In Silico Characterization of B Cell and T Cell Epitopes for Subunit Vaccine Design of Salmonella typhi PgtE: A Molecular Dynamics Simulation Approach.

Typhoid fever is an acute illness in humans, caused by Salmonella typhi, a gram-negative bacterium. Outer membrane proteins of S. typhi have strong potential for its use in the development of subunit vaccine against typhoid. In the current study, peptide-based subunit vaccine was constructed from outer membrane protease E (PgtE) against S. typhi. B cell and T cell epitopes were identified at fold level with a validated three-dimensional modeled structure. T cell epitopes from PgtE (IHPDTSANY) have 99.5% binding to a maximum number of major histocompatibility complex class I and class II alleles. They also bind to the typhoid-resistant human leukocyte antigen (HLA) alleles DRB1*0401. PgtE epitopes were docked with HLA-DR4 (PDB ID: 1D5M) and a contact map was constructed. A simulation search for the binding site for full flexibility of the peptide from CABS- (Cα, Cß, side-chain)-dock shows stable interactions. Molecular dynamics simulation studies revealed that the PgtE-epitope complex structure was more stable throughout the simulation (20 ns) and interaction did not change the radius of gyration. In conclusion, computational analysis, molecular docking, and molecular dynamics (MD) simulation of PgtE-epitope complex were used to elucidate the binding mode, and the dynamical changes of epitopes were more suitable for vaccine development against typhoid.

B-cell and T-cell epitope identification with stability analysis of AI-2 import ATP-binding cassette LsrA from S. typhiIn silico approach.

Typhoid fever is a severe illness in humans, caused by Salmonella typhi, a Gram-negative bacterium. Membrane proteins of S. typhi have strong potential for its use in development of subunit vaccine against typhoid. In current study, peptide-based subunit vaccine constructed from AI-2 import ATP-binding cassette transporter protein (LsrA) against S. typhi. B-cell and T-cell epitopes were identified at fold level with validated 3-D theoretical modelled structure. T-cell epitope from LsrA (LELPGSRPQ) has binds to maximum number (82.93%) of MHC class I and class II alleles. LsrA epitope was docked with HLA-DR4 and contact map were constructed to analyze molecular interaction (docking) studies. Simulation search for the binding site for full flexibility of the peptide from CABS-dock shows the stable interactions. MD simulation analysis reveals that LsrA epitope was binding and interacting firmly with the HLA-DR4. Hence, we are proposing that LsrA epitope would be a prominent epitope vaccine for human specific pathogen of S. typhi, which requires further steps to be elevated as a vaccine drug in near future.

Beneficial effects of methanolic extract of Indigofera linnaei Ali. on the inflammatory and nociceptive responses in rodent models

ABSTRACT Indigofera linnaei Ali. (Tamil Name: Cheppu Nerinjil) belongs to the family Fabaceae, used for the treatment of various ailments in the traditional system of medicine. In the present study, the beneficial effects of methanol extract of whole plant of I. linnaei (MEIL) were evaluated on inflammation and nociception responses in rodent models. In vitro nitric oxide (NO), lipoxygenase (LOX) and cyclooxygense (COX) inhibitory activities were also performed to understand the mode of action. MEIL at the dose of 200 & 400 mg/kg, p.o. significantly inhibited carrageenan induced rat paw volume and reduced the weight of granuloma in cotton pellet granuloma model. The results obtained were comparable with the standard drug aceclofenac. The anti-nociceptive effect of MEIL in mice was evaluated in hot plate and acetic acid induced writhing model. The plant extract significantly reduced the number of writhes and the analgesic effect was higher than that of the standard drug aspirin. However, the extract fails to increase the latency period in hot plate method suggesting that the extract produce nociception by peripheral activity. The extract produced inhibitory effect on NO, LOX and COX in concentration dependent manner. The extract exhibited pronounced and selective COX-2 inhibition. Altogether, these results suggested that the methanol extract of Indigofera linnaei could be considered as a potential anti-inflammatory and analgesic agent.

RESUMO Indigofera linnaei Ali pertence à família Leguminosae e é utilizada para o tratamento de várias doenças na medicina tradicional. No presente estudo, os efeitos benéficos do extrato metanólico da planta inteira de I. linnaei (MEIL) foram avaliados em respostas inflamatórias e nocicepção em modelos de roedores. Testes in vitro de atividade inibitória do óxido nítrico (NO), lipoxigenase (LOX) e ciclooxigenase (COX) também foram realizados para compreender o modo de ação. MEIL nas doses de 200 e 400 mg/kg, p.o. inibiu significativamente o volume da pata de rato induzido por carragenana e reduziu o peso do granuloma no modelo de pélete de algodão. Os resultados obtidos foram comparáveis ao do fármaco padrão, aceclofenaco. O efeito anti-nociceptivo de MEIL foi avaliado em camundongos no modelo de placa quente e de contorção induzida por ácido acético. O extrato da planta reduziu significativamente o número de contorções e o efeito analgésico foi maior do que o do fármaco padrão, ácido acetilsalicílico. Porém, o extrato não conseguiu aumentar o período de latência no método da placa quente, sugerindo que este produz nocicepção por atividade periférica. O extrato produziu efeito inibitório sobre o NO, LOX e COX dependente da concentração. O extrato exibiu inibição acentuada e seletiva da COX-2. No seu conjunto, estes resultados sugerem que o extrato metanólico de Indigofera linnaei poderia ser considerado como agente anti-inflamatório e analgésico potencial.

