Potential of Selected Indian Herbs for COVID-19

Introduction:

Many environmental risk factors are associated with some form of chronic inflammation. The spread of COVID-19 across the world has impacted every one of us. The first case of coronavirus was reported on 30 January 2020 in India originating from China.

Study Area:

India has a tremendous capacity to deal with the coronavirus outbreak because of its high immunity and climatic conditions. Maintaining social distancing and hand washing is not a sufficient step for preventing COVID-19. Indian system of traditional medicine has a potential worth to enhance immunity, which can resist a novel coronavirus.

Material & Methods:

A detailed study was carried out by analyzing national and international scientific databases (PubMed, SciFinder, ScienceDirect, Scopus, and Web of Science, Mendeley), thesis, and recognized books. Only Indian herbs with high immunity resistant power were analyzed. Epidemiologic studies with information on COVID-19 risk factors and precautions also considered for study purposes.

Results:

Some herbs like Ocimum tenuiflorum (Tulsi), Glycyrrhiza glabra (Liquorice), Curcuma domestica Vahl (Turmeric), Tinospora cordifolia (Giloy), Withania somnifera (Ashwagandha), Cinnamon (Dalchini), Shoot of Triticumaestivum Linn. (Wheatgrass), Andrographis paniculata (Kalmegh), can help in boosting immunity for COVID-19 disease.

Discussion:

Despite the shreds of evidence for the efficacy of these herbs in treating coronavirus induced infections; the proper dose with ideal timing for such interventions needs to verify in clinical trials. Researchers must have to take the privilege to explore the potential of herbs to reduce such epidemics of environmental threats.

Viburnum nervosum Leaf Extract Mediated Green Synthesis of Silver Nanoparticles: A Viable Approach to Increase the Efficacy of an Anticancer Drug

BACKGROUND

There is an urgent need to devise improved alternatives for the efficient delivery of drugs to develop improved therapeutic interventions against cancers. Nanotechnology-based drug delivery vehicles are in-use with obvious issues of toxicity and bio-distribution. Therefore, green synthetic routes are being deployed to replace the conventional nanoparticle formulations for effective drug delivery aiming at developing interventional strategies against cancer.

OBJECTIVE

A simple, viable, and fast approach was used for the green synthesis of silver nanoparticles (AgNPs) using aqueous leaf-extract of Viburnum nervosum (VN) and to explore the anti-cancer potential of the crude extract of VN.

METHODS

Silver NPs were synthesized by reacting silver nitrate (AgNO₃) with leaf extract of VN. Various analytical techniques were used to characterize the AgNPs. Finally, the anti-cancer potential of VN was observed when delivered through AgNPs.

RESULTS

The surface plasmon spectra for AgNPs exhibited absorbance peak at 445 nm, and Fourier-Transform Infrared Spectroscopy investigation revealed the presence of biomolecules acting as an effective reducing and capping agent for converting silver nitrate to AgNPs. Further, our results suggest the spherical size of synthesized AgNPs ranging from 12-17 nm. Moreover, in vitro studies conducted for VN extract with breast (MCF-7) and epidermal carcinoma (A431) cells showed biocompatibility.

CONCLUSION

Doxorubicin loaded AgNPs documented an increased bioavailability of the drug compared to the free drug, suggesting the use of AgNPs as "novel drug delivery vectors".

Molecular Docking Based Analysis to Elucidate the DNA Topoisomerase IIβ as the Potential Target for the Ganoderic Acid; A Natural Therapeutic Agent in Cancer Therapy

INTRODUCTION

Intermediate covalent complex of DNA-Topoisomerase II enzyme is the most promising target of the anticancer drugs to induce apoptosis in cancer cells. Currently, anticancer drug and chemotherapy are facing major challenges i.e., drug resistance, chemical instability and, dose-limiting side effect. Therefore, in this study, natural therapeutic agents (series of Ganoderic acids) were used for the molecular docking simulation against Human DNATopoisomerase II beta complex (PDB ID:3QX3).

METHODS

Molecular docking studies were performed on a 50 series of ganoderic acids reported in the NCBI-PubChem database and FDA approved anti-cancer drugs, to find out binding energy, an interacting residue at the active site of Human DNA-Topoisomerase II beta and compare with the molecular arrangements of the interacting residue of etoposide with the Human DNA topoisomerase II beta. The autodock 4.2 was used for the molecular docking and pharmacokinetic and toxicity studies were performed for the analysis of physicochemical properties and to check the toxicity effects. Discovery studio software was used for the visualization and analysis of docked pose.

RESULTS AND CONCLUSION

Ganoderic acids (GS-1, A and DM) were found to be a more suitable competitor inhibitor among the ganoderic acid series with appropriate binding energy, pharmacokinetic profile and no toxicity effects. The interacting residue (Met782, DC-8, DC-11 and DA-12) shared a chemical resemblance with the interacting residue of etoposide present at the active site of human topoisomerase II beta receptor.

Nutritional and Medicinal Values of Chlorophytum borivilianum: Minireview of Current Status and Future Possibilities

Background:

The knowledge of herbs and its uses is not fully explored in India. Chlorophytum borivilianum (family: Liliaceae) is one of the highest valued medicinal plants found in the Indian forest. Traditionally, it is used after delivery by the females in different compositions in the form of “Laddoos”.

Objective:

This study reviewed the nutritional and medicinal applications of Chlorophytum borivilianum properties with the current status and future possibilities. Chlorophytum borivilianum is a well-known tonic and an aphrodisiac drug extensively used in Ayurvedic medicines. The main source is from the forest area, efforts are made for its cultivation to fulfill the growing demand.

Methods:

A detailed study was carried out by analyzing national and international scientific databases like Pub Med, SciFinder, Scopus and Web of Science, thesis, and recognized books. The researcher himself cultivated Chlorophytum borivilianum on his farm during the period from 2000 to 2008.

Results:

Chlorophytum borivilianum roots are used for the preparation of nutritional tonic used in general sexual weaknesses. It has a huge and consistent demand in the national and international markets. The pharmaceutical and therapeutic value of Chlorophytum borivilianum has a great significance due to the presence of a specific constituent, i.e., saponins of secondary metabolites. Recent studies of Chlorophytum borivilianum have identified a wide range of pharmacological applications, most importantly, aphrodisiac, immune-modulatory, and anticancer activities.

Conclusion:

Some of the barriers are observed, such as a lack of research and development on highyielding varieties, quality control, and products and process development. The difficulties in marketing, an unestablished local market for primary processed products, unskilled human power, and equipment, knowledge of the latest technologies and market information are the major constraints observed in the promotion of Chlorophytum borivilianum.

An evaluation of liposome-based diagnostics of pulmonary and extrapulmonary tuberculosis

Introduction: Tuberculosis (TB) is still one of the major global health threats and delayed diagnosis or misdiagnosis continues to fuel the global epidemic. The conventional diagnostic approaches have shortcomings that might hinder the process of diagnosis of the disease and ultimately affect the prognosis.Area covered: We emphasize on the process of the synthesis of liposomes, its physicochemical properties affecting the formulation and their utilization in the field of molecular diagnostics for TB. The review also sheds a light on other nanoparticle-based molecular diagnostic approaches for TB. Despite the advent of science, we are yet to have a diagnostic tool that is simple, rapid, sensitive, and specific, and most importantly, one that enables us to demarcate patients with active tuberculosis from those with quiescent lesions, prior vaccination, or other diseases.Expert opinion: The utility of liposomes for diagnostic purposes has been attempted so as to overcome the challenges posed by conventional diagnostic tools for TB. Through this review, we present insights into liposome formulation and selection processes, various studies that report the use of liposome-based diagnostic tools for TB, as well as the limitations associated with the same that can be improvised to make the technology more efficient.

