Secalonic Acid-D Represses HIF1α/VEGF-Mediated Angiogenesis by Regulating the Akt/mTOR/p70S6K Signaling Cascade.

Tumor angiogenesis is a validated target for therapeutic intervention, but agents that are more disease selective are needed. Here, we report the isolation of secalonic acid-D (SAD), a mycotoxin from a novel source that exhibits potent antiangiogenic antitumor activity. SAD inhibited multiple HIF1α/VEGF-arbitrated angiogenesis dynamics as scored in human umbilical vascular endothelial cells and human MCF-7 breast tumor xenografts. Similarly, SAD suppressed VEGF-induced microvessel sprouting from rat aortic ring and blood vessel formation in the Matrigel plug assay in C57/BL6J mice. Under normoxic or hypoxic conditions, SAD inhibited cell survival through the Akt/mTOR/p70S6K pathway, with attendant effects on key proangiogenesis factors, including HIF1α, VEGFR, and MMP-2/MMP-9. These effects were reversed by cotreatment with the Akt inhibitors perifosine and GSK69069 or by the addition of neutralizing VEGF antibodies. The apoptotic properties of SAD were determined to be both extrinsic and intrinsic in nature, whereas the cell-cycle inhibitory effects were mediated by altering the level of key G1-S transition-phase proteins. In experimental mouse models of breast cancer, SAD dosing produced no apparent toxicities (either orally or intraperitoneal) at levels that yielded antitumor effects. Taken together, our findings offered a preclinical validation and mechanistic definition of the antiangiogenic activity of a novel mycotoxin, with potential application as a cancer-selective therapeutic agent.

Hepatoprotective activity of LC-ESI-MS standardized Iris spuria rhizome extract on its main bioactive constituents.

The study was designed to evaluate the hepatoprotective activity of Iris spuria against paracetamol induced toxicity at two different doses 100 and 200 mg/kg. The extract showed significant protective activity (p>0.01) at both the doses in dose dependent manner. Administration of the plant extract restored the paracetamol induced elevated levels of serum marker and distorted hepatic tissue architecture. The lipid peroxides (LPO) and glutathione (GSH) levels were also restored towards normal in liver tissue significantly. The main chemical constituents of the extract identified by the liquid chromatography-tandem mass spectrometry (LC-ESI-MSMS) were found to be flavones and isoflavonoids. Tectoridin and iristectorigenin A were the principal compounds present in the methanolic extract of Iris spuria.

Chemoprevention with aqueous extract of Butea monosperma flowers results in normalization of nuclear morphometry and inhibition of a proliferation marker in liver tumors.

Butea monosperma (Lam.) (family: Fabaceae) popularly known as 'Palas' or 'fire of forest' has been used traditionally as a hepatoprotective agent. This study evaluated the hepatoprotective and antitumorigenic properties of the aqueous extract and butanol fractions of B. monosperma flowers in animal models. Dried flowers of B. monosperma were extracted with water and fractionated further using n-butanol. The hepatoprotective activity of the aqueous extract was initially confirmed in a carbon tetrachloride-induced liver damage model of rats. Oral administration of the aqueous extract produced a strong hepatoprotective effect similar to silymarin and normalized the serum levels of ALT, AST, bilirubin and triglyceride in rats. However, it did not affect the levels of glutathione and malondialdehyde which are oxidative stress markers in liver. Intraperitoneal administration of the aqueous extract in the X15-myc oncomice not only maintained liver architecture and nuclear morphometry but also down-regulated the serum VEGF levels. Immunohistochemical staining of liver sections with anti-Ribosomal protein S27a antibody showed post-treatment abolition of this proliferation marker from the tumor tissue. The butanol fractions, however, did not show antitumorigenic activity. Thus, the aqueous extract of B. monosperma flowers is not only hepatoprotective but also antitumorigenic by preserving the nuclear morphometry of the liver.

Hepatoprotective activity of Woodfordia fruticosa Kurz flowers against carbon tetrachloride induced hepatotoxicity.

