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The emergence of drug resistance and multiple drug resistance has necessitated the discovery of novel strategies for development of new generation of antimicrobial agents from natural substances for control of microbial infections. Metal nanoparticles have proven to have antimicrobial properties, but the chemical methods used in their production use hazardous chemicals and nanoparticles produced are unstable. In this study, an alternative feasible environmentally friendly method was used for the synthesis of silver nanoparticles using Bridelia micrantha, a Kenyan medicinal plant as a reducing, stabilizing and capping agent. The reaction was done over ultrasonic bath. Formation of the nanoparticles was monitored by visual observation and also by use of UV-VIS spectrophotometer. The synthesized silver nanoparticles had an absorption peak at λmax 431 nm due to plasmon resonance. Energy dispersive X-ray (EDX) analysis showed the synthesized nanoparticles were pure silver. High resolution transmition electron microscope (HRTEM) analysis showed the nanoparticles had non uniform surface and were spherical with an average size of 16.07±3.192 nm. Scanning area electron diffraction (SAED) showed distinct shiny spots, confirming the crystallinity of the nanoparticles. Fourier transform infrared (FTIR) analysis indicated the presence of biomolecules capping the nanoparticles. The silver nanoparticles inhibited growth of Escherichia coli and Staphylococcus aureus. The data from this study will significantly contribute in designing novel methods geared towards development of drugs to combat pathogens by use of silver nanoparticles synthesized in an environmentally and ecofriendly way. Key words: Antibacterial activity, Bridelia micrantha, energy dispersive X-ray (EDX), scanning area electron diffraction (SAED), high resolution transmition electron microscope (HRTEM), silver nanoparticles (AgNPs).

Bridelia micrantha is a medicinal plant used traditionally for the treatment of wounds. However, there are no documented scientific reports on the wound healing activities of this plant. This study was conducted to investigate the antimicrobial, antioxidant and wound healing activities of methanol leaf extract of B. micrantha (BME). The antimicrobial activity was determined using the agar well diffusion and broth dilution methods. Antioxidant activity was performed in vitro using the DPPH scavenging antioxidant activity followed by in vivo wound healing activities using the excision wound model. Preliminary phytochemical screening of BME showed the presence of saponins, tannins, flavonoids, alkaloids, triterpenes, glycosides, steroids and coumarins. BME exhibited dose-dependent antimicrobial activities. The most susceptible organism to BME was N. gonorrhoeae with mean zones of inhibition ranging from 20.50 ± 1.00 to 28.50 ± 1.00 mm. The least susceptible organism was S. typhi with mean zones of inhibition in the range of 15.50 ± 0.00 to 21.50 ± 0.00 mm. The MICs of BME against the test organisms were in the range of 1.25 to 2.5 mg/mL. Sub-inhibitory concentrations of BME potentiated the activities of ciprofloxacin and ketoconazole. BME showed a dose-dependent increase in antioxidant activity with IC50 of 0.2626 µg/mL. The BME formulated creams at concentrations of 0.625, 2.5, and 10% w/w showed a significant (p

Insect pest infestation is a major factor militating against okra production and farmers generally adopt synthetic insecticides for its management. A field trial was undertaken to evaluate the insecticidal potency of Bridelia micrantha and Dalbergia lactea for the management of Podagrica uniforma (Jacoby) and Nisotra dilecta (Jacoby) insect pest of okra ( Abelmoschus esculentus L. Moench). The treatments consisted of aqueous leaf extracts of Bridelia micrantha and Dalbergia lactea and Cypermethrin as check; laid out in Randomized Complete Block Design and repli-cated three times. Data was collected on insect population before treatment application and 3 days after spraying of insecticides at 28, 35, 42, 56 days after planting (DAP). Yield parameters data collected were number of fruits and fruit weight. Results obtained showed that the plant extracts exhibited effectiveness in reducing the insect population and improved okra fruit yield compared to Cypermethrin. The order of effectiveness in decreasing sequence was found to be Cypermethrin ˃ D. lacteal ˃ B. micrantha . D. lacteal and B. micrantha crude extracts could be explored as promising insecticidal agents to provide valuable alternatives to chemical control of insect infestation on okra. Further study is recommended to determine the chemical constituents responsible for the plant insecticidal activity.

