Effects of Hibiscus sabdariffa L. on serum lipids: A systematic review and meta-analysis

Ethnopharmacological relevance

Prevention of cardiovascular disease by modifying its major risk factors, including serum cholesterol levels, is an important strategy. Hibiscus sabdariffa L. has been promoted for reducing cholesterol levels, but its reported impact on cholesterol levels has been inconsistent. The study aimed to assess systematically the evidence and quality of current research on the effect of Hibiscus sabdariffa L. on blood lipids and its adverse effects.

Materials and methods

Electronic databases were searched up to June 2013 for relevant randomised controlled trials (RCTs). Journals and conference proceedings were also searched. The quality of the selected trials was assessed using the Cochrane Risk of Bias Assessment Tool. The efficacy results of similar studies were pooled if they used the same comparator. Outcomes examined were levels of total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol and triglycerides.

Results

Six studies involving 474 subjects met our inclusion criteria. These studies varied in terms of the types of interventions, comparators used, and duration of trials. Overall, Hibiscus sabdariffa L. did not produce any significant effect on any of the outcomes examined, when compared with placebo, black tea or diet. With short-term use it is well tolerated.

Conclusions

The available evidence from RCTs does not support the efficacy of Hibiscus sabdariffa L. in lowering serum lipids. Further rigorously designed trials with larger sample sizes are warranted to confirm the effects of HS on serum lipids.     

Antihypertensive activity of Salvia elegans Vahl. (Lamiaceae): ACE inhibition and angiotensin II antagonism

Ethnopharmacological relevance

Salvia elegans Vahl. (Lamiaceae), recognized with the popular name of “mirto” is widely used in Mexico for healing purposes, and also them as antihypertensive treatment.

Aim of the study

The high prevalence of this illness and the side effects of antihypertensive drugs conducted us to the evaluation of the Salvia elegans extract on angiotensin II action.

Materials and methods

The acute response of blood pressure to angiotensin II administration was measured in mice. We also tested in vitro the inhibitory effect on angiotensin convertase enzyme. Additionally, characterization of the pharmacological effect of the extract fraction was obtained.

Results

We obtained dose–response curve for the administration of complete extract and extract fractions. Due to the hydroalcoholic extract (SeHA) treatment blood pressure decreased significantly from systolic dose of 0.75 mg kg⁻¹ (p < 0.05) and even had an antihypertensive effect that was greater than that treatment with losartan. SeHA extract decreased the E_max of the AG II hypertensive effect by about 20% in both systolic and diastolic pressures, treatment with losartan also decreased the same parameter between 6% and 8% for systolic and diastolic pressures, respectively. Fractions SeF8 and SeF8-8 showed similar levels of AG II ED₅₀ for both pressures compared with losartan, these fractions showed major compounds with maximum absorbance peaks at 221, 289 and 330 nm typical of flavonoids. In the inhibition assay the activity of angiotensin converting enzyme (ACE), the extract SeHA showed percentage inhibition (%IACE) of 50.27 ± 5.09% (n = 5). SeBuOH fraction is found to have greater inhibitory capacity of achieving a IACE 78.40 ± 2.24% (n = 5), which was similar to the values obtained in the presence of the SeF8-22 fraction (82.61 ± 1.74%) and lisinopril (87.18 ± 1.16%). The changes in the value of K_M suggest that components of the extracts and fractions were recognized by the enzyme's active site. The main compounds of the fractions SeBuOH, SeF8-22 were by flavonoid and phenyl propanoid types, according to UV absorption spectra of the fractions.

Conclusions

The experimental results demonstrated the antihypertensive effect of Salvia elegans and it was due to the AG II antagonism and inhibition of angiotensin converting enzyme.     

