Protective nature of mangiferin on oxidative stress and antioxidant status in tissues of streptozotocin-induced diabetic rats

Oxidative stress plays an important role in the progression of diabetes complications. The aim of the present study was to investigate the beneficial effect of oral administration of mangiferin in streptozotocin (STZ)-induced diabetic rats by measuring the oxidative indicators in liver and kidney as well as the ameliorative properties. Administration of mangiferin to diabetic rats significantly decreased blood glucose and increased plasma insulin levels. The activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) and level of reduced glutathione (GSH) were significantly (P < 0.05) decreased while increases in the levels of lipidperoxidation (LPO) markers were observed in liver and kidney tissues of diabetic control rats as compared to normal control rats. Oral treatment with mangiferin (40 mg/kg b.wt/day) for a period of 30 days showed significant ameliorative effects on all the biochemical and oxidative parameters studied. Diabetic rats treated with mangiferin restored almost normal architecture of liver and kidney tissues, which was confirmed by histopathological examination. These results indicated that mangiferin has potential ameliorative effects in addition to its antidiabetic effect in experimentally induced diabetic rats

Antimicrobial and antioxidant activity of the endophytic fungus Phomopsis sp. GJJM07 isolated from Mesua ferrea

Abstract Phomopsis sp. GJJM07 was isolated as an endophyte from the medicinal plant, Mesua ferrea. The crude ethyl acetate extract of the fungus was evaluated for antimicrobial and free radical scavenging (DPPH) activity. Hence this endophytic fungus were grown in different media and were tested for its potent antimicrobial activity against the test pathogens, gram positive bacteria viz., Bacillus subtilis, Micrococcus luteus; gram negative bacteria viz., Escherichia coli, Klebsiella pneumoniae and yeast, Candida albicans. Among the different media, M1D medium showed good growth 1.57 g MDW/100 ml and broad spectrum of antimicrobial activity by exhibiting prominent zone of inhibition against the test pathogens such as E. coli (16±0.14), K. pneumonia

Diversity and biological activities of endophytic fungi associated with Catharanthus roseus

Background: The present study involves diversity and bioactivity of the endophytic fungal community from Catharanthus roseus inhabiting the coastal region. This study has been conducted hypothesizing that the microbial communities in the coastal regions would tolerate a range of abiotic stress such as salinity, humidity, temperature and soil composition, and it may produce new metabolites, which may possess bioactive property. Therefore in the current study, the cytotoxicity and free radical scavenging potential of the fungal organic extracts have been investigated. Moreover, the apoptotic and the antioxidant potential of the fungus that exhibited the best activity in preliminary screening has also been demonstrated. Results: Twenty endophytic fungal isolates were obtained from different parts of the plant, and identified using internal transcribed spacer region analysis. Based on the colonization frequency, the dominant genera were found to be Colletotrichum, Alternaria and Chaetomium with colonization frequency % of 8.66, 7.00 and 6.33, respectively. It was observed that the species diversity and richness was the highest in bark followed by leaf and stem regions of the plant. On screening the fungal ethyl acetate extracts for cytotoxicity against the HeLa cells, the Chaetomium nigricolor extract exhibited potent cytotoxic activity of 92.20% at 100 mu g mL(-1) concentration. Comparison between the different organic extracts (ethyl acetate, chloroform, dichloromethane and hexane) of Chaetomium nigricolor mycelial and culture filtrate, it was observed that the mycelial as well the culture filtrate ethyl acetate extracts and the culture filtrate hexane extract showed significant cytotoxic potential against the HeLa and MCF-7 cells, respectively. The apoptotic-and mitochondrial membrane depolarisation-induction potential of the Chaetomium nigricolor ethyl acetate extract has also been demonstrated in this study. Further the screening of antioxidant potential of the ethyl acetate fungal extracts using DPPH scavenging assay showed that Chaetomium nigricolor extract exhibited potential activity with a significant EC50 value of 22 mu g mL(-1). The ethyl acetate extract of Chaetomium nigricolor also exhibited superoxide radical scavenging potential. Conclusion: These results indicated that diverse endophytic fungal population inhabits Catharanthus roseus. One of the fungal isolate Chaetomium nigricolor exhibited significant cytotoxic, apoptotic and antioxidant potential

Biochemical insights into the recombinant 10-deacetylbaccatin III-10-beta-O-acetyltransferase enzyme from the Taxol-producing endophytic fungus Lasiodiplodia theobromae

