A chloroform extract obtained from a decoction of Ficus carica leaves improves the cholesterolaemic status of rats with streptozotocin-induced diabetes

The antidiabetic effects of Ficus carica leaf extracts have been reported previously. From the aqueous decoction of fig leaves, after treatment with HCI, centrifuging, treatment with sodium hydroxide (NaOH) and extraction with chloroform (CHCl3), the administration of the organic phase rats with streptozotocin-induced diabetes led to a decline in the levels of total cholesterol and an decrease in the total cholesterol/HDL cholesterol ratio (with respect to the control group), together with a reduction of the hyperglycaemia.     

High-resolution gas-chromatographic analysis of the secondary metabolites obtained by subcritical-fluid extraction from Colombian rue (Ruta graveolens L.)

Subcritical (CO(2)) extraction, carried out in a J&W Scientific High Pressure Soxhlet Extractor, was used to isolate secondary metabolites from leaves, flowers, stems and roots of Colombian rue (Ruta graveolens L.). The various extracts were analyzed by capillary chromatography, on an HP-5 (30 m) column, using nitrogen-phosphorus, flame ionization, and mass selective detection systems. Kováts indexes and mass spectra (electron impact, 70 eV) were employed for compound identification. The extracts from the various parts of rue studied had different compositions. The number of compounds detected at concentrations above 0.01% (w/w) in the extracts from leaves, flowers, stems and roots, was 78, 45, 25 and 24, respectively. 2-Nonanone (8.9%), 2-undecanone (13.4%), chalepensin (13.0%), and geijerene (19.3%) were the main constituents found in the extracts from rue leaves, flowers, stems and roots, respectively. Furanocoumarins, furoquinolines, hydrocarbons and benzodioxol derivatives were the main compound families found in all extracts, at total concentrations between 3.7 and 33.9%, depending on the part of the plant. The extraction method used has low environmental impact and produced solvent-free extracts in good yield with no pigments, waxes, resins, or high-molecular weight compounds which may interfere with the isolation and analysis of the alkaloids responsible for rue's biological activity, which were extracted in relatively high yield.     

黄荆提取物对棉蚜的生物活性

【目的】探讨黄荆Vitex negundo提取物对棉蚜Aphis gossypii的生物活性,并明确其中的有效成分,为进一步开发利用该杀虫植物提供理论基础。【方法】采用不同有机溶剂、超临界CO2萃取和水蒸气蒸馏3种提取方法,分别从黄荆的种子和叶片中提取活性物质。采用浸渍法测定了各提取物对棉蚜无翅成蚜的杀虫活性;并采用酸水提取法提取了其中的生物碱,采用毛细管点滴法测定黄荆生物碱对棉蚜生长发育及蜜露产生的影响。【结果】二氯甲烷种子提取物、甲醇种子提取物和水蒸气蒸馏得到的叶片精油对棉蚜无翅成蚜杀虫活性高,1 200 mg/L处理24 h校正死亡率分别达到86.98%,65.01%和85.27%。黄荆生物碱对棉蚜无翅成蚜有一定的忌避活性,20~40 mg/m L处理12 h时,忌避率在50%以上;对棉蚜无翅成蚜毒杀活性略低于黄荆种子二氯甲烷提取物,LD30浓度处理存活成蚜的产仔量和蜜露分泌量均较对照明显降低,处理到第10天棉蚜已经全部死亡,而对照组棉蚜第10天的存活率却为70%,生物碱处理后的9 d平均单雌棉蚜累计产仔量比对照减少了57.66%。排蜜频率、总排蜜量及单滴蜜露重量较对照处理组分别降低了13.18%,20.00%和8.79%。【结论】黄荆种子二氯甲烷提取物杀棉蚜活性最高,其中的生物碱是主要的杀蚜活性成分且对棉蚜生长发育及产仔和蜜露分泌具有一定的抑制作用。     

