Thekkekara Devassy Babu

Cytotoxic and antioxidant properties of selected Scutellaria species from the Western Ghats of Peninsular India

Context: Scutellaria (Lamiaceae), commonly known as ‘Skullcaps’, has been extensively used in Traditional Chinese Medicine (TCM). Recently, much emphasis has been given to this genus due to the rich source of bioflavonoids that contribute to its biological properties. Therefore, different species of Scutellaria are being explored worldwide. Objectives: Cytotoxic, antioxidant, and phytochemical properties of Scutellaria colebrookiana Benth and S. violacea (Heyne ex Benth) Don collected (October 2009–February 2010) from Western Ghats of India have been analysed. Materials and methods: In vitro cytotoxicity and free radical scavenging effects of root extracts in various solvents were analysed. Spectrophotometric and HPLC methods were performed for phytochemical analysis. Results: Chloroform extract exhibited significant cytotoxicity in Dalton’s Lymphoma Ascites (DLA) and Ehrlich Ascites Carcinoma (EAC) cells with IC50 values 150 and 140 µg/mL for S. colebrookiana and 250 and 280 µg/mL for S. violacea, respectively. Moreover, the extract was effective in scavenging free radicals and inhibiting membrane peroxidation in vitro with IC50 values 158.3 and 167.5 (superoxide), 17.5 and 28.0 (hydroxyl), 76.25 and 69.75 (DPPH), 24.5 and 28.0 (ABTS), 69.75 and 64.6 (lipid peroxidation), 41 and 31.5 µg/mL (erythrocyte hemolysis), respectively. Antioxidant effect observed with acetone extract was also comparable to that of chloroform extract. Phytochemical screening revealed the presence of baicalein. Discussion and conclusion: Scutellaria species of Western Ghats showed cytotoxic and antioxidant potential and the presence of baicalein. This suggests that S. colebrookiana and S. violacea could be used as alternative sources for baicalein in view of the reported scarcity of S. baicalensis.

Evaluation of Cytotoxic and Antitumour Properties of Apodytes dimidiata and Characterisation of the Bioactive Component.

Apodytes dimidiata, belonging to the family Icacinaceae, is used for treating inflammation and various gastrointestinal ailments in Zulu traditional medicine. In the present study, significant cytotoxicity was exhibited by the methanolic extract of the A. dimidiata leaf against various cancer cell lines. The extract was purified partially through silica gel column by successive elution using various solvents of increasing polarity. Among these, the active methanolic fraction was found to be the most cytotoxic with IC50 values ranging from 0.92 to 3.95 µg/mL for Ehrlichs ascites carcinoma (a carcinoma cell line), Jurkat (human T lymphocyte cell line), and SK-BR-3 (mammary tumour cell line). The treated cells showed morphological alterations characteristic of apoptosis. Upon oral administration of active methanolic fraction at a dose of 250 mg/kg body weight, the solid tumour volume in mice was significantly reduced to 55.14% and the life span of the ascites tumour-bearing mice increased to 44.65% compared to untreated control. The active fraction with Rf value 0.56 was purified from the methanolic fraction by preparative thin-layer chromatography and was subjected to high-performance thin-layer chromatography, high-performance liquid chromatography, liquid chromatography-mass spectrometry, and nuclear magnetic resonance analysis. The iridoid glycoside genipin was identified as the active component.

