Cacalol Acetate, a Sesquiterpene from Psacalium decompositum, Exerts an Anti-inflammatory Effect through LPS/NF-KB Signaling in Raw 264.7 Macrophages.

Inflammatory diseases remain critical health problems worldwide. The search for anti-inflammatory drugs is a primary activity in the pharmaceutical industry. Cacalol is a sesquiterpene with anti-inflammatory potential that is isolated from Psacalium decompositum, a medicinal plant with several scientific reports supporting its anti-inflammatory activity. Cacalol acetate (CA) is the most stable form. Nevertheless, the participation of CA in the main signaling pathway associated with inflammation is unknown. Our aim was to study the anti-inflammatory effect of CA and to determine its participation in NF-κB signaling. In TPA-induced edema in mice, CA produced 70.3% inhibition. To elucidate the influence of CA on the NF-κB pathway, RAW 264.7 macrophages were pretreated with CA and then stimulated with LPS, evaluating NF-ΚB activation, IKK phosphorylation, IΚB-α, p65, cytokine expression, and COX-2 release and activity. CA inhibited NF-κB activation and its upstream signaling, decreasing phosphorylation IKB-α and p65 levels. CA also reduced expression and secretion of TNF-α, IL-1ß, and IL-6. Additionally, it decreased the activity and expression of COX-2 mRNA. These data support that CA regulates the NF-κB signaling pathway, which might explain, at least in part, its anti-inflammatory effect. CA is a bioactive molecule useful for the development of anti-inflammatory agents with innovative mechanisms of action.

Beetle (Ulomoides dermestoides) fat improves diabetes: effect on liver and pancreatic architecture and on PPARγ expression.

Ulomoides dermestoides is a beetle traditionally consumed to treat diabetes. In this study, we performed a composition analysis of U. dermestoides to obtain the principal fractions, which were used to assess the effect on glycemia, liver and pancreatic architecture, and PPARγ and GLUT4 expression. Normal mice and alloxan-induced diabetic mice were administered fractions of chitin, protein or fat, and the acute hypoglycemic effect was evaluated. A subacute study involving daily administration of these fractions to diabetic mice was also performed over 30 days, after which the liver and pancreas were processed by conventional histological techniques and stained with hematoxylin and eosin to evaluate morphological changes. The most active fraction, the fat fraction, was analyzed by gas chromatography-mass spectrometry (GC-MS), and PPARγ and GLUT4 mRNA expressions were determined in 3T3-L1 adipocytes. The protein and fat fractions exhibited hypoglycemic effects in the acute as well as in the 30-day study. Only the fat fraction led to elevated insulin levels and reduced glycemia, as well as lower intake of water and food. In the liver, we observed recovery of close hepatic cords in the central lobule vein following treatment with the fat fraction, while in the pancreas there was an increased density and percentage of islets and number of cells per islet, suggesting cellular regeneration. The GC-MS analysis of fat revealed three fatty acids as the major components. Finally, increased expression of PPARγ and GLUT4 was observed in 3T3-L1 adipocytes, indicating an antidiabetic effect.

CHRONIC UNPREDICTABLE MILD STRESS PROGRESSIVELY DISTURBS GLUCOSE METABOLISM AND APPETITE HORMONES IN RATS.

CONTEXT: Chronic stress is characterized by increased release of catecholamines, glucocorticoids and other neurohumoral factors, predisposing individuals to obesity, insulin resistance and vascular disease, pathologies considered priority health problems. Study of alterations induced by stress on metabolism in association with food intake modulatory hormones (insulin, leptin and ghrelin) is mandatory. OBJECTIVE: This research studied temporal course during 60 days of chronic unpredictable mild stress (CUMS) on glucose and lipids metabolism, and on the neuroendocrine system that regulates appetite-satiety balance. MATERIALS AND METHODS: Wistar rats were exposed to CUMS for 20, 40 and 60 days. Corticosterone stayed high during 60 days of CUMS; after 40 days, body weight, cholesterol and triglycerides decreased and glucose intolerance was evident at day 60; insulin and ghrelin increased at 20 and 40 days, respectively; leptin decreased after day 20. Data suggest that 60 days of CUMS progressively disturb metabolism of carbohydrates and lipids as well as food intake regulatory hormones, affecting the metabolism, and can lead to the development of chronic degenerative diseases, such as cardiovascular disease, metabolic syndrome and type 2 diabetes.

