M.S. Latha

Protective effect of Amorphophallus campanulatus (Roxb.) Blume. tuber against thioacetamide induced oxidative stress in rats.

OBJECTIVE To identify the phytochemical constituents of Amorphophallus campanulatus (A. campanulatus) tuber and to evaluate its antioxidant potential through in vitro and in vivo models. METHODS Phytochemical screening and in vitro antioxidant activities of A. campanulatus tuber n-hexane extract (ACHE) and methanolic extract (ACME) were evaluated using DPPH, hydroxyl radical, reducing power and total antioxidant capacity assays. The total phenolic and flavonoid contents were also investigated. The protective potential of two different doses of ACME (125 and 250 mg/kg) was also evaluated against thioacetamide (TAA) induced oxidative stress in rats. Silymarin used as a standard drug control. Hepatotoxicity was assessed by quantifying the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). The antioxidant potential of ACME were also evaluated by the estimation of catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), reduced glutathione (GSH) and lipid peroxidation (Thiobarbituric acid reactive substances) in hepatic and renal tissues. Histopathologic changes of liver were also evaluated. RESULTS In vitro studies revealed that ACME has higher antioxidant and radical scavenging activity than ACHE, which may be attributed to its higher phenolic and flavonoid content. ACME significantly prevented the elevation of serum AST, ALT, ALP, LDH, and tissue malondialdehyde levels(P < 0.05). Hepatic and renal GSH, GST, GR, GPx, and catalase levels were remarkably increased by the treatment with the extract. Quantification of histopathological changes also supported the dose dependent protective effects of ACME. CONCLUSIONS The results do suggest that A. campanulatus tuber could be considered as a potential source of natural antioxidant.

Plumbagin reduces human colon cancer cell survival by inducing cell cycle arrest and mitochondria-mediated apoptosis

Despite increased use of early detection methods and more aggressive treatment strategies, the worldwide incidence of colorectal cancer is still on the rise. Consequently, it remains urgent to identify novel agents with enhanced efficacy in prevention and/or therapeutic protocols. Our studies focused on the use of Plumbagin, a natural phytochemical that showed promising results against other tumor types, to determine its effectiveness in blocking the proliferation and survival of colon cancer cells in experimental protocols mimicking the environment in primary tumors (attached culture conditions) and in circulating tumor cells (unattached conditions). Under both experimental settings, exposure of HCT116 cells to Plumbagin concentrations in the low micromolar range resulted in cell cycle arrest at the G1 phase, apoptosis via the mitochondrial cell death pathway, and increased production of reactive oxygen species. The cell cycle effects were more noticeable in attached cells, whereas the induction of cell death was more evident in unattached cells. These effects were consistent with the nature and the magnitude of the alterations induced by Plumbagin on the expression levels of a set of proteins known to play key roles in the regulation of cell cycle dynamics, apoptosis mechanisms and cell proliferation. In light of its previously reported lack of toxicity on normal colon cells and the striking anti-survival effect on colon cancer cells observed in our study, Plumbagin should be considered a promising drug for the treatment of colon cancer.

Cytotoxic and apoptotic activities of Amorphophallus campanulatus (Roxb.) Bl. tuber extracts against human colon carcinoma cell line HCT-15.

Colorectal cancer is one of the leading causes of cancer death worldwide and is the third most common form of malignancy in both men and women. Several possible colon cancer chemopreventive agents are found in edible plants. Amorphophallus campanulatus (Roxb.) Blume (family: Araceae) is a tuber crop, largely cultivated throughout the plains of India for using its corm as food. This tuber has also been traditionally used for the treatment of abdominal tumors, liver diseases, piles etc. The aim of this study was to evaluate the dose-dependent cytotoxic and apoptosis inducing effects of the sub fractions of A. campanulatus tuber methanolic extract (ACME) viz. petroleum ether fraction (PEF), chloroform fraction (CHF), ethyl acetate fraction (EAF) and methanolic fraction (MEF) on the colon cancer cell line, HCT-15. Antiproliferative effects of the sub fractions of ACME were studied by MTT assay. Apoptotic activity was assessed by DAPI, Annexin V-FITC and JC-1 fluorescent staining. The chemotherapeutic drug, 5-flurouracil (5-FU) was used as positive drug control. The sub fractions of ACME significantly inhibited the proliferation of HCT-15 cells in a dose-dependent manner. In addition, the extracts were found to induce apoptosis and were confirmed by DAPI, Annexin V-FITC and JC-1 fluorescent staining. A pronounced results of cytotoxic and apoptotic activities were observed in the cells treated with 5-FU and CHF, whereas, EAF and MEF treated cells exhibited a moderate result and the least effect was observed in PEF treated cells. Our results suggested that, among the sub fractions of ACME, CHF had potent cytotoxic and apoptotic activity and thus it could be explored as a novel target for anticancer drug development. Furthermore, these findings confirm that the sub fractions of ACME dose-dependently suppress the proliferation of HCT-15 cells by inducing apoptosis.