RNA-loaded dendritic cells: more than a tour de force in cancer therapeutics

A wide array of therapeutic strategies has been implemented against cancers, yet their clinical benefit is limited. The lack of clinical efficacy of the conventional treatment options might be due to the inept immune competency of the patients. Dendritic cells (DCs) have a vital role in initiating and directing immune responses and have been frequently used as delivery vehicles in clinical research. The recent clinical data suggest the potential use of DCs pulsed with nucleic acid, especially with RNA holds a great potential as an immunotherapeutic measure with compare to other cancer therapeutics. This review mainly deals with the DCs and their role in transfection with RNA in cancer immunotherapy.

Metabolomic and biotechnological approaches to determine therapeutic potential of Withania somnifera (L.) Dunal: A review

BACKGROUND

Withania somnifera, a high value medicinal plant is a major source of pharmaceutically important active compounds withanolides. Withania somnifera has been used in ayurveda as health restorative and anabolic agent besides having anti-arthritic, antidepressant, anti-microbial, anti-inflammatory, anti-diabetic, anti-stress, neuroprotective and cardio-protective activities.

HYPOTHESIS/PURPOSE

The mining of the compound(s) of interest offers opportunity to identify desired attributes in the therapeutic area of interest. Metabolomic has become an important tool in the field of pharmacological and functional genomics of medicinal plants. The analysis supports the information regarding differential outline of the gene expression for increasing important withanolides viz. withanolide A and withaferin A in W. somnifera.

STUDY DESIGN

The bioinformatics and biotechnological approaches viz. tissue culture, genetic transformation, genomic, transcriptomic, proteomic, gene mining and metabolomic studies have opened new windows about engineering of withanolide production.

METHODS

Target and network analysis for maximum therapeutic potential of Withania somnifera have been determined by employing Genemania software for finding interactions among various human genes that are being affected by active constituents.

RESULTS

Some of the major bioactive compounds of Withania somnifera have been discussed on protein-protein, protein-DNA and genetic interactions with respect to gene and protein expression data, protein domains, metabolic profiling, root organ culture, genetic transformation and phenotypic screening profiles CONCLUSION: The implementation of latest bioinformatic tools in combination with biotechnological techniques for breeding platforms are important in conservation of medicinal plant species in danger. The current review is based on molecular and in vitro methodologies employed in W. somnifera for accepting their importance in the improvement of this valuable medicinal species.

Chickpea Lectin Inhibits Human Breast Cancer Cell Proliferation and Induces Apoptosis Through Cell Cycle Arrest

BACKGROUND

Breast cancer demands safe adjuvant to overcome the side effects of standard drug tamoxifen. Diet derived bioactive compounds are reported to exhibit modulation of cancer growth leading to cell death. Chickpea is a protein rich edible legume with several bioactive compounds that includes lectin as well. Characterization of chickpea lectin for its effect against cancer cells has been investigated in this study.

METHOD

Cicer arietinum L. lectin (CAL) agglutinating trypsin-treated rabbit blood cells was purified employing DEAE-cellulose and SP-sephadex ion exchange chromatography. The lectin was characterized for its biological activity vis-à-vis antiproliferative and apoptotic effects through cell cycle arrest in MCF-7 human breast cancer cells.

RESULT

There is a significant inhibition of the survival of breast cancer cells due to chickpea lectin in a dose dependent manner for 24 hr. Lectin treated cells revealed distinct features of apoptosis. Flow cytometric analysis at 80 µg/ml of lectin induced S and G2 phase cell cycle arrest. CAL induced apoptosis in MCF-7 cells associated with lactate dehydrogenase leakage, cell cycle arrest and reactive oxygen species generation.

CONCLUSION

Our studies show that chickpea lectin exerted anticancer activity and could be exploited as an essential source for medicine leading to the treatment of breast cancer.

Microbiome diversity in the sputum of patients with pulmonary tuberculosis

TB is a worldwide pandemic. India has the highest burden of TB, with WHO statistics for 2013 giving an estimated incidence figure of 2.1 million cases for India out of a global incidence of 9 million. Microbiota have been shown to be associated with many disease conditions; however, only few studies have been reported for microbiota associated with TB infection. For the first time, we characterized the composition of microbiota of TB patients of India, using high-throughput 16S rRNA gene sequencing and compared it with healthy controls. Phylum-level analysis showed that the relative abundance of Firmicutes and Actinobacteria was significantly higher in TB samples and Neisseria and Veillonella were two dominant genera after Streptococcus. In our study, significantly different core genera in TB and normal population were found as compared with the reported studies. Also, the presence of diverse opportunistic pathogenic microbiota in TB patients increases the complexity and diversity of sputum microbiota. Characterization of the sputum microbiome is likely to provide important pathogenic insights into pulmonary tuberculosis.

Potential Compounds for Oral Cancer Treatment: Resveratrol, Nimbolide, Lovastatin, Bortezomib, Vorinostat, Berberine, Pterostilbene, Deguelin, Andrographolide, and Colchicine

Oral cancer is one of the main causes of cancer-related deaths in South-Asian countries. There are very limited treatment options available for oral cancer. Research endeavors focused on discovery and development of novel therapies for oral cancer, is necessary to control the ever rising oral cancer related mortalities. We mined the large pool of compounds from the publicly available compound databases, to identify potential therapeutic compounds for oral cancer. Over 84 million compounds were screened for the possible anti-cancer activity by custom build SVM classifier. The molecular targets of the predicted anti-cancer compounds were mined from reliable sources like experimental bioassays studies associated with the compound, and from protein-compound interaction databases. Therapeutic compounds from DrugBank, and a list of natural anti-cancer compounds derived from literature mining of published studies, were used for building partial least squares regression model. The regression model thus built, was used for the estimation of oral cancer specific weights based on the molecular targets. These weights were used to compute scores for screening the predicted anti-cancer compounds for their potential to treat oral cancer. The list of potential compounds was annotated with corresponding physicochemical properties, cancer specific bioactivity evidences, and literature evidences. In all, 288 compounds with the potential to treat oral cancer were identified in the current study. The majority of the compounds in this list are natural products, which are well-tolerated and have minimal side-effects compared to the synthetic counterparts. Some of the potential therapeutic compounds identified in the current study are resveratrol, nimbolide, lovastatin, bortezomib, vorinostat, berberine, pterostilbene, deguelin, andrographolide, and colchicine.

