Neurobehavioral and Immunohistochemical Studies of the Cerebral Cortex Following Treatment with Ethyl Acetate Leaf Fraction of Tamarindus indica During Prenatal Aluminum Chloride Exposure in Wistar Rats.

Purpose: The recent increase in aluminum exposure and its effect on the development of the brain call for serious attention. The study investigated the behavioral and immunohistochemical changes in the cerebral cortex of Wistar rats following prenatal co-administration of ethyl acetate leaf fraction of Tamarindus indica (EATI) and aluminum chloride (AlCl3). Methods: Pregnant Wistar rats were divided into 5 groups (n=4). Group I (negative control), Group II-V were experimental groups treated with 200 mg/kg of AlCl3 s/c. Group III and IV received an additional 400 mg/kg and 800 mg/kg of EATI respectively, while Group V received an additional 300 mg/kg of Vitamin E for 14 days (prenatal days 7-21) via the oral route. The pups were then exposed to cliff avoidance, negative geotaxis, and elevated plus maze (EPM) test on the post-natal day (PoND) 4-6, 7-10, and 18 respectively. On PoND 21 pups were sacrificed, and the skull dissected to remove the brain. The harvested brain tissues were processed for Cresyl fast (CF) and glial fibrillary acid protein (GFAP). Results: The study showed that EATI administration during AlCl3 exposure was associated with significant improvement in sensory-motor development. The EPM, CF, and GFAP results revealed significant improvement in anxiety-like behavior, motor activities, GFAP expression, pyramidal cell count, and Nissl staining following prenatal EATI administration during AlCl3 exposure. Conclusion: The present study concludes that EATI was associated with some protective potential during prenatal AlCl3 exposure in Wistar rats.

Tamarindus indica ameliorates behavioral and cytoarchitectural changes in the cerebellar cortex following prenatal aluminum chloride exposure in Wistar rats.

Aluminium exposure has been linked with developmental neurotoxicity in humans and experimental animals. The study aimed to evaluate the ameliorative effect of Tamarindus indica on the developing cerebellar cortex, neurobehavior, and immunohistochemistry of the cerebellar cortex following prenatal aluminum chloride (AlCl3) exposure. Pregnant timed Wistar rats were divided into 5 groups (n=4). Group I (negative control) was given distilled water, group II was treated with 200 mg/kg of AlCl3, group III were given 200 mg/kg of AlCl3 and 400 mg/kg of ethyl acetate leaf fraction of Tamarindus indica (EATI), group IV were given 200 mg/kg of AlCl3 and 800 mg/kg of EATI, and group V were treated with 200 mg/kg of AlCl3 s/c and 300 mg/kg of vitamin E for 14 days (prenatal day 7-21) via the oral route. Male pups (n=6) were randomly selected and taken for neurobehavioral studies, and humanely sacrificed via intraperitoneal injection of thiopental sodium. The cerebellum was removed, fixed and tissue processed for histological and immunohistochemical studies. The results revealed that prenatal AlCl3 exposure impacted neurodevelopment and neurobehaviour among exposed pups. Prenatal AlCl3 exposure was marked with delayed cytoarchitectural development of the cerebellar cortex and increased GFAP expression in the cerebellar cortex. On the other hand, treatment with EATI and vitamin E were marked with significant improvements. The present study therefore concluded treatment with EATI shows an ameliorative effect to prenatal AlCl3 exposure.

Antimicrobial resistance pattern of methicillin-resistant Staphylococcus aureus isolated from sheep and humans in Veterinary Hospital Maiduguri, Nigeria.