Chemopreventive effect of Amorphophallus campanulatus (Roxb.) blume tuber against aberrant crypt foci and cell proliferation in 1, 2-dimethylhydrazine induced colon carcinogenesis.

Colorectal cancer is one of the leading causes of cancer death, both in men and women. This study investigated the effects of Amorphophallus campanulatus tuber methanolic extract (ACME) on aberrant crypt foci (ACF) formation, colonic cell proliferation, lipid peroxidative damage and the antioxidant status in a long term preclinical model of 1, 2-dimethylhydrazine (DMH) induced colon carcinogenesis in rats. Male Wistar rats were divided into six groups, viz., group I rats served as controls; group II rats treated as drug controls receiving 250 mg/ kg body weight of ACME orally; group III rats received DMH (20 mg/kg body weight) subcutaneously once a week for the first 15 weeks; groups IV, V and VI rats received ACME along with DMH during the initiation, post- initiation stages and the entire period of the study, respectively. All the rats were sacrificed at the end of 30 weeks and the intestinal and colonic tissues from different groups were subjected to biochemical and histological studies. Administration of DMH resulted in significant (p ≤ 0.05) intestinal and colonic lipid peroxidation (MDA) and reduction of antioxidants such as catalase, glutathione peroxidase, glutathione reductase, glutathione-S- transferase and reduced glutathione. Whereas the supplementation of ACME significantly (p ≤ 0.05) improved the intestinal and colonic MDA and reduced glutathione levels and the activities of antioxidant enzymes in DMH intoxicated rats. ACME administration also significantly suppressed the formation and multiplicity of ACF. In addition, the DMH administered rats showed amplified expression of PCNA in the colon and decreased expression of this proliferative marker was clearly noted with initiation, post-initiation and entire period of ACME treatment regimens. These results indicate that ACME could exert a significant chemopreventive effect on colon carcinogenesis induced by DMH.

Antioxidant and antihepatotoxic efficacy of methanolic extract of Elephantopus scaber Linn in Wistar rats

Objective To determine the in vitro and in vivo antioxidant and hepatoprotective activity of methanolic extract of Elephantopus scaber root against CCl4 induced liver damage in rats.

Dose-response effects of Elephantopus scaber methanolic extract on N-nitrosodiethylamine-induced hepatotoxicity in rats

AIM A decoction of Elephantopus scaber (Asteraceae) root is used to treat liver disorders in Indian and Chinese traditional medicine. The study was designed to examine the dose response effects of E. scaber methanolic extract on rats exposed to N-nitrosodiethylamine (NDEA) induced hepatotoxicity (0.02% NDEA in water five days per week, per oral) in preventive and curative models. METHODS In preventive groups, NDEA was administered for six weeks. Daily doses of E. scaber methanolic extract (200 and 100 mg·kg-1) started one week before the onset of NDEA intoxication and continued for six weeks. In curative animals, NDEA was administered for six weeks followed by treatment with the methanolic n-hexane extract of E. scaber (200 and 100 mg·kg-1) for ten days. RESULTS E. scaber extract treatment significantly (P ≤ 0.05) reduced the levels of AST, ALT, and MDA in both experimental groups. The extract also enhanced the antioxidant enzyme and protein levels in rats intoxicated with NDEA. Treatment with the extract dose dependently protected the liver from NDEA-induced hepatotoxicity with normal hepatocytes and uniform sinusoids, but in some areas showed degenerating hepatic cells in both treatment groups. CONCLUSION E. scaber methanolic extract dose dependently prevented and reversed the hepatotoxicity induced by NDEA in both experimental models.

Role of antioxidant defence, renal toxicity markers and inflammatory cascade in disease progression of acute pyelonephritis in experimental rat model

Urinary tract infections are the most common bacterial infections affecting millions of people each year worldwide. The animal model provides an excellent and suitable system for studying cystitis and pyelonephritis caused by Escherichia coli and other uropathogens. Using this established model, we evaluate the role of antioxidant defence system, renal injury markers, and blood parameters in the diseases progression during Escherichia coli infection on 0th day, 12h and 7th day. The antioxidant enzymes like SOD, CAT, GSH, GPx, GR levels were evaluated. The blood parameters like AST, ALT, ALP, Total protein, BUN, creatinine level were estimated in infection model. The relative organ weights, anti microbial status of kidney, CRP, WBC count were done for the evaluation of inflammatory response associated with the infection. The oxidative stress marker like MDA was also evaluated. Histopathological analysis of renal tissue provides direct vision to tissue damage. The antioxidant status of renal tissue was decreased during the 7th day of infection. Likewise, renal toxicity markers were significantly increased during bacterial infection. The inflammatory markers like CRP, WBC count and oxidative stress marker like MDA were significantly increased by the infection on 7th day. The histopathology of renal tissue also reveals the inflammation and tissue damage associated with acute pyelonephritis.

