Seema Dhankhar

Cassia occidentalis L.: a review on its ethnobotany, phytochemical and pharmacological profile.

Cassia occidentalis L. is an annual or perennial Ayurvedic plant which is used in several traditional medicines to cure various diseases. This weed has been known to possess antibacterial, antifungal, antidiabetic, anti-inflammatory, anticancerous, antimutagenic and hepatoprotective activity. A wide range of chemical compounds including achrosin, aloe-emodin, emodin, anthraquinones, anthrones, apigenin, aurantiobtusin, campesterol, cassiollin, chryso-obtusin, chrysophanic acid, chrysarobin, chrysophanol, chrysoeriol etc. have been isolated from this plant. The presented review summarizes the information concerning the botany, ethnopharmacologyquery, phytochemistry, biological activity and toxicity of the C.occidentalis plant.

Investigations Towards New Antidiabetic Drugs from Fungal Endophytes Associated with Salvadora Oleoides Decne

The nature has provided abundant natural resources which can be explored for their medicinal uses. The present study was undertaken to investigate the antidiabetic and hypolipidemic activity of various extracts fractions obtained from mycelia of seventeen endophytic fungi in different solvents (methanol, acetone and aqueous) isolated from Salvadora oleoides Decne (Salvadoraceae) in glucose loaded fasting and alloxan induced diabetic Wistar albino rats. Only four extracts namely; unidentified fungus (aqueous), Aspergillus sp.JPY2 (methanol), Aspergillus sp.JPY1 (methanol) and Phoma sp. (acetone) significantly reduced blood glucose levels as revealed by glucose tolerance test. It has been observed that in alloxan induced diabetic rats, the maximum reduction in blood glucose level was after 5 hours in the acute treatment experiment and on14th day in sub acute treatment at a dose of 250mg/kg of body weight (P<0.05). The reduction in blood glucose in long term treatment experiment was ranged from 11.3% to 28.04%, whereas standard drug tolbutamide reduced the blood glucose level up to 40%. In long term treatment, unidentified fungus (aqueous) extract showed significant improvement in parameters like body weight and lipid profile of alloxan induced diabetic rats. The gas chromatography mass spectrometer (GCMS) analysis of bioactive fraction (aqueous) of unidentified fungus and methanolic extract fraction of Aspergillus sp.JPY1 revealed that the main constituents were 2, 6-di-tert-butyl-p-cresol and Phenol, 2, 6-bis (1, 1-dimethylethyl)-4-methyl respectively. The results have also suggested that the above four bioactive fractions have good margin of safety and did not show any lethal effects on the animals up to the doses of 1000mg/kg b.w. along with safe doses up to 500 μg/ ml to human erythrocytes.

Analysis Toward Innovative Herbal Antibacterial & Antifungal Drugs

The antimicrobial activities of four medicinal plants Argemona mexicana, Achyranthes aspera, Catharanthus roseus, and Syzygium cumini were evaluated against Escherichia coli, Vibrio cholerae, Klebsiella pneumoniae, Proteus vulgaris, Bacillus subtilis, Salmonella typhi and three Aspergillus species. Extracts from Achyranthes aspera and Catharanthus roseus showed the highest antimicrobial potential (MIC 0.375-0.750 mg/ml) while extract from Argemona mexicana and Syzygium cumini, showed less activity. In disc diffusion assay, only eight out of twenty extracts showed antimicrobial activity at a concentration of 25.0 μg/ disc. The GCMS investigation reveals the existence of 2-bornanone; 1, 2-benzenedicarboxylic acid, bis (2-methylpropyl) ester; hexadecanoic acid, methyl ester and hexatriacontane in water extract fraction of C. roseus. The present research article provides a review of some medicinal plants incorporating antimicrobial drugs, together with recent advances in emerging therapeutics in clinical development and related patents for exploitation of herbal medicine.