Inhibition of angiotensin converting enzyme (ACE) by flavonoids isolated from Ailanthus excelsa (Roxb) (Simaroubaceae)

In our screening program for antihypertensive properties of plants, the leaves of Ailanthus excelsa (Roxb), a plant used in Egyptian traditional medicine, were analysed. Chromatographic separation of A. excelsa MeOH extract yielded six flavonoids for the first time from this species, namely apigenin, luteolin, kaempferol-3-O-alpha-arabinopyranoside, kaempferol-3-O-beta-galactopyranoside, quercetin-3-O-alpha-arabinopyranoside and luteolin-7-O-beta-glucopyranoside. The in vitro hypotensive activities of the MeOH extract and the isolated compounds were elucidated. All the flavonoids tested exhibited ACE inhibitory activity, in particular the most active compound was kaempferol-3-O-beta-galactopyranoside with an IC(50) value of 260 microm.     

Inhibition of angiotensin converting enzyme by lithospermic acid B isolated from Radix Salviae miltiorrhiza Bunge

The roots of Salviae miltiorrhiza (RSM) have been traditionally used for treatment of hypertensive disease in China, Korea, and Japan. Bioassay guided fractionation and purification as assayed by angiotensin converting enzyme (ACE) inhibitory assay resulted in the isolation of lithospermic acid B (LSB) as an active principle. The ACE plasma activities were significantly inhibited by the addition of LSB in a dose-dependent manner of which IC50 value was 86 microg/ml (120 microM). Moreover, angiotensin I-induced contraction was markedly attenuated by prior exposure of endothelium-intact aortic rings to LSB. These results suggest that RSM-induced antihypertensive effect may be, at least in part, due to ACE inhibitory effect of LSB.     

Pharmacological characterization of the diuretic effect of Hibiscus sabdariffa Linn (Malvaceae) extract

Ethnopharmacological relevance

Hibiscus sabdariffa L. (Malvaceae) populary known in Mexico as “Jamaica”, “flor de Jamaica”, has widely used in Mexican Traditional Medicine as antihypertensive and diuretic, although the latter activity has been reported the present work show evidence about the diuretic, natriuretic and potassium-sparing effects.

Aim of the study

To evaluate the diuretic activity of Hibiscus sabdariffa aqueous extract on in vivo and in situ models.

Materials and methods

The Hibiscus sabdariffa aqueous extract was administrated in increasing doses and evaluated the diuresis produced and disposal of electrolytes. Moreover, in isolated kidney was determined the renal filtration rate with plant extract, furosemide and amiloride.

Results

The yield of Hibiscus sabdariffa aqueous extraction was 28.3% and the chemical standardization from 1 g of extract was: 56.5 mg delphinidin-3-O-sambubioside, 20.8 mg/g cyanidin-3-O-sambubioside, 3.2 mg/g quercetin, 2.1 mg/g rutin and 2.7 mg/g chlorogenic acid. The diuretic and natriuretic effect of Hibiscus sabdariffa aqueous extract showed a dose-dependent behavior. The pharmacological constants of natriuretic effect was ED50 = 86 mg/kg and Emax = 0.9 mEq/100 g/5 h. In the model of kidney in situ was observed that renal filtration increased 48% with the aqueous extract of Hibiscus sabdariffa and an additive effect when was perfuse with furosemide.

Conclusion

The compound presents in Hibiscus sabdariffa as quercetin had effect on the vascular endothelium causing oxide nitric release, increasing renal vasorelaxation by increasing kidney filtration. Therefore, the diuretic effect of Hibiscus sabdariffa may be mediated by nitric oxide release.     

Anthelmintic activity of Ziziphus nummularia (bark) and Acacia nilotica (fruit) against Trichostrongylid nematodes of sheep

Ethnopharmacological relevance

Ziziphus nummularia (Rhamnaceae) and Acacia nilotica (Fabaceae) are being used as anthelmintics in ethnoveterinary medicinal system of Pakistan.

Aim of the study

Present study was conducted to determine the anthelmintic activity of Ziziphus nummularia (bark) and Acacia nilotica (fruit) in order to justify their traditional use in veterinary medicine.

Materials and methods

In vitro anthelmintic activity of crude methanolic extract (CME) of both the plants was determined against Haemonchus contortus by the adult motility assay, the egg hatch test and the larval development assay. In vivo anthelmintic activity was evaluated in sheep naturally infected with gastrointestinal nematodes by administering increasing doses of crude powder (CP) and CME (1.0–3.0 g/kg).

