Antimicrobial and toxicological activities of five medicinal plant species from Cameroon Traditional Medicine

<p>Abstract</p> <p>Background</p> <p>Infectious diseases caused by multiresistant microbial strains are on the increase. Fighting these diseases with natural products may be more efficacious. The aim of this study was to investigate the <it>in vitro </it>antimicrobial activity of methanolic, ethylacetate (EtOAc) and hexanic fractions of five Cameroonian medicinal plants (<it>Piptadeniastum africana</it>, <it>Cissus aralioides, Hileria latifolia, Phyllanthus muellerianus </it>and <it>Gladiolus gregasius) </it>against 10 pathogenic microorganisms of the urogenital and gastrointestinal tracts.</p> <p>Methods</p> <p>The fractions were screened for their chemical composition and <it>in vivo </it>acute toxicity was carried out on the most active extracts in order to assess their inhibitory selectivity.</p> <p>The agar well-diffusion and the micro dilution methods were used for the determination of the inhibition diameters (ID) and Minimum inhibitory concentrations (MIC) respectively on 8 bacterial species including two Gram positive species (<it>Staphylococcus aureus, Enterococcus faecalis)</it>, and six Gram negative <it>(Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, Shigella flexneri, Salmonella typhi) </it>and two fungal isolates (<it>Candida albicans, Candida krusei)</it>. The chemical composition was done according to Harbone (1976), the acute toxicity evaluation according to WHO protocol and the hepatic as well as serum parameters measured to assess liver and kidney functions.</p> <p>Results</p> <p>The chemical components of each plant's extract varied according to the solvent used, and they were found to contain alkaloids, flavonoids, polyphenols, triterpens, sterols, tannins, coumarins, glycosides, cardiac glycosides and reducing sugars. The methanolic and ethylacetate extracts of <it>Phyllanthus muellerianus </it>and <it>Piptadeniastum africana </it>presented the highest antimicrobial activities against all tested microorganisms with ID varying from 8 to 26 mm and MIC from 2.5 to 0.31 mg/ml. The <it>in vivo </it>acute toxicity study carried out on the methanolic extracts of <it>Phyllanthus muellerianus </it>and <it>Piptadeniastrum africana </it>indicated that these two plants were not toxic. At the dose of 4 g/kg body weight, kidney and liver function tests indicated that these two medicinal plants induced no adverse effect on these organs.</p> <p>Conclusion</p> <p>These results showed that, all these plant's extracts can be used as antimicrobial phytomedicines which can be therapeutically used against infections caused by multiresistant agents.</p> <p>Phyllanthus muellerianus, Piptadeniastum africana, antimicrobial, acute toxicity, kidney and liver function tests, Cameroon Traditional Medicine</p

HANDBOOK OF TOXICOLOGIC PATHOLOGY VOLUME 2

,973 hlm;22,5 x 28 c

Haschek and Rousseaux\u27s Handbook of Toxicologic Pathology, 3/E.

Haschek and Rousseaux\u27s Handbook of Toxicologic Pathology is a key reference on the integration of structure and functional changes in tissues associated with the response to pharmaceuticals, chemicals and biologics. The 3e has been expanded by a full volume, and covers aspects of safety assessment not discussed in the 2e. Completely revised with many new chapters, it remains the most authoritative reference on toxicologic pathology for scientists and researchers studying and making decisions on drugs, biologics, medical devices and other chemicals, including agrochemicals and environmental contaminants. New topics include safety assessment, the drug life cycle, risk assessment, communication and management, carcinogenicity assessment, pharmacology and pharmacokinetics, biomarkers in toxicologic pathology, quality assurance, peer review, agrochemicals, nanotechnology, food and toxicologic pathology, the environment and toxicologic pathology and more. • Provides new chapters and in-depth discussion of timely topics in the area of toxicologic pathology and broadens the scope of the audience to include toxicologists and pathologists working in a variety of settings • Offers high-quality and trusted content in a multi-contributed work written by leading international authorities in all areas of toxicologic pathology • Features hundreds of full color images in both the print and electronic versions of the book to highlight difficult concepts with clear illustration

