Essential Oils of Dennettia Tripetala Bak. f. Stem Bark and Leaf – Constituents and Biological Activities:

The essential oil from the stem bark and leaves of Dennettia tripetala Bak. f. (Annonaceae) growing wild in Ondo State, Nigeria, has been characterized by combined gas chromatography (GC) and gas chromatography-mass spectrometry (GC- MS) analyses. Overall, thirty-six components have been fully identified, thirty-two in the stem-bark oil, and only seven in the leaf oil. In both oils, 2-phenylnitroethane was the main component, ranging between 70 – 76% of the total oils. The profile of the stem bark oil was characterized by a large number of sesquiterpenes, whereas among the few components in the leaf oil, linalool reaches over 17%. When both oils were assayed for antimicrobial activity, only Staphylococcus aureus was susceptible to the stem-bark oil which was more active than leaf oil. For protective effects against UV radiation–induced peroxidation in phosphatidylcholine (PC) liposomes, stem-bark oil also showed greater effectiveness. Activity of the leaf oil against Trichomonas gallinae, was also remarkable

Chemical Composition and Larvicidal Activities of the Himalayan Cedar, Cedrus deodara Essential Oil and Its Fractions Against the Diamondback Moth, Plutella xylostella

Plants and plant-derived materials play an extremely important role in pest management programs. Essential oil from wood chips of Himalayan Cedar, Cedrus deodara (Roxburgh) Don (Pinales: Pinaceae), was obtained by hydrodistillation and fractionated to pentane and acetonitrile from which himachalenes and atlantones enriched fractions were isolated. A total of forty compounds were identified from these fractions using GC and GC-MS analyses. Essential oils and fractions were evaluated for insecticidal activities against second instars of the diamondback moth, Plutella xylostella L. (Lepidoptera: Yponomeutidae), using a leaf dip method. All samples showed promising larvicidal activity against larvae of P. xylostella. The pentane fraction was the most toxic with a LC50 value of 287 µg/ml. The himachalenes enriched fraction was more toxic (LC50 = 362 µg/ml) than the atlantones enriched fraction (LC50 = 365 µg/ml). LC50 of crude oil was 425 µg/ml and acetonitrile fraction was LC50 = 815 µg/ml. The major constituents, himachalenes and atlantones, likely accounted for the insecticidal action. Present bioassay results revealed the potential for essential oil and different constituents of C. deodara as botanical larvicides for their use in pest management

Identification of mosquito repellent odours from Ocimum forskolei

<p>Abstract</p> <p>Background</p> <p>Native mosquito repellent plants have a good potential for integrated mosquito control in local settings. <it>Ocimum forskolei</it>, Lamiaceae, is used in Eritrea as a spatial mosquito repellent inside houses, either through crushing fresh plants or burning dry plants. We verified whether active repellent compounds could be identified using gas-chromatography coupled electroantennogram recordings (GC-EAD) with headspace extracts of crushed plants.</p> <p>Results</p> <p>EAD active compounds included (R)-(-)-linalool, (S)-(+)-1-octen-3-ol, trans-caryophyllene, naphthalene, methyl salicylate, (R)-(-)-α-copaene, methyl cinnamate and (E)-ocimene. Of these compounds (R)-(-)-linalool, methyl cinnamate and methyl salicylate reduced landing of female <it>Aedes aegypti </it>on human skin-odor baited tubes. The latter two are novel mosquito repellent compounds.</p> <p>Conclusions</p> <p>The identification of mosquito repellent compounds contributes to deciphering the mechanisms underlying repulsion, supporting the rational design of novel repellents. The three mosquito repellent compounds identified in this study are structurally dissimilar, which may indicate involvement of different sensory neurons in repulsion. Repulsion may well be enhanced through combining different repellent plants (or their synthetic mimics), and can be a locally sustainable part in mosquito control efforts.</p

In vitro Anticancer Screening of 24 Locally Used Nigerian Medicinal Plants

Background: Plants that are used as traditional medicine represent a relevant pool for selecting plant candidates that may have anticancer properties. In this study, the ethnomedicinal approach was used to select several medicinal plants native to Nigeria, on the basis of their local or traditional uses. The collected plants were then evaluated for cytoxicity. Methods: The antitumor activity of methanolic extracts obtained from 24 of the selected plants, were evaluated in vitro on five human cancer cell lines. Results: Results obtained from the plants screened indicate that 18 plant extracts of folk medicine exhibited promising cytotoxic activity against human carcinoma cell lines. Erythrophleum suaveolens (Guill. & Perr.) Brenan was found to demonstrate potent anti-cancer activity in this study exhibiting IC50 = 0.2-1.3 $\mu$g/ml. Conclusions: Based on the significantly potent activity of some plants extracts reported here, further studies aimed at mechanism elucidation and bio-guided isolation of active anticancer compounds is currently underway.Chemistry and Chemical Biolog

COMPARATIVE ANALYSIS OF ESSENTIAL OILS FROM THE LEAF, FRUIT AND STEM BARK OF HARUNGANA MADAGASCARIENSIS (HYPERICACEAE)

Leaves and stem bark of H. madagascariensis are used in African traditional medicine as a remedy for anaemia, wounds and malaria. Leaf aqueous extracts of the plant were reported to show antimicrobial and antitrichomonal activities among others. No report has been documented on the essential oil constituents of the plant. As part of the efforts to generate a data bank for essential oils of Nigeria, we undertook for the first time a comparative analysis of hydro-distilled oils of the leaf, stem bark and fruit of the plant by combined gas chromatography-mass spectrometry (GC-MS). Both qualitative and quantitative differences existed in the composition of the three oils which comprised mainly sesquiterpene hydrocarbons (66.8 - 69.6 %). â-caryophyllene (32.4 % and 18.4 % respectively for leaf and fruit oils only),á-humulene (10.4 %, 9.8 % and 7.3 % respectively for leaf, stem bark and fruit oils), germacrene D (8.7 % for leaf oil only), and á-farnesene (37.4 % and 10.4 % respectively for stem bark and fruit oils only) are the predominant constituents, which may possibly account for the various reported biological activities of the plant

Attempted self-removal of Implanon®: A case report

A 34-year-old woman with Bipolar Affective Disorder attempted self-removal of an impalpable Implanon® from her arm with a pair of non-sterile implements, resulting in an infected and swollen arm. The device was removed after ultrasound imaging without any complications. This instance is useful for enhancing cognizance of the possibility of self-removal of contraceptive implants and the need for specific follow-up arrangements and timely appointments when a patient requests removal. It also underscores the need for a detailed history, including elucidation of past and current medical problems, in all women requesting contraception guidance

Insecticidal use of Nigerian-grown plants

No Abstract. Discovery and Innovation Vol. 18(2) 2006: 123-14