ETHNOPHARMACOLOGICAL RELEVANCE: Dried flowers of Woodfordia fruticosa Kurz. Family Lythraceae are used in variety of diseases in traditional Indian system of medicine including hepatic ailments. AIMS OF STUDY: The aim of present study was to validate hepatoprotective activity of flowers of Woodfordia fruticosa Kurz. MATERIALS AND METHODS: Petroleum ether (WF1), chloroform (WF2), ethyl alcohol (WF3) and aqueous (WF4) extracts of the flowers of Woodfordia fruticosa were evaluated for hepatoprotective activity against carbon tetrachloride induced hepatotoxicity using biochemical markers, hexobarbitone sleep time, bromosulphalein (BSP) clearance test and effect on bile flow and bile solids. RESULTS: The aqueous extract (WF4) was most potent among the four extracts studied in detail. WF4 showed significant hepatoprotective activity against carbon tetrachloride induced hepatotoxicity as evident by restoration of serum transaminases, alkaline phosphatase, bilirubin and triglycerides. The restoration of microsomal aniline hydroxylase and amidopyrine-N-demethylase activities indicated the improvement in functional status of endoplasmic reticulum. Restoration of lipid peroxidation and glutathione contents suggests the antioxidant property of WF4. The recovery in bromosulphalein clearance and stimulation of bile flow suggested the improved excretory and secretary capacity of hepatocytes. Light microscopy of the liver tissue further confirmed the reversal of damage induced by hepatotoxin. CONCLUSION: Present study showed that the aqueous extract of Woodfordia fruticosa significantly restores physiological integrity of hepatocytes. WF4 did not show any sign of toxicity up to oral dose of 2g/kg in mice.

Hepatoprotective potential of Aloe barbadensis Mill. against carbon tetrachloride induced hepatotoxicity.

Aloe barbadensis Mill. Syn. Aloe vera Tourn. ex Linn.(Liliaceae) has been used in variety of diseases in traditional Indian system of medicine in India and its use for hepatic ailments is also documented. In the present study an attempt has been made to validate its hepatoprotective activity. The shade dried aerial parts of Aloe barbadensis were extracted with petroleum ether (AB-1), chloroform (AB-2) and methanol (AB-3). The plant marc was extracted with distilled water (AB-4). All the extracts were evaluated for hepatoprotective activity on limited test models as hexobarbitone sleep time, zoxazolamine paralysis time and marker biochemical parameters. AB-1 and AB-2 were observed to be devoid of any hepatoprotective activity. Out of two active extracts (AB-3 and AB-4), the most active AB-4 was studied in detail. AB-4 showed significant hepatoprotective activity against CCl4 induced hepatotoxicity as evident by restoration of serum transaminases, alkaline phosphatase, bilirubin and triglycerides. Hepatoprotective potential was confirmed by the restoration of lipid peroxidation, glutathione, glucose-6-phosphatase and microsomal aniline hydroxylase and amidopyrine N-demethylase towards near normal. Histopathology of the liver tissue further supports the biochemical findings confirming the hepatoprotective potential of AB-4. The present study shows that the aqueous extract of Aloe barbadensis is significantly capable of restoring integrity of hepatocytes indicated by improvement in physiological parameters, excretory capacity (BSP retention) of hepatocytes and also by stimulation of bile flow secretion. AB-4 did not show any sign of toxicity up to oral dose of 2 g/kg in mice.

Isolation, structure elucidation and in vivo hepatoprotective potential of trans-tetracos-15-enoic acid from Indigofera tinctoria Linn.

The bioassay guided fractionation of the dried aerial part of Indigofera tinctoria Linn. led to the identification of an active fraction labelled as indigotin. On further chemical analysis, a compound isolated from indigotin was identified and characterized as trans-tetracos-15-enoic acid (TCA). The chemical structure of this compound was established on the basis of physical properties and spectral data, including NMR. It afforded significant hepatoprotection against carbon tetrachloride and paracetamol induced hepatotoxicity in experimental models. Silymarin, a well known plant based hepatoprotective agent, and N-acetylcysteine, which has proven efficacy as a replenisher of sulfhydryls, were used for relative efficacy. TCA was found to reverse the altered hepatic parameters in experimental liver damage. In the safety evaluation study the oral LD50 was found to be more than 2000 mg/kg, with no signs of abnormalities or any mortality for the 15 day period of observation after administration of a single dose of drug in mice. The studies revealed significant and concentration dependent hepatoprotective potential of TCA as it reversed the majority of the altered hepatic parameters in experimental liver damage in rats and mice and may be useful in the management of liver disorders.

Chemistry and hepatoprotective activity of an active fraction from Barleria prionitis Linn. in experimental animals.

Iridoid enriched fraction IF from the ethanol-water extract of aerial parts (leaves and stems) of Barleria prionitis Linn. was evaluated for hepatoprotective activity in various acute and chronic animal test models of hepatotoxicity. It afforded significant hepatoprotection against carbon tetrachloride, galactosamine and paracetamol induced hepatotoxicity. Silymarin, was used as reference hepatoprotective. In the safety evaluation study the oral LD50 was found to be more than 3000 mg/kg, with no signs of abnormalities or any mortality observed for 15 days period under observation after single dose of drug administration whereas intraperitoneal LD50 was found to be 2530 mg/kg+/-87 mg/kg. SE (n=10) in mice. The studies revealed significant and concentration dependent hepatoprotective potential of 'IF' as it reversed the majority of the altered hepatic parameters in experimental liver damage in rodents.