Antimicrobial and anti-inflammatory activities, wound-healing effectiveness and chemical characterization of the latex of Jatropha neopauciflora Pax.

ETHNOPHARMACOLOGICAL RELEVANCE: Jatropha neopauciflora Pax is an endemic species to Mexico, and its latex is used in traditional medicine to treat mouth infections when there are loose teeth and to heal wounds. In this research, we evaluated the antimicrobial activity, wound healing efficacy and chemical characterization of J. neopauciflora latex in a murine model. MATERIALS AND METHODS: The antibacterial activity was determined using Gram positive and negative strains, the antifungal activity was determined using yeast and filamentous fungi, and the wound healing efficacy of the latex was determined using the tensiometric method. The anti-inflammatory activity was evaluated using the plantar oedema model in rats, administering the latex orally and topically. Cytotoxic activity was determined in vitro in two different cell lines. Antioxidant capacity, total phenolics, total flavonoids, reducing carbohydrates and latex proteins were quantified. The latex analysis was performed by High Performance Liquid Chromatography (HPLC). Finally, molecular exclusion chromatography was performed. RESULTS: The latex demonstrated antibacterial activity. The most sensitive strains were Gram positive bacteria, particularly S. aureus (MIC=2mg/mL), and the latex had bacteriostatic activity. The latex did not show antifungal activity. The latex demonstrated a wound-healing efficacy, even the positive control (Recoveron). The orally administered latex demonstrated the best anti-inflammatory activity and was not toxic to either of the 2 cell lines. The latex had a high antioxidant capacity (SA50=5.4µg/mL), directly related to the total phenolic (6.9mg GAE/mL) and flavonoid (12.53µg QE/mL) concentration. The carbohydrate concentration was 18.52µg/mL, and fructose was the most abundantly expressed carbohydrate in the latex (14.63µg/mL, 79.03%). Additionally, the latex contained proteins (7.62µg/mL) in its chemical constitution. As secondary metabolites, the HPLC analysis indicated the presence of phenols and flavonoids. CONCLUSIONS: The J. neopauciflora latex promotes the wound healing process by avoiding microorganism infections, inhibiting inflammation and acting as an antioxidant.

BIOLOGICAL PROPERTIES AND CHEMICAL COMPOSITION OF JATROPHA NEOPAUCIFLORA PAX.

BACKGROUND: Ethnopharmacological relevance. Jatropha neopauciflora (Pax) is an endemic species of the Tehuacan- Cuicatlan Valley, Mexico. This species has long been used as a remedy to alleviate illnesses of bacterial, fungal and viral origin. Aim of the study. Experimentally test the traditional use of Jatropha neopauciflora in Mexican traditional medicine. MATERIALS AND METHODS: The methanol extract (MeOH1), of Jatropha neopauciflora (Euphorbiaceae) was obtained by maceration. Next, the methanol (MeOH2) and hexane (H) fractions were obtained. The essential oil was obtained by hydro- distillation. The extract, fractions and essential oil were analyzed by GC-MS. The antimicrobial activity was measured by the disc diffusion agar and radial inhibition growth methods. RESULTS: The extract and fractions showed antibacterial activity against eleven strains (five Gram-positive and six Gram- negative) and a bacteriostatic effect in the survival curves for Staphylococcus aureus and Vibrio cholerae. The extract and fractions were also shown to have antifungal activity, particularly against Trichophyton mentagrophytes (CF50 = MeOH1: 1.07 mg/mL, MeOH2: 1.32 mg/mL and H: 1.08 mg/mL). The antioxidant activity of MeOH1 (68.6 µg/mL) was higher than for MeOH2 (108.1 µg/mL). The main compounds of the essential oil were ß-pinene, 1,3,8-p-menthatriene, ledene, m- menthane, linalyl acetate and 3-carene. The main compounds of MeOH1 were ß-sitosterol, lupeol and pyrogallol; the main compounds of MeOH2 were ß-sitosterol, spathulenol, coniferyl alcohol and lupeol; and the main compounds of H were ß-sitostenone, γ-sitosterol and stigmasterol. CONCLUSIONS: This study indicates that Jatropha neopauciflora is a potential antibacterial and antifungal agent.

