Stem Bark Of Khaya Senegalensis Research Articles

Effect of single and combination therapy on methanol extracts of Khaya senegalensis stem bark, Vernonia amygdalina leaves and Garcinia kola seed in Leptospira interrogans-infected mice

Ethnopharmacological relevancePastoralists in Nigeria mix Garcinia kola seed (GK), Khaya senegalensis stem bark (KS), and Vernonia amygdalina leaves (VA) to treat leptospirosis. AimTo determine the in vitro and in vivo effect on single and combination therapy on Leptospira interrogans-infected mice. Materials and MethodsEvaluation of in vitro assay for anti-leptospiral motility of the extracts was carried out in triplicates. For the in vivo assessment, 40 adult male mice inoculated with Leptospira were randomly allocated into 8 groups of 5 mice each. Groups IV-IX were treated with 800mg/kg b.w. of KS, GK, VA, KS+GK, KS+VA, GK+VA for 5 days. Group I was negative control, II was model control, and III was treated with penicillin (3.7mg/kg b.w.) intramuscularly. ResultsIn vitro, at 90 min, all the extracts at 800, 400, and 200 mg/ml showed complete cessation of motility which was significantly (p < 0.05) different when compared to the negative control. A significant (p < 0.05) IC50 of 0.18mg/ml was recorded with GK when compared to KS (0.40mg/ml), VA (0.25mg/ml), and procaine penicillin (0.31mg/ml). Mean packed cell volume, haemoglobin concentration, and mean corpuscular haemoglobin concentration decreased significantly (p < 0.05) in all infected groups and returned to almost pre-infection values. However, significant leucocytosis (p < 0.05) was observed in group II. AST and ALP showed a significant increase (p < 0.001). Histopathological evaluation showed the extracts to prevent the distortion of normal architecture of the selected organs. ConclusionThis study demonstrates the significant potential of Garcinia kola, Khaya senegalensis, and Vernonia amygdalina extracts singly and in combination to combat leptospirosis.

Antiplasmodial and Antileishmanial Activities of a New Limonoid and Other Constituents from the Stem Bark of Khaya senegalensis.

Plasmodium falciparum and Leishmania sp. resistance to antiparasitic drugs has become a major concern in malaria and leishmaniasis control. These diseases are public health problems with significant socioeconomic impacts, and mostly affect disadvantaged populations living in remote tropical areas. This challenge emphasizes the need to search for new chemical scaffolds that preferably possess novel modes of action to contribute to antimalarial and antileishmanial research programs. This study aimed to investigate the antimalarial and antileishmanial properties of a methanol extract (KS-MeOH) of the stem bark of the Cameroonian medicinal plant Khaya senegalensis and its isolated compounds. The purification of KS-MeOH led to the isolation of a new ordered limonoid derivative, 21β-hydroxybourjotinolone A (1a), together with 15 known compounds (1bc-14) using a repeated column chromatography. Compound 1a was obtained in an epimeric mixture of 21α-melianodiol (1b) and 21β-melianodiol (1c). Structural characterization of the isolated compounds was achieved with HRMS, and 1D- and 2D-NMR analyses. The extracts and compounds were screened using pre-established in vitro methods against synchronized ring stage cultures of the multidrug-resistant Dd2 and chloroquine-sensitive/sulfadoxine-resistant 3D7 strains of Plasmodium falciparum and the promastigote form of Leishmania donovani (1S(MHOM/SD/62/1S). In addition, the samples were tested for cytotoxicity against RAW 264.7 macrophages. Positive controls consisted of artemisinin and chloroquine for P. falciparum, amphotericin B for L. donovani, and podophyllotoxin for cytotoxicity against RAW 264.7 cells. The extract and fractions exhibited moderate to potent antileishmanial activity with 50% inhibitory concentrations (IC50) ranging from 5.99 ± 0.77 to 2.68 ± 0.42 μg/mL, while compounds displayed IC50 values ranging from 81.73 ± 0.12 to 6.43 ± 0.06 μg/mL. They were weakly active against the chloroquine-sensitive/sulfadoxine-resistant Pf3D7 strain but highly potent toward the multidrug-resistant PfDd2 (extracts, IC50 2.50 ± 0.12 to 4.78 ± 0.36 μg/mL; compounds IC50 2.93 ± 0.02 to 50.97 ± 0.37 μg/mL) with selectivity indices greater than 10 (SIDd2 > 10) for the extract and fractions and most of the derived compounds. Of note, the limonoid mixture [21β-hydroxylbourjotinolone A (1a) + 21α-melianodiol (1b) + 21β-melianodiol (1c)] exhibited moderate activity against P. falciparum and L. donovani. This novel antiplasmodial and antileishmanial chemical scaffold qualifies as a promising starting point for further medicinal chemistry-driven development of a dually active agent against two major infectious diseases affecting humans in Africa.