Design and characterization of ofloxacin niosomes.

Niosomes are non ionic surfactant vesicles and potential surrogate for liposomes. The aim of the present investigation was to formulate and evaluate niosomes. The formulated ofloxacin niosomes were evaluated for their particle size, zeta potential, surface morphology, entrapment efficiency, in vitro drug release and in vivo pharmacokinetic studies. Niosomes of ofloxacin were prepared by thin film hydration technique using rotary flash evaporator. The formulated ofloxacin niosomes showed a vesicle size of 3.0-3.8 µm and zeta potential of -9 to -13 mV. The in vitro release studies showed 98.79% of ofloxacin release in sustained manner following first order kinetics. The stability study confirmed the stability of Ofloxacin niosomes. Pharmacokinetics studies of ofloxacin niosomes made with Span 60 showed increased Cmax AUC, AUMC, t1/2 and MRT values compared to marketed intravenous ofloxacin product. The designed ofloxacin niosomes with span 60 showed good physicochemical properties, good stability, improved pharmacokinetic parameters, prolonged action and improved bioavailability than the commercially available conventional dosage form which might be a potential carrier system to improve the patient compliance and reduce the side effects.

In vitro and in vivo anticancer activity of Indigofera cassioides Rottl. Ex. DC.

OBJECTIVE: To evaluate the antitumor, cytotoxic and antioxidant activities of methanolic leaf extract of Indigofera cassioides (MEIC) against transplantable tumors and human cancer cell lines. METHODS: MEIC was investigated for its short term cytotoxicity on EAC and DLA cells by trypan blue dye exclusion method and in vitro cytotoxicity on HeLa, HEp-2, HEpG-2, MCF-7, HT-29, Vero and NIH 3T3 cells by MTT assay. In vivo antitumor activity was studied on EAC and DLA tumor bearing mice. Activity was assessed by monitoring the mean survival time, effect on hematological parameters, antioxidant enzyme levels and solid tumor volume. RESULTS: MEIC exhibit potent in vitro cytotoxicity against all the tested cancer cell lines, but it was found to be safe on normal cells. The extract significantly (P < 0.001) increase the mean survival time and also have a protective effect on the hemopoietic system at the tested dose levels (200 and 400 mg/kg). The extract prevented lipid peroxidation and restored the antioxidant enzymes catalase, superoxide dismutase, glutathione peroxidase and glutathione-s-transferase in the liver of tumor control animals. It also significantly (P < 0.01) reduce the solid tumor volume. CONCLUSIONS: The results strongly support that MEIC shows potent antitumor and cytotoxic effects against EAC, DLA and human cancer cell lines. The extract prevents lipid peroxidation and promotes the enzymatic antioxidant defense system in tumor bearing animals which might be due to activities like scavenging of free radicals by the phytochemicals in MEIC.

Antitumor and cytotoxic activities of methanol extract of Indigofera linnaei Ali.

Methanol extract of Indigofera linnaei (MEIL) was investigated for antitumor, cytotoxic and antioxidant activities against transplantable tumors and human cancer cell lines. In vitro cytotoxicity was evaluated in HeLa, Hep-2, HepG-2, MCF-7, HT-29, Vero and NIH 3T3 cells by MTT assay and in vivo antitumor activity with Ehrlich ascites carcinoma (EAC) and Dalton's ascites lymphoma (DLA) tumor-bearing mice. Activity was measured by monitoring the mean survival time, effect on hematological parameters, antioxidant enzyme levels and solid tumor volume. The extract exhibited strong in vitro cytotoxicity against all the tested cancer cell lines, but it was found to be safe with normal cells. MEIL at the dose of 200 and 400 mg/kg, significantly increase the mean survival time (P<0.001), exerted a protective effect on the hemopoietic system, demonstrated in vivo antioxidant activity and significantly reduce solid tumor volume (P<0.01). These results show a significant antitumor and cytotoxic effect of MEIL against EAC, DLA and human cancer cell lines and support the ethnomedical use of Indigofera linnaei.

Antitumor Activity of Prosopis glandulosa Torr. on Ehrlich Ascites Carcinoma (EAC) Tumor Bearing Mice.

The antitumor activity of ethanol extract of Prosopis glandulosa Torr. (EPG) was evaluated against Ehrlich ascites carcinoma (EAC) tumor model in Swiss albino mice on dose dependent manner. The activity was assessed using survival time, average increase in body weight, hematological parameters and solid tumor volume. Oral administration of EPG at the dose of 100, 200 and 400 mg/Kg, significantly (p < 0.001) increased the survival time and decreased the average body weight of the tumor bearing mice. After 14 days of inoculation, EPG was able to reverse the changes in the hematological parameters, protein and PCV consequent to tumor inoculation. Oral administration of EPG was effective in reducing solid tumor mass development induced by EAC cells. The results indicate that EPG possess significant antitumor activity on dose dependent manner.