Arsenic-induced abnormalities in glucose metabolism: Biochemical basis and potential therapeutic and nutritional interventions

Health hazards due to the consumption of heavy metals such as arsenic have become a worldwide problem. Metabolism of arsenic produces various intermediates which are more toxic and cause toxicity. Arsenic exposure results in impairment of glucose metabolism, insulin secretion in pancreatic β-cells, altered gene expressions and signal transduction, and affects insulin-stimulated glucose uptake in adipocytes or skeletal muscle cells. Arsenic toxicity causes abnormalities in glucose metabolism through an increase in oxidative stress. Arsenic interferes with the sulfhydryl groups and phosphate groups present in various enzymes involved in glucose metabolism including pyruvate dehydrogenase and α-ketoglutarate dehydrogenase, and contributes to their impairment. Arsenic inhibits glucose transporters present in the cell membrane, alters expression of genes involved in glucose metabolism, transcription factors and inflammatory cytokines which stimulate oxidative stress. Some theories suggest that arsenic exposure under diabetic conditions inhibits hyperglycemia. However, the exact mechanism behind the behavior of arsenic as an antagonist or synergist on glucose homeostasis and insulin secretion is not yet fully understood. The present review delineates the relationship between arsenic and the biochemical basis of its relationship to glucose metabolism. This review also addresses potential therapeutic and nutritional interventions for attenuating arsenic toxicity. Several other potential nutritional supplements are highlighted in the review that could be used to combat arsenic toxicity.

Potential therapeutic targets for oral cancer: ADM, TP53, EGFR, LYN, CTLA4, SKIL, CTGF, CD70

In India, oral cancer has consistently ranked among top three causes of cancer-related deaths, and it has emerged as a top cause for the cancer-related deaths among men. Lack of effective therapeutic options is one of the main challenges in clinical management of oral cancer patients. We interrogated large pool of samples from oral cancer gene expression studies to identify potential therapeutic targets that are involved in multiple cancer hallmark events. Therapeutic strategies directed towards such targets can be expected to effectively control cancer cells. Datasets from different gene expression studies were integrated by removing batch-effects and was used for downstream analyses, including differential expression analysis. Dependency network analysis was done to identify genes that undergo marked topological changes in oral cancer samples when compared with control samples. Causal reasoning analysis was carried out to identify significant hypotheses, which can explain gene expression profiles observed in oral cancer samples. Text-mining based approach was used to detect cancer hallmarks associated with genes significantly expressed in oral cancer. In all, 2365 genes were detected to be differentially expressed genes, which includes some of the highly differentially expressed genes like matrix metalloproteinases (MMP-1/3/10/13), chemokine (C-X-C motif) ligands (IL8, CXCL-10/-11), PTHLH, SERPINE1, NELL2, S100A7A, MAL, CRNN, TGM3, CLCA4, keratins (KRT-3/4/13/76/78), SERPINB11 and serine peptidase inhibitors (SPINK-5/7). XIST, TCEAL2, NRAS and FGFR2 are some of the important genes detected by dependency and causal network analysis. Literature mining analysis annotated 1014 genes, out of which 841 genes were statistically significantly annotated. The integration of output of various analyses, resulted in the list of potential therapeutic targets for oral cancer, which included targets such as ADM, TP53, EGFR, LYN, CTLA4, SKIL, CTGF and CD70.

Anti-hyperglycemic and anti-hyperlipidemic potential of a polyherbal preparation "Diabegon" in metabolic syndrome subject with type 2 diabetes

BACKGROUND

In the present study, "Diabegon" a poly-herbal preparation, with hypoglycemic activity, was evaluated for its preventive effect in metabolic syndrome subjects with type 2 diabetes and also to reveal its side effects, on liver and kidney.

MATERIALS AND METHODS

Type 2 diabetic subjects with metabolic syndrome (N=58) were categorized on the basis of age and fasting blood glucose. The grouping was as follows: Group I (35-50 yrs), Group II (51-65 yrs), Group III >65 yrs, Group IV FBS<145.9, Group V FBS>145. Each group was administered 4 gm of diabegon daily. Blood glucose levels, lipid profile, liver and kidney function of the subjects were regularly monitored within 3 months of interval to 18 months.

RESULTS

The reduction in fasting blood glucose level ranged from 12.3% (P<0.05) to 42% (P<0.001) after 18 month of therapy whereas in postprandial blood glucose, the decrease ranged from 28% (P<0.05) to 32% (P<0.05) after 18 month of therapy. Overall reductions in the individual parameters of the metabolic syndrome subjects were significantly higher in Group I. Cholesterol level decreased from 11% to 27.2% (P<0.001), triglyceride levels decreased from 24% to 55%, VLDL and LDL levels reduced by 60% & 54% respectively after 18 months of therapy. The HDL-C level increased in all groups. Moreover, diabegon administration for 1.5 years exhibited no alteration in liver and kidney function tests, which indicate its non-toxicity.

CONCLUSION

Our study suggests that diabegon could be included as a preventive treatment in metabolic syndrome subjects with type 2 diabetes especially for long term treatment as it efficiently shows anti-hyperglycemic and anti-lipidemic effects with no adverse impacts on the liver and kidney.

Efficient ELISA for diagnosis of active tuberculosis employing a cocktail of secretory proteins of Mycobacterium tuberculosis

Rapid and accurate diagnosis is important for preventing transmission of Mycobacterium tuberculosis. Currently available tuberculosis (TB) diagnostic methods lack desired sensitivity and specificity, and require sophisticated equipment and skilled workforce including weeks' long duration to yield results. In this study, extracellular proteins or secretory protein antigens of M. tuberculosis H37Rv have been isolated using ion exchange chromatography, immunocharacterized and exploited for the development of efficient enzyme-linked immunosorbent assay (ELISA) for diagnosis of active TB with enhanced specificity and sensitivity. Apparent molecular masses for purified proteins were found to be 6, 27, 30, 38 and 64 kDa. Out of five purified proteins, one (64 kDa) was found to be novel. Of the five proteins, four (6, 27, 30 and 38 kDa) were found significant to be used in the development of ELISA for pulmonary and extra-pulmonary TB. The immune responses of serum samples of TB patients and other healthy subjects against the above-mentioned antigens' cocktail were evaluated. Critical parameters of newly developed ELISA were optimized and it was observed that the cocktail antigens have a greater specificity (98.06 %) and sensitivity (98.67 %) as compared to other commercially available diagnostic tests. The present findings suggest that the developed ELISA is an effective tool for routine screening and early-stage diagnosis of TB.

“Diabegon”, a safe and effective polyherbal therapy for type 2 diabetes mellitus

AIM: To investigate the antihyperglycemic, antihyperlipidemic and antioxidant functions of a polyherbal formulation, “Diabegon”, in human subjects with type 2 diabetes mellitus.

METHODS: A total of 33 human subjects with type 2 diabetes mellitus were recruited for the study and all anthropological and biochemical parameters were recorded at the time of registration. The subjects were given hot water extract obtained from 10 gm of “Diabegon” powder, “Diabegon kwath”, on an empty stomach everyday in the morning under personal supervision for 6 mo. The therapeutic functions of the “Diabegon kwath” was assessed by monitoring the blood glucose levels at monthly intervals and glycosylated hemoglobin, lipid profile and biomarkers of oxidative stress, liver and kidney function markers at three monthly intervals in the study subjects.

RESULTS: Daily administration of hot water extract of “Diabegon” regularly for 6 mo resulted in significant reductions of blood glucose and glycosylated hemoglobin levels. There was also a significant increase in high density lipoprotein cholesterol levels with concomitant decreases in total cholesterol, triglycerides, low density lipoprotein cholesterol and very low density lipoprotein. A significant improvement in glycosuria and proteinuria was also observed. Also, the subjects exhibited a significant improvement in enzymatic and nonenzymatic biochemical markers of oxidative stress. The kidney and liver functions remained normal and in fact improved in many subjects.

CONCLUSION: The study which is first of its kind, advocates “Diabegon kwath” as a safe and effective Ayurvedic therapy for the treatment of human type 2 diabetes mellitus and further placebo controlled trial may substantiate the therapeutic efficacy of the formulation.