Inhibitors of recombinant protein-tyrosine phosphatase 1B (PTP1B) from Khaya senegalensis: Towards a strategic target for therapeutic intervention in trypanosomiasis

Background: Tyrosine dephosphorylation, catalyzed by protein-tyrosine phosphatase (PTP), prevents trypanosome differentiation to a procyclic form that lacks diverse mechanisms for survival within the mammalian host's bloodstream. Thus, differentiation to a procyclic form in the mammalian host's bloodstream would be potentially lethal to the parasite. This demonstrates that PTP is a critical regulator of trypanosome differentiation, making it a strategic therapeutic target for trypanosomiasis.Purpose: The in vitro inhibitory effect of seven compounds from the active fraction of Khaya senegalensis stem bark (4‑hydroxy-2-butanone, 1,3-butanediol, 2-methylpropyl butanoate, n-tridecanoic acid (CH3-(CH2)11-COOH), n-tetratriacontane, n-hexadecanoic (CH3-(CH2)14-COOH), and 14-pentadecenoic acid (CH2=CH-(CH2)12-COOH)) on the enzymatic activity of recombinant human PTP1B (MBL-SE332–0050) was investigated in this study.Method: The inhibition study was performed according to the standard procedure for analytical experiment and was monitored spectrophotometrically. PTP1B was assayed with 10 mM of p-nitrophenylphosphate. Bioassay-guided fractionation of methanol stem bark extract from K. senegalensis yielded the potent PTP1B inhibitors. Sodium orthovanadate was used as the positive control for inhibition. The kinetic parameters were determined by Lineweaver-Burk plots and calculated using Sigma Plot (SPCC Inc., Chicago, IL, USA)Results: The active fraction that contains the seven compounds inhibited PTP1B dose-dependently with an IC50 of 1.32 µM. Lineweaver-Burk plots revealed that PTP1B was inhibited non-competitively with a Ki of 0.46 ± 0.03 mg/ml, while sodium orthovanadate inhibited the enzyme competitively with an IC50 of 1.02 µM and Ki of 0.26 ± 0.01 mg/ml. Cleavage of the substrate para-Nitrophenylphosphate (pNPP) by PTP1B showed a KM of 4.99 mM and Vmax of 0.053 µmol/min.Conclusion: The mixture of compounds tested is potent PTP1B inhibitors that could serve as scaffolds for new trypanocidal drug candidates that target protein-tyrosine phosphatase activity.

Chemical composition, antimicrobial and free- radical scavenging activity of essential oils from Khaya senegalensis (Desr) A. Juss

Investigations were conducted to evaluate the chemical composition, free-radical scavenging activity and the antimicrobial efficacy of essential oils obtained from the leaf and stem bark of Khaya senegalensis (Desr) A. Juss. The plant materials (leaf and stem bark) were dried under shade, blended and sieved to obtain their respective powders. The essential oils obtained by subjecting the powders to hydro distillation method for 3hr in a Clevenger type apparatus were then investigated using standard methods. The average percentage yields of the oils were 0.85± 0.01%) and 0.50± 0.00% for the leaf and stem bark respectively. The major constituents of the essential oils were khayasinine (39.11%), 7-diacetyl-7oxogedunine (27.09%) and methyl- angolensate (11.51%) for the leaf oil and ivorenolide (28.77%), khivorine (16.33) and 3-diacetyl khivorine (16.10%) for the stem oil. The inhibitory concentration (IC50) of the free radical scavenging activity of the oils were 1.40± 0.29 and 1.00± 0.02 for the leaf and stem oils respectively. The mean diameter of the zones of inhibition exhibited by the oils at 50 µg/ml was between 7.67± 0.67mm and 16.33 ±0.33mm while the MIC was between 5 µg/ml and 40µg/ml for the plant materials. The plant oils remarkably inhibited the growth of Bacillus subtilis ATCC6633, Candida albicans ATCC10231, Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus. The activity of the plant oils compared favourably with the antibiotics used as positive control. The demonstration of significant antimicrobial and high free radical scavenging activities in addition to the presence of bioactive compounds in the plant materials could explain the basis for the use of K. senegalensis in the traditional treatment of diseases caused by the test microorganisms.