The influence of epidermal windows on the light environment within the leaves of six succulents

An omni-directional fibre optic microprobe was used to measure the quantity and quality of light within the leaves of six succulents having epidermal windows, three species having a subterranean growth habit (Haworthia truncata, Lithops olivacea, and Opthalmophyllum longum) and three growing above ground (Peperomia dolabriformis, P. graveolens, and the sprawling vine Senecio rowleyanus). Although light levels at most locations inside the leaves of all species were high, near those incident on the window surfaces, light levels inside the leaves of the two species of Peperomia often greatly exceeded incident light levels, indicating considerable light scattering and focusing by the leaf tissue. The spectral quality of light inside the leaves of all taxa reflected the absorption properties of chlorophyll, with most of the photons in the green wavelengths. Light quality and quantity inside the leaves did not correlate with the growth habit of the plants, the size of the window (as a proportion of the total leaf area), or location inside the leaf, although light levels generally declined and wavelengths increased deeper in the leaves. Application of reflective tape to the windows reduced internal light levels in L. olivacea and S. rowleyanus, although reductions were not always statistically significant. Although light levels throughout the leaves of P. graveolens were substantially and significantly reduced as a result of the application of reflective tape to its windows, the light levels even at the basal chlorenchyma on the abaxial side of the leaf remained high. In all species investigated, the levels of near-infrared radiation inside the leaves were surprisingly high, yet also declined deeper inside the succulent leaves. This near-infrared radiation may add to the heat load of these plants. Furthermore, application of reflective tape to the windows also reduced the amount of near-infrared radiation inside the leaves of the three succulents examined. These results led to a novel, testable hypothesis that may help to explain previous findings that application of reflective tape to the windows of the leaves of these succulents did not effect a reduction in photosynthetic activity.     

Composition and antioxidant activity of aqueous and ethanolic Pelargonium radula extracts

Pelargonium radula (Cav.) L'Hér is a plant with hypoglycaemic properties originating from South Africa. Since oxidative stress plays a major role in the development of diabetic complications, the aim of this study was to evaluate if P. radula, besides its glucose-lowering properties, can have additional beneficial effects on diabetes. For preparation of extracts fresh or dried leaves were extracted at 20 °C with either ethanol or water. Since P. radula is commercially cultivated for its essential oil, the residues obtained after steam distillation of essential oil from dry or fresh leaves were also included in the investigation. Content of phenols (total phenols, flavonoids and tannins) was determined in the extracts. Antioxidant activity was established as radical scavenging and chelating activity, reducing power and activity in β-carotene-linoleic acid assay. To establish possible intracellular effects of the extracts, lactate dehydrogenase (LDH) leakage was determined in Hep G2 cells with glucose induced oxidative stress. All the extracts were found to possess antioxidant activities and were able to reduce LDH leakage from Hep G2 cells. In addition to having excellent extraction yields the residues obtained after steam distillation of essential oil showed the most pronounced antioxidant activity in our study. The results of the present study suggest that P. radula leaf might be useful as complementary therapy in diabetes.     

Phytochemical analysis and in vitro evaluation of the biological activity against herpes simplex virus type 1 (HSV-1) of Cedrus libani A. Rich.

Cedrus libani are widely used as traditional medicine in Lebanon for treatment of different infection diseases. In the present study we reported the phytochemical composition analyzed by GC-MS of wood essential oil and cones and leaves ethanol extracts. The main components of wood essential oil were himachalol (22.50%), beta-himachalene (21.90%), and alpha-himachalene (10.50%). Leaves ethanol extract was characterized by a high content of germacrene d (29.40%). The same extract obtained from cones essentially contained alpha-pinene (51.0%) and beta-myrcene (13.0%). Moreover, we investigated extracts, essential oil, and identified compounds for their in vitro antiviral activities against herpes simplex virus type 1 (HSV-1). Cytotoxicity was evaluated by MTT assay in Vero cells. Cones and leaves ethanol extracts exhibited an interesting activity with IC50 of 0.50 and 0.66 mg/ml, respectively, at non-cytotoxic concentration. A comparable activity was found when essential oil was tested (IC50 of 0.44 mg/ml).     