Investigating Antimicrobial Properties of Endophytic fungi Associated with Salvadora oleoides Decne

Virtually all fungal endophytes produce a variety of bioactive molecule, which is currently attracting worldwide scientific attention towards isolation and exploration of their biotechnological promise. In the present study, 17 endophytic fungi (identified by way of morphological and/or sequence based molecular methods) were screened for antimicrobial activity against pathogenic strains of six bacteria and three Aspergilli sp. The seventeen culturable fungi extracted with three solvents in increasing polarity; acetone, methanol and water were examined for antimicrobial activity in crude extracts using microbroth dilution assay. Tetracycline and Amphotericin B were used as positive controls against different bacterial strains and Aspergilli respectively. The crude extracts of Aspergillus sp. JPY1, Aspergillus sp. JPY2, Aspergillus niger and an unidentified sp. exhibited the maximum activity against three pathogenic Aspergilli sp. Their in vitro minimum inhibitory concentrations (MICs) against Aspergilli were found to be 0.387-12.50 mg/ml by microbroth dilution. In disc diffusion assay, only eleven out of fifty-one fungal extracts were found to be endowed with antimicrobial activity at a preset concentration of 50 μg/ disc which could be the potential source to develop new antimicrobial agents. The work on study of cytotoxicity and phytochemical screening (preliminary and GC-MS) of crude extracts endowed with antimicrobial properties is reported here. It is the first report of Salvadora oleoides associated endophytic fungi with antimicrobial activity, which could be an essential source of bioactive compounds useful for developing better antifungal or antibacterial drugs with good therapeutic index value.

In vitro evaluation of combination of polyenes with EDTA against Aspergillus spp. by different methods (FICI and CI Model)

We investigated in vitro activity of polyene drugs (amphotericin B, Amp B; and nystatin, NYS;) in combination with ethylene diamine tetra acetic acid (EDTA) against 8 pathogenic isolates of Aspergillus spp.

Safety and Efficacy of Green Foliage in the Treatment of Fungal Infections and Associated Clinical Conditions

Forty five crude extracts of nine selected medicinal plants, based on their use in respiratory and other disorders in traditional systems of medicine were analyzed for their potential activity against three pathogenic species of Aspergillus. The presence of phenols, tannins, flavanoids, terpenoid, steroids, alkaloids and saponins in the different extracts was established. The crude extracts were examined for antifungal activity in concentration ranging from 5000.0 to 19.53 µg/ml using microbroth dilution assay in which twenty two extracts exhibited the anti-Aspergilli activity. The petroleum ether extract of Justicia adhatoda and water extract of Commelina bengalensis exhibited the maximum activity against Aspergillus fumigatus, Aspergillus flavus and Aspergillus niger. Their in vitro minimum inhibitory concentrations (MICs) were found to be 156.0-312.0 µg/ml by microbroth dilution and spore germination inhibition assays. In disc diffusion assay, at concentration of 10 µg/disc of some crude extracts showed significant activity against Aspergilli. The toxicity (in vitro and in vivo) of bio-active fractions was evaluated, in which the extracts isolated from J. adhatoda were found to be non-toxic. Gas chromatography-mass spectrometry (GCMS) studies were performed for various extracts (petroleum ether, chloroform and acetone) of J. adhatoda which resulted in the identification of several bioactive compounds. The antifungal activity along with acute toxicity, cyto-toxicity as well as genotoxicity of extract fractions from J. adhatoda justifies the use of such screening in the expedition for new drugs.

Inhibition of conidiophore development in Aspergillus fumigatus by an Escherichia coli DH5α strain, a promising antifungal candidate against aspergillosis

The opportunistic human pathogen Aspergillus fumigatus produces a massive number of asexual spores (conidia) as the primary means of dispersal, survival, genome protection and infection of hosts. In this report, we investigated secretory and cytosolic proteins of non-pathogenic bacterial species (mostly belonging to human microbiome) for antifungal potential against A. fumigatus, A. flavus and A. niger. Our preliminary results revealed that cytosolic proteins of E. coli DH5α were most active and the less toxic against various pathogenic isolates of A. fumigatus (the major pathogenic species), depicting a minimum inhibitory concentration (MIC) of 62.50 μg/mL, 62.50 μg/mL and 12.50 μg/disc using microbroth dilution assay (MDA), percentage spore germination inhibition assay (PSGI) and disc diffusion assay (DDA), respectively. E. coli protein was non-toxic against human erythrocytes at doses up to 1000 μg/mL as compared to standard drug, amphotericin B which lysed 100% of erythrocytes at a concentration of 37.50 μg/mL. Time kill analysis proved it to be fungicidal in a concentration and time-dependent manner. Scanning electron microscopic studies (SEM) were carried out to prevail what kind of damage it causes to A. fumigatus. SEM results reported that conidiophore (structures forming conidia) development was halted as a major consequence, reducing the number of conidiophores to insignificant values as well as alteration in their morphological attributes. This feature may contribute to the development of new prevention strategies against Aspergillus infections. Hyphal atrophy was also observed, evidenced by shrinking and flattening of hyphal walls and reduced, abrupt hyphal branching. Such actions may effectively reduce the invasive ability of Aspergillus as well as it can sterilize the fungal burden by obstructing the conidiation pathway of A. fumigatus. Hence, E. coli DH5α, being a commensal species, can lead to the development of antifungal molecule with novel targets in fungal metabolism, which will help in combating the antifungal resistance and toxicity associated with current therapy.