Induction of apoptosis and sensitization of head and neck squamous carcinoma cells to cisplatin by targeting survivin gene expression

Survivin is known to be highly-expressed in various carcinomas; and is associated with their biologically aggressive characteristics and drug resistance. We have previously reported survivin as an important anti-apototic protein involved in head and neck squamous cell carcinoma (HNSCC) tumorigenesis and providing resistance to conventional cancer therapies. The purpose of present study was to investigate the potential of survivin as a therapeutic target in HNSCC. This study was designed to explore the effect(s) of survivin-siRNA therapy on the apoptosis in HNSCC cells, and its influence on cisplatin-sensitivity. Lentivirus vector was developed to deliver survivin specific siRNA into cancer cells. The data indicates that silencing of survivin-mediated by Lentivirus-siRNA therapy effectively suppressed cancer cell proliferation and induced caspase-dependent apoptosis in HNSCC cells. The study also shows that the response of HNSCC cells to cisplatin drug treatment at clinically relevant level was limited. We observed survivin to be a key factor involved in this cisplatin-resistance mechanism, and down-regulation of survivin significantly increased sensitivity of cancer cells to cisplatin-mediated apoptosis. Thus, this combination therapy acts as a multimodality regimen with significant potential to improve clinical outcomes in head and neck cancers.

Cardiac troponins I and T: molecular markers for early diagnosis, prognosis, and accurate triaging of patients with acute myocardial infarction

Acute myocardial infarction (AMI) is the leading cause of death worldwide, with early diagnosis still being difficult. Promising new cardiac biomarkers such as troponins and creatine kinase (CK) isoforms are being studied and integrated into clinical practice for early diagnosis of AMI. The cardiac-specific troponins I and T (cTnI and cTnT) have good sensitivity and specificity as indicators of myocardial necrosis and are superior to CK and its MB isoenzyme (CK-MB) in this regard. Besides being potential biologic markers, cardiac troponins also provide significant prognostic information. The introduction of novel high-sensitivity troponin assays has enabled more sensitive and timely diagnosis or exclusion of acute coronary syndromes. This review summarizes the available information on the potential of troponins and other cardiac markers in early diagnosis and prognosis of AMI, and provides perspectives on future diagnostic approaches to AMI.

An omics approach to understand the plant abiotic stress

Abiotic stress can lead to changes in development, productivity, and severe stress and may even threaten survival of plants. Several environmental stresses cause drastic changes in the growth, physiology, and metabolism of plants leading to the increased accumulation of secondary metabolites. As medicinal plants are important sources of drugs, steps are taken to understand the effect of stress on the physiology, biochemistry, genomic, proteomic, and metabolic levels. The molecular responses of plants to abiotic stress are often considered as a complex process. They are mainly based on the modulation of transcriptional activity of stress-related genes. Many genes have been induced under stress conditions. The products of stress-inducible genes protecting against these stresses includes the enzymes responsible for the synthesis of various osmoprotectants. Genetic engineering of tolerance to abiotic stresses help in molecular understanding of pathways induced in response to one or more of the abiotic stresses. Systems biology and virtual experiments allow visualizing and understanding how plants work to overcome abiotic stress. This review discusses the omic approach to understand the plant response to abiotic stress with special emphasis on medicinal plant.

Biology of Cox-2: an application in cancer therapeutics

Cyclooxygenase-2 (Cox-2) is an inducible enzyme involved in the conversion of arachidonic acid to prostaglandin and other eicosanoids. Molecular pathology studies have revealed that Cox-2 is over-expressed in cancer and stroma cells during tumor progression, and anti-cancer chemo-radiotherapies induce expression of Cox-2 in cancer cells. Elevated tumor Cox-2 is associated with increased angiogenesis, tumor invasion and promotion of tumor cell resistance to apoptosis. Several experimental and clinical studies have established potent anti-cancer activity of NSAID (Non-steroidal anti-inflammatory drugs) and other Cox-2 inhibitors such as celecoxib. Much attention is being focused on Cox-2 inhibitors as beneficial target for cancer chemotherapy. The mode of action of Cox-2 and its inhibitors remains unclear. Further clinical application needs to be investigated for comprehending Cox-2 biological functions and establishing it as an effective target in cancer therapy.

Lentinus edodes: a macrofungus with pharmacological activities

Lentinus edodes is the first medicinal macrofungus to enter the realm of modern biotechnology. It is the second most popular edible mushroom in the global market which is attributed not only to its nutritional value but also to possible potential for therapeutic applications. Lentinus edodes is used medicinally for diseases involving depressed immune function (including AIDS), cancer, environmental allergies, fungal infection, frequent flu and colds, bronchial inflammation, heart disease, hyperlipidemia (including high blood cholesterol), hypertension, infectious disease, diabetes, hepatitis and regulating urinary inconsistencies. It is the source of several well-studied preparations with proven pharmacological properties, especially the polysaccharide lentinan, eritadenine, shiitake mushroom mycelium, and culture media extracts (LEM, LAP and KS-2). Antibiotic, anti-carcinogenic and antiviral compounds have been isolated intracellularly (fruiting body and mycelia) and extracellularly (culture media). Some of these substances were lentinan, lectins and eritadenine. The aim of this review is to discuss the therapeutic applications of this macrofungus. The potential of this macrofungus is unquestionable in the most important areas of applied biotechnology.

Ganoderma lucidum: a potent pharmacological macrofungus

Ganoderma lucidum (Ling Zhi) is a basidiomycete white rot macrofungus which has been used extensively as "the mushroom of immortality" in China, Japan, Korea and other Asian countries for 2000 years. A great deal of work has been carried out on therapeutic potential of Ganoderma lucidum. The basidiocarp, mycelia and spores of Ganoderma lucidum contain approximately 400 different bioactive compounds, which mainly include triterpenoids, polysaccharides, nucleotides, sterols, steroids, fatty acids, proteins/peptides and trace elements which has been reported to have a number of pharmacological effects including immunomodulation, anti-atherosclerotic, anti-inflammatory, analgesic, chemo-preventive, antitumor, chemo and radio protective, sleep promoting, antibacterial, antiviral (including anti-HIV), hypolipidemic, anti-fibrotic, hepatoprotective, anti-diabetic, anti-androgenic, anti-angiogenic, anti-herpetic, antioxidative and radical-scavenging, anti-aging, hypoglycemic, estrogenic activity and anti-ulcer properties. Ganoderma lucidum has now become recognized as an alternative adjuvant in the treatment of leukemia, carcinoma, hepatitis and diabetes. The macrofungus is very rare in nature rather not sufficient for commercial exploitation for vital therapeutic emergencies, therefore, the cultivation on solid substrates, stationary liquid medium or by submerged cultivation has become an essential aspect to meet the driving force towards the increasing demands in the international market. Present review focuses on the pharmacological aspects, cultivation methods and bioactive metabolites playing a significant role in various therapeutic applications.

