N. Gopalan Kutty

Synthesis and antitumor activity of optically active thiourea and their 2-aminobenzothiazole derivatives: a novel class of anticancer agents.

A novel series of optically active 2-aminobenzothiazole derivatives were synthesized by reaction of optically active amine (I) with thiophosgene to obtain optically active isothiocyanates (IIa-h) which on condensation with 4-fluoro-3-chloro aniline (III) yielded various optically active thioureas (IVa-h). Further oxidative cyclisation in the presence of bromine and chloroform yielded title compounds (Va-h). The structures of these compounds were established by IR, (1)H NMR, (13)C NMR, Mass and HRMS. The compounds (IVa-h and Va-h) were evaluated for in vitro cytotoxicity against mouse Ehrlich Ascites Carcinoma (EAC) and two human cancer cell lines (MCF-7 and HeLa). In preliminary MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] cytotoxicity studies the optically active thiourea derivatives (IVe, IVf and IVh) were found most effective. In EAC cells the IC(50) values for IVe, IVf, IVh and Vg were found in the range of 10-24 microM, whereas in MCF-7 and HeLa cells the IC(50) values were observed in the range of 15-30 microM and 33-48 microM, respectively. In alkaline comet assay the compounds (IVe and IVf) showed dose-dependent DNA damaging activity.

Silymarin liposomes improves oral bioavailability of silybin besides targeting hepatocytes, and immune cells

BACKGROUND Silymarin, a hepatoprotective agent, has poor oral bioavailability. However, the current dosage form of the drug does not target the liver and inflammatory cells selectively. The aim of the present study was to develop lecithin-based carrier system of silymarin by incorporating phytosomal-liposomal approach to increase its oral bioavailability and to make it target-specific to the liver for enhanced hepatoprotection. METHODS The formulation was prepared by film hydration method. Release of drug was assessed at pH 1.2 and 7.4. Formulation was assessed for in vitro hepatoprotection on Chang liver cells, lipopolysaccharide-induced reactive oxygen species (ROS) production by RAW 267.4 (murine macrophages), in vivo efficacy against paracetamol-induced hepatotoxicity and pharmacokinetic study by oral route in Wistar rat. RESULTS The formulation showed maximum entrapment (55%) for a lecithin-cholesterol ratio of 6:1. Comparative release profile of formulation was better than silymarin at pH 1.2 and pH 7.4. In vitro studies showed a better hepatoprotection efficacy for formulation (one and half times) and better prevention of ROS production (ten times) compared to silymarin. In in vivo model, paracetamol showed significant hepatotoxicity in Wistar rats assessed through LFT, antioxidant markers and inflammatory markers. The formulation was found more efficacious than silymarin suspension in protecting the liver against paracetamol toxicity and the associated inflammatory conditions. The liposomal formulation yielded a three and half fold higher bioavailability of silymarin as compared with silymarin suspension. CONCLUSIONS Incorporating the phytosomal form of silymarin in liposomal carrier system increased the oral bioavailability and showed better hepatoprotection and better anti-inflammatory effects compared with silymarin suspension.

Normal and delayed wound healing is improved by sesamol, an active constituent of Sesamum indicum (L.) in albino rats

UNLABELLED ETHNO-PHARMACOLOGICAL RELEVANCE: The seeds of Sesamum indicum Linn. (Pedaliaceae) has been used traditionally for the treatment of wounds in Buldhana district of Maharashtra state. Sesamol is the main anti-oxidative constituent contained mainly in the processed sesame seed oil which has not been explored scientifically for its wound healing activity. AIM OF THE STUDY To investigate the influence of sesamol (SM) on wound repair, both in normal and dexamethasone (DM) delayed healing processes in albino rats. MATERIALS AND METHODS Incision, excision and dead space wounds were inflicted on albino rats (180-220 g) of either sex, under ketamine anaesthesia. Group I served as control, group II received SM 50 mg/kg i.p., group III was treated with dexamethasone (DM) i.m. (0.17 mg/kg) and SM+DM was given to group IV. The tensile strength, wound contraction, hydroxyproline, lysyl oxidase and total RNA and DNA levels (in granulation tissue) were measured. RESULTS The tensile strength significantly (p<0.05) increased with SM at 471.40±14.66 g when compared to control at 300.60±9.16 g in normal and DM suppressed healing. No significant change was observed in duration of wound contraction and lysyl oxidase when compared to control at 2.98±0.10 mg. SM treated rats showed a significant (p<0.05) rise in hydroxyproline levels at 6.45±0.45 mg when compared to control at 1.75±0.20 mg. CONCLUSION These results indicate that sesamol could be a promising drug in normal as well as delayed wound healing processes.