Handbook of toxicologic pathology /

A comprehensive understanding of toxicologic pathology is essential for those in industry, academia, and government who make decisions concerning the safety and efficacy of drugs and chemicals. Toxicologic Pathology relies heavily on the fields of both toxicology and pathology, which are well covered individually in various texts and references; however, there are few texts that address the field of toxicologic pathology. The Handbook of Toxicology Pathology fills this void and is thus essential for all health professionals within or interacting with the field of toxicologic pathology. This two-volume set provides the reader with a single reference for toxicologic pathology. In volume I, the book covers toxicologic pathology in its basic aspects, including its definition, the basic biochemical and morphologic mechanisms underlying the discipline, the basic practice of toxicologic pathology (including special techniques) and issues essential to the understanding of toxicologic pathology such as risk assessment, experimental design, and statistical analysis. Next, the book moves to specific issues affecting the "practice" toxicologic pathology, including issues such as knowledge management, regulatory affairs and writing pathology reports. Finally, Volume I closes with several chapters that deal with specific classes of environmental toxicants such as endocrine disruptors and heavy metals. Volume II addresses the toxicologic pathology in a thoroughly standardized systems manner, addressing the basic structure and function of a particular organ system, its response to toxic injury, mechanisms of injury and methods of evaluation of such injury. Key Features * Easy to find, up-to-date reference information * Graphic and photographic plates * Current hot topics and anticipated changes in toxicologic pathology * Standardized chapter format * Topics that are addressed in both a broad and deep manner, resulting in a stand alone text * Added coverage of important environmental toxicants * Chapters authored by internationally recognized experts and peer-reviewed.A comprehensive understanding of toxicologic pathology is essential for those in industry, academia, and government who make decisions concerning the safety and efficacy of drugs and chemicals. Toxicologic Pathology relies heavily on the fields of both toxicology and pathology, which are well covered individually in various texts and references; however, there are few texts that address the field of toxicologic pathology. The Handbook of Toxicology Pathology fills this void and is thus essential for all health professionals within or interacting with the field of toxicologic pathology. This two-volume set provides the reader with a single reference for toxicologic pathology. In volume I, the book covers toxicologic pathology in its basic aspects, including its definition, the basic biochemical and morphologic mechanisms underlying the discipline, the basic practice of toxicologic pathology (including special techniques) and issues essential to the understanding of toxicologic pathology such as risk assessment, experimental design, and statistical analysis. Next, the book moves to specific issues affecting the "practice" toxicologic pathology, including issues such as knowledge management, regulatory affairs and writing pathology reports. Finally, Volume I closes with several chapters that deal with specific classes of environmental toxicants such as endocrine disruptors and heavy metals. Volume II addresses the toxicologic pathology in a thoroughly standardized systems manner, addressing the basic structure and function of a particular organ system, its response to toxic injury, mechanisms of injury and methods of evaluation of such injury. Key Features * Easy to find, up-to-date reference information * Graphic and photographic plates * Current hot topics and anticipated changes in toxicologic pathology * Standardized chapter format * Topics that are addressed in both a broad and deep manner, resulting in a stand alone text * Added coverage of important environmental toxicants * Chapters authored by internationally recognized experts and peer-reviewed.Volume 1: General Toxicologic Pathology -- Preface. -- Contributors. -- Part A: Basics of Toxicologic Pathology -- Toxicologic Pathology: An Introduction. -- Biochemical Basis of Toxicity. -- Morphologic Manifestation of Toxic Cell Injury. -- Organelle Biochemistry and Regulation of Cell Death. -- Carcinogenesis. -- Applied Clinical Pathology in Preclinical Toxicology Testing. -- Nomenclature. -- Part B: The Practice of Toxicologic Pathology -- Basic Techniques. -- Managing Pitfalls in Toxicologic Pathology. -- Special Techniques in Toxicologic Pathology. -- Application of New Technologies to Toxicologic Pathology. -- Issues in Laboratory Animal Science for the Toxicologic Pathologist. -- New Animal Models in Toxicology. -- Pathology Issues in the Design of Toxicology Studies. -- Use and Misuse of Statistics in the Design and Interpretation of Studies. -- Preparation of the Report for a Toxicology/Pathology Study. -- Part C: Selected Topics in Toxicologic Pathology -- Risk Assessment: The Changing Paradigm. -- Principles of Risk Communication: Building Trust and Credibility with the Public. -- Biomedical Devices and Biomaterials. -- Biotechnology and Its Products. -- Endocrine Disruptors. -- Radiation and Heat. -- Nutritional Toxicologic Pathology. -- Phycotoxins. -- Mycotoxins. -- Heavy Metals. -- Volume 2: Organ Specific Toxicologic Pathology -- Organ-Specific Toxicologic Pathology: An Introduction. -- Respiratory System. -- Skin and Oral Mucosa. -- Gastrointestinal Tract. -- Liver. -- Pancreas. -- Kidney. -- Lower Urinary Tract. -- Cardiovascular and Skeletal Muscle Systems. -- Bones and Joints. -- Nervous System. -- The Eye. -- Immune System. -- Hematopoietic System. -- Endocrine System. -- Male Reproduction. -- Female Reproduction. -- Embryo and Fetus. -- Index.Includes bibliographical references and index.Electronic reproduction.Master and use copy. Digital master created according to Benchmark for Faithful Digital Reproductions of Monographs and Serials, Version 1. Digital Library Federation, December 2002.digitizedPrint version record.Elsevie