Background and Aim: Methicillin-resistant Staphylococcus aureus (MRSA), an important opportunistic pathogen, is a Gram-positive coccus known to be resistant to ß-lactam antibiotics. Its virulence depends on a large range of factors, mainly extracellular proteins, such as enzymes and exotoxins, that contribute to causing a wide range of diseases in human and animal species. The major reasons for the success of this pathogen are its great variability, which enables it to occur and thrive at different periods and places with diverse clonal types and antibiotic resistance patterns within regions and countries. Infections caused by antibiotic-resistant S. aureus bring about serious problems in the general population (humans and animals). Infections with these pathogens can be devastating, particularly for the very young, adults and immunocompromised patients in both humans and animals. This study aimed to determine the presence of MRSA in both apparently healthy and sick sheep brought to the veterinary hospital as well as veterinary staff and students on clinical attachment in the hospital. Materials and Methods: A total of 200 nasal swab samples were collected aseptically from sheep and humans (100 each) for the isolation of MRSA. The samples were processed by appropriately transporting them to the laboratory, then propagated in nutrient broth at 37°C for 24 h followed by subculturing on mannitol salt agar at 37°C for 24 h, to identify S. aureus. This was followed by biochemical tests (catalase and coagulase tests) and Gram staining. MRSA was isolated using Clinical Laboratory Standard Institute (CLSI) guideline and confirmed by plating onto Oxacillin (OX) Resistance Screening Agar Base agar. The antimicrobial susceptibility pattern of the MRSA isolates was determined using the disk diffusion method against 12 commonly used antimicrobial agents. Results: The total rate of nasal carriage of S. aureus and MRSA was found to be 51% and 43% in sheep and humans, respectively. The MRSA prevalence in male and female sheep was 18% and 8%, while 9% and 8% were for male and female human samples, respectively. The antimicrobial susceptibility test showed 100% resistance to OX, cefoxitin, oxytetracycline, cephazolin, and penicillin-G (Pen) by MRSA isolates from humans. Conversely, there was 100% susceptibility to ciprofloxacin, imipenem, and gentamicin; for linezolid (LZD), it was 87.5%, norfloxacin (NOR) (71%), and erythromycin (ERY) (50%) susceptibility was recorded. The MRSA isolates from sheep recorded 100% resistance to the same set of drugs used for human MRSA isolates and were equally 100% susceptible to gentamicin, imipenem, LZD, ciprofloxacin, NOR (92%), and ERY (50%). Conclusion: This study determined the presence of MRSA in sheep and humans from the Veterinary Hospital, Maiduguri. It appears that certain drugs such as ciprofloxacin, imipenem, and gentamicin will continue to remain effective against MRSA associated with humans and sheep. Reasons for the observed patterns of resistance must be explored to reduce the burdens of MRSA resistance. Furthermore, the present study did not confirm the MRSA resistance genes such as mecA and spa typing to ascertain the polymorphism in the X-region using appropriate molecular techniques. Hence more studies need to be conducted to elucidate these findings using robust techniques.

Ethanol Extract of Securidaca longipedunculata Induces Apoptosis in Brain Tumor (U87) Cells.

Incidence of cancer is estimated to be on the increase and current anticancer drugs are characterized by narrow margin of safety and side effects. There is the need to explore new drugs especially from plants since plants serve as major source of drugs. Securidaca longipedunculata Fresen plant is called the mother of all medicines in northern Nigeria and is used traditionally in the treatment of cancers by most traditional medicine practitioners in the region. This study is aimed at evaluating the anticancer activity of the plant extract using U87 brain tumor cell line. Ethanol extract of its root bark was prepared and fractionated by silica gel column chromatography. In vitro activity of the extract and fractions were assessed on the viability of U87 malignant brain tumor cell line by using hemacytometer, annexin V-PE and 7AAD flow cytometry and western blot detection of Poly-ADP-Ribose-Polymerase (PARP) cleavage. The results showed that the extract significantly (p<0.01) inhibited proliferation of U87 cell line with IC50 of 20.535 µg/ml. Apoptosis was induced by the extract (41.53 ± 10.33%) and the polar fraction (47.3 ± 2.7%) via cleavage of PARP. It was concluded that the ethanol extract of S. longipedunculata root bark inhibited proliferation of U87 cell line and induced apoptosis by cleavage of PARP, thus supporting folkloric use of the plant in the management of cancers.

Antibacterial activity of stilbene oligomers against vancomycin-resistant Enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) and their synergism with antibiotics.

Two resveratrol trimers, gnemonol B isolated from Gnetum gnemon and gnetin E obtained from the Gnetum species, were found to exhibit strong antibacterial activities against vancomycin-resistant Enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA). The MIC values of gnemonol B against five strains of VRE and nine strains of MRSA were 12.5 and 6.25 microg/ml, respectively. The MIC values of gnetin E against five strains of VRE and nine strains of MRSA ranged from 12.5 to 25microg/ml. These compounds also showed synergistic effects when used in combination with commercially available antibiotics according to the evaluation method using FIC indices. These findings suggested that the application of the test compounds alone or in combination with antibiotics might be useful in controlling and treating VRE and MRSA infections

Growth inhibition of stilbenoids in Welwitschiaceae and Gnetaceae through induction of apoptosis in human leukemia HL60 cells.

Fifty-six stilbenoids isolated from the families of Welwitschiaceae and Gnetaceae were screened for growth inhibitory activity against HL60 cells, and two compounds (gnemonol G and gnetin I) among them exhibited a strong activity with IC(50) of 10.0 microM and 12.2 microM at 48 h incubation, respectively. The growth suppression by gnemonol G and gnetin I was found to be in part due to apoptosis which was assessed by morphological findings such as nuclear condensation and fragmentation, and DNA ladder formation in human leukemia HL60 cells.

Resveratrol oligomers and their O-glucosides from Cotylelobium lanceolatum.

Three new resveratrol oligomers, cotylelophenol C (1) (resveratrol tetramer) and cotylelosides A (2) and B (3) (O-glucosides of resveratrol trimer), together with four known glucosides of resveratrol oligomers (vaticasides A, B, C, D) and piceid, were isolated from an acetone soluble part of stem of Cotylelobium lanceolatum (Dipterocarpaceae). The structures of new compounds were determined by spectral data analysis. The characteristic properties observed in the NMR spectra of 1 were also discussed.

Flavonol glycosides in leaves of two Diospyros species.