Combination therapy of vitamin C and phenolics-rich fraction of Khaya senegalensis stem bark extract against Trypanosoma brucei brucei infection

The phenolics-rich fraction of Khaya senegalensis A. Juss (Meliaceae) stem bark extract (pfks) has been previously reported to possess potent antitrypanosomal activity at 300 mg/kg body weight (bw) but could not completely prevent disease-induced anemia and organ damage in addition to being slightly hepatotoxic at the same dose. Therefore, the effects of a combined administration of low dose pfks and vitamin C on the severity of Trypanosoma brucei brucei infection in rats were investigated. Daily oral administration of a combined treatment of pfks (100 mg/kg bw) and vitamin C (100 mg/kg bw) for seven days significantly (p < 0.05) reduced the number of T. brucei brucei in the bloodstream compared to infected untreated control with an ED50 of 51.15 mg/kg bw. Also, the trypanosome-induced pathological alterations such as anemia, hepatic and renal damages were significantly (p < 0.05) prevented by the same dosage of the combined treatment. Thus, the results obtained suggest that the combined treatment of a low dose of pfks and vitamin C is therapeutically potent as antitrypanosomal regimen and could effectively ameliorate the trypanosome-induced anemia and organ damage.

Characterization and Anti-diabetic Activity of Dihydrophenantherene Isolated from Khaya senegalensis Stem Bark

Characterization and Anti-diabetic Activity of Dihydrophenantherene Isolated from Khaya senegalensis Stem Bark

English

Khaya senegalensis A. Juss (Meliaceae) is a medicinal plant used in folk medicine of Burkina Faso. Its stem barks are used to treat several diseases such as inflammation, arthritis, infections, ulcer, malaria, fever and dermatosis. The antioxidant activity of aqueous ethanol extract and fractions of Khaya senegalensis stem bark was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH&bull;), 2,2&#39;-azino-bis (ABTS&bull;+), ferric reducing antioxidant power (FRAP) and lipidic peroxidation methods. Total phenolic, tannins, flavonoids and flavonol contents of extract and fractions were determined. Butanol fraction had the highest value with IC50 =1.76 &plusmn; 0.19 &micro;g ml-1 (ARP = 0.56) with DPPH&bull; assay, however n-hexan fraction showed the highest capacity to scavenge ABTS&bull;+; FRAP values varied from 13.04 &plusmn; 0.25 to 13.60 &plusmn; 0.09 mmol Trolox Equivalent per gram (mmol TE g-1) of extract or fraction. Ethyl acetate fraction presented the best activity (70.30 &plusmn; 0.40%, 100 &micro;g ml-1) using lipid peroxidation inhibition method. Aqueous fraction contained the highest of total phenolics and tannins contents with, respectively 3.68 &plusmn; 0.11 and 2.65 &plusmn; 0.18 g TAE/100 g of dry weight (dw) of plant material. Aqueous fraction also showed the highest of total flavonoids (0.04 &plusmn; 0.01 g QE/100 g dw) and flavonol (0.10 &plusmn; 0.01 g QE/100 g dw) contents. K. senegalensis possesses a potential antioxidant effect and contains phenolic compounds. These results provide scientific evidence that validates the use of K. senegalensis in traditional medicine. Key words: Khaya senegalensis, antioxidant, phenolic, flavonoids, tannins

Anti-Hyperglycemic Activity of Solvents Extract of Khaya senegalensis Stem Bark in Alloxan Induced Diabetic Rats

Anti-Hyperglycemic Activity of Solvents Extract of Khaya senegalensis Stem Bark in Alloxan Induced Diabetic Rats

Antihyperglycemic Activity and Phytochemical Screening of &amp;lt;i&amp;gt;Khaya Senegalensis&amp;lt;/i&amp;gt; (Meliaceae) in Wistar Rats

