in the tail flick test (p < 0.05 and p < 0.001, respectively) and in the hot plate test (p < 0.01 and p < 0.001, respectively) compared to the control group. CONCLUSIONS: These results show that THME had antinociceptive activity using several models of nociception, and they suggest that the effect is mediated by the participation of both peripheral and central antinociceptive mechanisms.