Fourteen flavonol glycosides including two new compounds were isolated from the leaves of two Diospyros plants (D. cathayensis and D. rhombifolia). The structures of isolated compounds were determined by spectroscopic analysis. The scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical of the isolated compounds was also investigated.

Resveratrol derivatives from Upuna borneensis.

Four new resveratrol derivatives, upunaphenols B (1), C (4), D (5) (resveratrol tetramer) and E (6, resveratrol dimer with a C6-C1 unit), together with nine known resveratrol oligomers and resveratrol were isolated from an acetone soluble part of stem of Upuna borneensis (Dipterocarpaceae). The structures of new compounds were determined by spectral analysis including 1D and 2D NMR experiments.

Two novel trimeric resveratrol derivatives from Cotylelobium lanceolatum.

Two new resveratrol (= 5-[(E)-2-(4-hydroxyphenyl)ethenyl]benzene-1,3-diol) trimers, cotylelophenols A (1) and B (2), were isolated from the stem of Cotylelobium lanceolatum (Dipterocarpaceae), together with ten known resveratrol oligomers (3-12). The structures of the isolates were established on the basis of spectroscopic analyses, including a detailed NMR spectroscopic investigation of 1 under different conditions. Compound 1 is the first resveratrol trimer with a rearranged 4-hydroxyphenyl group. Four possible biogenetic pathways towards resveratrol oligomers are proposed (Scheme).

New resveratrol tetramers from the stem bark of Upuna borneensis.

Five new resveratrol (=5-[(E)-2-(4-hydroxyphenyl)ethenyl]benzene-1,3-diol) tetramers, upunaphenols H-J (1-3) and trans-(4) and cis-upunaphenol K (5), were isolated from the stem of Upuna borneensis (Dipterocarpaceae). Their structures were elucidated on the basis of 1D- and 2D-NMR as well as FAB-MS data. Compounds 1-3 bear a rare biphenyl bond in their frameworks. Compounds 1 and 2 have an unprecedented nonacyclic fused ring system, and compounds 2 and 3 have symmetrical structures.

Four new trimeric stilbene glucosides from Welwitschia mirabilis.

Four new trimeric stilbene glucosides, mirabilosides C-F (1-4) were isolated from MeOH extract of stem and root of Welwitschia mirabilis (Welwitschiaceae) along with three known stilbenoids, resveratrol (5), gnemonoside B (6), and gnetin G (7). The structures of these compounds were elucidated by spectroscopic methods.

Gnetol as a potent tyrosinase inhibitor from genus Gnetum.

Gnetol (2,3',5',6-tetrahydroxy-trans-stilbene), a naturally occurring compound particularly found in the genus Gnetum, had a strong inhibitory effect on murine tyrosinase activity. Gnetol (IC50, 4.5 microM) was stronger than kojic acid (IC50, 139 microM) as a standard inhibitor for murine tyrosinase activity. Moreover, gnetol significantly suppressed, melanin biosynthesis in murine B16 melanoma cells.

Phenolic constituents of Gnetum klossii.

Four new phenolic derivatives, gnetofurans A-C (1-3) and dihydropinosylvindiol (4), were isolated from a methanol-soluble extract of the stems of Gnetum klossii, together with nine known compounds [gnetifolin F (5), isorhapontigenin, gnetulin, gnetins E and C, latifolol, gnetol, (-)-epsilon-viniferin, and trans-resveratrol]. The structures of the new compounds were determined by spectral data analysis.

Stilbene derivatives from Gnetum gnemon Linn.

Four stilbene derivatives, gnemonols K and L (resveratrol trimers), M (isorhapontigenin dimer), and gnemonoside K (glucoside of resveratrol trimer) together with eleven known stilbenoids and a lignan were isolated from the acetone, methanol and 70% methanol soluble parts of the root of Gnetum gnemon (Gnetaceae). The structures of the isolates were determined by spectral analysis. The antioxidant activity of the stilbenoids on lipid peroxide inhibition and super oxide scavenging activity were also investigated.

Three new trimeric stilbenes from Gnetum gnemon.

Three stilbene trimers (gnemonols D, E, F) were isolated from the root of Gnetum gnemon. The structures were determined by spectroscopic analysis. In addition, the antioxidant activity of the compounds on lipid peroxide inhibition and super oxide scavenging activity were also investigated.

Stilbenoids from the stem of Gnetum latifolium (Gnetaceae).

An acetone extract of the stem of Gnetum latifolium Blume afforded the stilbene trimer (latifolol) together with five known stilbenoids (gnetin E, gnetin D, gnetin C, (-)epsilon -viniferin and resveratrol). Their structures were elucidated on the basis of spectral evidence, in particular by using 2D NMR methods.

Stilbene derivatives from two species of Gnetaceae.

Five new stilbene oligomers (gnemonols A, B and C, gnemonoside E and gnetal) were isolated together with 2b-hydroxyampelopsin F and gnetin E from Gnetum gnemon and G. gnemonoides. The structures of the compounds were elucidated on the basis of spectral evidence.