10-deacetylbaccatin III-10-beta-O-acetyltransferase (DBAT) is a key rate-limiting enzyme of the Taxol biosynthetic pathway, which is uncharacterized in Taxol-producing endophytic fungi. Here, an open reading frame of DBAT was cloned from the Taxol-producing endophytic fungus Lasiodiplodia theobromae (LtDBAT). The LtDBAT enzyme was heterologously expressed and purified by the affinity and gel filtration chromatography methods. The molecular weight of the purified protein was 49 kDa and its identity was confirmed by western blot. The purified LtDBAT enzyme was capable of catalyzing 10-deacetylbaccatin III into baccatin III, as shown by liquid chromatography-mass spectroscopy. The mass spectra of baccatin III were identical to the authentic baccatin III. The LtDBAT enzyme was characterized and the kinetic parameters of catalysis were determined. In addition, localization of LtDBAT was performed by using confocal microscopy and the result showed that the enzyme was localized in lipid droplets. Together, this study provides biochemical insights into the fungal recombinant DBAT enzyme that is involved in the Taxol biosynthetic pathway. In the near future, engineering of the LtDBAT enzyme and the Taxol biosynthetic pathway in endophytic fungi could be an eco-friendly and economically feasible alternative source for production of Taxol and its precursors

Cloning and sequence analysis of 10-deacetylbaccatin III-10-O-acetyl transferase gene and WRKY1 transcription factor from taxol-producing endophytic fungus Lasiodiplodia theobromea

In this study, we have isolated an endophytic fungal strain Lasiodiplodia theobromae from non-Taxus host plant Piper nigrum. The strain L. theobromae identity was confirmed by morphological characteristics and internal transcribed spacer sequence analysis. Taxol produced by L. theobromae was observed to be identical to the authentic taxol as analyzed by chromatography and spectroscopy methods. The quantity of taxol produced by the fungus was estimated to be 247 mu g L-1, and fungal taxol showed potent cytotoxic activity towards cancer cell line. Evidence to support the independent production of taxol by L. theobromea, the gene encoding 10-deacetylbacccation-III-O-acetyltransferase (DBAT), as well as, for the first time, open reading frame (ORF) of WRKY1 transcription factor (TF) were cloned and sequenced. The predicted amino sequence of L. theobromae dbat gene shared high homology with the taxol-producing plant and fungal dbat gene. Not only dbat gene, ORF of WRKY1 TF too shared high homology with Taxus chinensis WRKY1 TF ORF. To the best of our knowledge, this is the first report on cloning of dbat gene and its transcription factor from endophytes of non-Taxus host plant

Bioprospecting of Bioactive Metabolites from Monochaetia karstenii

In the present study, to optimize the media for the production of bioactive compounds from Monochaetia karstenii was carried out and compounds were identified by GC-MS. M. karstenii was identified from infected Camellia japonica leaves by classical and molecular taxonomy. It was cultured in different media and determined their mycelial biomass and antibacterial activity. Further Maltose Maltose tartrate broth (MTB) was altered for its media components such as carbon, nitrogen, minerals, amino acids and vitamins sources and physical parameters like temperature, pH and incubation periods for growth and production of secondary metabolites from M. karstenii. The antimicrobial and antioxidant compounds were performed from three different solvent extracts (Chloroform, Dichloromethane and Ethyl acetate) of M. karstenii from optimized medium. M. karstenii had optimum growth in MTB showing mycelial growth of 13.16 g/L. The ethyl acetate extract observed significant antibacterial activity against Escherichia coli (21 mm), Staphylococcus aureus (20 mm) and Vibrio chloreae (18 mm). In-vitro antioxidant activity revealed that, the IC50 values for 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS), 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and total antioxidant radical scavenging assay of 100.58 μg/ml, 140 μg/ml and 141.91 μg/ml from ethyl acetate extract respectively. Thus the antimicrobial and antioxidant activity of the fungal extract has been due to the presence of biocompounds such as cyclohexenone derivatives, cinnamic acid, isooxazoline 3-phenyl- benzodiazepine, 2- propenoic acid 3-phenyl-(E)-dodecene and 3-undecen -1-yne (E) were characterized by gas chromatography-mass spectrometry (GC–MS) and reported first time in M. karstenii. We conclude that M. karstenii possess excellent antimicrobial and antioxidant potential and can be exploited for the discovery of new drug molecules

Naphthalene Carbohydrazone Based Dizinc(II) Chemosensor for a Pyrophosphate Ion and Its DNA Assessment Application in Polymerase Chain Reaction Products

A new naphthalene carbohydrazone based dizinc(II) complex has been synthesized and investigated to act as a highly selective fluorescence and visual sensor for a pyrophosphate ion with a quite low detection limit of 155 ppb; this has also been used to detect the pyrophosphate ion released from polymerase-chain-reaction

Naphthalene Carbohydrazone Based Dizinc(II) Chemosensor for a Pyrophosphate Ion and Its DNA Assessment Application in Polymerase Chain Reaction Products

A new naphthalene carbohydrazone based dizinc(II) complex has been synthesized and investigated to act as a highly selective fluorescence and visual sensor for a pyrophosphate ion with a quite low detection limit of 155 ppb; this has also been used to detect the pyrophosphate ion released from polymerase-chain-reaction