Baccharis anomala DC. extract reduces inflammation and attenuates hepatic fibrosis in vivo by decreasing NF-kB and extracellular matrix compounds.

Baccharis anomala DC. (BA) is a plant species found in the tropical regions of South America and is widely used for its hepatoprotective effects, as well as for the treatment of gastrointestinal diseases. Studies have recently reported its antioxidant and anti-inflammatory potential. BA extract can reverse the activated phenotype of hepatic stellate cells (HSC), which plays a central role in extracellular matrix (ECM) deposition in the development of liver fibrosis. Thus, this study aimed to evaluate the effects of the treatment with BA extract on liver fibrosis in a CCl4-induced liver fibrosis model in BALB/c mice. Methanolic extract was obtained from BA leaves, a gas chromatography/mass spectrometry (GC/MS) to detect the compounds present was performed, and then administered by intraperitoneal injection in Balb/C mice at a concentration of 50 and 100 mg/kg together with the administration of CCl4 for inducing liver fibrosis. After 10 weeks, blood analysis, histopathology, oxidative stress, as well as protein and gene expression in the hepatic tissue were performed. Treatment with BA extract was able to reduce profibrotic markers by reducing the expression of α-SMA and Col-1 proteins, as well as reducing the formation of free radicals and lipid peroxidation. (BA extract showed anti-inflammatory effects in the liver by suppressing NF-kB activation and reducing gene expression of signaling targets (IL-6 and iNOS). The data obtained showed that BA extract has antifibrotic and anti-inflammatory effects.

Streptomyces spp. enhance vegetative growth of maize plants under saline stress.

Saline stress is one of the abiotic stresses that most compromises the yield of crops and can be mitigated by plant growth-promoting rhizobacteria (PGPR). This work characterized rhizobacteria isolates from the genus Streptomyces as PGPR and evaluated their role on growth and alleviation of the effects caused by saline stress in maize (Zea mays L.). Production of indolic compounds (IC), siderophores, ACC deaminase, phenazines, and promotion of plant growth were determined to characterize bacterial isolates. Salinity tolerance was accessed by culturing the Streptomyces isolates under NaCl increasing concentrations (0-300 mM). Four Streptomyces isolates exhibiting PGPR traits and salinity tolerance were selected and their effect on tolerance of maize plants to saline stress was evaluated. Plants obtained from bacterized seeds and submitted to 100 and 300 mM NaCl were used. All Streptomyces spp. produced IC and siderophores, CLV178 being the best producer of these two compounds. ACC deaminase was detected in six of the 10 isolates (CLV95, CLV97, CLV127, CLV179, CLV193, and CLV205), while phenazines were found only in CLV186 and CLV194. All isolates were tolerant to salinity, growing at concentrations up to 300 mM NaCl, with exception of CLV188. Increased concentrations of IC were detected in most of the isolates exposed to salinity. CLV97 and CLV179 significantly promoted growth of roots and leaves of maize plants and attenuated the negative effects of salinity on plant growth. Root colonization by Streptomyces spp. was confirmed in plants cultivated 20 days under saline stress.

Streptomyces sp. CLV45 from Fabaceae rhizosphere benefits growth of soybean plants.

Plant growth-promoting bacteria such as Streptomyces are an attractive alternative for increasing the sustainability of agricultural systems. In this study, Streptomyces isolates obtained from rhizosphere soil of plants in the family Fabaceae were characterized for their plant growth-promoting traits, including the production of siderophores, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, indole-3-acetic acid (IAA), and phenazines. Soybean seeds were bacterized with selected isolates to test growth promotion. All isolates produced IAA, and the isolate CLV45 was the most efficient, reaching 398.53 mg of IAA per gram of cells. CLV41, CLV45, and CLV46 showed high activity for ACC deaminase whereas CLV42, CLV44, and CLV46 were efficient in siderophore production. Pyocyanin was detected in all isolates; CLV41, CLV43, and CLV45 produced phenazine-carboxylic acid as well. Selected for IAA and ACC deaminase production combined with production of siderophores and phenazines, CLV42, CLV44, and CLV45 were tested for their growth promotion potential. Seed bacterization with CLV45 resulted in plants with increased shoot growth (36.63%) and dry mass (17.97%) compared to control plants. Results suggest that moderate or high levels of auxin and ACC deaminase production by the isolate CLV45 positively affected the growth of soybean plants, making it a strong candidate for further studies on biofertilizer formulation.