Cucurbita ficifolia (Cucurbitaceae) modulates inflammatory cytokines and IFN-γ in obese mice.

This study investigated the effect of aqueous extract of Cucurbita ficifolia Bouché on systemic chronic inflammation in an obesity model induced by monosodium glutamate (MSG) via modulating the expression of adipokines (TNF-α, IL-6, resistin, and adiponectin) and immune-regulatory cytokines (IFN-γ and IL-10). Cucurbita ficifolia extract was administered daily by gavage to lean and MSG-obese mice for 30 days. At the end of treatment, cytokine mRNA expression in adipose tissue was determined by real-time polymerase chain reaction (PCR), and the protein levels of these cytokines were also quantified by enzyme-linked immunosorbent assay (ELISA). Cucurbita ficifolia extract decreased body mass and inflammation in MSG-obese mice by reducing the expression of TNF-α and IL-6; these decreases were parallel to significant reductions in protein levels. The extract also increased protein levels of IL-10 in lean mice and IFN-γ in both lean and MSG-obese mice. In conclusion, C. ficifolia extract modulates systemic chronic inflammation in MSG-obese mice and could have a beneficial effect on the adaptive immune system in obesity.

Antidepressant-like activity of Tagetes lucida Cav. is mediated by 5-HT(1A) and 5-HT(2A) receptors.

It has been demonstrated that the aqueous extract of Tagetes lucida Cav. shows an antidepressant-like effect on the forced swimming test (FST) in rats. The aim of this study was to analyze the participation of the serotoninergic system in the antidepressant-like effect of the aqueous extract of T. lucida. Different doses of the extract of T. lucida were administered at 72, 48, 24, 18 and 1 h before FST. The animals were pretreated with a 5-HT1A receptor antagonist (WAY-100635, 0.5 mg/kg), a 5-HT2A receptor antagonist (ketanserin, 5 mg/kg), a ß-noradrenergic receptor antagonist (propranolol, 200 mg/kg), and with a α2-noradrenergic receptor antagonist (yohimbine, 1 mg/kg) alone or combined with the extract and pretreated with a serotonin synthesis inhibitor (PCPA) before treatment with 8-OH-DPAT + the extract of T. lucida. In addition, suboptimal doses of the 5-HT1A agonist (8-OH-DPAT) + non-effective dose of extract was analyzed in the FST. To determine the presence of flavonoids, the aqueous extract of T. lucida (20 µl, 4 mg/ml) was injected in HPLC; however, a quercetin concentration of 7.72 mg/g of extract weight was detected. A suboptimal dose of 8-OH-DPAT + extract of T. lucida decreased immobility and increased swimming and climbing. An antidepressant-like effect with the aqueous extract of T. lucida at doses of 100 and 200 mg/kg was observed on the FST with decreased immobility behavior and increased swimming; however, this effect was blocked by WAY-100635, ketanserin and PCPA but not by yohimbine and propranolol, suggesting that the extract of T. lucida could be modulating the release/reuptake of serotonin.

Effect of an aqueous extract of Cucurbita ficifolia Bouché on the glutathione redox cycle in mice with STZ-induced diabetes.