Results

Both the plants exhibited dose- and time-dependent anthelmintic effects by causing mortality of worms, and inhibiting egg hatching and larval development. Acacia nilotica (LC₅₀ = 512.86 and 194.98 μg/ml) was found to be more potent than Ziziphus nummularia (LC₅₀ = 676.08 and 398.11 μg/ml) in egg hatch test and larval development assay, respectively. In vivo, maximum fecal egg count reduction (84.7%) was recorded on day 13 post-treatment in sheep treated with Ziziphus nummularia CME (3.0 g/kg) followed by 78.5% on same day with Acacia nilotica CME (3.0 g/kg).

Conclusions

These data show that both Ziziphus nummularia and Acacia nilotica possess anthelmintic activity in vitro and in vivo, justifying their use in traditional veterinary medicine in Pakistan.     

土鳖虫纤溶酶编码区序列的克隆与表达

目的:获得土鳖虫纤溶酶编码区序列,并进行原核和真核表达。方法:根据已报道的多种动物纤溶酶基因cDNA序列设计引物,用RT-PCR和3′RACE法克隆得到土鳖虫纤溶酶编码区序列;将该序列克隆进入大肠杆菌和毕赤酵母进行表达。结果:序列分析表明,所克隆的纤溶酶编码区序列长672bp,共编码224个氨基酸残基,起始氨基酸序列为IVGG,与多种动物纤溶酶一致。将此cDNA序列在大肠杆菌和毕赤酵母中进行表达,前者获得没有活性的表达蛋白,后者获得具有纤溶活性的重组表达蛋白。结论:首次报道了土鳖虫纤溶酶编码区序列,并进行了初步表达,为进一步研究其功能奠定了基础。     

金花葵花挥发油的气质联用成分分析

目的: 分析金花葵花挥发油的化学成分。 方法: 采用微波萃取法与水蒸气蒸馏法从金花葵花中提取挥发油,用归一化法测定其百分含量。用气相色谱一质谱法对化学成分进行鉴定。 结果: 微波萃取法提取的挥发油共鉴定了34种成分,占挥发油总成分的99.35%左右,水蒸气蒸馏法提取挥发油共鉴定了37种成分,占挥发油总成分的94.81%左右。 结论: 所用方法为金花葵花的合理利用提供了科学依据。     

Inhibition of myeloperoxidase activity by the alkaloids of Peganum harmala L. (Zygophyllaceae)

Ethnopharmacological relevance

Seeds and aerial parts of Peganum harmala L. are widely used in Algeria as anti-inflammatory remedies. Evaluation of Peganum harmala total alkaloids extracts and pure β-carboline compounds as an anti-inflammatory treatment by the inhibition of an enzyme key of inflammatory, myeloperoxidase (MPO) and HPLC quantification of the alkaloids from the different parts of plant.

Materials and methods

MPO inhibition was tested using taurine chloramine test. The inhibition of LDL oxidation induced by MPO was carried out. The molecular docking analysis of Peganum harmala alkaloids on MPO was performed using the Glide XP docking protocol and scoring function and the redox potential of alkaloids was determined using an Epsilon potentiostat. The concentration of harmala alkaloids was determined using HPLC analysis.