SC-CO2和乙酸乙酯萃取芸香中活性成分的比较分析

为了探讨超临界二氧化碳(supercritical carbon dioxide, SC-CO2)技术与提取物的分级分离在萃取芸香活性成分的应用价值,本研究采用SC-CO2和乙酸乙酯萃取芸香中植物蜡和活性成分,并调查粒径和CO2流量对提取产量的影响。在250 bar、40℃条件下提取,并使第一个分离器冷却到-10℃,可获得较好的提取效率。当粒径较小时,提取过程更快,即内部传质控制该过程。分级分离可选择性去除表皮植物蜡,约占由SC-CO2处理产生的总提取物的77.5%W/W。第二分离器中的获得的提取物中活性化合物可达86.3%W/W。随后采用气相色谱-质谱联用仪(gas chromatography-mass spectrometry, GC-MS)分析表明,乙酸乙酯提取物低于SC-CO2提取物的萃取效率,主要是由于提取物中含有大量的植物蜡。本研究为超临界二氧化碳技术在萃取芸香活性成分方面的提供技术参考。     

Developmental Control of Monoterpene Content and Composition in Micromeria fruticosa(L.) Druce

White micromeria [ Micromeria fruticosa(L.) Druce, Lamiaceae]is a dwarf evergreen shrub endemic to Israel and the easternMediterranean. The essential oil of M. fruticosa largely comprisesthe monoterpenes (+)-pulegone and isomenthol. Seasonal variationsin the levels and composition of the monoterpene componentsof the essential oil of M. fruticosa were noted. During thesummer months, when growth rates are maximal, (+)-pulegone constitutedup to 80% of the essential oil, while in early winter, a periodof growth-rest in Mediterranean climates, (+)-pulegone levelsdropped dramatically to a few percent, while isomenthol constitutedup to 80% of the essential oil. Experiments in which plantswere grown under controlled temperature and photoperiodic regimesindicated that the variation was not directly associated withenvironmental conditions, but the composition of the monoterpenesobtained from mature flowering branches was strikingly differentto that obtained from young vegetative branches. Additionally,there were marked differences in the extracts obtained fromindividual leaf pairs from the same plant. In young upper leaves,the main component was (+)-pulegone, constituting up to 70%of the total essential oil extracted. During maturation, levelsof this component dropped steadily, becoming negligible in olderleaves. Reciprocally, levels of isomenthol increased steadilywith leaf position, from 0% in young leaves to more than 60%in older leaves. Less pronounced but significant decreases inthe levels of limonene, isopulegone, piperitenone oxide, germacreneD and bicyclogermacrene, accompanied by increases in neoiso-isopulegol,isopulegol, neoisomenthol and pulegol were noted. This studyindicates that the strong seasonal variation observed in thechemical composition of M. fruticosa is primarily due to leafmaturation. Copyright 2001 Annals of Botany Company Micromeria fruticosa, Lamiaceae, essential oil, leaf age, monoterpenes, (+)-pulegone, isomenthol, pulegol     

Antifungal effects of herbal essential oils alone and in combination with ketoconazole against Trichophyton spp