ETHNOPHARMACOLOGICAL IMPORTANCE: Cucurbita ficifolia is used in Mexican traditional medicine as an anti-diabetic and anti-inflammatory agent and its actions can be mediated by antioxidant mechanisms. Disturbance in the homeostasis of glutathione has been implicated in the etiology and progression of diabetes mellitus and its complications. MATERIAL AND METHODS: It was evaluated, the effect of an aqueous extract of Cucurbita ficifolia on glycemia, plasma lipid peroxidation; as well as levels of reduced (GSH) and oxidized (GSSG) glutathione and activities of enzymes involved in glutathione redox cycle: glutathione peroxidase (GPx) and glutathione reductase (GR) in liver, pancreas, kidney and heart homogenates of streptozotocin-induced diabetic mice. RESULTS: Increased blood glucose and lipid peroxidation, together with decreased of GSH concentration, GSH/GSSG ratio and its redox potential (E(h)), and enhanced activity of GPx and GR in liver, pancreas and kidney were the salient features observed in diabetic mice. Administration of the aqueous extract of Cucurbita ficifolia to diabetic mice for 30 days, used at a dose of 200 mg/kg, resulted in a significant reduction in glycemia, polydipsia, hyperphagia and plasma lipid peroxidation. Moreover, GSH was increased in liver, pancreas and kidney, and GSSG was reduced in liver, pancreas and heart, therefore GSH/GSSG ratio and its E(h) were restored. Also, the activities involved in the glutathione cycle were decreased, reaching similar values to controls. CONCLUSIONS: An aqueous extract of Cucurbita ficifolia with hypoglycemic action, improve GSH redox state, increasing glutathione pool, GSH, GSH/GSSG ratio and its E(h), mechanism that can explain, at least in part, its antioxidant properties, supporting its use as an alternative treatment for the control of diabetes mellitus, and prevent the induction of complications by oxidative stress.

Antioxidant and anti-inflammatory effects of a hypoglycemic fraction from Cucurbita ficifolia Bouché in streptozotocin-induced diabetes mice.

Type 2 diabetes is characterized by oxidative stress and a chronic low-grade inflammatory state, which also play roles in the pathogenesis of this disease and the accompanying vascular complications by increasing the production of free radicals and pro-inflammatory cytokines. Cucurbita ficifolia Bouché (C. ficifolia) is an edible Mexican plant whose hypoglycemic activity has been demonstrated in several experimental and clinical conditions. Recently, D-chiro-inositol has been proposed as the compound responsible for the hypoglycemic effects; however, the antioxidant and anti-inflammatory potential of this plant has not yet been explored. The aim of this research is to study the influence of a hypoglycemic, D-chiro-inositol-containing fraction from the C. ficifolia fruit (AP-Fraction) on biomarkers of oxidative stress, as well as on the inflammatory cytokines in streptozotocin-induced diabetes. The AP-Fraction obtained from the mature fruit of C. ficifolia contained 3.31 mg of D-chiro-inositol/g of AP-Fraction. The AP-Fraction was administrated daily by gavage to normal mice for 15 days as a preventive treatment. Then these animals were given streptozotocin, and the treatments were continued for an additional 33 days. Pioglitazone was used as a hypoglycemic drug for comparison. Administration of the AP-Fraction significantly increased glutathione (GSH) and decreased malondialdehyde (MDA) in the liver without significantly affecting the levels in other tissues. The AP-Fraction reduced TNF-α and increased IL-6 and IFN-γ in serum. Interestingly, the AP-Fraction also increased IL-10, an anti-inflammatory cytokine. These results suggest that C. ficifolia might be used as an alternative medication for the control of diabetes mellitus and that it has antioxidant and anti-inflammatory properties in addition to its hypoglycemic activity.

Anti-inflammatory and antioxidant effects of a hypoglycemic fructan fraction from Psacalium peltatum (H.B.K.) Cass. in streptozotocin-induced diabetes mice.