Results

The HPLC profiling of the active total alkaloids indicates that β-carboline e.g. harmine, harmaline, harmane, harmol and harmalol are major components. As β-carbolines resemble tryptamine, of which derivatives are efficient inhibitors of MPO, the harmala alkaloids were tested for their activity on this enzyme. Total alkaloids of the seeds and of the aerial parts strongly inhibited MPO at 20 µg/mL (97±5% and 43±4%, respectively) whereas, at the same concentration, those of the roots showed very low inhibition (15±6%). Harmine, harmaline and harmane demonstrated a significant inhibition of MPO at IC₅₀ of 0.26, 0.08 and 0.72 µM respectively. These alkaloids exerted a similar inhibition effects on MPO-induced LDL oxidation. Molecular docking analysis of Peganum harmala alkaloids on MPO showed that all active Peganum harmala alkaloids have a high affinity on the active site of MPO (predicted free energies of binding up to −3.1 kcal/mol). Measurement of redox potentials versus the normal hydrogen electrode clearly differentiated (i) the high MPO inhibitory activity of harmine, harmaline and harmane (+1014, 1014 and 1003 mV, respectively); and (ii) the low activity of harmalol and harmol (+629/778 and 532/644 mV, respectively). A reverse phase HPLC method has been developed to determine simultaneously five alkaloids of Peganum harmala. Seeds contained all five β-carboline derivatives with the main active alkaloids, harmaline and harmine, being up to 3.8% and 2.9%, respectively. Up to 3.2% of harmine was determined in the roots. The four β-carboline derivatives, harmine, harmaline, harmane and harmalol were identified in the aerial parts. The highest inhibitory effect observed in seeds and the moderate effect of aerial parts could be explained by their harmine and harmaline content. In contrast, the very weak inhibition of the root extract, despite the presence of harmine, may tentatively be explained by the high concentration of harmol which can reduce Compound II of MPO to the native form.

Conclusion

The inhibition of MPO by Peganum harmala β-carboline alkaloids, herein reported for the first time, may explain the anti-inflammatory effect traditionally attributed to its herbal medicine.     

Prophylactic and curative activities of extracts from Warburgia ugandensis Sprague (Canellaceae) and Zanthoxylum usambarense (Engl.) Kokwaro (Rutaceae) against Plasmodium knowlesi and Plasmodium berghei

Ethnopharmacological relevance

This work reports the anti-plasmodial activities of Warburgia ugandensis and Zanthoxylum usambarense commonly used as phytomedicines against malaria by some Kenyan communities.

Aim of study

To determine the anti-plasmodial activities of extracts from Warburgia ugandensis and Zanthoxylum usambarense against Plasmodium knowlesi and Plasmodium berghei.

Materials and methods

Eight plant extracts were screened for in vitro anti-plasmodial activity against Plasmodium knowlesi, in a 96-well plate incubated at 37 °C on a RPMI culture medium supplemented with baboon serum. Of the eight, three were investigated for prophylactic and curative activities in BALB/c mice against drug-sensitive Plasmodium berghei in a 4-day test at a dose rate of 200 mg/kg/day.

Results

Inhibitory concentrations (IC₅₀) values of between 3.14 and 75 μg/ml, up to 69% chemosuppression of parasites growth and over 80% survivorship of treated mice were observed.

Conclusion

The two medicinal plants, Warburgia ugandensis and Zanthoxylum usambarense possess bioactive compounds against malaria parasites and could be exploited for further development into malaria therapy.     

Inhibition of the toxic effects of Bothrops asper venom by pinostrobin,a flavanone isolated from Renealmia alpinia (Rottb.) MAAS

Ethnopharmacological relevance

Renealmia alpinia has been traditionally used to treat snakebites by indigenous Embera-Katíos tribes belonging to the regions of Antioquia and Chocó, Colombia, and it has been shown to inhibit the enzymatic and biological activities of Bothrops venoms and their purified phospholipase A₂ (PLA₂) toxins. In addition to its common local usage against snakebites, Renealmia alpinia is commonly used to treat pain. To evaluate the inhibitory ability of pinostrobin, the main compound in the dichloromethane extract of Renealmia alpinia, on the toxic effects of Bothrops asper venom through in vitro and in vivo models and to evaluate its activity against pain and edema.

Materials and methods

Pinostrobin was isolated from the dichloromethane extract of Renealmia alpinia leaves. The protective properties of the extract and of pinostrobin against the indirect hemolytic, coagulant and proteolytic effects of Bothrops asper venom were evaluated in vitro, and the anti-hemorrhagic and anti-inflammatory activity were evaluated in vivo.

Results

Renealmia alpinia extract significantly inhibited the proteolytic activity and indirect hemolytic activity of Bothrops asper venom at a venom:extract ratio of 1:20. Moreover, the present data demonstrate that pinostrobin may mitigate some venom-induced local tissue damage due to hemorrhagic effects, and the compound is also responsible for the analgesic and anti-inflammatory activity of the extract from Renealmia alpinia. This is the first report to describe pinostrobin in the species Renealmia alpinia and its properties in vitro against Bothrops asper venom.