Adaptogenic activity of glyco-peptido-lipid fraction from the alcoholic extract of Trichopus zeylanicus Gaerten (part II).

Anti-stress activity was carried out on glyco-peptido-lipid (AF) fraction from the alcoholic extract of Trichopus zeylanicus Gaerten and demonstrated against a battery of tests in rats and mice. AF exhibited significant anti-stress activity in dose-related manners in all the parameters studied against different models used to induce non-specific stress viz physical and chemically. The major parameters studied were immobilization induced gastric ulceration, adjuvant-induced trauma (Stress); humoral antibody synthesis in normal and immuno-suppressed mice and delayed type of hypersensitivity (DTH) reaction, chemically stress-induced alteration in hepatic function and anti-oxidant activity. The extract of Withania somnifera root (a commercial preparation available locally, Dabur India ltd.) was used to compare the results. In the safety evaluation study the maximum tolerance dose (MTD) and oral LD50 were found to be more than 3000 mg/kg, with no signs of abnormalities or any mortality observed for 15 days period under observation after single dose of drug administration. Feeding behaviour and fecal output were normal.

Adaptogenic activity of a novel withanolide-free aqueous fraction from the roots of Withania somnifera Dun. (Part II).

In the Indian traditional system of medicine Withania somnifera Dun. is widely regarded as the Indian Ginseng. A new withanolide-free hydrosoluble fraction was isolated from the roots of Withania somnifera Dun. and was evaluated for putative antistress activity against a battery of tests to delineate the activity of this fraction. The latter fraction exhibited significant antistress activity in a dose-related manner (Singh et al., 2001) and was further studied against chemical and physical induced stress in rats and mice. The extract of Withania somnifera root (a commercial preparation available locally) was also used to compare the results. A preliminary acute toxicity study in mice showed a good margin of safety with a high therapeutic index.

Anti-inflammatory activity of 'TAF' an active fraction from the plant Barleria prionitis Linn.

'TAF' fraction from the methanol-water extract of Barleria prionitis Linn. was evaluated for anti-inflammatory and anti-arthritic activities against different acute and chronic animal test models. It exhibited significant anti-inflammatory activity against different inflammagens like carrageenan, histamine and dextran. The anti-inflammatory activity in adrenalectomised rats was maintained showing that the effect of fraction 'TAF' is not activated by the pituitary-adrenal axis. Significant anti-arthritic activity was observed in adjuvant-induced polyarthritis test in rats. 'TAF' also showed inhibition of vascular permeability and leucocytes migration in vivo into the site of inflammatory insult.Ibuprofen (Cadilla India Ltd., Mumbai) was used as a standard reference drug. The oral (p.o.) LD(50) was more than 3000mg/kg, with no signs of abnormalities or any mortality observed for 15 days after single-dose drug administration. The intraperitoneal (i.p.) LD(50) was found to be 2530mg/kg (+/-87mg/kg S.E.) [Proceedings of Society of Experimental Biological Medicine 57 (1944) 261].

Adaptogenic activity of a glyco-peptido-lipid fraction from the alcoholic extract of Trichopus zeylanicus Gaertn.

A glyco-peptido lipid fraction ("AF") from the alcoholic extract of Trichopus zeylanicus Gaertn. was evaluated for putative antistress activity in a battery of tests. "AF" exhibited significant antistress activity in dose dependent manner in all the parameters studied, against the different stresses use to induce non-specific stress. Ashwagandha, the commercial extract of Withania somnifera roots was used as control: A preliminary acute toxicity study in mice showed a good margin of safety, as the ALD50 value was more than 3000 mg/kg body wt. p.o. with no signs of abnormalities.

Hepatoprotective activity of indigtone--a bioactive fraction from Indigofera tinctoria Linn.

A bioactive fraction, indigtone (FA), obtained by fractionation of a petroleum ether extract of the aerial parts of Indigofera tinctoria, showed significant dose related hepatoprotective activity against CCl(4) induced liver injury in rats and mice. Hexobarbitone induced 'sleeptime', zoxazolamine induced 'paralysis time', levels of transaminases, bilirubin and total protein in serum were employed as indices of liver injury. Pre and post treatment with FA significantly reversed the majority of the parameters altered by the hepatotoxin. This indicated the preventive and restorative effect of FA in the process of CCl(4) induced liver damage. The fraction possessed a high therapeutic ratio, as no mortality was observed up to a dose of 2 g/kg p.o. in mice.

Adaptogenic activity of a novel, withanolide-free aqueous fraction from the roots of Withania somnifera Dun.