ETHNOPHARMACOLOGICAL IMPORTANCE: Psacalium peltatum (H.B.K.) Cass. (Asteraceae) is used medicinally to treat diabetes, rheumatic pains, as well as gastrointestinal and kidney ailments. Previous pharmacological and chemical assays have demonstrated that an aqueous fraction from Psacalium peltatum (AP-fraction) contains a carbohydrate-type compound with hypoglycemic activity. Nevertheless, studies have not yet considered the hypoglycemic action of the AP-faction by sub-chronic administration nor on other healing properties, some of which might be associated with DM2 and other inflammatory processes. AIM OF STUDY: To determine whether a hypoglycemic carbohydrate fraction (AP-fraction) from Psacalium peltatum roots has antioxidant and anti-inflammatory effects in streptozotocin-induced diabetes mice. MATERIAL AND METHODS: Healthy mice received either saline, the AP-fraction with a high content of fructans, or pioglitazone (a positive control) daily by gavage. After 15 days of treatment, these animals received a single intraperitoneal administration of streptozotocin and all treatments were continued for additional 33 days. The antioxidant and anti-inflammatory properties of the AP-fraction were evaluated through the quantification of biomarkers of oxidative stress (glutathione (GSH) and malondialdehyde (MDA)) and inflammation (interleukin (IL)-6, tumor necrosis factor alpha (TNF-α), interferon-gamma (IFN-γ), and IL-10). RESULTS: The AP-fraction reduced glycemia and the glycated hemoglobin. Furthermore, animals treated with the AP-fraction had increased GSH, while MDA was decreased in the liver and the heart, without changes in the kidneys and the pancreas. The AP-fraction significantly reduced TNF-α serum levels but did not modify IL-6; in addition, this fraction increased IFN-γ and IL-10 levels. The increase in IL-10 levels may indicate an inhibition of the production of pro-inflammatory cytokines such as TNF-α, whereas the increase in IFN-γ might be indicative of a beneficial effect on the immune system. CONCLUSIONS: The AP-fraction hypoglycemic fructans from Psacalium peltatum roots showed antioxidant and anti-inflammatory properties in mice with streptozotocin-induced diabetes. The Psacalium peltatum hypoglycemic fructans may be valuable in preventing insulin resistance, as well as the development and progression of diabetic complications caused by chronic inflammation.

Glycine regulates inflammatory markers modifying the energetic balance through PPAR and UCP-2.

Obesity is widely recognized as cause of metabolic syndrome and cardiovascular disease. It is provoked by imbalance between the spending and consumption of energy associated with a chronic inflammatory condition due to excessive storage of fat tissue. Obese patients have an impaired inflammatory profile that contributes to the development of vascular complications, with fat tissue being partially responsible for controlling both processes: energy balance (through PPAR) and inflammatory condition (through inflammatory markers). White adipose tissue produces cytokines (IL-6, TNF-α, resistin, adiponectin, etc.) and participates in a broad spectrum of processes. Recently, glycine has been reported to have anti-inflammatory properties which reduce TNF-α and IL-6 levels and increase adiponectin in 3T3-L1 adipocytes and in fat tissue of obese mice. In this study, the possible regulatory role of glycine on some factors involved in storage and energy burning (PPAR-γ, PPAR-α, PPAR-δ and UCP-2) was analyzed in lean and monosodium glutamate-induced obese mice (MSG/Ob mice). Glycine clearly increased fat tissue PPAR-γ expression in lean but not in MSG/Ob mice. The PPAR-γ and PPAR-α liver expression was repressed in both groups of mice, while the expression of PPAR-δ decreased only in lean mice. Interestingly, glycine treatment also suppressed the expression of UCP-2, TNF-α and IL-6 in lean mice, and increased adiponectin and insulin serum levels. In conclusion, glycine regulates the production of inflammatory cytokines through PPAR-γ. These results provide clues on glycine signaling mechanisms as an anti-inflammatory agent that might be useful for treatment of metabolic and vascular complications associated to inflammation in obesity.

Glycine regulates the production of pro-inflammatory cytokines in lean and monosodium glutamate-obese mice.

Fat tissue plays an important role in the regulation of inflammatory processes. Increased visceral fat has been associated with a higher production of cytokines that triggers a low-grade inflammatory response, which eventually may contribute to the development of insulin resistance. In the present study, we investigated whether glycine, an amino acid that represses the expression in vitro of pro-inflammatory cytokines in Kupffer and 3T3-L1 cells, can affect in vivo cytokine production in lean and monosodium glutamate-induced obese mice (MSG/Ob mice). Our data demonstrate that glycine treatment in lean mice suppressed TNF-alpha transcriptional expression in fat tissue, and serum protein levels of IL-6 were suppressed, while adiponectin levels were increased. In MSG/Ob mice, glycine suppressed TNF-alpha and IL-6 gene expression in fat tissue and significantly reduced protein levels of IL-6, resistin and leptin. To determine the role of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) in the modulation of this inflammatory response evoked by glycine, we examined its expression levels in fat tissue. Glycine clearly increased PPAR-gamma expression in lean mice but not in MSG/Ob mice. Finally, to identify alterations in glucose metabolism by glycine, we also examined insulin levels and other biochemical parameters during an oral glucose tolerance test. Glycine significantly reduced glucose tolerance and raised insulin levels in lean but not in obese mice. In conclusion, our findings suggest that glycine suppresses the pro-inflammatory cytokines production and increases adiponectin secretion in vivo through the activation of PPAR-gamma. Glycine might prevent insulin resistance and associated inflammatory diseases.