AIMS: To determine the effects of herbal essential oils on Trichophyton spp. growth and to evaluate the effects of Pelargonium graveolens oil and its main components citronellol and geraniol combined with ketoconazole against Trichophyton spp. METHODS AND RESULTS: Growth inhibition of six Trichophyton spp. by herbal essential oils was accessed and the combined effects of P. graveolens oil and its main components citronellol and geraniol were evaluated using a checkerboard microtitre assay against T. schoenleinii, T. erinacei and T. soudanense. The essential oil fraction of P. graveolens and its main components, geraniol and citronellol, exhibited strong synergism with ketoconazole against T. schoenleinii and T. soudanense, with fractional inhibitory concentration (FIC) indices in the range of 0.18-0.38. CONCLUSIONS: The antifungal effects of ketoconazole against Trichophyton spp. are enhanced significantly by administering it in combination with the essential oil fraction of P. graveolens or its main components, because of strong synergism, especially against T. soudanense and T. schoenleinii. SIGNIFICANCE AND IMPACT OF THE STUDY: The combination of ketoconazole and the essential oil fraction from P. graveolens or its main components for treatment of infections caused by Trichophyton species may reduce the minimum effective dose of ketoconazole, and thus minimize the side-effects of ketoconazole.     

Pharmacological evidence for the use of Cissus assamica as a medicinal plant in the management of pain and pyrexia

The existing therapeutic agents for the management of pain and pyrexia are not very efficient and accompanied by numerous side effects. Thus, new effective agents are the most needed. The present study investigates bioactivities and phytochemical screening of different parts of Cissus assamica (Vitaceae), a Bangladeshi tribal medicinal plant. Three plant parts stems, leaves and roots were collected, washed, dried, powdered and then prepared for cold extraction. The methanolic stems and leaves extracts were fractioned with four and two solvents respectively. Different plant extracts were then investigated for in vivo antinociceptive activity and only methanolic leaves extract was investigated for in vivo antipyretic activity. In Swiss-albino mice, 200 and 400 mg/kg body weight doses were used for all extracts. In the peripheral antinociceptive activity, the methanolic stem extract and its dichloromethane, chloroform, pet ether fractions and methanolic roots extract at their both doses showed significant antinociceptive responses when compared to standard diclofenac sodium (60.49% inhibition). In the central antinociceptive activity, the response was found significant for methanolic stem and methanolic roots extract in their both doses compared to standard morphine. In antipyretic activity, methanolic leaves extract significantly reduced pyrexia level at 400 and 200 mg/kg body weight doses after two, three and 4 h of administration when compared to standard. So our findings indicate that this plant possesses noteworthy pharmacological activities which may be a basis for further researches to establish a possible mode of action of its different parts.     

Potential allelochemicals from the essential oil of Ruta graveolens

The essential oil of aerial parts of Ruta graveolens was obtained by hydrodistillation with a 0.74% yield on a dry weight basis. Thirty-eight components were identified by GC and GC-MS analyses. 2-Ketones predominated in the essential oil, with undecan-2-one (46.8%) and nonan-2-one (18.8%) as the main constituents. The essential oil and some of its constituents were tested for their allelopathic activity in vitro on radish germination and radicle growth in light and darkness. The essential oil and some of its minor constituents were effective and dose-dependent inhibitors of both the germination and radicle growth; 2-ketones are not active. The possible allelopathic activity of rue essential oil and some its isolated constituents is reported.     

元宝草挥发油化学成分的研究

目的：首次研究元宝草叶及果实挥发油的成分,并比较它们的化学成分。方法：元宝草的叶和果实中的挥发油分别经同时蒸馏萃取的挥发油提取器提取（水蒸气蒸馏、乙酸乙酯萃取）,通过气相色谱－质谱分析,结合计算机检索技术对其化学成分进行分离和鉴定,应用色谱峰面积归一化法测定各成分的相对百分含量。结果：从元宝草叶及果实中分别鉴定了30和44种成分,各占挥发油的总量的85．13％和63．26％。叶与果实挥发油的化学成分相差很大。     

