METHODS: Endophytic bacteria were isolated from the leaves of L. leucocephala and 16S rRNA gene sequencing was used to establish their identity. The in vitro antioxidant effect of endophytic crude extract (LL) was evaluated using 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) free radical scavenging methods. The in vitro antidiabetic properties of LL were evaluated using α-amylase and α-glucosidase enzyme inhibition assay.
RESULTS: The isolated endophytic bacteria were identified as Cronobacter sakazakii. LL displayed potent free radical scavenging effect against ABTS and DPPH radicals with an inhibitory concentration 50% (IC50) value of 17.49 ± 0.06 and 11.3 ± 0.1 μg/mL respectively. LL exhibited α-amylase and α-glucosidase inhibition with an IC50 value of 23.3 ± 0.08 and 23.4 ± 0.1 μg/mL respectively compared to the standard drug (acarbose). Both glucose loaded normoglycemic rats and STZ induced diabetic rats treated with LL (200 mg/kg) exhibited a considerable reduction in blood glucose levels p<0.01 after 8 h of treatment when compared to normal and diabetic control rats respectively.
CONCLUSIONS: Thus, the study shows that LL has a wellspring of natural source of antioxidants, and antidiabetic agents and phytoconstituents present in endophytes could be the rich source for bioactive compounds.
OBJECTIVES: In the present study, an endophyte was isolated from the leaves of T. indica and screened for its antimicrobial potential.
METHODS: The selected endophyte was identified by 16s rRNA partial genome sequencing and investigated for their antimicrobial potency. The preliminary phytochemical tests were conducted for the affirmation of phytoconstituents in the endophytic crude ethyl acetate extract of T. indica (TIM) and total phenolic content was performed. The antimicrobial potential of TIM was evaluated against human pathogenic ATCC gram-positive and gram-negative bacterial strains.
RESULTS: TIM exhibited an appreciable amount of gallic acid equivalent phenolic content (21.6 ± 0.04 mg GAE/g of crude extract). TIM showed the Minimum Inhibitory Concentration (MIC) at 250 μg/mL and Minimum Bactericidal Concentration (MBC) at 500 μg/mL among the selected human pathogenic ATCC strains. At MIC of 500 μg/mL, TIM displayed a significant zone of inhibition against P. aeruginosa and N. gonorrhoeae.
CONCLUSION: The results from our study highlighted for the first time the antimicrobial potential of endophytic bacterial strain Bacillus velezensis in T. indica leaves and it could be further explored as a source of natural antimicrobial agents.
MATERIALS AND METHODS: The antioxidant effect of these compounds was initially performed in vitro using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay methods before subjecting them to in vivo experiments. Compounds showing potent antioxidant activity (CS-1 and CS-2) were investigated further for their antidepressant activity using the forced swim test (FST) and tail suspension test (TST). Ascorbic acid (AA) and fluoxetine (20 mg/kg, p.o) were used as reference drugs for comparison in the antioxidant and antidepressant experiments, respectively.
RESULTS: It was observed that CS-2 and CS-3 exhibited highest DPPH (half maximal inhibitory concentration [IC50]: 16.22 and 25.18 μg/mL) and ABTS (IC50: 17.2 and 28.86 μg/mL) radical scavenging activity, respectively, compared to AA (IC50: 15.73 and 16.79 μg/mL) and therefore, both CS-2 and CS-3 were tested for their antidepressant effect using FST and TST as experimental models. Pretreatment of CS-2 and CS-3 (20 mg/kg) for 10 days considerably decreased the immobility time in both the FST and TST models.
CONCLUSION: The antioxidant and antidepressant effect of CS-2 and CS-3 may be attributed to the presence of azomethine linkage in the molecule.