The aim of this study was to identify the chemical group, evaluate an acute toxicity study and analyze the effect of aqueous extract Khaya senegalensis (Meliaceae), on experimentally induced hyperglycemic condition in rats. The phytochemical study of the aqueous extract of Khaya senegalensis revealed the presence of active secondary metabolic compounds such as flavonoids, polyphenols, catechol tannins, quinones, saponins, sterols and terpenes. The stem bark of Khaya senegalensis was used for acute toxicity study by gavage in Swiss mice. The aqueous extract of Khaya senegalensis (AEKS) at the dose of 35±5 mg/kg administrated by gavage showed that all the mice treated were living after 24 hours. The lethal dose obtained by intraperitoneal administration with graded doses to the mice was 1778 mg/kg. This extract could be non-toxic. The study of AEKS activity on blood glucose in rats showed a significant (p <0.01) the concentration of glucose in the serum of the treated rats with the AEKS (96.2 ± 30 mg/dl) and Glibenclamide (92.4±10 mg/dL), compared to glucose concentrations in the serum of hyperglycemic rats (197.1 ± 50 mg/dl). Thus, the study showed hypoglycemic activity of aqueous extract of Khaya senegalensis. In conclusion, the administration of AEKS causes hypoglycemic activity in rats given oral glucose load. Hypoglycemia this is due to the presence of active chemical groups in the extract of this plant, such as flavonoids, catechin tannins, polyphenols, quinones, sterols and terpenes. These results confirm the therapeutic indication in traditional medicine Khaya senegalensis in the treatment of diabetic disease.

Haematological and serum biochemical indices of three different strains of pullets supplemented with Khaya senegalensis stem bark meal as anticoccidial in the diets.

The effects of supplementing different levels of Mahogany (khaya senegalensis) stem bark (KSSB) meal in the diet of pullets on some blood parameters was investigated. A total of 360 day-old chicks were arraigned in a 5 x 3 factorial design of 5 dietary levels (Diet 1 served as negative control without supplementation, Diet 2 was supplemented with 100 mg/kg of anti coccidiostat (sulphaquinoxaline), Diets 3 and 4 were supplemented with 100 and 200mg/kg KSSB respectively at intervals of 21st -27th, 42nd – 48th and 112th - 118th day, while diet 5 was supplemented with 100mg/kg KSSB which was continuously fed from 1st -118th day) and 3 strains of chickens (Isa Brown, Nera Black and Oba Blue). Results showed (P&lt;0.05) lowered packed cell volume (PCV) and higher white blood cell count in Isa brown and Nera black fed diet 1. Uric acid, creatinine, alkaline phosphatase and aspartate aminotransferase values were highest (P&lt; 0.05) in pullets fed diets 1 and 5 irrespective of the strain. These results revealed that KSSB at 100mg/kg and 200mg/kg can be included in the diets of pullets at intervals without deleterious effect on the health of the birds. However, continuous usage of KSSB in the diet of the pullets showed some level of toxicity in the blood.

Limonoids from the stem bark of Khaya senegalensis.

Six new limonoids with modified furan ring, khaysenelide A-F (1-6), together with six known limonoids (7-12) were isolated from the stem bark of Khaya senegalensis. The basic skeletons of these new limonoids belong to mexicanolide (1, 2) and rearrangement phragmalin (3-6), which were elucidated on the basis of spectroscopic methods including high resolution-electrospray ionization (HR-ESI)-MS, one and two dimensional (1D and 2D)-NMR and confirmed by single-crystal X-ray crystallography using CuKα radiation of 1 and 3. Their absolute configurations were determined by the X-ray crystallography data and comparison of their electronic circular dichroism spectra. The inhibitory effect on nitric oxide (NO) production in lipopolysaccaride-activated RAW264.7 macrophages of new compounds was also tested.