Petroleum ether extract of Cissus quadrangularis (LINN) stimulates the growth of fetal bone during intra uterine developmental period: a morphometric analysis

OBJECTIVE The aim of the present study was to analyze the effect Cissus quadrangularis plant petroleum ether extract on the development of long bones during the intra-uterine developmental stage in rats. METHODS Pregnant rats (n=12) were randomly assigned into either a control group (n=6) or a Cissus quadrangularis treatment (n=6) group. Pregnant rats in the Cissus quadrangularis group were treated with Cissus quadrangularis petroleum ether extract at a dose of 500 mg/kg body weight from gestation day 9 until delivery. The animals in the control group received an equal volume of saline. Newborn pups were collected from both groups for alizarin red S - alcian blue staining to differentiate ossified and unossified cartilage. The ossified cartilage (bone) was morphometrically analyzed using Scion image software. RESULTS Morphometric analysis revealed that the percentage of the total length of ossified cartilage (bone) in pups born to treated dams was significantly higher (P<0.001– 0.0001) than that of the control group. CONCLUSION The results of the present study suggest that maternal administration of Cissus quadrangularis petroleum ether extract during pregnancy can stimulate the development of fetal bone growth during the intra-uterine developmental period.

Antioxidant, anti-inflammatory and anti-hyperglycaemic activities of heterocyclic homoprostanoid derivatives

A series of 19 heterocyclic homoprostanoids were synthesized from easily available oleic and ricinoleic acids and evaluated for their possible antioxidant, anti-inflammatory and anti-hyperlipidaemic activities. Compounds with thioxo- and oxoimidazole ring (1) and (2) have shown potent antioxidant activity with IC(50) values 0.23±0.09 and 0.41±0.01mM comparable with standard ascorbic acid. Compound (3) with a quinoxaline ring showed maximum inhibition of BSA denaturation at 1mM concentration and comparable with standard diclofenac. Incorporation of electron withdrawing substitutions like chloro- and nitro-groups in the quinoxaline ring has resulted in an increase anti-inflammatory activity. Test compounds (3), (3a) and (3c) showed modest inhibition of DPP-IV in vitro. However, the unsubstituted quinoxaline (3) and substituted quinoxalines (3b and 3c) reduced plasma glucose levels indicating the presence of hypoglycemic activity.

Synthesis and evaluation of a series of novel imidazolidinone analogues of 6-aminoflavone as anticancer and anti-inflammatory agents

The flavone moiety is a potential pharmacophore known for its diverse range of pharmacological activities. Aminoflavones have recently been the subject of considerable attention as lead molecules in several cancer research projects. Imidazolidinone heterocycles represent another biologically active scaffold with known cytotoxic properties. In an attempt to provide synergistic cytotoxic activity, these two moieties have been combined, and the resulting novel analogues evaluated for their anticancer and anti-inflammatory activities. The results revealed that the cytotoxicities of these compounds were fivefold greater than those of aminoflavone. DNA histograms obtained from cell cycle analysis in the presence of these compounds were apoptotic in their nature. Furthermore, the in vivo screening of these compounds using Ehrlich’s ascites tumour model showed an increase in life span, whereas an in vivo anti-inflammatory study resulted in the enhancement of the anti-inflammatory potential. The results therefore supported the hypothesis that there is a relationship between inflammation and cancer.

Nitrooxyethylation reverses the healing-suppressant effect of Ibuprofen.