Effect of Saraca asoca (Asoka) on estradiol-induced keratinizing metaplasia in rat uterus

Abstract Background: Estrogen-mediated uterus endometrium instability is considered as one of the etiological factors in dysfunctional uterine bleeding (DUB) and uterine cancer. Saraca asoca (Family: Fabaceae) and its fermented preparation, Asokarishta, are extensively used as uterine tonic to treat gynecological disorders in Ayurveda. The present study evaluated the effect of S. asoca (Asoka) on estrogen-induced endometrial thickening of rat uterus. Methods: Endometrial thickening was induced by intraperitoneal injection of estradiol (20 μg/kg b.wt) to 8-day-old immature rats for alternate 5 days. Methanolic extract (200 mg/kg b. wt) from S. asoca bark was given orally along with estradiol. Uterus endometrial thickening was analyzed histopathologically and serum estrogen level by radioimmunoassay (RIA). Cyclooxygenase (COX-2) expression in rat uterus was also estimated by Western blot. Anti-inflammatory activity of the extract was analyzed by formalin- and carrageenan-elicited paw edema models in mouse. Results: Uterus endometrium proliferation and keratinized metaplasia with seven to eight stratified epithelial layers on day 16 was observed in rats administered with estradiol. Treatment with S. asoca reduced the thickening to two to four layers and the serum estrogen level diminished significantly to 82.9±12.87 pg/mL compared to rats administered with estrogen alone (111.2±10.68 pg/mL). A reduction of formalin- and carrageenan-induced paw edema in mouse by S. asoca extract was observed. Lower level of lipopolysaccharides (LPS)-induced COX-2 enzyme in rat uterus by the extract further confirms its anti-inflammatory activity. Conclusions: Present study reveals the antiproliferative and antikeratinizing effects of S. asoca in uterus endometrium possibly through its anti-estrogenic and anti-inflammatory properties.

Coconut phytocompounds inhibits polyol pathway enzymes: Implication in prevention of microvascular diabetic complications

Coconut oil (CO), the primary choice of cooking purposes in the south Asian countries, is rich in medium chain saturated fatty acids, especially lauric acid (50-52%). The oil has high medicinal use in Ayurvedic system and known to contain polyphenolic antioxidants. Studies have reported that CO improves insulin sensitivity and shows hypoglycemic effect. However, there is no information regarding its effect on chronic diabetic complications including retinopathy and nephropathy is available. The secondary diabetic complications are mediated by the activation of polyol pathway, where aldose reductase (AR) plays crucial role. In this study, in silico analysis has been used to screen the effect of CO as well as its constituents, MCFAs and phenolic compounds, for targeting the molecules in polyol pathway. The study revealed that lauric acid (LA) interacts with AR and DPP-IV of polyol pathway and inhibits the activity of these enzymes. Validation studies using animal models confirmed the inhibition of AR and SDH in wistar rats. Further, the LA dose dependently reduced the expression of AR in HCT-15 cells. Together, the study suggests the possible role of CO, particularly LA in reducing secondary diabetic complications.

Ameliorative effect of Apodytes dimidiata on cisplatin-induced nephrotoxicity in Wistar rats

Abstract Context Nutraceuticals possessing antioxidant potential have been used to alleviate side effects exerted by many chemotherapeutics, including cisplatin. Since Apodytes dimidiata E. Mey. Ex Arn. (Icacinaceae) shows antioxidant potential, it may possess significant chemoprotective effects. Objectives The study investigated whether A. dimidiata could attenuate cisplatin-induced renal damage. Materials and methods Nephrotoxicity was induced by cisplatin (single i.p., 16 mg/kg b wt.) in Wistar rats. Methanolic leaf extract of A. dimidiata (AMF) was administered at a dose of 250 mg/kg b. wt. orally for 5 consecutive days before/after cisplatin administration. Blood and renal parameters were analysed. Total phenolic and flavonoid content in AMF and its NO scavenging effect was determined. Results Significant protective effect of AMF on cisplatin-induced nephrotoxicity was observed in pre-treated animals. The reduction of urea, creatinine and lipid peroxidation was 58.31%, 42.19% and 60%, respectively, and the increase in haemoglobin and leucocyte count was 28.25% and 42.91%, respectively. The increase calculated for GSH, GPx, SOD and catalase was 35.64%, 18.14%, 74.42% and 35.46%, respectively. Tissue architecture of kidney was almost normal in AMF treated animals. The results were comparable to the standard drug, silymarin. AMF contained high level of polyphenols and flavonoids and was found to scavenge NO radicals (IC50 121.8 μg/mL). Discussion and conclusion AMF can effectively counteract cisplatin mediated renal acute toxicity possibly by scavenging reactive oxygen and nitrogen species. Accordingly, the study suggests that AMF can ameliorate free radical-induced damage associated with chemotherapeutic drugs.