Helicobacter pylori is a major risk factor for gastritis, ulcers and gastric cancer. This study was aimed to determine the antimicrobial activity of the stem bark of Bridelia. micrantha on H. pylori isolated in South Africa. Extracts and clarithromycin were tested against 31 clinical strains, including a standard strain (NCTC 11638) of H. pylori, by measuring the diameters of the corresponding inhibition zones, followed by determination of the Minimum Inhibitory Concentration (MIC) (using metronidazole, and amoxicillin as control antibiotics) and the rate of kill. Preliminary phytochemical screening was also done. Inhibition zone diameters which ranged from 0–23 mm were observed for all five of the extracts and 0–35 mm for clarithromycin. Marked susceptibility of strains (100%) was noted for the acetone extract (P < 0.05), followed by ethyl acetate extract (93.5%). The MIC50 values ranged from 0.0048 to 0.156 mg/mL for the ethyl acetate extract and 0.0048 to 0.313 mg/mL for the acetone extract. The MIC90 values ranged from 0.0048 to 2.5 mg/mL for the ethyl acetate extract and 0.078 to >0.625 mg/mL for the acetone extract, respectively. Insignificant statistical difference in potency was observed when comparing the crude ethyl acetate extract to metronidazole and amoxicillin (P > 0.05). Complete killing of strain PE430C by the ethyl acetate extract was observed at 0.1 mg/mL (2 × MIC) and 0.2 mg/mL (4 × MIC) at 66 and 72 h. For strain PE369C, 100% killing was observed at 0.1 mg/mL (2 × MIC) in 66 and 72 h. The ethyl acetate extract could thus be a potential source of lead molecules for the design of new anti-Helicobacter pylori therapies as this study further confirmed the presence of phytochemicals including alkaloids, flavonoids, steroids, tannins and saponins.

Bridelia micrantha (Hochst) Baill. (Euphorbiaceae), commonly known in English as “coast gold leaf” or “ogaofia” (the boss of the bush) in Igbo, is a semi-deciduous to deciduous tree up to 20 m tall with a dense rounded crown and tall, and bare stem indigenous to southern part of Nigeria. Its stem bark, which is yellow grey and smooth to slightly rough, has been of interest to researchers because of its use in the treatment of various disease conditions in Nigerian traditional medicine. The present study was targeted at investigating the antidiabetic and antioxidant effects of the methanol extract of B. micrantha leaves using alloxan-induced diabetic mice in vivo and in vitro. The extract, at the dose of 250, 500, and 1,500 mg/kg, showed a remarkable time-dependent decrease in blood glucose level in alloxan-induced diabetic mice. There was no significant difference between the extract-treated groups and the groups treated with 10 mg/kg distilled water and glibenclamide (2 mg/kg), respectively. Six hours posttreatment, the blood glucose level for the groups treated with 250 mg/kg of B. micrantha and glibenclamide (2 mg/kg), respectively, were lower than the normal blood glucose level respectively for the groups before the induction of diabetes. B. micrantha showed its optimum antioxidant activity in DPPH spectrophotometric assay at the concentration of 400 μg/ml. The ferric reducing antioxidant power showed a significant concentration-dependent increase in the total antioxidant power. These findings demonstrate that B. micrantha has both antidiabetic and antioxidant effects on experimental model of diabetes in mice and validate its use in Nigerian traditional medicine for the treatment of diabetes. Even in its crude form, the effects were comparable to that of glibenclamide, an oral sulfonylurea with proven antidiabetic activity. This finding suggests that the extract could be a potential source of a novel antidiabetic and antioxidant agent for the management of diabetes mellitus.