Nonsteroidal antiinflammatory drugs like ibuprofen impede tissue repair by virtue of retarding inflammation. The present study was undertaken to explore if linking of nitrooxyethyl ester to ibuprofen reverses its healing-depressant propensity. Nitrooxyethyl ester of ibuprofen (NOE-Ibu) was synthesized in our laboratory through a well-established synthetic pathway. NOE-Ibu was screened for its influence on collagenation, wound contraction and epithelialization phases of healing, and scar size of healed wound in three wound models, namely, incision, dead space, and excision wounds. Besides, its influence on the oxidative stress (levels of GSH and TBARS) was also determined in 10-day-old granulation tissue. NOE-Ibu was further screened for its antiinflammatory activity in rat paw edema model. NOE-Ibu promoted collagenation (increase in breaking strength, granulation weight, and collagen content), wound contraction and epithelialization phases of healing. NOE-Ibu also showed a significant antioxidant effect in 10-day-old granulation tissue as compared to ibuprofen. Results vindicate that the esterification of ibuprofen with nitrooxyethyl group reverses the healing-suppressant effect of ibuprofen. The compound also showed equipotent antiinflammatory activity as ibuprofen.

Endothelium Dependent and Independent Mechanisms of Vasorelaxant Activity of Synthesized 2,5-disubstituted-1,3,4-oxadiazole Derivatives in Rat Thoracic Aorta – Ex vivo and Molecular Docking Studies

Background: Vasoconstriction is a major pathological feature of cardiovascular diseases involving endothelium dependent and independent mechanisms. Oxadiazole moiety appeared to be effective in various pathologies.Objective: The aim of the study was to synthesize and evaluate the mechanism of vasorelaxation exhibited by synthesized oxadiazole derivatives.Method: The 2,5-disubstituted-1,3,4-oxadiazole derivatives were synthesized by an efficient and simple method. The derivatives were investigated for their ex-vivo vasorelaxant action on intact/denuded endothelium rat aortic rings precontracted with norepinephrine/ phenylephrine/KCl.Results: The contractions induced in the aortic rings by the addition of cumulative concentrations of norepinephrine,phenylephrine, KCl and calcium were significantly antagonized by a derivative, OXD-Z2. In another experiment, verapamil pretreatment inhibited phenylephrine and Ca2+-induced aortic contractions and OXD-Z2 did not alter verapamilinduced inhibition. This indicated the role of L-type Ca2+-channels in the OXD-Z2-induced vasorelaxation via inhibition of calcium influx. Further, atropine (muscarinic receptor antagonist), L-NAME (NO synthase inhibitor) and methylene blue (non-selective cGMP inhibitor) inhibited OXD-Z2-induced relaxation in other sets of experiments. These results indicate that OXD-Z2 also mediates vasorelaxation through NO release by muscarinic receptor activation. In addition, the molecular docking studies showed that OXD-Z2 interacts with L-type Ca2+-channel, muscarinic (M2) receptor and eNOS.Conclusion: Thus, it is deduced from the above findings that the vasorelaxant activity of OXD-Z2 involves muscarinic receptor-mediated nitric oxide release in addition to direct inhibition of L-type Ca2+-channels.

Hepatoprotective Action of Dehydrozingerone in Carbon Tetrachloride and Thioacetamide-induced Hepatotoxicity in Wistar Rats