Momordica balsamina: a medicinal and neutraceutical plant for health care management

Momordica balsamina, African pumpkin (Cucurbitaceae), is a tendril-bearing, wild climber containing wide spectrum of medicinal and nutritional values and has been used as a traditional folk medicine in many countries. The leaves, fruits, seeds, and bark of the plant contains resins, alkaloids, flavonoids, glycosides, steroids, terpenes, cardiac glycoside, saponins having various medicinal importance viz. anti-HIV, anti-plasmodial, shigellocidal, anti-diarrheal, anti-septic, anti-bacterial, anti-viral, anti-inflammatory, anti-microbial, hypoglycemic, antioxidant, analgesic and hepatoprotective properties. The therapeutic agent 'Momordin' is capable of inhibiting the growth of HIV and other viruses. The leaves are also important source of nutrients having 17 amino acids with adequate mineral composition like potassium, magnesium, phosphorus, calcium, sodium, zinc, manganese and iron. It also helps to combat the problem of micronutrient deficiencies in soil and high value of protein and fat with low fibre content. High potassium content is a good source for the management of hypertension and other cardiovascular conditions. This plant is being promoted as a protein supplement for cereal-based diets in poor rural communities. The commercial exploitation of this plant for biopharmaceuticals and neutraceuticals are some of the prospective future potential of this wild herb. This review discusses the potential of medicinal and nutritional importance of this wild herb for health care management.

Indoor resting density pattern of mosquito species in Fingeswar block of Raipur district in Chhattisgarh, central India

Anopheline mosquitoes are vectors of human malaria and hence they are of greatest concern. Around 40% of the world's population resides in malaria affected areas. Malaria affects poor communities and causes enormous economic losses. The deadly disease annually causes clinical illness in 400-600 million people and kills 2-3 millions annually (WHO 2008). Faunistic survey was conducted in Fingeswar block in Raipur district of Chhattisgarh state of India during January 2003 to March 2004 to asses the prevalence of different species of mosquitoes and their seasonal variations.Indoor resting mosquitoes were collected from selected houses in 5 villages using aspirator tube and torch light in the morning between 06:00-08:00. Adult mosquitoes were identified using standard morphological and pictorial keys following Rao (1984), Das et al. (1991) and Reuben et al. (1994) and assessed as person hour density.A total of 13,248 mosquitoes were collected during the study period. Nine species of mosquitoes comprising of 4 genera with 5 Anopheles, two Culex and one each Armigeres and Aedes were recorded. The malaria vectors constituted 14.09% of the total mosquito collections. Anopheles subpictus (25.81%) showed the dominance followed by A. annularis (8.68%), A. barbirostris (6.76%), A. culicifacies (5.41%) and A. pallidus (4.11%). The other genus recorded included Culex quinquefasciatus (38.38%), C. vishnui (3.32%), Armigeres subalbatus (6.92%) and Aedes albopictus (0.29%). The density of all the species were high in months of August, September and October, decreased in month of May and June 2003. There was a significant (p < 0.01) positive correlation between temperature and density of A. culicifacies and A. annularis. The seasonal distribution pattern of A. culicifacies (primary) and A. annularis (secondary) malaria vectors along with other mosquito species was studied which is an important component of epidemiological study of malaria. This information will help in formulating a baseline structure for control program in the study region.

Impact of season on filarial vector density and infection in Raipur City of Chhattisgarh, India

BACKGROUND & OBJECTIVES

Bionomics and transmission dynamics of vector population are profoundly influenced by local climatic conditions. The study monitored variations in density, infection and infectivity rates of Culex quinquefasciatus with respect to season in randomly selected localities of Raipur City of Chhattisgarh state.

METHODS

The indoor resting density of Cx. quinquefasciatus, Wuchereria bancrofti infection and infectivity rates were monitored in Raipur City at regular monthly intervals for over a period of 12 months and the impact of meteorological conditions on transmission indices were assessed. The frequency distribution of different stages of filarial larvae in naturally infected vector population, host efficiency and transmission intensity index of the vector population was also worked out.

RESULTS

The mean vector density of Cx. quinquefasciatus during the study period was 55.22 while the mean vector infection and infectivity rates recorded in Raipur were 4.05 and 0.25% respectively. A gradual increase in Culex infection rate was recorded from June onwards with a maximum (22.14%) in August and minimum (2.38%) in February. No vector with filarial infection was detected during December when the vector density was high. Analysis of frequency distribution of different stages of larvae revealed dominance of microfilarial stage with a mean larval intensity of 5.37. The highest infectivity rate was observed during June (1.15%) and the lowest was in March (0.41%). Both the infection and infectivity rates were at their low during winter season although the density of Cx. quinquefasciatus was at its maximum. Highest mean host efficiency of 0.44 was recorded in February. The annual transmission intensity index (TII) was 32.72. The highest TII was recorded during January and February months.

INTERPRETATION & CONCLUSION

The climate appeared to have profound impact on vector density, infection and infectivity rates. The vector infection and infectivity rates were high in rainy season followed by summer and winter seasons. The highest host efficiency was observed in winter followed by summer and rainy seasons. An apparent negative correlation was observed between vector infection rate and vector density. Lower temperatures (23-25 degree) with low rainfall favoured progression of mf to L3 in Cx. quinquefasciatus in the study region.

Filarial infection is resisted differentially by subjects having different blood group phenotypes

This study was aimed to elucidate the relationship between major blood group antigens (BGAs) and susceptibility or resistance to human lymphatic filariasis. A total of 492 human subjects, living in Raipur city of Chhattisgarh, endemic for bancroftian filariasis in Central India, were screened for the presence of Wuchereria bancrofti microfilariae and disease manifestations. The frequency of BGAs was tabulated as a function of the status of filariasis, namely normal (no infection), mf carrier (presence of microfilariae in blood), and elephantiasis (confirmed clinical manifestations). The comparison of ABO phenotype distributions among all the three groups clearly indicated that disease status has a significant relationship with the blood group attributes. The result of chi2 analysis of the frequencies of ABO phenotypes observed in microfilaraemic and elephantiasis groups (observed frequency vs. expected frequency computed based on the distribution of the normal population) revealed that there has been a significant alteration in the distribution of ABO phenotypes in microfilaraemic, but not in elephantiasis, group. The susceptibility to filarial infection was computed as a function of blood group phenotypes in the population. The susceptibility and conditional susceptibility for elephantiasis were the least among the subjects with AB phenotypes. The mechanism of association between filariasis and ABO antigens needs to be further explored to understand how the distribution of BGAs affects susceptibility/resistance to infection.

Spirulina in health care management

Spirulina is a photosynthetic, filamentous, spiral-shaped and multicellular edible microbe. It is the nature's richest and most complete source of nutrition. Spirulina has a unique blend of nutrients that no single source can offer. The alga contains a wide spectrum of prophylactic and therapeutic nutrients that include B-complex vitamins, minerals, proteins, gamma-linolenic acid and the super anti-oxidants such as beta-carotene, vitamin E, trace elements and a number of unexplored bioactive compounds. Because of its apparent ability to stimulate whole human physiology, Spirulina exhibits therapeutic functions such as antioxidant, anti-bacterial, antiviral, anticancer, anti-inflammatory, anti-allergic and anti-diabetic and plethora of beneficial functions. Spirulina consumption appears to promote the growth of intestinal micro flora as well. The review discusses the potential of Spirulina in health care management.

Natural bioactive compounds and biotechnological potential of marine bacteria

Adaptation of marine bacteria to the harsh environments has led to a rich biological and genetic diversity. Marine bacteria are attracting attention as new biotechnological resources. These bacteria can be a potential source of new bioactive compounds for industrial, agricultural, environmental, pharmaceutical and medical uses. The present paper reveals the potential of the marine bacteria with biotechnological applications related to antimicrobial drug discovery, environmental remediation, and developing new resources for industrial processes.