Dysregulated Estrogen Receptor Signaling in the Hypothalamic-Pituitary-Ovarian Axis Leads to Ovarian Epithelial Tumorigenesis in Mice

<div><p>The etiology of ovarian epithelial cancer is poorly understood, mainly due to the lack of an appropriate experimental model for studying the onset and progression of this disease. We have created a mutant mouse model in which aberrant estrogen receptor alpha (ERα) signaling in the hypothalamic-pituitary-ovarian axis leads to ovarian epithelial tumorigenesis. In these mice, termed ERα^d/d, the ERα gene was conditionally deleted in the anterior pituitary, but remained intact in the hypothalamus and the ovary. The loss of negative-feedback regulation by estrogen (E) at the level of the pituitary led to increased production of luteinizing hormone (LH) by this tissue. Hyperstimulation of the ovarian cells by LH resulted in elevated steroidogenesis, producing high circulating levels of steroid hormones, including E. The ERα^d/d mice exhibited formation of palpable ovarian epithelial tumors starting at 5 months of age with 100% penetrance. By 15 months of age, 80% of ERα^d/d mice die. Besides proliferating epithelial cells, these tumors also contained an expanded population of luteinized stromal cells, which acquire the ability to express P450 aromatase and synthesize E locally. In response to the elevated levels of E, the ERα signaling was accentuated in the ovarian epithelial cells of ERα^d/d mice, triggering increased ERα-dependent gene expression, abnormal cell proliferation, and tumorigenesis. Consistent with these findings, treatment of ERα^d/d mice with letrozole, an aromatase inhibitor, markedly reduced circulating E and ovarian tumor volume. We have, therefore, developed a unique animal model, which serves as a useful tool for exploring the involvement of E-dependent signaling pathways in ovarian epithelial tumorigenesis.</p></div

The ERα^d/d mice form proliferative ovarian tumors.

<p>(<b>A</b>) Gross morphology of ERα^d/d, ERα^f/f, and ERα global KO mouse ovaries at 3, 5, and 8 months of age. (<b>B</b>) Immunohistochemistry of ERα^f/f ovary (panels a, c) and ERα^d/d ovaries (panels b, d) with tumors at 6 months of age using anti-PCNA antibody. Red staining indicates proliferating PCNA positive cells. Arrows point to hyperproliferative OSE (b) and tumor cells (d) in ERα^d/d ovarian tumors. F indicates follicle.</p

ERα localization in the tissues of HPO axis.

<p>(<b>A</b>) Histological sections of ERα^f/f (a) and ERα^d/d (b) hypothalami, ERα^f/f (c) and ERα^d/d (d) pituitaries, ERα^f/f ovary (e, g) and ERα^d/d ovarian tumor (f, h) from adult mice at 6 months of age stained with anti-ERα. Inserts i and j indicate higher magnification depicting ERα positive cells (red staining) in the OSC and ovarian tumor cells. 3 V indicates the third ventricle. A indicates the anterior lobe, I indicates the intermediate lobe, and P indicates the posterior lobe of the pituitaries. Arrows point to OSE cells or theca cells expressing ERα. (<b>B</b>) Ovarian sections obtained from ERα^f/f (left pictures) and ERα^d/d (right pictures) mice were subjected to immunohistochemistry using antibodies against phospho-ERα (S118) (panels a, b) and phospho-Akt (S473) (panels c,d).</p