Antidepressant-like effects of Tagetes lucida Cav. in the forced swimming test.

AIM OF THE STUDY: Tagetes lucida (Asteraceae), has been referred in Mexican traditional medicine for the treatment of different central nervous system (CNS) diseases, mainly depression. Nevertheless, the available scientific information about this species is scarce and there are no reports related to its possible effect on the CNS. In this work, the antidepressant-like effect of extract of Tagetes lucida was evaluated in rats, as well as its potential adverse effects on male sexual behavior (MSB). MATERIALS AND METHODS: Antidepressant activity was studied using forced swimming test (FST), motor activity in the open-field test and on MSB in sexually experienced male. The aqueous extract of Tagetes lucida in doses of 5, 10, 50, 100 and 200mg/(kgday)(-1) were administered orally for 14 consecutive days and evaluated on day 14, 2h after the last dose treatment. Fluoxetine (10mg/(kgday)(-1), p.o.) was used as the control positive. RESULTS: The aqueous extract (10, 50, 100mg/(kgday)(-1)) significantly reduced immobility and increased swimming without affecting climbing behavior in the FST. These same doses were not able to modify neither the motor activity nor the MSB. CONCLUSION: These data indicate that the extract of Tagetes lucida possesses antidepressant-like properties in rats.

Acute and chronic hypoglycemic effect of Ibervillea sonorae root extracts-II.

Ibervillea sonorae's root, or "wareque" (Cucurbitaceae), is widely used in Mexican traditional medicine for the control of diabetes mellitus. In the present study, the hypoglycemic effects produced by the acute and chronic administration of various extracts of Ibervillea sonorae were investigated. Both the traditional preparation (aqueous decoction) and the raw extract (juice) from the root resulted in significant reductions of glycemia in healthy mice after intraperitoneal administration at a dose of 600 mg/kg. Additionally, ground dried root was used to obtain a dichloromethane (DCM) extract and a methanol (MeOH) extract. The DCM extract induced a clear reduction of glycemia in healthy (P < 0.05) and in alloxan-diabetic mice. The intraperitoneally administered DCM extract caused a severe hypoglycemia that produced lethality in all the treated animals when doses of 300 and 600 mg/kg body weight were used. Since the DCM extract showed a marked hypoglycemic activity, it was administered daily per os to alloxan diabetic rats, employing corn oil and tolbutamide as controls. After 41 days of DCM extract administration at a dose of 300 mg/kg/day, diabetic rats showed improvement in glycemia, body weight, triglycerides, and GPT in comparison with the diabetic control group. Total cholesterol, GOT, and uric acid blood levels were not affected.

Evaluation of the hypoglycemic effect of Cucurbita ficifolia Bouché (Cucurbitaceae) in different experimental models.

Acute hypoglycemic effects of freeze-dried juice of Cucurbita ficifolia Bouché (Cucurbitaceae) fruits were studied in healthy and alloxan-diabetic mice. C. ficifolia fruit administered by intraperitoneal route produced, in a dose-dependent manner, a significant decrease of the glycemia in healthy mice. Although oral route of C. ficifolia fruit juice also caused significant reductions of blood glucose levels in healthy mice, the effect was minor. The juice administered by intraperitoneal route showed an acute hypoglycemic effect in alloxan-diabetic mice. In addition, daily oral administration of this preparation showed a highly significant reduction of the glycemia after 14 days of treatment. Freeze- dried juice caused acute toxicity when administered intraperitoneally, and also when it was administered daily by the oral route.

Investigation on the hypoglycaemic effects of extracts of four Mexican medicinal plants in normal and alloxan-diabetic mice.