Comparative phytochemical and biological property analysis to detect the genuineness of substitutes of the plant Moovila in drug preparations

Pseudarthria viscida is the preferred source of the raw drug Salaparni in Ayurvedic system of medicine, especially in the preparation of Dasamoolarishtam. Due to its scarcity, other trifoliate leguminous plants, particularly the species of Desmodium and Uraria are used as substitutes. The phytochemical and biological properties of these plants were analyzed to sort out the genuineness of the substitutes. Qualitative as well as quantitative chemical profiles obtained for P. viscida showed similarity to U. rufescens. In vitro antioxidant and in vivo gastroprotective assays carried out to determine the biological properties of the extracts revealed that the acetone extract of P. viscida inhibited the formation of hydroxyl, superoxide, nitric oxide radicals, and lipid peroxidation. The oral administration of P. viscida extract significantly reduced ethanol-induced gastric ulceration in mice. Even though more or less the same chemical profile was obtained for P. viscida and U. rufescens, only P. viscida exhibited significant biological properties.

EGFR gene regulation in colorectal cancer cells by garlic phytocompounds with special emphasis on S-Allyl-L-Cysteine Sulfoxide

Colorectal cancer is one among the most common cancers in the world and a major cause of cancer related deaths. Similar to other cancers, colorectal carcinogenesis is often associated with over expression of genes related to cell growth and proliferation, especially Epidermal Growth Factor Receptor (EGFR). There is an increasing attention towards the plant derived compounds in prevention of colorectal carcinogenesis by downregulating EGFR. Among plants, garlic (Allium sativum L.) is emerging with anticancer properties by virtue of its organosulfur compounds. The present study was aimed to analyze the interaction ability of garlic compounds in the active region of EGFR gene by in silico molecular docking studies and in vitro validation. This was conducted using the Discovery studio software version 4.0. Among the tested compounds, s-allyl-l-cysteine-sulfoxide (SACS)/alliin showed higher affinity towards EGFR. Furthermore, wet lab analysis using cell viability test and EGFR expression analysis in colorectal cancer cells confirmed its efficacy as a potent anticancer agent.

Attenuation of DMBA/croton oil induced mouse skin papilloma by Apodytes dimidiata mediated by its antioxidant and antimutagenic potential

Abstract Context Considering the role of cellular oxidative stress in mutations and subsequent transformation, phytochemicals with antioxidant potential has become a primary choice as chemopreventives. Apodytes dimidiata E. Mey. Ex. Arn (Icacinaceae), a widely used plant in Zulu traditional medicine, is reported to possess antioxidant activity. Objective To investigate the chemopreventive efficacy of methanol extract of A. dimidiata leaf (AMF). Materials and methods Antimutagenic potential of AMF (25, 50 and 75 μg/plate) was evaluated by the Ames test. The ability of AMF (100 and 250 mg/kg orally) on restoration of depleted antioxidant status by sodium fluoride (NaF) was analysed on BALB/c mice. 7,12-Dimethylbenz[a]anthracene/croton oil induced mouse skin papilloma model was studied up to 20 weeks to analyse the anticarcinogenic effect of AMF (1%, 3% and 5% topically, twice weekly for 6 weeks). Phytochemicals of AMF were characterized by GC–MS. Results AMF (75 μg/plate) reverted 4-nitro-o-phenylenediamine (NPDA) induced mutations in Salmonella typhimurium strains, TA 98, 100 and 102 by 74.8%, 72.5% and 69.3%, respectively. Against sodium azide, the percentage reversion was 80.4, 71.3 and 71.3. In mice, AMF (250 mg/kg for 4 days) increased the serum superoxide dismutase (SOD) and catalase activities by 48.71% and 30.3% against the NaF-induced drop. GSH level was improved by 48.59% with a concomitant decrease in TBARS (57.67%). The skin papilloma reduction was 79.32% for 5% AMF. Squalene, dodecanoic, tetradecanoic and hexadecanoic acids are the known antioxidant and chemopreventive molecules identified by GC–MS. Discussion and conclusion Antioxidant and antimutagenic activities of AMF might have contributed to its anticarcinogenic potential.