BACKGROUND Ethnopharmacological practitioners in Nigeria have used aqueous and ethanol extracts of Bridelia micrantha leaves to manage conditions associated with inflammation, and these include diabetes, chest pain, edema, arthritis and joint pains. This study aimed to evaluate the effects of methanol leaf extract of B. micrantha on chronic inflammation and oxidative stress which accompany diabetic conditions, in streptozotocin-induced diabetic Albino Wistar rats. METHODS The dried leaves were extracted by percolation in 80% methanol:water for 72 h after which the mixture was filtered using Whatman No. 1 (11 μm) filter papers. Acute toxicity studies were done using Wistar rats and given orally up to a dose of 2,000 mg/kg. The animals were monitored for 48 h. The experimental design involved five (5) groups of six (6) albino Wistar diabetic rats each. Groups A, B and C rats received 100, 200 and 400 mg/kg B. micrantha respectively while groups D (negative control) and E (positive control) rats received 10 mL/kg normal saline and 200 mg/kg acetylsalicylic acid (ASA) respectively by gastric gavage for 7 days. Two sterilized cotton pellets (10 mg each) were implanted subcutaneously into both sides of the dorsal area of each diabetic rat in all the groups. Post cotton pellet implantation, rats in three groups (A, B and C) were treated with 100, 200 and 400 mg/kg B. micrantha extract, while those in two groups (D and E) were treated with acetyl salicylic acid (ASA 200 mg/kg) and normal saline (10 mL/kg) respectively by gastric gavage for 7 days. Serum obtained from the animals on Day 8 of the cotton pellet test were used for malondialdehyde (MDA), catalase, superoxide dismutase (SOD) and glutathione (GSH) assays. RESULTS The administration of the leaf extract up to a dose of 2,000 mg/kg to rats produced absolutely no death or observable signs of toxicity in 48 h. The cotton pellet granuloma weights in 200 mg/kg (44.88±1.2 mg), 400 mg/kg (42.10±1.2 mg) B. micrantha extract treated groups and ASA at 200 mg/kg (43.25±1.8 mg) were significantly lower compared to weight of granuloma (85.50±3.2 mg) obtained in the group treated with normal saline. Serum malondialdehyde (MDA) level in the 200 mg/kg (3.32±0.72 nmol/mL) and 400 mg/kg (1.88±1.27 nmol/mL) B. micrantha extract treated groups were significantly (p

A study was conducted with the objective of evaluating the nutritive value of some browse species from Kenya. The species evaluated included: Bauhinia alba, Bauhinia variegata, Bridelia micrantha, Calliandra calothyrsus, Carisa edulis, Cratylia argentea, Gliricidia sepium, Lantana camara, Maerua angolensis, Sesbania micrantha and S. sesban. The browses were evaluated by their chemical composition including phenolics, in vitro gas production and tannin activity (tannin bioassay). All the species had high crude protein content (149-268 g/kg DM) and low NDF content (239-549 g/kg DM). The feeds had varying contents of total extractable tannins (TET) ranging from low (3-22 mg/g DM), moderate (42-58 mg/g DM) and high (77-152 mg/g DM). Calliandra calothyrsus had the highest tannin content. Significant (p

ObjectiveTo explore the hepatoprotective and anti-oxidant activities of the methanolic leaf extract of Bridelia micrantha (B. micrantha) on paracetamol induced liver damage in Wistar rats.MethodsParameters were measured including alanine aminotransaminase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), bilirubin and total protein. The anti-oxidant effects were studied using the 1, 1-Diphenynl-2-Picrylhydrazyl (DPPH) and Ferric Reducing Antioxidant Power (FRAP) assay methods.ResultsB. micrantha extract decreased the level of AST in the rats given PCM from (129.47±0.92I) IU/L to (57.78±1.71) IU/L (P

The methanolic leaf extract of Bridelia micrantha was tested for subacute antidiabetic and in vivo antioxidant effects in alloxan-induced hyperglycaemic rats. The subacute treatment of the extract (125, 250 and 500 mg/kg) produced 75, 68 and 63% reduction in fasting blood sugar level respectively, on day 14 of treatment. The extract produced time-dependent effect, but did not show a dose-dependent effect. Its optimum antidiabetic activity was noted at the dose of 125 mg/kg and this was comparable to glibenclamide 2 mg/kg (positive control). The extract (125 mg/kg) showed good oral glucose tolerance test (OGTT) effect in both normoglycaemic and hyperglycaemic rats. The OGTT effect of the extract (125 mg/kg) did not differ significantly (p>0.05) from glibenclamide (2 mg/kg). The antioxidant effect of the extract was assayed through the determination of the level of thiobarbituric acid reactive substance (TBARS) and catalase activity. The extract produced a dose-dependent decrease in the serum level of TBARS and gave its optimum catalase activity at the dose of 500 mg/kg. This study suggests that the B. micrantha extract has antihyperglycaemic and antioxidant activities. Therefore, could be a potential source of novel antidiabetic and antioxidant agent for the management of diabetes mellitus.

