Bark Ethyl Acetate Research Articles

Effect of Bridelia ferruginea Benth (Euphorbiaceae) ethyl acetate and acetone fractions on insulin resistance in fructose drinking mice

Ethnopharmacological relevanceThe root of Bridelia ferruginea is traditionally used as a treatment for type 2 diabetes. The present study was investigated to evaluate the effect of Bridelia ferruginea root bark fractions on some markers of type 2 diabetes on fructose drinking mice. Materials and methodsMice received a solution of fructose 15% during 42 days ad libitum; at the 15th day to the 42nd day, they received distilled water for fructose drinking control group, metformin 50mg/kg per day or fractions 50mg/kg per day for treatment groups. The normal control group received only distilled water during the experiment. After 6 weeks of experiment, OGTT, fasting blood glucose, plasma insulin, triglycerides (TG), total cholesterol, AST and ALT levels were measured. ResultsFructose drinking control group (F) showed significant (p<0.001) increase of glucose tolerance, plasma levels of total cholesterol, triglycerides and insulin index for insulin resistance (Homeostasis Model Assessment ratio HOMA-IR) as compared to normal control mice. In treated groups, there was a significant reduction of glucose intolerance respectively 74% (p<0.001), 25% (p<0.5) and 92% (p<0.001) for ethyl acetate fraction, acetone fraction and metformin at the same dose of 50mg/kg per day during 4 weeks administration. In ethyl acetate fraction and metformin treated groups, biochemical parameters and insulin index were significantly (p<0.001) lower than that of fructose drinking control group. ConclusionsThis indicates that Bridelia ferruginea root bark ethyl acetate fraction improved insulin resistance as metformin significantly in type 2 diabetes.

Antioxidant Activity and Cytotoxicity of the Leaf and Bark Extracts of &lt;i&gt;Tarchonanthus camphorates&lt;/i&gt;

Purpose: To investigate the antioxidant potential and cytotoxicity of the leaf and bark extracts of Tarchonanathus campharatus..Methods: The antioxidant activity of the aqueous leaf extract (Aq LF), methanol leaf extract (MET LF), dichloromethane leaf extract (DCM LF), methanol bark extract (MET BK), dichloromethane bark extract (DCM BK), and ethyl acetate bark extract (Et Ac BK) were examined by 1,1-Diphenyl-2-picryl-hydrazil (DPPH), 2f-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS.+), nitric oxide radical scavenging, reducing power and iron chelating activity methods. Brine shrimp lethality and MTT cytotoxicity testswere used to investigate the cytotoxicity of the extracts.Results: The Aq LF, DCM LF, MET LF and MET BK showed good DPPH, ABTS radical scavenging and total reducing power activities. Total reducing power was high and in the rank order of DCM LF &gt; Aq LF &gt; MET LF &gt; MET BK. All the extracts, however, showed weak nitric oxide scavenging activity aswell as weak iron chelating ability. Flavonoids, phenols, tannins and saponins were present in some of the extracts, but alkaloids, terpenoids, cardenolides and cardiac glycosides were absent in all the extracts. All the extracts did not show significant cytotoxic properties (p . 0.05) with 50% inhibitory concentration IC50 values &gt; 30 ƒÊg/ml in both cytotoxicity assays.Conclusion: The antioxidant activity and low cytotoxicity of Tarchonanthus camphoratus probably justify its use in folk medicine.Keywords: Tarchonanthus camphoratus, Antioxidant activity, Cytotoxicity

Alpha-amylase inhibitory activity of two Anthocleista species and in vivo rat model anti-diabetic activities of Anthocleista djalonensis extracts and fractions

