An assessment on the role of endophytic microbes in the therapeutic potential of Fagonia indica

Abstract

BackgroundNatural products of animals, plants and microbes are potential source of important chemical compounds, with diverse applications including therapeutics. Endophytic bacteria that are especially associated with medicinal plants presents a reservoir of therapeutic compounds. Fagonia indica has been recently investigated by numerous researchers because of its striking therapeutic potential especially in cancer. It is also reported that endophytes play a vital role in the biosynthesis of various metabolites; therefore we believe that endophytes associated with F. indica are of crucial importance in this regard. The present study aims successful isolation, molecular identification of endophytic bacteria and their screening for bioactive metabolites quantification and in vitro pharmacological activities.Methods16S rRNA gene sequencing was used for the identification of isolated endophytic bacteria. Methanolic extracts were evaluated for total phenolic contents (TPC), total flavonoids contents (TFC), DPPH free radical scavenging activity, reducing power and total anti-oxidant assays were performed. And also screened for antibacterial and antifungal activities by disc diffusion method and their MIC were calculated by broth dilution method using microplate reader. Further, standard protocols were followed for antileishmanial activity and protein kinase inhibition. Analysis and statistics were performed using SPSS, Table curve and Origin 8.5 for graphs.ResultsBacterial strains belonging to various genera (Bacillus, Enterobacter, Pantoea, Erwinia and Stenotrophomonas) were isolated and identified. Total phenolic contents and total flavonoids contents varies among all the bacterial extracts respectively in which Bacillus subtilis showed high phenolic contents 243 µg/mg of gallic acid equivalents (GAE) and Stenotrophomonas maltophilia showed high flavonoids contents 15.9 µg/mg quercitin equivalents (QA), total antioxidant capacity (TAC) 37.6 µg/mg of extract, reducing power (RP) 206 µg/mg of extract and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity with 98.7 μg/mL IC50 value. Although all the extracts tested were active to inhibit growth of selected pathogenic microbes (bacteria and fungi), but significant antibacterial activity was observed against Klebsiella pneumonia and B. subtilis. An Enterobacter cloaca was active against Leishmania tropica with IC50 value of 1.4 µg/mg extracts. B. subtilis and Bacillus tequilensis correspondingly exhibit significant protein kinase inhibition of 47 ± 0.72 and 42 ± 1.21 mm bald zones, indicating anti-infective and antitumor potential.ConclusionsOur findings revealed that crude extracts of selected endophytic bacteria from F. indica possess excellent biological activities indicating their potential as an important source of antibiotics (antifungal, antibacterial) compounds.

Endosphere microbiome assemblage in scented black rice is affected by plant development, with possible functional roles

“…7b). Previously, Rahman [37] ORS571 has also been reported to enhance the colonization of root in rice [4,48]. Therefore, several flavonoid synthesis genes have been reported in plants, and bacteria, we observed the genes for flavonoid synthesis in the functional gene pool of endophytic microbiome in scented black rice plants.…”

Anti-leishmanial and Anti-inflammatory Agents from Endophytes: A Review

“…It also appears that among endophytic organisms, limited genera of fungi have been investigated so far. Moreover, except for the report by Rahman et al [131], demonstrating the activity of extract from Enterobacter cloaca endophyte of Fagonia indica against Leishmania tropica (IC 50 value of 1.4 µg/mL), no information is available regarding the antileishmanial activity of extracts and metabolites from bacteria and actinomycetes endophytes. Overall, endophytes are still untapped sources of anti-leishmanial compounds waiting to be harness for the benefit of mankind.…”

Bioactivity-driven high throughput screening of microbiomes of medicinal plants for discovering new biological control agents

“…Streptomyces alboniger, Pseudomonas taiwanensis and Pseudomonas geniculata from Dodonaea viscosa, which were previously reported as potential plant growth promoting bacteria [21]. Enterobacter hormaechei and Bacillus subtilis has been suggested to play a role in the therapeutic properties of Fagonia indica [35]. Bacillus flexus and Pseudarthrobacter phenanthrenivorans, Delftia and Baciluus tequilis, which all displayed very potencies, are not widely studied for their biological control potential especially against Phytophthora disease.…”