Conclusion

Our studies of the activity of Renealmia alpinia against the venom of Bothrops asper have confirmed that this species possesses inhibitory effects against Bothrops asper venom in both in vitro and in vivo models and that these effects may be due to pinostrobin, supporting the traditional usage of the plant. Additionally, pinostrobin may be responsible for the anti-hemorrhagic and analgesic activity (peripheral analgesic activity) of Renealmia alpinia.     

In vitro and in vivo hepatoprotective and antioxidant activity of ethanolic extract from Meconopsis integrifolia (Maxim.) Franch

Ethnopharmacological relevance

Meconopsis integrifolia (Maxim.) Franch is a high mountain endemic species used as a traditional Tibetan and Mongolian herb to treat hepatitis, pneumonia, and edema. This study aims to investigate the hepatoprotective and antioxidant effects of Meconopsis integrifolia ethanolic extract (MIE) in vitro and in vivo.

Materials and methods

The in vitro antioxidant property of MIE was investigated by employing various established systems. Rats with carbon tetrachloride (CCl₄)-induced liver injury were used to assess the hepatoprotective and antioxidant effect of MIE in vivo. The level or activity of alkaline phosphatase (ALP), glutamate pyruvate transaminase (ALT), aspartate aminotransferase (AST), and total bilirubin (TB) in the blood serum and thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) in the liver and kidney of the rats were assayed using standard procedures.

Results

MIE exhibited strong antioxidant ability in vitro. In the rats with CCl₄-induced liver injury, the groups treated with MIE and silymarin showed significantly lower levels of ALT, AST, ALP, and TB. MIE demonstrated good antioxidant activities in both the liver and kidney of the rats in vivo.

Conclusions

MIE exhibits excellent hepatoprotective effects and antioxidant activities in vitro and in vivo, supporting the traditional use of Meconopsis integrifolia in the treatment of hepatitis.     

Antimicrobial activity of the methanolic extracts and compounds from Treculia obovoidea (Moraceae)

The crude extract from Treculia obovoidea was subjected to purification by repeated chromatography. Eight compounds were isolated from Treculia obovoidea and identified as Psoralen (1), Bergapten (2), 7-methoxycoumarin (3), 7-hydroxycoumarin (4), 4,2′,4′-trihydroxychalcone (5), 4,2′,4′-trihydroxy-3-prenylchalcone (6), 3-hydroxy-4-methoxybenzoic acid (7) and O-[3-(2,2-dimethyl-3-oxo-2H-furan-5-yl) butyl] bergaptol (8). These compounds together with the extract were tested for their antimicrobial activity against Gram-positive bacteria (six species), Gram-negative bacteria (12 species) and three Candida species using micro-dilution methods for the determination of the minimal inhibition concentration (MIC) and the minimal microbicidal concentration (MMC). The MIC values obtained with the crude extracts varied from 78.12 to 156.25 μg/ml against 17 (80.95%) of the 21 tested microorganisms. All the isolated compounds showed selective activity. The antimicrobial activity of this plant as well as that of compounds 6 and 8 is being reported for the first time. The obtained results provide promising baseline information for the potential use of these crude extract as well as some of the isolated compounds in the treatment of bacterial and fungal infections.     

高速逆流色谱结合UNIFAC数学模型分离纯化淡竹叶中的槲皮素-3-O-葡萄糖苷

目的:建立一个经济有效的方法用于淡竹叶Lophatherum gracile中槲皮素-3-O-葡萄糖苷的分离纯化。方法:采用高速逆流色谱(high-speed counter-current chromatography,HSCCC)进行分离纯化,所用溶剂体系为乙酸乙酯-正丁醇-水(2∶1∶3),其上相和下相是根据UNIFAC数学模型单独配制,并与传统配制方法配制所得溶剂系统的分离效率进行比较;分离所得产物的纯度经HPLC检测,结构经MS,UV,NMR鉴定。结果:HSCCC使用UNIFAC数学模型单独配制的溶剂系统成功的从竹叶中制备出纯度高于99%的槲皮素-3-O-葡萄糖苷,与传统溶剂系统配制方法相比,节省了乙酸乙酯、正丁醇和水的用量。结论:在淡竹叶中槲皮素-3-O-葡萄糖苷的HSCCC分离过程中,使用UNIFAC单独配制的溶剂系统既可保证较好分离效果,又可节省大量的有机溶剂,减少了资源浪费,益于环保。     

