Bioprospection of marine actinomycetes: recent advances,challenges and future perspectives

In exploring new sources for economically important products, marine environment draws particular attention because of its remarkable diversity and extreme conditions;it is known to produce metabolic products of great value. It represents untapped source for the discovery of novel secondary metabolites with varying potential such as antibiotic, anti-tumor, antifouling and cytotoxic properties. Marine actinomycetes distributed throughout the marine environment from shallow to deep sea sediments have proved to be a finest source for this discovery. Secondary metabolites derived from marine actinomycetes have proved their worth in industries based on the research on their properties and wide range applications. Spotlight of the review is range of marine based actinomycetes products and significant research in this field. This shows the capability of marine actinomycetes as bioactive metabolite producers. Additionally, the present review addresses some effective and novel approaches of procuring marine microbial compounds utilizing the latest screening strategies of drug discovery from which traditional resources such as marine actinobacteria has decreased due to declining yields. The aim is in the context of promoting fruitful and profitable results in the near future. The recent surfacing of new technologies for bioprospection of marine actinomycetes are very promising, resulting in high quality value added products, and will be de?ning a new era for bioactive compounds with medical and biotechnological applications.

Adenylate cyclase activator forskolin alleviates intracerebroventricular propionic acid-induced mitochondrial dysfunction of autistic rats

Neuronal mitochondrial dysfunction increases inflammatory mediators and leads to free radical generation and anti-oxidant enzymatic alterations,which are major neuropathological hallmarks responsible for autism.Mitochondrial dysfunction in autism is associated with decreased ATP levels due to reduced levels of cyclic adenosine monophosphate.Rat models of autism were established by intracerebroventricular injection of propionic acid.These rat models had memory dysfunction,decreased muscle coordination and gait imbalance.Biochemical estimation of propionic acid-treated rats showed changes in enzyme activity in neuronal mitochondrial electron transport chain complexes and increases in pro-inflammatory cytokines,oxidative stress and lipid biomarkers.Oral administration of 10,20 and 30 mg/kg adenylate cyclase activator forskolin for 15 days reversed these changes in a dose-dependent manner.These findings suggest that forskolin can alleviate neuronal mitochondrial dysfunction and improve neurological symptoms of rats with autism.This study was approved by the RITS/IAEC,SIRSA,HARYANA on March 3,2014(approval No.RITS/IAEC/2014/03/03).

Chemo-Divergence in Essential Oil Composition among Thirty One Core Collections of <i>Ocimum sanctum</i>L. Grown under Sub-Tropical Region of Jammu, India

Evaluation of thirty one core collections of Ocimum sanctum L. synonyms O. tenuiflorum L. collected from different ecological regions representing contrasting environment of India was carried out. All the collections were grown under sub-tropical region of Jammu, India. Study revealed wide range of variability in quantitive and qualitative attributes of oil. Essential oil content ranged between 0.16% ± 0.01% - 0.55% ± 0.08% showing the presence of fifteen constituents. Methyl eugenol (1.54% - 93.16%) and Eugenol (0.06% - 70.41%), were the major constituent. The other major constituent of the oil was β-Caryophyllene (4.60% - 33.77%) which was detected in almost all the collections. Borneol, Copane, α Caryophyllene were other constituents detected in almost all the accessions. α selinene was detected in traces in only three accessions (OS-01, OS-03, OS-50) and β-selinene was detected in four accessions (OS-01, OS-03, OS-50, OS-72. Accession OS-70 collected from Patna, showed distinct chemical profile having β-Elemene (32.81%), β-Cary- ophyllene (16.37%), Germacrene-D (18.05%), β-Ocimene (17.69%) and Copane (5.738%). Being distinct in oil profiling, Patna collection was designated as distinct chemotype. Collections OS-50 from Gwalior from Central India and OS-59 from Rajkot Western India have been identified as methyl eugenol (93.16%) and eugenol (70.41%) rich geno- types. The data collected provided useful information with respect to composition of essential oil among core collection evaluated representing various agro-climatic zones.