© 2011, INASL 40 Synthesis and Antihepatotoxic Activity of 5-(2,3-dihydro-1,4-benzodioxane-6-yl)-3-substitutedphenyl-4,5-dihydro-1H-pyrazole Derivatives Habibullah*,**, B Ahmed** *Department of Pharmaceutical Chemistry, Alwar Pharmacy College, Alwar, Rajasthan **Antihepatotoxic Research Laboratory, Faculty of Pharmacy, Jamia Hamdard, New Delhi Background and Objective: Silymarin isolated from seeds of Silybum marianum commonly known as ‘milk thistle’ has been found most potent antihepatotoxic agent against a variety of toxicants. The Silymarin has been found to be a mixture of three isomers of flavonolignan i.e., silybin, silychristin and silydianin. The silybin is the most potent component containing 1,4-dioxan ring system. Other isomer silychristin and silydianin do not possess 1,4-dioxan ring system and thus, do not display significant antihepatotoxic activity. Based on the above hypothesis we learned that 1,4-dioxane ring system plays an important role in exhibiting antihepatotoxic activity, and hence we have prepared some new pyrazoline derivatives bearing 1,4-dioxane ring system and evaluated them for antihepatotoxic activity against CCl4induced hepatotoxicity in rats. Material and Methods: The titled pyrazolines were prepared by refluxing 2,3-dihydro-1,4-benzodioxane-6-yl)-1-substituted-phenylprop2-en-1-one derivatives with hydrazine hydrate in absolute ethanol and few drops of glacial acetic acid. The synthesized compounds were evaluated for antihepatotoxic activity by measuring different biochemical parameters glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT), alkaline phosphatase (ALP) and total protein against CCl4-induced hepatotoxicity in Wistar albino rats as well as histopathological study of the liver. Results: The administration of silymarin (standard drug) and synthesized compounds at a dose level of 10 mg/Kg body weight, prevented CCl4-induced elevation of SGOT, SGPT, ALP, and prevented decrease in total protein. The histopathological studies also showed significant recovery of hepatocytes of the liver in the standard drug and compound-treated animals. Conflict of Interest: None Study of Silymarin on Ethanol Induced Hepatotoxicity and Expression of Bcl-2, Bax and p53 Levels P Vasanth Raj, K Nitesh, P Jain, M Neena Sankhe, J Venkata Rao, C Mallikarjuna Rao, N Udupa Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, Karnataka Background and Aims: Oxidative stress plays a pivotal role in the pathogenesis and progression of alcoholic liver disease (ALD). Considering the antihepatotoxic property of silymarin, a well known antioxidant (flavonoid); we investigated the hepatoprotective effect of silymarin and underlying mechanism(s). Methods: Twenty-four Wistar strain albino rats (180–200 g) of either sex were used. The animals were divided into three groups and treated for 60 days as follows: (1) normal control group received the vehicle (sodium CMC 0.3%); (2) ethanol group was administered ethanol 3.6 g/Kg (30%, 10 mL/Kg) 1 hour after ingestion of sodium CMC 0.3%; (3) ethanol plus silymarin group received silymarin 100 mg/Kg 1 hour prior to the administration of ethanol 3.6 g/Kg. Animals received ethanol and silymarin by oral route daily. Liver damage was evaluated by histopathology and liver function test. At molecular level, expression of P53, Bax and bcl-2 was determined by reverse transcriptase polymerase chain reaction (RT PCR). Results: Silymarin at 100 mg/Kg each ameliorated ethanol-induced macrovesicular steatosis and parenchymatous degeneration in hepatocytes, and decreased serum aminotransferases level. Ethanol downregulated antiapoptotic Bcl-2, upregulated pro apoptotic P53 and Bax mRNA levels in liver hepatocytes, thus, inducing apoptosis. However, this alteration in mRNA levels of P53, Bax and Bcl-2 was significantly prevented by silymarin treated animals at a dose of 100 mg/Kg body weight. Conclusion: Together, these results identify the biological efficacy of silymarin against ethanol-induced hepatotoxicity in rats. Hence, silymarin merits further investigation to support its molecular mechanism. Conflict of Interest: None Hepatoprotective Action of Dehydrozingerone in Carbon Tetrachloride and Thioacetamide-induced Hepatotoxicity in Wistar Rats N Kumar, P Vasanth Raj, A Tiwari, A Chaudhary, C Mallikarjuna Rao, N Gopalan Kutty, N Udupa Manipal College of Pharmaceutical Sciences, Manipal University, Manipal Background and Aims: Dehydrozingerone (DZ) is a prototype constituent of ginger and has shown radioprotection through its antioxidant activity. Chemically DZ is a chalcone in nature and can be prepared easily by reactions of vanillin with acetones. Antioxidant activity 03_JCEH-Abstract.indd 40 3/18/2011 11:13:05 AM