Streptomyces rhizobacteria modulate the secondary metabolism of Eucalyptus plants.

The genus Eucalyptus comprises economically important species, such as Eucalyptus grandis and Eucalyptus globulus, used especially as a raw material in many industrial sectors. Species of Eucalyptus are very susceptible to pathogens, mainly fungi, which leads to mortality of plant cuttings in rooting phase. One alternative to promote plant health and development is the potential use of microorganisms that act as agents for biological control, such as plant growth-promoting rhizobacteria (PGPR). Rhizobacteria Streptomyces spp have been considered as PGPR. This study aimed at selecting strains of Streptomyces with ability to promote plant growth and modulate secondary metabolism of E. grandis and E. globulus in vitro plants. The experiments assessed the development of plants (root number and length), changes in key enzymes in plant defense (polyphenol oxidase and peroxidase) and induction of secondary compounds(total phenolic and quercetinic flavonoid fraction). The isolate Streptomyces PM9 showed highest production of indol-3-acetic acid and the best potential for root induction. Treatment of Eucalyptus roots with Streptomyces PM9 caused alterations in enzymes activities during the period of co-cultivation (1-15 days), as well as in the levels of phenolic compounds and flavonoids. Shoots also showed alteration in the secondary metabolism, suggesting induced systemic response. The ability of Streptomyces sp. PM9 on promoting root growth, through production of IAA, and possible role on modulation of secondary metabolism of Eucalyptus plants characterizes this isolate as PGPR and indicates its potential use as a biological control in forestry.

Nephroprotective and anti-inflammatory effects of aqueous extract of Melissa officinalis L. on acetaminophen-induced and pleurisy-induced lesions in rats

This study assessed the bioactive properties of an aqueous extract of M. officinalis for its anti-inflammatory activity and its protection against hepatic and renal lesions induced by acetaminophen (APAP). Animals pre-treated with the crude extract in pleurisy induced by carrageenan showed a reduction in the amounts of exudate, in the numbers of leukocytes and polymorphonuclear cells. Intragastric administration of the extract for seven days prior to the APAP-induced lesion showed no protective effect on the liver. The treatment with the extract induced an increase of serum aspartate aminotransferase, indicating a rise of toxicity. Contrarily, the same treatment reduced the APAP induced lesion in kidney, with respect to ν-glutamyltransferase. The results suggested that the extract was not hepatoprotective and could lead to an increase in the lesions induced by the APAP. On the other hand, the extract was nephroprotective against the lesions induced by the APAP and showed an anti-inflammatory effect on pleurisy carrageenan-induced.

Long-term maintenance of in vitro cultures affects growth and secondary metabolism of St. John's Wort / A manutenção prolongada de culturas in vitro afeta o crescimento e o metabolismo secundário de hipérico

Hypericum perforatum is a traditional medicinal plant with wound healing and antidepressant properties. Efficiency of micropropagation is often related to the long term maintenance of tissues in culture, which may alter the secondary metabolism of plants. The objective of this study was to evaluate growth and secondary metabolism of in vitro shoots of H. perforatum on short and long term maintenance of cultures (30 and 100 days). The effect of BA and NAA supplementation was evaluated during 30 days of culture. Adventitious shoots were cultivated on MS medium supplemented with 4.4mM BA alone or in combination with 0.05mM NAA for 30 days. A hormone-free medium was used as control. Shoots cultivated for 100 days were maintained in presence of 4.4mM BA. Biomass, multiplication of shoots, contents of phenolic compounds, flavonoids and hypericin were evaluated. No difference between BA and BA+NAA was observed on growth, multiplication of shoots and levels of flavonoids at the end of 30 days of culture. Production of phenolic compounds was promoted by addition of BA+NAA to the medium, whereas hypericin was increased by the presence of BA. The time of culture (30 and 100 days) affected all the parameters analyzed, except the levels of flavonoids in the short term experiment.