The anti-diabetic activity of extracts and fractions from leaves of Bridelia micrantha was investigated in alloxan diabetic rats. Powdered leaves of B. micrantha were macerated with 80% MeOH for five days. The petroleum ether, CHCl3 and MeOH/H20 soluble portions were prepared from the crude aqueous MeOH extract and tested on the diabetic rats. Hyperglycaemia was induced by intraperitoneal injection of alloxan monohydrate (80mg/kg) and blood glucose monitored for seven days using a glucometer. The MeOH/H2O residue exhibited significant (p

Isolation of the title compound, C30H50O, from Bridelia micrantha yielded suitable crystals for an X-ray structure determination, showing it to be in the β-form. The crystal packing is determined by infinite zigzag O—H⋯O hydrogen-bonded chains.

Background : Plant cells fundamentally are chemical factories containing a rich supply of therapeutically useful phytocompounds that have the potential of being developed into potent antimicrobial agents. Aim of the Study: To investigate the antibacterial activity of fractionated extracts of the ethyl acetate extract of the stem bark of Bridelia micrantha (Hochst., Baill., Euphorbiaceae). Materials and Methods: Thin-layer chromatography and column chromatography were used to purify the extracts and antimicrobial activity performed on reference and clinical strains of Staphylococcus aureus, Shigella sonnei, Salmonella Typhimurium, and Helicobacter pylori using direct and indirect bioautographic methods respectively. Furthermore, the eluted compound fractions were then assayed for minimum inhibitory concentration (MIC 50 ) using the 96-well micro dilution technique. Results: Better separation of phytocompounds was obtained from the non-polar Benzene/Ethanol/Ammonia (BEA) and intermediate-polar Chloroform/Ethyl acetate/Formic acid (CEF) eluents compared to the polar Ethanol/Methanol/Water (EMW). Bioautography revealed the presence of three bioactive compounds (R f values; 0.12, 0.20, and 0.42) on the BEA plates, designated fractions 3, 7, and 8 with MIC 50 values; 0.0048mg/mL to 1.25mg/mL (fraction 3), 0.0024mg/mL to 5 mg/mL (fraction 7), and 0.0024mg/mL to 2.5mg/mL (fraction 8). Conclusion: Our findings demonstrate that ethyl acetate extract of the stem-bark of B. micrantha possess potent bioactive phytocompounds that may be developed into new antimicrobials.

Background Tuberculosis, caused by Mycobacterium tuberculosis (MTB), is the most notified disease in the world. Development of resistance to first line drugs by MTB is a public health concern. As a result, there is the search for new and novel sources of antimycobacterial drugs for example from medicinal plants. In this study we determined the in vitro antimycobacterial activity of n-Hexane sub-fraction from Bridelia micrantha (Berth) against MTB H37Ra and a clinical isolate resistant to all five first-line antituberculosis drugs. Methods The antimycobacterial activity of the n-Hexane sub-fraction of ethyl acetate fractions from acetone extracts of B. micrantha barks was evaluated using the resazurin microplate assay against two MTB isolates. Bioassay-guided fractionation of the ethyl acetate fraction was performed using 100% n-Hexane and Chloroform/Methanol (99:1) as solvents in order of increasing polarity by column chromatography and Resazurin microtiter plate assay for susceptibility tests. Results The n-Hexane fraction showed 20% inhibition of MTB H37Ra and almost 35% inhibition of an MTB isolate resistant to all first-line drugs at 10 μg/mL. GC/MS analysis of the fraction resulted in the identification of twenty-four constituents representing 60.5% of the fraction. Some of the 24 compounds detected included Benzene, 1.3-bis (3-phenoxyphenoxy (13.51%), 2-pinen-4-one (10.03%), N(b)-benzyl-14-(carboxymethyl) (6.35%) and the least detected compound was linalool (0.2%). Conclusions The results show that the n- Hexane fraction of B. micrantha has antimycobacterial activity.

The compounds friedelin, taraxerone, epifriedelinol, taraxerol, gallic acid and ellagic acid have been isolated from Bridelia micrantha. The presence of leucodelphinidin and caffeic acid was also indicated.