Rapid liposomal agglutination card test for the detection of antigens in patients with active tuberculosis

SETTING

A total of 1360 subjects with clinically confirmed pulmonary and extra-pulmonary tuberculosis (TB) and other non-tuberculous conditions.

OBJECTIVES

To develop a rapid, sensitive and specific diagnostic test for the detection of the glycolipid antigen of Mycobacterium tuberculosis in a variety of clinical samples.

STUDY DESIGN

Affinity-purified rabbit anti-glycolipid antibodies (IgG) were coupled to liposome particles (0.2-0.4 microm) in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinamide to prepare the working reagent of the TB/M card test.

RESULTS

Antibody-conjugated liposomes, when determined with the glycolipid antigens present in the specimens, formed a dark blue agglutination within 4 min. No clumping was observed in samples from normal healthy subjects or patients with other diseases. The test was shown to be effective in detecting glycolipid antigens of M. tuberculosis in clinical samples from patients with active TB with as low as 1 ng/ml analytical sensitivity, 97.4% clinical sensitivity and 96.9% specificity.

CONCLUSION

The TB/M card test was found to be comparatively economical (4 Indian Rupees or US$ 0.09/test), rapid (4 min) and seems fairly useful for mass testing of a variety of biological specimens (cerebrospinal, pleural and synovial fluids, serum, tissue biopsy extract) from patients with tuberculous meningitis, pulmonary TB and other extra-pulmonary TB in endemic countries.

Subjects with Impaired Glucose Tolerance Exhibit a High Degree of Tolerance to Honey

The present study compared the relative tolerance to honey and glucose of subjects with impaired glucose tolerance or mild diabetes. Thirty individuals 35-60 years old with a proven parental (mother or father) history of type II diabetes mellitus were subjected simultaneously to an oral glucose tolerance test (GTT) and a honey tolerance test (HTT). Glucose tolerance was found to be impaired in 24 subjects, while six of the subjects were diagnosed as mildly diabetic. All subjects with impaired glucose tolerance exhibited significantly lower plasma glucose concentrations after consumption of honey at all time points of the HTT in comparison to the GTT. The plasma glucose levels in response to honey peaked at 30-60 minutes and showed a rapid decline as compared to that to glucose. Significantly, the high degree of tolerance to honey was recorded in subjects with diabetes as well, indicating a lower glycemic index of honey. Thus, it is evident from the present investigation that honey may prove to be a valuable sugar substitute for subjects with impaired glucose tolerance or mild diabetes.

A synthetic gag p24 epitope chemically coupled to BSA through a decaalanine peptide enhances HIV type 1 serodiagnostic ability by several folds

p24 is an immunodominant gag core protein of HIV-1. The synthetic immunodominant epitope of p24 and the recombinant p24 show poor immunoreactivity and specificity, respectively. Their application is, therefore, severely limited in the serodiagnosis of HIV-1, although it is an important marker for early diagnosis. These limitations have been overcome by conjugating the synthetic p24 to BSA through a decaalanine peptide spacer. The engineered p24 shows about 5-fold more efficient immunoreactivity than the synthetic p24, and, at the same time, shows a several fold reduction in nonspecific cross-reactivity as compared to recombinant p24. Our strategy to conjugate the p24 peptide epitope to BSA worked well as a consistent and reliable immunodiagnostic marker. This strategy may also prove useful for the diagnosis of other diseases.

Does sphingosine 1-phosphate play a protective role in the course of pulmonary tuberculosis?

Sphingosine 1-phosphate (S1P) has recently been reported to induce antimycobacterial activity in vitro and in a mouse model of in vivo Mycobacterium tuberculosis infection. However, its role in the course of pulmonary tuberculosis in humans is still not known. This study shows that S1P levels in airway surface fluid of tuberculosis (TB) patients are significantly less than those observed in non-TB control patients. Moreover, the in vitro stimulation of bronchoalveolar lavage cells coming from TB patients with S1P significantly reduces intracellular growth of endogenous mycobacterial isolates. These results show that, in the course of pulmonary TB, airway epithelial fluid-associated S1P may play a protective role in the containment of intracellular mycobacterial growth and that its decrease may represent a novel pathogenic mechanism through which M. tuberculosis favors its replication.

Modern approaches to a rapid diagnosis of tuberculosis: promises and challenges ahead

The limitations of the conventional methods for diagnosing tuberculosis have spurred multi-faceted research activities in this field throughout the world. Chromatographic methods appear promising but may not be widely available in the developing countries. Immuno-diagnostic methods using combinations ("cocktails") of antigens have high sensitivity and specificity and can easily be applied in the peripheral laboratories and in the field settings. Though expensive, molecular methods for diagnosis of tuberculosis have advantages of speed, sensitivity, and specificity. Adequate training of the eligible personnels in molecular methods and prevention of laboratory-dependent contamination may help reduce false positive results. Although, there are no clear guidelines, so far on how to make out the best from the gene amplification methods, yet their use may be encouraged with adequate quality controls, because of the inherent ingenuity and promises of these methods. Phage-based molecular methods provide rapid results in susceptibility tests for anti-tubercular drugs. In future, many sophisticated techniques are expected to hit the market for a rapid diagnosis of tuberculosis. In the developing countries, it is necessary to evaluate availability of suitable infrastructure and trained personnels before adopting modern diagnostic methods.

Allele Frequency Profile of Three STR Loci in Nine North Indian Populations

POPULATION

Bhargavas (n=120), Chaturvedis (n=120), Brahmins (n=120), Muslim Sunni (n=120), Muslim Shiya (n=120), Kayastha (n=120), Mathurs (n=120), Rastogies (n=120), and Vaish (n=120).

Structural, functional and therapeutic biology of survivin

Survivin is a unique member of the inhibitor of apoptosis (IAP) protein family that interferes with post-mitochondrial events including activation of caspases. Survivin regulates cell cycle also. It is expressed in most of the human tumors, but it is barely detectable in the terminally differentiated normal cells/tissues. Molecular mechanisms of regulation of survivin in cancer are not clearly understood. Nevertheless, the functional loss of wild type p53 is often associated with upregulation of survivin. Tumors that over-express survivin generally bear a poor prognosis and are associated with resistance to therapy. The differential expression of survivin in cancer versus normal tissues makes it a useful tool in cancer diagnosis and a promising therapeutic target. A growing body of literature suggests nuclear expression of survivin as a good prognostic marker. Disruption of the survivin induction pathway has resulted in an increase in apoptosis and inhibition of tumor growth. Regular therapies, such as, radiotherapy in combination with anticancer drugs in clinical practice may yield promising results.

Micropropagation: a tool for the production of high quality plant-based medicines

Medicinal plants are the most important source of life saving drugs for the majority of the world's population. The biotechnological tools are important to select, multiply and conserve the critical genotypes of medicinal plants. Plant tissue culture techniques offer an integrated approach for the production of standardized quality phytopharmaceutical through mass-production of consistent plant material for physiological characterization and analysis of active ingredients. Micropropagation protocols for cloning of some medicinal plants such as Catharanthus roseus (Apocynaceae), Chlorophytum borivilianum (Liliaceae), Datura metel (Solanaceae), and Bacopa monnieri (Scrophulariaceae) have been developed. Regeneration occurred via organogenesis and embryogenesis in response to auxins and cytokinins. The integrated approaches of our culture systems will provide the basis for the future development of novel, safe, effective, and high-quality products for consumers.