English

α-Glucosidase inhibitory potential of selected anti-diabetic plants has been studied. The study evaluated α-glucosidase inhibition using α-glucosidase from Saccharomyces cerevisiae and p-nitrophenyl α-D-glucopyranoside as substrate. The result showed that the extract of Albizzia chevalieri leaf, Khaya senegalensis stem bark, Zizypus spina-christistem bark, Arachis hypogea seed varieties and Mangifera indica leaf had significant (P < 0.05) α-glucosidase inhibitory effect in a concentration dependant manner as compared to acarbose. Cardiac glycosides, alkaloids, saponins, flavonoids and tannins were identified in the extracts. The study concludes that the plant extract contain bioactive compound that may be source(s) of lead compounds with α-glucosidase inhibitory potentials and may explain their hypoglycaemic effects. Key words: Postprandial hyperglycaemia, α-glucosidase inhibitor, antidiabetic plants, hypoglycaemic potential.

Phenolics-rich fraction of Khaya senegalensis stem bark: Antitrypanosomal activity and amelioration of some parasite-induced pathological changes

Context: The stem bark of Khaya senegalensis A. Juss (Meliaceae) is currently used for the treatment of trypanosomiasis by traditional practitioners in Nigeria.Objectives: The present study investigated the anti-Trypanosoma brucei brucei activity of phenolics-rich fraction of K. senegalensis (pfks) and its ameliorative effects on trypanosome-induced pathological changes.Materials and methods: The fraction was initially analyzed by gas chromatography-mass spectrometry (GC-MS). A 60 min time course experiment was conducted with various concentrations of the fraction using a 96-well microtiter plate technique and was further used to treat T. brucei infected rats at 100, 200 and 300 mg/kg body weight (BW). Indices of anemia as well as hepatic and renal functions were analyzed in all experimental animals at the end of the experiment.Results: The GC-MS analysis of the pfks revealed that the most abundant phytochemicals are phloroglucinol (40.56%) and 3,4-(dihydroxyphenyl) acetic acid (41.76%). The fraction showed a concentration dependent in vitro antitrypanosomal activity. Interestingly, the fraction completely eliminated the parasites from the bloodstream of infected rats without relapse during the experimental period at the dose of 300 mg/kg BW and also kept the parasites consistently lower at 100 and 200 mg/kg BW than that was recorded in the untreated infected rats. Furthermore, the severity of T. brucei-induced anemia and hepatic damage was significantly (p < 0.05) ameliorated in the 300 mg/kg BW treatment group whereas the parasite-induced renal damage was significantly (p < 0.05) ameliorated in all treatment groups.Conclusion: Data from this study may suggest that phenolics play an important role in the antitrypanosomal activity of K. senegalensis.

Haemato-biochemical Effects of Aqueous Extract of Khaya senegalensis Stem Bark on Gentamicin-Induced Nephrotoxicity in Wistar Rats

Haemato-biochemical Effects of Aqueous Extract of Khaya senegalensis Stem Bark on Gentamicin-Induced Nephrotoxicity in Wistar Rats

Anti-hyperglycemic Effect of Khaya senegalensis Stem Bark Aqueous Extract in Wistar Rats

Aim: To investigate anti-hyperglycemic effect of aqueous extract of Khaya senegalensis stem bark (KSE) in alloxan-diabetic Wistar rats. Methodology: Thirty rats were randomly divided into six groups of 5 animals each. Group I (non-diabetic control) was given distilled water orally. Animals in the remaining five groups were treated with a single dose of alloxan (120mg/kg body weight, i.p) to induce diabetes mellitus. This resulted in significant increase in the fasting blood glucose level of the rats. Group I (non-diabetic control) and group II (hyperglycemic control) then received distilled water orally for 14 days. Group III, IV and V were treated orally with daily doses of 50, 100 and 150 mg/kg body weight of KSE respectively for 14 days. Group VI was given glibenclamide (5mg/kg, p.o) for the same period. Fasting blood glucose was determined by oxidative method in all the groups on day 0 (before treatment), day 7 and day 14. Oral glucose tolerance test and erythrocyte malondialdehyde (MDA) concentration were estimated after the two week treatment. Body weights of the animals were also measured on day 0, day 7 and day 14. Results: Treatment with KSE and glibenclamide caused significant (p<0.05) and dosedependent changes compared to the untreated animals with respect to body weight, blood glucose level and erythrocyte malondialdehyde (MDA) concentration. The antihyperglycemic effect of KSE was comparable to that of the standard drug, glibenclamide. Conclusion: The study showed that aqueous extract of Khaya senegalensis stem bark possesses anti-hyperglycemic activity.

