Debabrata Chanda

Experimental Assessment of Moringa oleifera Leaf and Fruit for Its Antistress, Antioxidant, and Scavenging Potential Using In Vitro and In Vivo Assays

We have investigated effect of Moringa oleifera leaf and fruit extracts on markers of oxidative stress, its toxicity evaluation, and correlation with antioxidant properties using in vitro and in vitro assays. The aqueous extract of leaf was able to increase the GSH and reduce MDA level in a concentration-dependent manner. The ethanolic extract of fruit showed highest phenolic content, strong reducing power and free radical scavenging capacity. The antioxidant capacity of ethanolic extract of both fruit and leaf was higher in the in vitro assay compared to aqueous extract which showed higher potential in vivo. Safety evaluation studies showed no toxicity of the extracts up to a dose of 100 mg/kg body weight. Our results support the potent antioxidant activity of aqueous and ethanolic extract of Moringa oleifera which adds one more positive attribute to its known pharmacological importance.

Natural antitubulin agents: Importance of 3,4,5-trimethoxyphenyl fragment

Microtubules are polar cytoskeletal filaments assembled from head-to-tail and comprised of lateral associations of α/β-tubulin heterodimers that play key role in various cellular processes. Because of their vital role in mitosis and various other cellular processes, microtubules have been attractive targets for several disease conditions and especially for cancer. Antitubulin is the most successful class of antimitotic agents in cancer chemotherapeutics. The target recognition of antimitotic agents as a ligand is not much explored so far. However, 3,4,5-trimethoxyphenyl fragment has been much highlighted and discussed in such type of interactions. In this review, some of the most important naturally occurring antimitotic agents and their interactions with microtubules are discussed with a special emphasis on the role of 3,4,5-trimethoxyphenyl unit. At last, some emerging naturally occurring antimitotic agents have also been tabulated.

Antitubercular potential of some semisynthetic analogues of phytol

Phytol, a diterpene alcohol was modified to several semisynthetic analogues. Some of the modifications were done logically to enhance lipophilicity of the molecule. Analogues 14, 16 and 18 exhibited antitubercular activity (MIC 15.6-50microg/mL) better than phytol (100microg/mL). The most potent analogue 18 was evaluated for in vivo toxicity in Swiss albino mice and was well tolerated by the experimental animals up to 300mg/kg body weight as a single oral acute dose.

Development of QSAR model for immunomodulatory activity of natural coumarinolignoids

Immunomodulation is the process of alteration in immune response due to foreign intrusion of molecules inside the body. Along with the available drugs, a large number of herbal drugs are promoted in traditional Indian treatments, for their immunomodulating activity. Natural coumarinolignoids isolated from the seeds of Cleome viscose have been recognized as having hepatoprotective action and have recently been tested preclinically for their immunomodulatory activity affecting both cell-mediated and humoral immune response. To explore the immunomodulatory compound from derivatives of coumarinolignoids, a quantitative structure activity relationship (QSAR) and molecular docking studies were performed. Theoretical results are in accord with the in vivo experimental data studied on Swiss albino mice. Immunostimulatory activity was predicted through QSAR model, developed by forward feed multiple linear regression method with leave-one-out approach. Relationship correlating measure of QSAR model was 99% (R2 = 0.99) and predictive accuracy was 96% (RCV2 = 0.96). QSAR studies indicate that dipole moment, steric energy, amide group count, lambda max (UV-visible), and molar refractivity correlates well with biological activity, while decrease in dipole moment, steric energy, and molar refractivity has negative correlation. Docking studies also showed strong binding affinity to immunomodulatory receptors.

Synthesis and anticancer activity of 2-benzylidene indanones through inhibiting tubulin polymerization.

In an attempt to discover a potent and selective anticancer agent, gallic acid has been modified to benzylidene indanones as tubulin polymerization inhibitors. These compounds were evaluated against several human cancer cell lines and also evaluated for inhibition of tubulin polymerase in in vitro assays. Three of the analogues exhibited strong cytotoxicity against human cancer cell lines IC(50)=10-880 nM and also showed tubulin polymerization inhibition (IC(50)=0.62-2.04 μM). Compound 9j, the best candidate of the series was found to be non-toxic in acute oral toxicity in Swiss-albino mice up to 1000 mg/kg dose.