Antiinflammatory and neurological activity of pyrithione and related sulfur-containing pyridine N-oxides from Persian shallot (Allium stipitatum)

Ethnopharmacological relevance

Persian shallot (Allium stipitatum) is a bulbous plant native to Turkey, Iran and Central Asia. It is frequently used in folk medicine for the treatment of a variety of disorders, including inflammation and stress. Antiinflammatory and neurological activities of pyrithione and four related sulfur-containing pyridine N-oxides which are prominent constituents of Allium stipitatum were tested.

Methods

The antiinflammatory activity was tested by the ability of the compounds to inhibit cyclooxygenase (COX-1 and COX-2), whereas the neurological activities were evaluated by assessing the compounds ability to inhibit monoamine oxidase-A (MAO-A) and acetylcholinesterase (AChE). The compounds? affinity for the serotonin transport protein (SERT) and the GABA_A–benzodiazepine receptor were also investigated.

Results

2-[(Methylthio)methyldithio]pyridine N-oxide showed very high antiinflammatory effects which are comparable with those of common pharmaceuticals (IC₅₀ of 7.8 and 15.4 µM for COX-1 and COX-2, respectively). On the other hand, neurological activities of the compounds were rather modest. Some compounds moderately inhibited AChE (IC₅₀ of 104–1041 µM) and MAO-A (IC₅₀ of 98–241 µM) and exhibited an affinity for the SERT and GABA_A–benzodiazepine receptor.

Conclusions

Our findings may help to rationalize the wide use of Persian shallot for the treatment of inflammatory disorders.     

Cardiovascular effects of Tulbaghia violacea Harv. (Alliaceae) root methanolic extract in Dahl salt-sensitive (DSS) rats

Ethnopharmacological relevance

In African folk medicine, Tulbaghia violacea Harv.(Alliaceae), a herbaceous plant also known by other common local names such as ‘wild garlic’, ‘society garlic’ and ‘sweet garlic’, has been used for the management, control and/or treatment of several human ailments; including hypertension.The aim of the present study was to investigate the cardiovascular effects of methanolic extract of Tulbaghia violacea Harv. in Dahl salt-sensitive (DSS) rats.

Materials and methods

DSS rats were treated intraperitoneally (i.p) as follows: distilled water, control (CON) (3 ml/kg/b.w.); captopril (CAP) (25 mg/kg/b.w.); or methanolic extract of Tulbaghia violacea (TVL) (50 mg/kg/b.w.) for 7 weeks. Systolic blood pressure (SBP) was measured bi-weekly whilst 24-hour urine volumes and sodium concentrations were assessed weekly. Animals were sacrificed on day 49 by halothane overdose. Blood was removed for the determination of aldosterone concentration and angiotensin converting enzyme (ACE) activity. Left kidney was harvested for angiotensin Ia (AT1a) receptor gene expression.

Results

CON showed a significant percentage increase in SBP (mmHg) on day 49 compared to day 0 (baseline values) (9.75±1.7% vs. 2.33±0.77%; p<0.05). CAP and TVL showed significant percentage decreases in SBP at week 7 when compared to baseline (8.13±1.23% and12.88±3.12% p<0.01). Urine volumes (ml) increased significantly in CAP from week 1 to week 4 (9.63±2.22 vs.10.97±1.75 p<0.05) and in TVL from week 2 to 7 (9.23±0.91 vs. 11.90±1.17 p<0.05). Urinary sodium concentration (mmol/L/24 h urine samples) was significantly higher in CAP (0.72±0.07 vs.1.31±0.03 p<0.05) and in TVL (0.71±0.09 vs. 1.68±0.16; p<0.05) at week 7 compared to baseline levels. There was no significant difference in the plasma aldosterone levels (pmol/L) of all the three groups. Serum ACE (U/L) activity was significantly higher in CAP compared to CON and TVL (277.0±11.6 vs. 121.5±3.93; and 147.0±6.63; p<0.05 respectively). CAP showed a significant 6.4 fold increase in AT1a mRNA expression vs. CON (p<0.05) and a 4.5 fold increase vs. TVL (p<0.05). There was no significant difference between CON and TVL treated rats. CAP and TVL showed no significant change in the expression of AT2.