Ethnopharmacological relevanceAnthocleista djalonensis (A. Chev) and Anthocleista vogelii Planch are plants being used in West Africa traditionally to treat various diseases such as malaria, hernia, hypertension, stomach aches, hemorrhoids, syphilis, and diabetes. Diabetes causes about 5% of all deaths globally each year. Chemotherapeutic agents such as biguanides, sulfonylureas, and thiozolidinediones are available for the treatment of diabetes, however, they have undesirable side effects. The need for newer, more effective and less toxic drugs is imperative and the biodiversity of Nigeria has a high potential for drug discovery based on plants used in the ethnomedicine. Aim of the studyTo investigate the leaves, stem bark and roots of these plants for their probable alpha-amylase inhibitory activities and establish their anti-diabetic activities. The overall goal is do bioassay-guided fractionation and isolation of active anti-diabetic compounds. Materials and methodsPowdered samples (leaves, stem bark and roots) macerated with 80% aqueous methanol were evaluated in vitro using alpha-amylase inhibitory assay while in vivo investigations were carried out on hyperglycemic rats. Diabetes was induced in albino rats by an intraperitoneal injection of alloxan monohydrate (80mg/kg). Plant extracts (1g/kg) were given orally for 7 days, while blood glucose levels were monitored using a one touch glucometer. The crude methanol extracts found to be most active were further partitioned into hexane and ethyl acetate fractions which were also tested in vivo on the diabetic animals. ResultsThe leaves and stem bark crude methanol extracts of Anthocleista djalonensis gave comparable α-amylase inhibition of 73.66% and 72.90%, respectively which were quite higher than the 38.93% and 22.90% of the same plant parts given by Anthocleista vogelii. The crude stem bark extract of Anthocleista djalonensis exhibited significant peak blood glucose reduction on day 6 (72.59%, p<0.05) which was higher than the leaves or roots which gave 45.73% and 47.46% (p<0.05), respectively The stem bark ethyl acetate fraction of Anthocleista djalonensis gave reduction in blood glucose level of 60.86% (p<0.05). ConclusionFrom our results, the leaves, stem bark and whole root of both plants exhibited α-amylase inhibitory activities with Anthocleista djalonensis also showing good anti-diabetic activities in vivo indicating that they contain active principles for the management of diabetes. There is justification for the use of the plants traditionally to manage diabetes.

A New Xanthone from the Bark Extract of Rheedia acuminata and Antiplasmodial Activity of Its Major Compounds

Bioassay-guided fractionation of the ethyl acetate bark extract of Rheedia acuminata led to the isolation of the new compound 1,5,6-trihydroxy-3-methoxy-7-geranyl-xanthone (1), together with four known compounds 2-5. These compounds were tested in vitro for their antiplasmodial activity on a chloroquine-resistant strain of Plasmodium falciparum (FcB1) and for their cytotoxicity against the human diploid embryonic lung cell line MRC-5.

Antioxidant activities and related polyphenolic constituents of the methanol extract fractions from Broussonetia papyrifera stem bark and wood

Broussonetia papyrifera radix, fruits, leaves, and stems exhibit antioxidant, antinociceptive, antityrosinase, anti-inflammatory, and antiplatelet activities. However, study of the antioxidant activity of stem bark has been limited. In this work the antioxidant activity of stem bark and wood extracts were compared using different methods, and their phenolic constituents were analyzed. The bark ethyl acetate fraction exhibited the highest 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) radical, hydroxyl radical scavenging activity, and the highest total phenolic and flavonoid contents. Both bark and wood n-butanol fractions showed stronger superoxide anion radical scavenging activity and reducing potential than other fractions. The bark and wood hexane fraction provided the highest level of ion chelating power. The high performance liquid chromatography (HPLC) analysis reveals there are more phenolic compounds in bark than in wood. These findings suggest that bark exhibits a higher antioxidant capacity than wood and that ethyl acetate and n-butanol fractions of B. papyrifera bark are potential natural resources for pharmacology of functional foods.