Protective effect of Scutellaria species on AAPH-induced oxidative damage in human erythrocyte.

Abstract Background: Scutellaria baicalensis is a well-known plant in traditional Chinese medicine. Recently, several Scutellaria species with therapeutic potential have been recognized worldwide. Scutellaria colebrookiana and Scutellaria violacea, native to the Western Ghats of India, are reported to possess free radical scavenging efficacy. At present, the protective effect of these Scutellaria spp. against 2,2′ azobis (2-amidinopropane) hydrochloride (AAPH)-induced oxidative damage in human erythrocytes has been analyzed. Methods: Oxidative stress in erythrocyte was induced by AAPH. The inhibition of hemolysis, membrane lipid peroxidation, and protein damage by chloroform extracts of Scutellaria spp. was assessed biochemically. Phytochemicals of the extracts were analyzed by Fourier transform infrared spectrophotometer (FTIR). Results: Approximately 95% of erythrocytes were lysed by AAPH over 3 h of incubation. Significant reduction in hemolysis was observed by the extracts, and the IC50 values were 18.3 and 23.5 μg/mL for S. colebrookiana and S. violacea, respectively. Both the extracts were found to inhibit AAPH-induced lipid peroxidation in ghost membrane with IC50 92±2.8 and 70±5.6 μg/mL. In the analysis of the membrane proteins using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the AAPH-induced degradation of actin was found reduced by both the extracts. The FTIR spectrum revealed the presence of polyphenols, carboxylic acids, alkanes, and aromatic compounds in extracts. In quantitative analysis, the total polyphenolic content estimated was 380±0.23 and 203.7±1.4 mg of gallic acid equivalent per gram extract of S. colebrookiana and S. violacea. Conclusions: Results indicate that S. colebrookiana and S. violacea are capable of protecting erythrocytes from oxidative damage. This cytoprotective effect of the extract is possibly by its antioxidant property.

Non-enzymatic conversion of primary oxidation products of Docosahexaenoic acid into less toxic acid molecules

Docosahexaenoic acid (DHA) is long chain omega-3 fatty acid with known health benefits and clinical significance. However, 4-hydroxy hexenal (HHE), an enzymatic oxidation product of DHA has recently been reported to have health-damaging effects. This conflict raises major concern on the long-term clinical use of these fatty acids. Even though the enzymatic and non-enzymatic conversion of HHE to nontoxic acid molecules is possible by the aldehyde detoxification systems, it has not yet studied. To address this, primary oxidation products of DHA in lipoxidase system were subjected to non-enzymatic conversion at physiological temperature over a period of 1 week. The reaction was monitored using HPLC, IR spectroscopy and biochemical assays (based on the loss of conjugated dienes, lipid peroxides aldehydes). Short term and long term cytotoxicity of the compounds generated at various time points were analyzed. IR and HPLC spectra revealed that the level of aldehydes in the primary oxidation products reduced over time, generating acids and acid derivatives within a week period. In short term and long term cytotoxicity analysis, initial decomposition products were found more toxic than the 1-week decomposition products. Further, when primary oxidation products were subjected to aldehyde dehydrogenase mediated oxidation, it generated products that are also less toxic. The study suggests the possible non-enzymatic conversion of primary oxidation products of DHA to less cytotoxic acid molecules. Exploration of the physiological roles of these acid molecules may explain the biological potential of omega-3 fatty acids.