The hypoglycaemic activities of four water ethanol extracts (WEE) prepared from Bidens pilosa L., Salvia officinalis L., Psacalium peltatum H.B.K. (Cass) and Turnera diffusa Willd. were investigated in healthy and alloxan-diabetic mice. The WEE of S. officinalis significantly reduced the blood glucose of fasting normal mice 120 (15.7%) and 240 min (30.2%) after intraperitoneal administration (p < 0.05). The WEE of P. peltatum and B. pilosa also significantly diminished glycaemia in healthy mice at 240 min (19.6% and 13.8%, respectively). In mildly diabetic mice, the WEE of P. peltatum lowered the basal blood glucose level 120 (16%) and 240 min (54%) after intraperitoneal administration (p < 0.05 and p < 0.01, respectively). The WEE of B. pilosa and S. officinalis also significantly diminished the hyperglycaemia in mildly diabetic mice at 240 mins (32.6% and 22.7%, respectively). The administration of these three extracts to animals with severe hyperglycaemia did not cause a significant decrease. The WEE of T. diffusa did not show any hypoglycaemic activity. Thus, three of the WEE studied conserved the hypoglycaemic activity originally detected in the traditional preparations of the studied antidiabetic plants. It appears that these extracts require the presence of insulin to show hypoglycaemic activity.

Hypoglycemic effect of extracts and fractions from Psacalium decompositum in healthy and alloxan-diabetic mice.

The hypoglycemic effect of the hexane, methanol and water extracts obtained from roots of Psacalium decompositum (Asteraceae) was investigated in fasting healthy mice. Only the water extract significantly reduced blood glucose in a dose-dependent manner in normal mice after intraperitoneal administration (P<0.05). This water extract was macerated with methanol obtaining a precipitate (WMP fraction), and it was studied in healthy and alloxan-diabetic mice. The WMP fraction showed significant hypoglycemic activity in healthy and mild diabetic mice, but the administration of this fraction to animals with severe diabetes did not cause any significant decrease in blood glucose levels. Two polysaccharide components isolated from WMP fraction showed hypoglycemic effect when tested in healthy mice.

Hypoglycemic activity of root water decoction, sesquiterpenoids, and one polysaccharide fraction from Psacalium decompositum in mice.

The hypoglycemic activity of Psacalium decompositum (Asteraceae) was investigated in fasting healthy mice and alloxan-diabetic mice. The freeze-dried water decoction significantly reduced the blood glucose in normal mice (from 50.9 +/- 4.7 to 32.5 +/- 3.1 mg/dl) and in mild diabetic mice (from 208.5 +/- 13.0 to 52.3 +/- 7.0 mg/dl), 240 min after intraperitoneal administration (P < 0.005). This preparation also diminished fasting glycemia in severe diabetic mice, but the effects were minor (from 394.4 +/- 9.4 to 289.3 +/- 39.5 mg/dl). The main sesquiterpenoid constituents from P. decompositum roots, cacalol, cacalone and maturin, as well as the transformation product cacalol acetate, did not show a hypoglycemic effect on healthy mice. Nevertheless, two polysaccharide fractions (F1 and F3) obtained from the freeze-dried water extract significantly reduced the fasting glycemia in healthy mice. The best results were obtained with the F1 fraction.

Effects of three Mexican medicinal plants (Asteraceae) on blood glucose levels in healthy mice and rabbits.

The effects of Psacalium decompositum, Psacalium peltatum and Acourtia thurberi (Asteraceae) on blood glucose levels were investigated in fasting mice and temporally hyperglycemic rabbits. The root decoction of P. decompositum reduced the blood glucose of normal mice from 49.1 +/- 3.8 to 35.7 +/- 2.0 mg/dl after intraperitoneal administration (P < or = 0.005) and significantly lowered the hyperglycemic peak (17.1%) in rabbits with temporal hyperglycemia. P. peltatum and A. thurberi decoctions also diminished fasting glycemia in mice and hyperglycemia in rabbits, but the effects were minor. A preliminary phytochemical study using thin layer chromatography showed that water decoctions of the three roots contained alkaloids and sugars. P. decompositum and P. peltatum showed the presence of maturine. However, other furoeremophylanes, such as cacalol and cacalone were only present in P. decompositum. A. thurberi root water decoction showed the presence of the benzoquinone perezone, and its derivative pipitzol.