The effects of Coptidis Rhizoma extract on a hypercholesterolemic animal model

The serum cholesterol (total, free, esterified, low density lipoprotein (LDL) and oxidized LDL) levels of rats fed a diet containing, by weight, 1% cholesterol and 0.5% cholic acid increased, as compared with those of rats fed a normal diet. The levels, especially of total cholesterol, LDL and oxidized LDL, were reduced significantly in a dose-dependent manner, in rats given Coptidis Rhizoma extract orally at doses of 50 and 100 mg/kg body wt./day for 30 days. These results indicate that Coptidis Rhizoma extract is effective in reducing the pathological damage caused by hypercholesterolemia, through lowering of serum cholesterol levels. In addition, Coptidis Rhizoma extract reduced the level of liver cholesterol, but it did not reduce that of fecal cholesterol, suggesting that the cholesterol level-lowering effect resulted from the reduction of cholesterol synthesis, not the enhancement of its excretion. Furthermore, the serum thiobarbituric acid-reactive substance level decreased after oral administration of Coptidis Rhizoma extract, indicating that Coptidis Rhizoma could prevent hypercholesterolemic disease through reducing lipid peroxidation. This study demonstrates that Coptidis Rhizoma may be a useful therapy for hypercholesterolemia through reducing oxidative stress and cholesterol levels.     

Reduction of hyperlipidemia in the LA/N-corpulent rat by dietary fish oil containing n-3 fatty acids

The LA/N rat, when homozygous for the corpulent gene (cp/cp), is obese, hyperphageous, hyperinsulinemic, hypertriglyceridemic and prone to the development of vascular and myocardial lesions. The hypertriglyceridemia, which in 3-month-old cp/cp males is 282 +/- 42 mg/dl and in females, 512 +/- 83 mg/dl, results from the presence of a large triacylglycerol-rich VLDL. The moderate hypercholesterolemia in these animals is largely due to markedly elevated HDL levels, which reach 172 +/- 21 mg total lipid/dl in males and 154 +/- 22 mg total lipid/dl in females. The LA/N-cp rat is thus an interesting animal model of endogenous hypertriglyceridemia in which to examine the hypolipidemic effects of pharmacological agents and also dietary oil supplements containing the n-3 fatty acids. In this study, 1-month-old male and female cp/cp rats were fed a normal low fat laboratory chow supplemented with either 10% olive oil or 10% redfish (Sebastes marinus) oil ad libitum for a period of 2 months. The redfish oil contained 4.9 +/- 0.1% of its total fatty acids as eicosapentaenoic (20:5(n-3)) and 2.3 +/- 0.5% as docosahexaenoic acid (22:6(n-3)), the predominant fatty acids being gondoic (20:1(n-3)), 21.9 +/- 0.9% and cetoleic acid (22:1(n-11)), 21.7 +/- 1.7%, which are of dietary origin. Daily caloric intake was similar to the oil-fed versus control rats. However, the oil-fed animals weighed significantly more than the controls after 2 months of oil supplementation. Redfish oil reduced serum triacylglycerols by 54% in males and 45% in females after 2 months. VLDL levels, after the same time period, were reduced by 44% in males and 39% in females. HDL lipid mass was significantly reduced in both sexes (by 27% in males and 49% in females). However, the levels remained above those of male LA/N +/+ rats of the same age and Long-Evens rats. Olive oil feeding significantly reduced serum cholesterol, triacyglycerols and phospholipids in male but only cholesterol and phospholipids in female animals. This oil had no significant effect upon VLDL total lipid levels in either sex, but significantly increased the particle diameter with a concomitant reduction in the cholesterol and phospholipid content. HDL total lipid levels were unaffected: However, HDL total cholesterol increased significantly in males only. Both oils markedly reduced serum LDL levels in both sexes.(ABSTRACT TRUNCATED AT 400 WORDS)     

Moderate doses of EPA and DHA from re-esterified triacylglycerols but not from ethyl-esters lower fasting serum triacylglycerols in statin-treated dyslipidemic subjects: Results from a six month randomized controlled trial