Evaluation of Antioxidant Activity of Stem and Root Extracts of Salvadora oleoides, a Medicinal Plant

The phenolic concentrations and antioxidant activities of root and stem extracts of Salvadora oleoides were analysed by different methods. The acetone fraction of root as well as acetone and aqueous extracts of the stem showed the highest antioxidant activity compared to other tested extracts. There was a positive correlation between the phenolic concentration of extracts and their respective antioxidant activity. The highest activity in superoxide radical scavenging assay was observed in the acetone stem extract (58.2%, r = 0.9744), while in hydroxyl radical scavenging assay, the aqueous stem extract (34.1%, r = 0.8750) was the most potent scavenger. Acetone root extract showed maximum metal chelating (59.6%, r = 0.9241) and nitric oxide radical scavenging activity (52.6%, r = 0.9463).

Isolation and Biological Evaluation of Novel Tetracosahexaene Hexamethyl, an Acyclic Triterpenoids Derivatives and Antioxidant from Justicia adhatoda

Forty five extracts fraction of nine selected Indian medicinal plants, based on their use in traditional systems of medicine were analyzed for their antioxidant potential. All the extracts were investigated for phenol content value calculated in Gallic acid equivalents (% of GAE) and antioxidant potential. Moreover, total phenolic content (% dw equivalents to gallic acid) of all plant extracts were found in the range of 3.04 to 24.03, which correlated with antioxidant activity. The findings indicated a promising antioxidant activity of crude extracts fractions of three plants (Justicia adhatoda, Capparis aphylla and Aegle marmelos) and required the further exploration for their effective utilization. Results indicated that petroleum ether fraction of J. adhatoda out of three plants also possesses the admirable antioxidant abilities with high total phenolic content. Following, in vitro antioxidant activity-guided phytochemical separation procedures, twelve fractions of petroleum ether extract of J. adhatoda were isolated by silica gel column chromatography. One fraction (Rf value: 0.725) showed the noticeable antioxidant activity with ascorbic acid standard in hydroxyl radical scavenging assays. The molecular structures elucidations of purified antioxidant compound were carried out using spectroscopic studies ((1)H NMR, (13)C NMR and MS). This compound was reported from this species for the first time. The results imply that the J. adhatoda might be a potential source of natural antioxidants and 2,6,10,14,18,22-Tetracosahexaene, 2,6,10,15,19,23-hexamethyl is an antioxidant ingredient in J. adhatoda.

A Novel and Significant Method for Antioxidant Activity Utilizing Microtitre-plate (Resazurin Reducing Power Assay)

There are number of methods used for detection of antioxidant activities. We have developed a new method using a compound (resazurin) which undergoes a visible colour shift by chemical or physical interaction with ascorbate and other antioxidant compounds. This novel method was developed to measure the antioxidant activity using the resazurin dye in microtitreplate. The experiment protocol, which is rapid and inexpensive, ensures sensitivity and reproducibility in the measure of antioxidant activity of hydrophilic or water soluble antioxidant compounds. This method is able to achieve more accuracy in the determination of the minimum antioxidant concentration (MAC) values of natural products, including crude extract, chromatographic fractions or purified compounds comparing with ascorbic acid and other standard antioxidant. Therefore, in our opinion this procedure can quickly provide useful information on the antioxidant contents of foods and plants extracts using a very small sample quantity.