Adjuvanticity of stealth liposomes on the immunogenicity of synthetic gp41 epitope of HIV-1

Present study aims to enhance the efficacy of liposomes as an adjuvant by steric protection and strengthen the path of vaccine research. PEG grafted liposomes carrying epitopes on their surface showed enhanced adjuvanticity than liposomes carrying epitopes for elicitation and prolongation of immune response to an antigenic epitope of gp41, a transmembrane protein of HIV-1. The multiples of epitope were incorporated onto the surface of liposomes by conjugating them with phosphatidylethanolamine that was used in the formulation of liposomes at an optimized ratio. Furthermore, the liposomes carrying epitopes on their surface were sterically protected by shielding with methoxy-poly(ethylene glycol), mass 20 kDa. Methoxy-poly(ethylene glycol) was activated to its electrophilic N-succinimide carbonate derivative, methoxy-poly(ethylene glycol)-N-succinimide carbonate, that formed a urethane linkage with the amino group of phosphatidylethanolamine. The epitope was covalently coupled to phosphatidylethanolamine through an amide bond between the -COOH group of the epitope and -NH2 group of phosphatidylethanolamine under the catalysis of 1-ethyl-3-(3-dimethylaminopropy-1)-carbodiimide. PEG grafted epitopes carrying liposomes showed about two times higher immune response and prolonged persistence of antibodies than that of liposomes carrying epitopes without PEG moieties.

Nutritional and therapeutic potential of Spirulina

Spirulina, a filamentous cyanobacterium, possesses diverse biological activities and nutritional significance due to high concentration of natural nutrients, having bio-modulatory and immuno-modulatory functions. Different Spirulina preparations influence immune system viz. increase phagocytic activity of macrophages, stimulating the production of antibodies and cytokines, increase accumulation of NK cells into tissue and activation and mobilization of T and B cells. Spirulina have also shown to perform regulatory role on lipid and carbohydrate metabolism by exhibiting glucose and lipid profile correcting activity in experimental animals and in diabetic patients. Preparations have been found to be active against several enveloped viruses including herpes virus, cytomegalovirus, influenza virus and HIV. They are capable to inhibit carcinogenesis due to anti-oxidant properties that protect tissues and also reduce toxicity of liver, kidney and testes.

Glycolipids of Mycobacterium tuberculosis strain H37Rv are potential serological markers for diagnosis of active tuberculosis

A simple and cost-effective diagnostic tool (TB Screen Test) for the screening of patients with pulmonary and extrapulmonary tuberculosis and for differentiation of those individuals from individuals without tuberculosis, other common infections, and healthy controls has been developed. The serological responses of purified mycobacterial glycolipid antigens were examined by a liposome agglutination assay. The assay was able to detect very low antiglycolipid antibody concentrations in the infected individuals. The sera from the tuberculosis patient group had significantly higher concentrations of antiglycolipid antibody than the sera from uninfected control subjects, with 94% sensitivity and 98.3% specificity. Glycolipids of Mycobacterium tuberculosis H37Rv antigens were isolated, purified, and characterized. After interchelation with liposome particles, these purified antigens specifically bound to the antiglycolipid antibodies present in the sera of patients with tuberculosis, resulting in the formation of a blue agglutination. This protocol clearly differentiates healthy controls and M. bovis BCG-vaccinated subjects from those with active tuberculosis. The resultant diagnostic tool, the TB Screen Test, is more economical and rapid (4 min) than other currently available products and can be used for the mass screening of a heavily afflicted population.

Analysis of the shotgun expression library of the Mycobacterium tuberculosis genome for immunodominant polypeptides: potential use in serodiagnosis

A recombinant DNA strategy was applied to analyze and screen the shotgun expression library from a clinically confirmed local virulent isolate of Mycobacterium tuberculosis with sera from tuberculosis patients, which led to expression and purification of highly immunoreactive and specific mycobacterial antigens expressed during the course of active disease which could be of diagnostic significance. An enzyme-linked immunoassay for diagnosis of tuberculosis was devised by using a shotgun immunoexpression library in the lambdagt11 vector. DNA from a virulent M. tuberculosis patient isolate (TBW-33) confirmed with the BACTEC 460 system was sheared and expressed to generate shotgun polypeptides. beta-Galactosidase fusion proteins capable of demarcating active tuberculosis infections from Mycobacterium bovis BCG-vaccinated healthy subjects or people harboring environmental mycobacteria were selected by comparative immunoreactivity studies. Promising mycobacterial DNA cassettes were subcloned and expressed into the glutathione S-transferase (GST) fusion vector pGEX-5X-1 with a strong tac promoter and were expressed in Escherichia coli BL21. These fusion proteins were severed at a built-in factor Xa recognition site to separate the GST tags and were utilized in an indirect enzyme-linked immunoassay for serodiagnosis of patients with active tuberculosis. The system offered a clear demarcation between BCG-vaccinated healthy subjects and patients with active tuberculosis and proved to be effective in detecting pulmonary as well as extrapulmonary tuberculosis, with an overall sensitivity of 84.33% and an overall specificity of 93.62%.

Diagnosis of tuberculosis: available technologies, limitations, and possibilities

Rapid diagnosis and treatment are important for preventing transmission of Mycobacterium tuberculosis. However, the diagnosis of tuberculosis continues to pose serious problems, mainly because of difficulties in differentiating between patients with active tuberculosis and those with healed lesions, normal mycobacterium boris BCG (Bacillus Calmette Guerin) vaccinated individuals, and unvaccinated Manteux positives. Physicians still rely on conventional methods such as Ziehl-Neelsen (ZN) staining, fluorochrome staining, sputum culture, gastric lavage, and other non-traditional methods. Although the tuberculin test has aided in the diagnosis of tuberculosis for more than 85 years, its interpretation is difficult because sensitization with nontuberculous mycobacteria leads to false-positive tests. There have been numerous unsuccessful attempts to develop clinically useful serodiagnostic kits for tuberculosis. A number of proteinaceous and nonprotein antigens (such as acyltrehaloses and phenolglycolipids) have been explored from time to time for the development of such assays but they have not proved to be clinically useful. It has been difficult to develop an ELISA utilizing a suitable antigen because M. tuberculosis shares a large number of antigenic proteins with other microorganisms that may or may not be pathogenic. With the advent of molecular biology techniques, there have been significant advances in nucleic acid-based amplification and hybridization, which are helping to rectify existing flaws in the diagnosis of tuberculosis. The detection of mycobacterial DNA in clinical samples by polymerase chain reaction (PCR) is a promising approach for the rapid diagnosis of tuberculous infection. However, the PCR results must be corrected for the presence of inhibitors as well as for DNA contamination. In the modern era of genetics, marked by proteomics and genomics, the day is not far off when DNA chip-based hybridization assays will instantly reveal mycobacterial infections.