Recently, in a supplementation study over six months, it has been demonstrated that re-esterified omega-3 fatty acid triacylglycerols (n3-FA-rTAGs) led to a higher increase in omega-3-index compared to identical doses of n3-FA ethyl-esters (n3-FA-EEs), suggesting a better long-term bioavailability. The aim of this study was to examine whether differences occur between the two forms in affecting fasting serum lipid levels. 150 dyslipidemic statin-treated participants were randomized to corn oil as a placebo or fish oil either as rTAG or EE in identical doses (1.01 g EPA+0.67 g DHA). No changes in total cholesterol, HDL or LDL levels were observed. In the rTAG-group, but not in the EE-group, fasting serum TAG levels were significantly reduced from baseline after three and six months. There was no significant difference between the two n3-FA-groups. However, serum TAG levels were significantly lowered after six months in the rTAG-group compared to the placebo-group in contrast to the EE-group.     

Antibacterial effect of some essential oils administered alone or in combination with Norfloxacin

The objective of the present study was that of verifying a possible synergistic antibacterial effect between Pelargonium graveolens [Lis-Balchin, M., Deans, S.G., Hart, S., 1996. Bioactive Geranium oils from different commercial sources. J. Essential Oil Res. 8, 281-290.] essential oil (and its main components) and Norfloxacin antibiotic. As a first step growth inhibition by some types of essential oils was assessed in five microbial species. The antimicrobial effects of P. graveolens oil, as well as those of its components, were evaluated by means of the agar dilution method (ADM) against Bacillus cereus ATCC 11778, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 35218, Staphylococcus aureus ATCC 6538 and S. aureus ATCC 29213. The results obtained highlighted the occurrence of a pronounced synergism between P. graveolens essential oil and Norfloxacin against three of the five bacterial species under study with a FIC index in the 0.37-0.50 range. Such antibacterial effects were also shown to increase, although to a lesser extent, when Norfloxacin was given with the main components of P. graveolens essential oil. SIGNIFICANCE AND IMPACT OF THE STUDY: The combination of Norfloxacin with either P. graveolens essential oil, or with some of the main components of this latter, in the treatment of infections caused by some bacterial species is likely to reduce the minimum effective dose of Norfloxacin thus minimizing the side effects of the antibiotic.     

北细辛超临界萃取物挥发性成分的GC-MS分析

采用超临界流体萃取法(SFE)和水蒸气蒸馏法分别对北细辛根及根茎进行提取分离,分别得5.5%SFE萃取物和2.8%挥发油。应用GC-MS分析,从北细辛SFE萃取物中鉴定出7种化学成分,占萃取物总量的72.70%,其中甲基丁香酚为44.62%;从细辛挥发油中鉴定出19种化学成分,占挥发油总量的88.53%,其中甲基丁香酚为43.02%。两种方法有6种成分完全相同,其中致癌物质黄樟油素SFE法比蒸馏法低2.8倍。北细辛根及根茎超临界萃取物与水蒸汽蒸馏挥发油主要成分相同,但其化学组成存在较大差异,提示药效亦不相同。超临界流体萃取法是剂型改革的有效方法之一。     

Antifungal mechanism of the combination of Cinnamomum verum and Pelargonium graveolens essential oils with fluconazole against pathogenic Candida strains