Development of a validated UPLC-qTOF-MS/MS method for determination of bioactive constituent from Glycyrrhiza glabra

An ultra-performance liquid chromatography quadrupole time of flight mass spectrometry （UPLC-qTOF-MS/MS） method was developed and validated for the simultaneous determination of glycyrrhizin and glycyrrhetic acid. These analytes were separated on a reverse phase C18 column using a mobile phase of acetonitrile：2% acetic acid in water （75：25, v/v） with a flow rate of 200 μL/min. The qTOF-MS was operated under multiple reaction monitoring （MRM） mode using the electrospray ionization （ESI） technique with positive ion polarity. A comparison of three different extraction techniques i.e. accelerated solvent extraction （ASE）, extraction under ultrasonic waves （USW） and the classical extraction by percolation （CE） method was done and quantification of these extracts was also carried out by the proposed method.

In vitro and in vivo anticancer potential and molecular targets of the new colchicine analog ⅢM-067

Objective: The current study evaluated various new colchicine analogs for their anticancer activity and to study the primary mechanism of apoptosis and in vivo antitumor activity of the analogs with selective anticancer properties and minimal toxicity to normal cells.Methods: Sulforhodamine B(SRB) assay was used to screen various colchicine analogs for their in vitro cytotoxicity. The effect of N-[(7S)-1,2,3-trimethoxy-9-oxo-10-(pyrrolidine-1-yl)5,6,7,9-tetrahydrobenzo[a] heptalene-7-yl] acetamide(ⅢM-067) on clonogenicity, apoptotic induction, and invasiveness of A549 cells was determined using a clonogenic assay, scratch assay, and staining with 4’,6-diamidino-2-phenylindole(DAPI) and annexin V/propidium iodide. Mitochondrial membrane potential(MMP) and reactive oxygen species(ROS) levels were observed using fluorescence microscopy. Western blot analysis was used to quantify expression of proteins involved in apoptosis, cell cycle, and phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)/mammalian target of rapamycin(mTOR) signaling. Pharmacokinetic and in vivo efficacy studies against Ehrlich ascites carcinoma(EAC) and Ehrlich solid tumor models were conducted using Swiss albino mice.Results: ⅢM-067 showed potent cytotoxicity and better selectivity than all other colchicine analogs screened in this study. The selective activity of ⅢM-067 toward A549 cells was higher among other cancer cell lines,with a selectivity index(SI) value of 2.28. ⅢM-067 demonstrated concentration-and time-dependent cytotoxicity against A549 cells with half-maximal inhibitory concentration values of 0.207, 0.150 and0.106 μmol/L at 24, 48 and 72 h, respectively. It also had reduced toxicity to normal cells(SI > 1) than the parent compound colchicine(SI = 1). ⅢM-067 reduced the clonogenic ability of A549 cells in a dose-dependent manner. ⅢM-067 enhanced ROS production from 24.6% at 0.05 μmol/L to 82.1% at 0.4 μmol/L and substantially decreased the MMP(100% in control to 5.6% at 0.4 μmol/L). The annexin V-FITC assay demonstrated78% apoptosis at 0.4 μmol/L. ⅢM-067 significantly(P < 0.5) induced the expression of various intrinsic apoptotic pathway proteins, and it differentially regulated the PI3K/AKT/mTOR signaling pathway. Furthermore,ⅢM-067 exhibited remarkable in vivo anticancer activity against the murine EAC model, with tumor growth inhibition(TGI) of 67.0% at a dose of 6 mg/kg(i.p.) and a reduced mortality compared to colchicine. ⅢM-067also effectively inhibited the tumor growth in the murine solid tumor model with TGI rates of 48.10%, 55.68%and 44.00% at doses of 5 mg/kg(i.p.), 6 mg/kg(i.p.) and 7 mg/kg(p.o.), respectively.Conclusion: ⅢM-067 exhibited significant anticancer activity with reduced toxicity both in vitro and in vivo and is a promising anticancer candidate. However, further studies are required in clinical settings to fully understand its potential.