The practitioners of the traditional Indian system of medicine regard Withania somnifera Dun. as the 'Indian ginseng'. A new withanolide-free aqueous fraction was isolated from the roots of this plant and was evaluated for putative antistress activity against a battery of tests such as hypoxia time, antifatigue effect, swimming performance time, swimming induced gastric ulceration and hypothermia, immobilization induced gastric ulceration, autoanalgesia and biochemical changes in the adrenal glands. This bioactive fraction exhibited significant antistress activity in a dose-related manner in all the parameters studied. The extract of Withania somnifera root (a commercial preparation available locally) was used to compare the results. A preliminary acute toxicity study in mice showed a good margin of safety.

In vivo hepatoprotective activity of active fraction from ethanolic extract of Eclipta alba leaves.

The alcoholic extract of fresh leaves of the plant Eclipta alba (Ea), previously reported for is hepatoprotective activity was fractionated into three parts to chemically identify the most potent bioactive fraction. The hepatoprotective potential of the fraction prepared from extract was studied in vivo in rats and mice against carbon tetrachloride induced hepatotoxicity. The hepatoprotective activity was determined on the basis of their effects on parameters like hexobarbitone sleep time, zoxazolamine paralysis time, bromosulphaline clearance, serum transaminases and serum bilirubin. Fraction EaII (10-80 mg/kg, p.o.) containing coumestan wedelolactone and desmethylwedelolactone as major components with apigenin, luteolin, 4-hydroxybenzoic acid and protocateuic acid as minor constituents exhibited maximum hepatoprotective activity and is the active fraction for hepatoprotective activity of Eclipta alba leave. The acute toxicity studies have shown that like Ea, Fraction EaII also high safety margin.

3,4,5-Trihydroxy benzoic acid (gallic acid), the hepatoprotective principle in the fruits of Terminalia belerica-bioassay guided activity.

Compound I isolated from fraction TB5 of Terminalia belerica and finally identified as 3,4,5-trihydroxy benzoic acid (gallic acid) was evaluated for its hepatoprotective activity against carbon tetrachloride (CCl4)-induced physiological and biochemical alterations in the liver. The main parameters studied were hexobarbitone-induced sleep, zoxazolamine induced paralysis, serum levels of transaminases and bilirubin. The hepatic markers assessed were lipid peroxidation, drug metabolising enzymes, glucose-6-phosphatase and triglycerides. Administration of Compound I led to significant reversal of majority of the altered parameters. Our results confirm the presence of hepatoprotective activity in altered parameters. Our results confirm the presence of hepatoprotective activity in Compound I.

Actions of some flavonoids on specific and non-specific immune mechanisms.

The immunomodulatory activity of some flavonoids on antigen specific humoral and cell mediated immune responses and complement-mediated hemolysis has been investigated and compared with that of levamisole. Flavanone, 6-methoxyflavanone, 7-methoxyflavanone and bavachinin enhanced the sheep erythrocyte (SRBC), induced primary and secondary humoral immune responses in mice, and 6-hydroxyflavanone, 7-hydroxyflavanone and rutin inhibited primary response. Levamisole slighly stimulated the primary and suppressed the secondary response. All the flavonoids tested decreased the manifestation of SRBC induced delayed type hypersensitivity reaction and showed no effect on classical or alternative pathway dependent hemolysis. The studies revealed the significant immunomodulatory potential of these flavonoids, methoxy derivatives having immunostimulatory activity and hydroxy derivatives immunosuppressive properties.

Structure and hepatoprotective activity of a biflavonoid from Canarium manii.

Canarium manii (Burseraceae) was chemically investigated and the presence of the biflavonoid agathisflavone is reported for the first time from this plant. Pharmacologically, this biflavonoid in doses 50.0 mg and 100.0 mg given orally exhibited dose-dependent hepatoprotective activity against experimentally-induced carbon tetrachloride-hepatotoxicity in rats and mice.

An evaluation of Lawsonia alba extract as hepatoprotective agent.

The hepatoprotective activity of an ethanol-water (1:1) extract of Lawsonia alba has been studied against CCl4-induced liver toxicity. The effects of the extract on hexobarbitone-induced sleep, BSP clearance, and on certain biochemical parameters indicated its protective role. There was no effect on bile flow. The extract did not show any signs of toxicity and the minimum lethal dose was greater than 2.0 g/kg p.o. in mice.

Boerhaavia diffusa: a study of its hepatoprotective activity.

An alcoholic extract of whole plant Boerhaavia diffusa given orally exhibited hepatoprotective activity against experimentally induced carbon tetrachloride hepatotoxicity in rats and mice. The extract also produced an increase in normal bile flow in rats suggesting a strong choleretic activity. The extract does not show any signs of toxicity up to an oral dose of 2 g/kg in mice.