Larvicidal properties of three plants on Anopheles gambiae

The larvicidal and growth inhibitory properties of methanol extracts of the leaves, stem and root barks of Quassia africana (Simaroubaceae), the leaves and stem bark of Khaya senegalensis (Meliaceae) and the leaves of Lippia multiflora (Verbanaceae), against Anopheles gambiae were evaluated in the laboratory. Extracs were applied at concentrations between 12.5 and 200 mg/ml in dechlorinated water. Larvicidal activity was concentration dependent. All extracts showed some larval toxicity after 24 hours of exposure, with the root and stem extracts of Q. africana producing 100% mortality at 50 mg/ml. Extracts also affected pupal development. No larvae exposed to Q. africana developed into pupae while development was also curtailed when exposed to K. senegalensis and L. multiflora extracts. Larvicidal activity was concentration dependent. These plants could be sources of botanical insecticides for malarial control.Journal of Pharmacy and Bioresources, Vol. 6 no. 2, pp. 50-53 (September 2009)

In-vitro and -vivo anti-Trypanosoma evansi activities of extracts from different parts of Khaya senegalensis.

The in vitro activities of the aqueous and ethanolic extracts of the leaves, root bark and stem bark of Khaya senegalensis on Trypanosoma evansi were evaluated. The ethanolic extract of the stem bark was found to possess the highest in vitro activity among the six extracts tested; as it eliminated the parasites within 5 min post incubation at concentrations of 0.5 and 1 mg/ml. This extract was therefore used to treat rats experimentally infected with T. evansi at concentrations of 20, 40 and 80 mg/kg body weight, beginning 7 days post infection (p.i). At the termination of the experiment on day 13 p.i, the stem bark ethanolic extract significantly (P < 0.05) kept the parasitemia lower than was observed in the untreated infected rats, whereas the parasites were eliminated from the bloodstream of Diminal-treated rats at day 9 p.i. All the infected animals developed anaemia whose severity could not be ameliorated by the extract treatment. It was therefore concluded that the stem bark ethanolic extract of K. senegalensis possessed both in vitro and in vivo anti-T. evansi activity but could not prevent the disease –induced anaemia. Key words: Khaya senegalensis, Trypanosoma evansi, anti – trypanosomal.

6S,8α-Dihydroxy-14,15-Dihydrocarapin (Khayanone) from the Stem Bark of Khaya Senegalensis (Meliaceae): Isolation and its Crystal Structure

Khayanone was isolated from the stem bark of African mahogany, Khaya senegalensis (Meliaceae), and characterized as 6S,8α-dihydroxy-14,15-dihydrocarapin on the basis of spectral analysis and single crystal X-ray diffraction study. The compound crystallizes in the tetragonal space group P41212 with unit cell parameters: a = 13.2315(19) A, c = 29.118(6) A, Z = 8. The crystal structure has been solved by direct methods and refined to R = 0.0375 for 4552 unique reflections. The six-membered rings A and B exist in boat conformations, rings C and D in chair conformations, and the furan ring is planar. The crystal structure is stabilized by O-H···O and C-H···O interactions. This is the first report about 6S configuration of mexicanolide revealed by X-ray diffraction analysis. The configuration of oxygenated C-6 in mexicanolide-group limonoids is discussed.

Increased liver alkaline phosphatase and aminotransferase activities following administration of ethanolic extract of &lt;i&gt;Khaya senegalensis&lt;/i&gt; stem bark to rats

The effect of daily, oral administration of ethanolic extract of Khaya senegalensis stem bark (2mg/kg body weight) for 18days on the alkaline phosphatase, aspartate and alanine aminotransferase activities of rat liver and serum were investigated. Compared with the control, the activities of liver alkaline phosphatase (ALP), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) increased significantly for the 6 and 18 days period of extract administration (P 0.05). The results indicate that the ethanolic extract of Khaya senegalensis stem bark has brought about induction of synthesis of the liver enzymes studied which is an important biochemical symptom of cytolysis.

Effect of Oral Administration of Aqueous Extract of Khaya senegalensis Stem Bark on Phenylhydrazine-induced Anaemia in Rats

Effect of Oral Administration of Aqueous Extract of Khaya senegalensis Stem Bark on Phenylhydrazine-induced Anaemia in Rats