The present study aimed to investigate the anti-Candida activity of ten essential oils (EOs) and to evaluate their potential synergism with conventional drugs. The effect on secreted aspartic protease (SAP) activity and the mechanism of action were also explored. The antifungal properties of essential oils were investigated using standard micro-broth dilution assay. Only Cinnamomum verum, Thymus capitatus, Syzygium aromaticum, and Pelargonium graveolens exhibited a broad spectrum of activity against a variety of pathogenic Candida strains. Chemical composition of active essential oils was performed by gas chromatography-mass spectrometry (GC-MS). Synergistic effect was observed with the combinations C. verum/fluconazole and P. graveolens/fluconazole, with FIC value 0.37. Investigation of the mechanism of action revealed that C. verum EO reduced the quantity of ergosterol to 83%. A total inhibition was observed for the combination C. verum/fluconazole. However, P. graveolens EO may disturb the permeability barrier of the fungal cell wall. An increase of MIC values of P. graveolens EO and the combination with fluconazole was observed with osmoprotectants (sorbitol and PEG6000). Furthermore, the combination with fluconazole may affect ergosterol biosynthesis and disturb fatty acid homeostasis in C. albicans cells as the quantity of ergosterol and oleic acid was reduced to 52.33 and 72%, respectively. The combination of P. graveolens and C. verum EOs with fluconazole inhibited 78.31 and 64.72% SAP activity, respectively. To our knowledge, this is the first report underlying the mechanism of action and the inhibitory effect of SAP activity of essential oils in synergy with fluconazole. Naturally occurring phytochemicals C. verum and P. graveolens could be effective candidate to enhance the efficacy of fluconazole-based therapy of C. albicans infections.     

Physiological investigations on the effect of olive and rosemary leaves extracts in male rats exposed to thioacetamide

Physiologically, it is known that thioacetamide (TAA) toxicity is generally associated with hepatic fibrosis induction, complicated metabolic disorders and health problems. The capability of extracts of olive and rosemary leaves to attenuate the severe physiological disturbances induced by thioacetamide (TAA) intoxication in male rats has been evaluated. Healthy male Wistar rats were used in the present study and were divided randomly into eight groups. Rats of the first group were served as normal control. Rats of the second group were administrated with TAA. Rats of the third, fourth and fifth groups were exposed to TAA plus olive leaves extract, TAA plus rosemary leaves extract and TAA plus olive and rosemary leaves extracts respectively. The sixth, seventh and eighth groups were supplemented with olive leaves extract, rosemary leaves extract, and olive and rosemary leaves extracts respectively. After 12 weeks of experimental treatments, the levels of serum glucose, total protein, albumin and high density lipoprotein cholesterol were significantly decreased, while the levels of triglycerides, cholesterol, low density lipoprotein cholesterol, very low density lipoprotein cholesterol, creatine kinase and lactate dehydrogenase were statistically increased in rats exposed to TAA. Administration of the studied extracts inhibited the hematobiochemical parameters and improved the physiological disturbances induced by TAA intoxication. Additionally, most improvements were noted in rats administrated with rosemary leaves extract followed by olive and rosemary leaves extracts and olive leaves extract. These results suggested that the effect of these extracts might be due to their antioxidant activities against TAA toxicity.     

Chronic treatment with bark infusion from Croton cajucara lowers plasma triglyceride levels in genetic hyperlipidemic mice

Aqueous infusion and preparations containing dehydrocrotonin (DHC) and essential oil from Croton cajucara bark were tested for plasma lipid-lowering effects in genetically modified hyperlipidemic mice. Two mouse models were tested: 1) primary hypercholesterolemia resulting from the LDL-receptor gene knockout, and 2) combined hyperlipidemia resulting from crosses of LDL-receptor knockout mice with transgenic mice overexpressing apolipo protein (apo) CIII and cholesteryl ester-transfer protein. Mice treated with bark infusion, DHC, essential oil, or placebos for 25 days showed no signals of toxicity as judged by biochemical tests for liver and kidney functions. The bark infusion reduced triglyceride plasma levels by 40%, while essential oil and DHC had no significant effects on plasma lipid levels. The bark infusion treatment promoted a redistribution of cholesterol among the lipoprotein fractions in combined hyperlipidemic mice. There was a marked reduction in the VLDL fraction and an increase in the HDL fraction, in such a way that the (VLDL + LDL)/HDL ratio was reduced by half. The bark infusion treatment did not modify cholesterol distribution in hypercholesterolemic mice. In conclusion, C. cajucara bark infusion reduced plasma triglycerides levels and promoted a redistribution of cholesterol among lipoproteins in genetically combined hyperlipidemic mice. These changes modify risk factors for the development of atherosclerotic diseases.