Mutational Engineering of the cyanobacterium Nostoc muscorum for resistance to growth-inhibitory action of LiCl and NaCl

The effect of NaCl on two vital processes of cyanobacterial metabolism, viz. N(2) fixation and oxygenic photosynthesis, was studied in the cyanobacterium Nostoc muscorum grown diazotrophically. An increase in NaCl concentration suppressed the formation of heterocyst and adversely affected the nitrogenase activity in the parent, whereas in Li(+)-R and Na(+)-R mutants NaCl stress did not cause any adverse effect. The rate of photosynthetic O(2)-evolution was also adversely affected by the NaCl stress, but the magnitude was less than that of nitrogenase activity. L-Proline, the well-known osmoprotectant, provided protection to the cyanobacterium against NaCl stress. The parent strain utilized L-proline as a nitrogen source and suppressed heterocyst formation and nitrogenase activity, while mutants showed normal heterocyst frequency and nitrogenase activity. Therefore, it may be that the proline metabolism is altered as a result of mutation. The intracellular levels of proline in the parent were enhanced about threefold in the medium containing 1 mol x m(-3) proline, while in mutants there was no significant increase in the intracellular level of proline. In the medium containing both NaCl and proline, the intracellular level of proline was enhanced in the parent as well as in both mutant strains. This suggests that the parent strain possessed both normal proline uptake and salt-induced proline uptake systems, whereas the mutant strains were defective in normal proline uptake and had only salt-induced proline uptake. The over-accumulation of proline in the presence of NaCl stress is due either to the loss of proline oxidase activity or to the accumulation of exogenous proline.

Regulation of potassium uptake in the sodium-resistant (NaCl(r)) and thalium-resistant (TlCl(r)) mutant strain of diazotrophic cyanobacterium Anabaena variabilis

A thalium chloride-resistant (TlCl(r)) mutant strain and a sodium chloride-resistant (NaCl(r)) mutant strain of the diazotrophic cyanobacterium Anabaena variabilis have been isolated by spontaneous and chemical mutagenesis by using TlCl, a potassium (K(+)) analog, and nitrosoguanidine (NTG), respectively. The TlCl(r) mutant strain was found to be defective in K(+) transport and showed resistance against 10 microM TlCl. However, it also showed sensitivity against NaCl (LD(50), 50 m M). In contrast, neither wild-type A. variabilis nor its NaCl(r) mutant strain could survive in the presence of 10 microM TlCl and died even at 1 microM TlCl. The TlCl(r) mutant strain exhibited almost negligible K(+) uptake, indicating the lack of a K(+) uptake system. High K(+) uptake was, however, observed in the NaCl(r) mutant strain, reflecting the presence of an active K(+) uptake system in this strain.DCMU, an inhibitor of PS II, inhibited the K(+) uptake in wild-type A. variabilis and its TlCl(r) and NaCl(r) mutant strains, suggesting that K(+) uptake in these strains is an energy-dependent process and that energy is derived from photophosphorylation. This contention is further supported by the inhibition of K(+) uptake under dark conditions. Furthermore, the inhibition of K(+) uptake by KCN, DNP, and NaN(3) also suggests the involvement of oxidative phosphorylation in the regulation of an active K(+) uptake system. The whole-cell protein profile of wild-type A. variabilis and its TlCl(r) and NaCl(r) mutant strains growing in the presence of 50 m M KCl was made in the presence and absence of NaCl. Lack of transporter proteins in TlCl(r) mutant strain suggests that these proteins are essentially required for the active transport and accumulation of K(+) and make this strain NaCl sensitive. In contrast, strong expression of the transporter proteins in NaCl(r) mutant strain and its weak expression in wild-type A. variabilis is responsible for their resistance and sensitivity to NaCl, respectively. Therefore, it appears that the increased salt tolerance of the NaCl(r) mutant strain was owing to increased K(+) uptake and accumulation, whereas the salt sensitivity of the TlCl(r) mutant strain was owing to the lack of K(+) uptake and accumulation.

Physiological alterations and regulation of heterocyst and nitrogenase formation in Het(-) Fix(-) mutant strain of Anabaena variabilis

Physiological alterations and regulation of heterocyst and nitrogenase formation have been studied in Het(-) Fix(-) mutant strain of diazotrophic cyanobacterium Anabaena variabilis. Het(-) Fix(-) mutant strain of A. variabilis has been isolated by N-methyl-N'-nitro-N"-nitrosoguanidine (NTG) mutagenesis and was screened with the penicillin enrichment (500 microg ml(-1)). Growth, heterocyst differentiation, nitrogenase and glutamine synthetase (biosynthetic and transferase), (14)CO(2)-fixation, nitrate reductase (NR), nitrite reductase (NiR), glucose-6-phosphate dehydrogenase (G6PDH), and isocitrate dehydrogenase (IDH) activities, and NO(3)(-), NO(2)(-), and NH(4)(+) uptake and whole cell protein profile in different metabolic conditions were studied in the Het(-) Fix(-) mutant strain taking wild-type A. variabilis as reference. Het(-) Fix(-) mutant strain was incapable of assimilating elemental nitrogen (N(2)) due to its inability to form heterocysts and nitrogenase and this was the reason for its inability to grow in BG-11(0) medium (free from combined nitrogen). In contrast, wild-type strain grew reasonably well in the absence of combined nitrogen sources and also showed heterocyst differentiation (8.5%) and nitrogenase activity (10.8 etamol C(2)H(4) formed microg(-1) Chl a h(-1)) in N(2)-medium. Wild-type strain also exhibited higher NR, NiR, and GS activities compared to its Het(-) Fix(-) mutant strain, which may presumably be due to acquisition of high uptake of NO(3)(-), NO(2)(-), and NH(2)(+). Wild-type strain in contrast to its Het(-) Fix(-) mutant strain also exhibited high level of G6PDH, IDH, and (14)CO(2) fixation activities. Low levels of G6PDH and IDH activities in Het(-) Fix(-) mutant strain further confirmed the lack of heterocyst differentiation and nitrogenase activity in the Het(-) Fix(-) mutant strain.NR, NiR, and GS activities in both the strains were energy-dependent and the energy required is mainly derived from photophosphorylation. Furthermore, it was found that de novo protein synthesis is necessarily required for the activities of NR, NiR, and GS in both wild-type and its Het(-) Fix(-) mutant strain.

Physiological and biochemical alterations in Anabaena 7120 under iron stress

Various physiological and biochemical process like growth, NO3- -uptake, nitrate reductase, glutamine synthetase and ATPases (Mg2+ and Ca2+ dependent) in the cyanobacterium Anabaena 7120 were observed under iron stress. Growth was found to be maximum in 50 microM Fe3+ added cells however, 20 microM Fe3+ (the Fe3+ concentration generally used for routine culturing of cyanobacterial cell in Chu 10 medium) incubation resulted in lower growth. Fe3+ starvation on the other hand showed very poor growth up to 4th day but once the growth started it reached at significant level on 7th day. Higher Fe3+ concentration reflected reduced growth with lethality at 500 microM Fe3+. Chlorophyll a fluorescence under Fe3+ stress reflected almost the similar results as in case of growth. However, the pigment was found to be more sensitive as compared to protein under Fe3+ stress. Similar results have been observed in case of NO3-uptake with only 80% reduction in nutrient uptake in 500 microM Fe3+ incubated cells. Nitrate reductase activity was lower in Fe3+ starved cells as compared to significant enzyme activity in 20 and 50 microM Fe3+ incubated cells. Similar to nitrate reductase, glutamine synthetase also showed maximum level in 50 microM Fe3+ added cells, however, higher Fe3+ concentration (300-500 microM ) resulted in reduced enzymatic activity. Glutamine synthetase activity was less sensitivity as compared to nitrate reductase activity under Fe3+ stress. ATPase (Mg2+ and Ca2+ dependent) always showed higher level with increasing Fe3+ concentration.