Antidermatophytic Activity of Mikania micrantha Kunth: An Invasive Weed

Context: The incidence of dermatophytosis has risen dramatically in recent years. Limited availability of side-effect free drugs has led to a search for new antidermatophytic agents. Objective: The objective was to investigate antidermatophytic activity and in vitro anti-inflammatory activity (protease inhibition assay) of whole plant (aerial parts only) of Mikania micrantha. Materials and Methods: The dried and powdered aerial parts of M. micrantha were extracted separately with petroleum ether, ethyl acetate and methanol. Antidermatophytic activity was determined by agar tube dilution method against Epidermophyton floccosum var. nigricans, Microsporum canis, Microsporum gypseum and Trichophyton rubrum. The activities of various parts of the plant - flowers, leaves and stem were separately analyzed using their ethyl acetate extract. Fungicidal efficacy and trypsin inhibiting activity of the whole plant, flowers and leaves were also analyzed using the ethyl acetate extracts. Statistical Analysis Used: For trypsin inhibition assay results are expressed as mean ± standard division. For antidermatophytic assay, the significance of the difference between control and test was analyzed statistically using Fisher′s exact test. Results: Ethyl acetate extract of M. micrantha exhibited excellent antidermatophytic activity, followed by petroleum ether and methanolic extracts. Ethyl acetate extracts of whole plant, flowers, leaves and stem completely inhibited the growth of dermatophytes at the tested concentration of 2 mg/mL. Furthermore, ethyl acetate extracts of whole plant, leaves and flowers were fungicidal, and the percentages of trypsin inhibition exhibited were 33.73 ± 0.306, 39.0 ± 0.505 and 35.53 ± 0.503, respectively. Conclusions: Since M. micrantha possesses antidermatophytic as well as anti-inflammatory activities, the plant is an excellent candidate for the development of new medicaments against dermatophytoses in traditional as well as modern medicine.

Acute oral toxicity and anti-inflammatory evaluation of methanolic extract of Rotula aquatica roots in Wistar rats

Background The plant Rotula aquatica Lour. was traditionally well known due to its large number of pharmacological action and medicinal uses. The plant is a necessary component of many Ayurvedic drug preparations since historical times. It is widely used as a crucial ancient drug for kidney and bladder stones. Objectives The main objective of the study was to evaluate the acute toxicity and anti inflammatory efficacy of methanolic extract of R.aquatica Lour. in in vivo models. Materials and methods The qualitative phytochemical analysis and invitro antioxidant activity of the roots of methanolic extract of R.aquatica Lour. (MERA) was evaluated. The acute toxicity effect of MERA was evaluated with two different doses (550, 2000 mg/kg body weight), were administrated orally to Wistar rats. The rats were observed for sign and symptoms of toxicity and mortality for 14 days. The parameters measured including relative organ weight, blood, biochemical and histopathological parameters of hepatic and renal toxicity. The anti-inflammatory effect of MERA was also evaluated in carrageenan and dextran-induced paw edema models. Results The phytochemical evaluation of MERA shows the presence of secondary metabolites like alkaloids, flavonoids, phenolics and tannins, phytosterols, reducing sugars, proteins and terpenoids. The results of in-vitro antioxidant evaluation of MERA reveal its capability to scavenging free radical at a lower concentration. The MERA did not show any visible signs of toxicity up to the dose of 2000 mg/kg body weight. The results obtained from our carrageenan and dextran-induced paw edema model study also proved the anti-inflammatory effect of MERA in rat model. Conclusion The result shows the potential of MERA as an anti-inflammatory drug to reduce the signs of inflammation devoid of any toxic effect.

Ethyl acetate fraction of Terminalia bellirica (Gaertn.) Roxb. fruits inhibits proinflammatory mediators via down regulating nuclear factor-κB in LPS stimulated Raw 264.7 cells

Inflammation has been considered as a major risk factor for various kinds of human diseases. Macrophages play substantial roles in host defense against infection. It can be activated by lipopolysaccharide (LPS), the major component of the outer membrane of Gram-negative bacteria. The current study aims to investigate the anti-inflammatory effects of ethyl acetate fraction isolated from T. bellerica (EFTB) in LPS stimulated RAW 264.7 macrophage cell lines. The inhibitory effects of EFTB on total cyclooxygenase (COX), 5-lipoxygenase (5-LOX) activity, nitrate and inducible nitric oxide synthase (iNOS) level, reactive oxygen species (ROS) production were studied. The gene level expression of COX-2, tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6) and Nuclear factor-κB (NF-κB) were also studied in LPS stimulated RAW 264.7 cells. EFTB (100μg/mL) inhibited all inflammatory markers in dose dependent manner. Moreover, EFTB down regulated the mRNA expression of TNF-α, IL-6, COX-2 and NF-κB against LPS stimulation. Our results demonstrated that EFTB is able to attenuate inflammatory response possibly via suppression of ROS and NO species, inhibiting the production of arachidonic acid metabolites, proinflammatory mediators and cytokines release.