Anticancer activity, toxicity and pharmacokinetic profile of an indanone derivative

The present study describes anticancer effect of gallic acid based indanone derivative (1). Indanone 1 exhibited in vivo anticancer activity against Erhlich ascites carcinoma in Swiss albino mice by inhibiting tumor growth by 54.3% at 50 mg/kg b.wt. It showed antitubulin effect by inhibiting tubulin polymerase enzyme. In cell cycle analysis, it inhibited G2/M phase and induced apoptosis. It significantly suppressed VEGF-R1, VEGF-R2 and HIF-α in human breast cancer MCF-7 cells, thus exhibiting antiangiogenic activity. In acute oral toxicity, indanone 1 was well tolerated and was found to be non-toxic up to 1000 mg/kg b.wt. in Swiss albino mice. Pharmacokinetic studies in rabbits revealed rate of absorption, half life, volume of distribution with high plasma and blood clearance after i.v. administration. Indanone 1, is a safe and moderately active anticancer agent.

Syntheses of lipophilic chalcones and their conformationally restricted analogues as antitubercular agents.

Lipophilic chalcones and their conformationally restricted analogues were synthesized and evaluated for their antitubercular efficacy against Mycobacterium tuberculosis H37Rv strain. Compounds 16, 24, 25a and 25c were found to be active MIC at 60, 30, 3.5 and 7.5 μg-mL(-1). In vitro cytotoxicity of compounds 16, 24, 25a, 25c and 26 in non-cancerous human epithelial kidney cell line (HEK-293) showed that most active compound 25a was approximately 2.85 times selective towards tubercular versus healthy cells whereas compound 24 was found to be 16 times selective.

In silico exploration of anti-inflammatory activity of natural coumarinolignoids.

Natural coumarinolignoids isolated from the seeds of Cleome viscosa consist of a racemic mixture of cleomiscosins A, B and C. To screen out potential lead, anti‐inflammatory activity of the isolated compounds was evaluated through molecular docking and QSAR studies by using reported in vivo activity of Swiss albino mice. Based on docking binding affinity, a possible mechanism of action has been hypothesized which constitute toll‐like receptors (TLR‐4), cluster of differentiation molecules (CDs), iNOS, COX‐2 and STAT‐6 proteins. It was very interesting to find that the 3D topology of the active site of COX‐2 from the docking was in good agreement with QSAR model and in silico ADME/T parameters. A forward feed multiple linear regression model was developed with r2 = 0.92 and rCV2 = 0.87. This study showed that chemical descriptors, for example dipole vector‐X, dipole vector‐Y, steric energy, LUMO energy, size of smallest ring, size of largest ring and carboxyl group count, correlate reasonably well with experimental in vivo activity (logLD50). QSAR study indicates that dipole vector‐Y and carboxyl group count have negative correlation with activity. Cleomiscosins also showed compliance with 95% of in silico ADME/T properties of available drugs, e.g. serum protein binding, blood–brain barrier, CNS activity, HERG K+ channel activity, apparent Caco‐2 permeability, apparent MDCK permeability, skin permeability and human oral absorption in GI. Besides, toxicity screening study suggests that cleomiscosin molecules possess no toxicity risk parameters. This study offer useful references for understanding and molecular design of inhibitors with improved anti‐inflammatory activity.

Gallic acid based steroidal phenstatin analogues for selective targeting of breast cancer cells through inhibiting tubulin polymerization.

Phenstatin analogues were synthesized on steroidal framework, for selective targeting of breast cancer cells. These analogues were evaluated for anticancer efficacy against breast cancer cell lines. Analogues 12 and 19 exhibited significant anticancer activity against MCF-7, hormone dependent breast cancer cell line. While analogues 10-14 exhibited significant anticancer activity against MDA-MB-231, hormone independent breast cancer cell line. Compound 10 showed significant oestrogen antagonistic activities with low agonistic activity in in vivo rat model. These analogues also retain tubulin polymerization inhibition activity. The most active analogue 10 was found to be non-toxic in Swiss albino mice up to 300 mg/kg dose. Gallic acid based phenstatin analogues may further be optimized as selective anti-breast cancer agents.

FT-NIR spectroscopy for rapid and simple determination of nimesulide in rabbit plasma for pharmacokinetic analysis

High-throughput analysis of a large number of samples for pharmacokinetic study is necessary in drug development and pharmacovigilance. Usually, drug quantification for pharmacokinetics and bio-availability is achieved through matrix extraction and HPLC analysis, which is time, labour and cost intensive method. A prompt and solvent free method is the quest for such analysis in the present times. Pharmacokinetic analysis of nimesulide from plasma samples of rabbits through Fourier transform near infrared (FT-NIR) spectroscopy analysis combined with partial least squares (PLS) regression model was undertaken with validation through HPLC analysis. Pharmacokinetic parameters obtained through FT-NIR and HPLC were found to be statistically similar with errors below the acceptable limits. The study demonstrates the use of FT-NIR for pharmacokinetics and bio-availability studies. This high throughput method analyses more than 50 samples in an hour without solvents usage and provide ample scope for automation and commercial utilization.