Conclusion

This study showed that TVL possesses antihypertensive effect in Dahl salt-sensitive rats when administered over a long-term.     

In-vitro and in-vivo antiadipogenic,hypolipidemic and antidiabetic activity of Diospyros melanoxylon (Roxb)

Ethnopharmacological relevance

The plant Diospyros melanoxylon (Roxb) belongs to the family Ebenaceae that is native to India and Sri-lanka. This is a medium-sized tree, reaching a height of 15 m and is well known for its beedi making leaves throughout the world. The purpose of the present study is to assess the effect of Diospyros melanoxylon leaves petroleum ether extract on blood glucose level, lipid level, insulin level, body weight, water and food intake in Streptozotocin (STZ) induced diabetic rats.

Materials and methods

Two different doses of extract AK001 (250 mg/kg) and AK002 (500 mg/kg) of Diospyros melanoxylon leaves were taken to evaluate different activities. The animals were divided into five groups namely normal control, diabetic control, reference group, AK001 and AK002 each containing six animals for in-vivo study. In-vitro study for antiadipogen activity was performed on 3T3-L1 cell line.

Results

The extract showed dose dependent fall in Fasting Glucose Level (FSG) in experimental diabetic animals with significant reduction in food and water intake and increase in body weight. The extract exhibited hypocholesterolemic and hypotriglyceridemic effects while increased level of HDL in diabetes induced rats. In-vitro activity showed more than 75% viability of cells and significant inhibition in differentiated cells as compared to non-differentiate cells in 3T3-L1 cell line. The extract exhibited the concentration-dependent inhibitory effect with an IC₅₀ value of 689.22 μg/ml.

Conclusions

The extract exhibited significant results for antiadipogenic, antidiabetic and hypolipidemic activity both in-vivo and in-vitro and it may prove to be effective for the treatment of both types of diabetes, i.e. Insulin Dependent Diabetes Mellitus (IDDM) and Noninsulin Dependent Diabetes Mellitus (NIDDM).     

Antimicrobial activity of the extracts of Craniotome furcata (Lamiaceae)

Ethnopharmacological relevance

Craniotome furcata (Link.) O. Kuntze (Lamiaceae) is used in the traditional medicine for the treatment of cuts and wounds indicating antimicrobial activity.

Aim of the study

To validate the traditional medicinal claim, in vitro antimicrobial activity of the extracts was screened against eleven human pathogenic bacteria and fungi.

Materials and methods

The ethyl acetate (CE) and n-butanol (CB) extracts of the aerial parts of Craniotome furcata were tested against four Gram-positive bacteria, four Gram-negative bacteria and three fungi species. Antimicrobial activity was determined by the tube-dilution method.

Results

The CE and CB extracts showed antimicrobial activity against all of the tested microorganisms, with minimum inhibitory concentration (MIC) values in the range of 0.41–4.58 mg/ml.

Conclusions

The tested microbes Micrococcus flavus and Escherichia coli were highly susceptible to extract CE and antimicrobial activity of CB is comparable to that of extract CE against Escherichia coli and Staphylococcus faecalis while it is better than that of extract CE, against Klebsiella pneumoniae. Both the extracts were found less susceptible against tested fungi.     

Screening of the topical anti-inflammatory activity of the bark of Acacia cornigera Willdenow, Byrsonima crassifolia Kunth, Sweetia panamensis Yakovlev and the leaves of Sphagneticola trilobata Hitchcock

Ethnopharmacological relevance

An investigation of topical anti-inflammatory activity was undertaken on plants used in Central America traditional medicine.