In vitro biological activities of niloticane, a new bioactive cassane diterpene from the bark of Acacia nilotica subsp. kraussiana

Ethnopharmacological relevance Acacia nilotica subsp. kraussiana was reported in African traditional medicine for the treatment of various ailments. Isolation of an active compound in this study from the bark extract may lead to the validation of its efficiency as a traditional crude drug. Aims of the study This study aimed to isolate active compound(s) from an ethyl acetate bark extract of Acacia nilotica subsp. kraussiana and to investigate some of its biological activity. Materials and methods The isolation process was carried out using bioassay-guided fractionation. The isolated compound was tested for antibacterial activity using the micro-dilution assay; anti-inflammatory activity using the COX-1 and COX-2 assays and investigated for inhibitory effect against acetylcholinesterase using the microplate assay. Results A new bioactive compound was isolated and identified as a cassane diterpene, niloticane. Niloticane showed antibacterial activity against Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus with MIC values of 4 and 8 μg/mL, respectively. With Gram-negative bacteria, niloticane showed weak activity. MIC values obtained were 16 and 33 μg/mL against Klebsiella pneumonia and Escherichia coli, respectively. In the cyclooxygenase test, niloticane possessed activity with IC 50 values of 28 and 210 μM against COX-1 and COX-2, respectively. IC 50 values observed with indomethacin (positive control) were 3.6 μM for COX-1 and 189 μM for COX-2. In the acetylcholinesterase test, niloticane showed anti-cholinesterase activity with an IC 50 value of 4 μM. IC 50 values obtained by the galanthamine (positive control) was 2.0 μM. Conclusion The results obtained support the traditional uses of the bark of Acacia nilotica subsp. kraussiana in African traditional medicine for the treatment of some ailments that relate to microbial diseases, inflammation and central nervous system disorders.

Turrianes from Kermadecia rotundifolia as new acetylcholinesterase inhibitors

Four new kermadecins, together with the known kermadecins A, B and D have been isolated from the Kermadecia rotundifolia ethyl acetate bark extract. These compounds are derivatives of the (20-membered- o,- p)cyclophane skeleton and belong to the turriane family. The structures were elucidated by mass spectrometry, extensive one- and two-dimensional NMR spectroscopy and through comparison with data reported in the literature. Isokermadecin D ( 2) and kermadecins D and J ( 7 and 4) possess significant inhibitory effect on acetylcholinesterase.

ANTIBACTERIAL AND ANTIFUNGAL TERPENES FROM Pilgerodendron uviferum (D. DON) FLORIN

Ten sesquiterpenes (a-cubebene, copaene, a-caryophyllene, caryophyllene-4,5-epoxide, d-cadinene, cubenol, epicubenol, torreyol, humulene-1,2-epoxide, 15-copaenol) and six diterpenes (hinokione, hinokiol, ferruginol, 6,7-dehydroferruginol, totarol, sugiol) were isolated and identified from Pilgerodendron uviferum (D. Don) Florin wood and bark. The molecular structures were elucidated by spectroscopic methods. Twelve pure compounds were tested for antimicrobial activity against standard bacterial (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aureginosa, Streptococcus pyogenes) and fungal strains (Ophiostoma piliferum, Rhizoctonia solani, Phragmidium violaceum, Fusarium graminearum, Pythium irregulare, Botrytis cinerea, Schizophyllum commune), as were crude total extracts, n-hexane, dichloromethane, and ethyl acetate partial extracts. All the compounds tested exhibited biological activity, with the most active being ferruginol, hinokiol, 15-copaenol, cubenol, torreyol, and n-hexane wood extracts and ethyl acetate bark extract

Cyclooxygenase inhibiting and anti-bacterial activities of South African Erythrina species

Aqueous, ethanolic and ethyl acetate extracts of the bark and leaves of five South African Erythrina species Erythrina caffra, Erythrina humeana, Erythrina latissima, Erythrina lysistemon and Erythrina zeyheri were screened for prostaglandin synthesis-inhibitory and anti-bacterial activity. The bark generally displayed higher activity than the leaves in both bioassays. The highest cyclooxygenase inhibiting activity and anti-bacterial activity was recorded for the ethanol and ethyl acetate bark extracts of E. caffra, E. latissima and E. lysistemon. An anti-bacterial compound, 4′,5,7-trihydroxy-6-prenylisoflavone, was isolated by bioassay-guided fractionation from bark of E. lysistemon.