Hypericum perforatum é uma planta medicinal que apresenta propriedades cicatrizante e antidepressiva. Frequentemente, a eficiência da micropropagação está relacionada à manutenção dos tecidos em cultura por longos períodos, o que pode alterar o metabolismo secundário das plantas. O objetivo deste trabalho foi avaliar o crescimento e o metabolismo secundário de brotações adventícias de H. perforatum mantidas por diferentes tempos de cultivo (30 e 100 dias). O efeito da adição de BA e ANA foi avaliado no período de 30 dias. As brotações foram cultivadas em meio MS suplementado com 4,4mM BA como único regulador ou em combinação com 0,05mM ANA, por 30 dias. Um meio de cultivo sem adição de reguladores foi utilizado como controle. As brotações cultivadas por 100 dias foram mantidas em presença de 4,4mM BA. A biomassa, a multiplicação dos brotos, as concentrações de compostos fenólicos, flavonoides e hipericina foram os parâmetros avaliados. Nenhuma diferença entre a adição de BA ou BA+ANA foi observada quanto ao crescimento, ao número de brotos e aos níveis de flavonoides ao final de 30 dias de cultivo. Diferenças neste período foram detectadas nos níveis de compostos fenólicos e de hipericina quando os brotos foram cultivados em presença de BA+NAA e de BA, respectivamente. O tempo de cultivo (30 e 100 dias) afetou todos os parâmetros avaliados, com exceção dos níveis de flavonoides no período de 30 dias.

Plant regeneration through somatic embryogenesis of yacón [smallanthus sonchifolius (poepp. and endl.) H. Robinson]

Smallanthus sonchifolius has tuberous roots containing large amounts of fructo-oligosaccharides and its medicinal use has increased due to the hypoglycemic properties reported for this species. An efficient system for propagation via somatic embryogenesis is reported using petiole segments cultivated on MS medium supplemented with combinations of BA, kinetin and 2,4-D, under light and darkness conditions. Embryogenic callus was formed in most of the treatments; however, somatic embryogenesis was promoted by the presence of light. Clusters of somatic embryos appeared on callus surface after 50 days of culture. The highest number of embryos was produced on 0.45 µM BA and 4.5 µM 2,4-D. Embryogenic calli were maintained on MS medium containing 4.5 µM BA and 0.045 µM 2,4-D. Embryos converted on hormone-free half-strength MS medium with 2 g.L-1 activated charcoal and plantlets were transferred to non-sterile conditions for acclimatization, showing 100 percent of survival.

Smallanthus sonchifolius apresenta raízes tuberosas, que contêm grandes quantidades de frutoligosacarídeos e seu uso medicinal tem aumentado devido à propriedade hipoglicemiante relatada para esta espécie. Um sistema eficiente para propagação via embriogênese somática é descrito, utilizando segmentos peciolares cultivados em meio MS suplementado com diversas combinações de BA, cinetina e 2,4-D, sob condições de luz ou escuro. A maioria dos tratamentos resultou na formação de calos embriogênicos; no entanto, a embriogênese somática foi promovida em presença de luz e agregados de embriões somáticos foram observados na superfície dos calos após 50 dias de cultivo. O maior número de embriões foi obtido em presença de 0,45 µM BA e 4,5 µM 2,4-D. Os calos embriogênicos foram mantidos em meio MS com adição de 4,5 µM BA e 0,045 µM 2,4-D. A conversão dos embriões somáticos foi obtida em meio MS, com a concentração de sais reduzida à metade, 2 g.L-1 de carvão ativado, sem reguladores de crescimento. As plantas regeneradas foram aclimatadas em condições ambientais, com sobrevivência de 100 por cento.