Aim of study

Four herbal drugs used in the folk medicine of Central America to treat inflammatory skin affections (Acacia cornigera bark, Byrsonima crassifolia bark, Sphagneticola trilobata leaves and Sweetia panamensis bark) were evaluated for their topical anti-inflammatory activity.

Materials and methods

Petroleum ether, chloroform and methanol extracts were obtained for herbal medicines and then extracts were tested on Croton oil-induced ear dermatitis model in mice.

Results

Almost all the extracts reduced the Croton oil-induced ear dermatitis in mice and the chloroform ones showed the highest activity, with ID₅₀ (dose giving 50% oedema inhibition) values ranging from 112 μg/cm² (Byrsonima crassifolia) to 183 μg/cm² (Sphagneticola trilobata). As reference, ID₅₀ of the non-steroidal anti-inflammatory drug indomethacin was 93 μg/cm².

Conclusions

Lipophilic extracts from these species can be regarded as potential sources of anti-inflammatory principles.     

Inhibition of tumor proliferation associated with cell cycle arrest caused by extract and fraction from Casearia sylvestris (Salicaceae)

Ethnopharmacological relevance

Casearia sylvestris is a tree found in tropical America. In Brazil it is known mainly as Guaçatonga. Literature reports suggest that the leaves and other plant parts have been used by indigenous populations from South America in preparations, mainly aqueous or hydroethanolic macerations or decoctions, most times taken orally for the primary treatment of several diseases, including cancer.

Aim of the study

This article reports the results of an investigation about the antiproliferative effects of Casearia sylvestris on tumor cells in vitro and in vivo.

Material and methods

Aqueous ethanolic maceration and column chromatography were done to obtain a crude aqueous ethanolic extract (CAE) and a chloroform fraction (f-CHCl₃). The human breast cancer cell line MCF-7 was used in culture. In vitro, non-cytotoxic concentrations were determined by MTT assay and the antiproliferative effect was assessed by the colony forming unit assay using non-cytotoxic concentrations. Effects on the cell cycle were observed through flow cytometry using a propidium iodide kit. Casearin C was identified in f-CHCl₃ by chromatography and H¹ nuclear magnetic resonance. The effect on some key proteins of DNA damage (phosphorylation on the histone H2AX) and cell cycle control (p53, p16, cdk2) was evaluated through immunoblot. Antiproliferative effects in vivo were measured in tumor tissue from Ehrlich ascites-bearing mice through the ³H-thymidine uptake assay and the trypan blue exclusion method.

Results

In vitro, EC₅₀ values found at 24 h on MCF-7 cells were 141 µg/mL for CAE and 66 µg/mL for f-CHCl₃. Inhibition on proliferation was recorded at concentrations as low as 4 µg/mL in the case of the f-CHCl₃ (up to 40%) and up to 50% when CAE was added at 9 µg/mL. The cell cycle arrest was demonstrated by the reduction in terms of number of cells in phases G2/M and S, up to 38.9% and 51.9% when cells were treated with CAE, and 53.9% and 66.2%, respectively, when cells were treated with f-CHCl₃. The number of cells in G1 was increased when the cells were treated with CAE (21.4%) or f-CHCl₃ (27.8%). Key proteins of cell cycle control were affected. The treatments caused activation of p53, p16 and DNA damage found by the appearance of bands corresponding to γ-H2AX. The treatments caused inhibition of cdk2. CAE and particularly f-CHCl₃ caused significant inhibition on tumor growth in mice (40% and 60%, respectively). Uptake of ³H-thymidine, thus proliferation was reduced in tumor cells from mice treated with CAE (>30%) or f-CHCl₃ (up to 50%) compared to cells from control animals. Data from the trypan blue assay indicating a lower number of tumor cells in treated animals. From the overall, data from this study are in line with the traditional claims for the antitumor effect of Casearia sylvestris.

Conclusions

This investigation suggests that whether the extracts from Casearia sylvestris are cytotoxic at high concentrations, lower concentrations have antiproliferative effect and could be useful to complement conventional cytotoxic chemotherapy, and should be evaluated further.