Oladipupo A. Lawal

Phytochemisty and spermatogenic potentials of aqueous extract of Cissus populnea (Guill. and Per) stem bark.

In vivo clinical trials involving the administration of crude extracts of Cissus populnea to male subjects (normospermic, oligospermic, and azoopermic) in a 72-day study revealed that continuous exposure of the subjects to the extracts over this period did not significantly (p ≤ 0.05) alter sperm count, morphology, motility, or volume. Antimicrobial screening of the extract against some selected microbial isolates secondarily implicated in male infertility revealed total inactivity against the microbial isolates screened, i.e., Staphylococcus aureus, Salmonella paratyphi, Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Candida albicans, and Klebsiella sp. Phytochemistry revealed the presence of tannins, flavonoids, saponins, and steroids. The presence of these secondary metabolites was confirmed by thin layer chromatography. We conclude that oral administration of aqueous extracts of the stem bark of Cisssus populnea over a 72-day period to human subjects apparently had no fertility enhancement effects on sperm parameters monitored in this study.

Essential Oils from the Medicinal Plants of Africa

Numerous species of medicinal plants from Africa are important aromatic and ornamental plants, as well as being medicinal. Many of these species produce essential oils, which have applications in folk and modern medicine, cosmetics, and pharmaceutical industries. Essential oils generally have a broad spectrum of bioactivity, owing to the presence of several active ingredients that work through various modes of action. Due to their mode of extraction, mostly by distillation, essential oils contain a variety of volatile molecules such as terpenes and phenol-derived aromatic and aliphatic components. Aromatic and medicinal plants of Africa, comprises of important families which are currently the subject of phytochemical attention due to their biological and chemical diversity. The genera are widespread throughout the world, and are important plants in African traditional medicine, being used for the treatment of diseases such as malaria, hepatitis, cancer, inflammation, and infections by fungi, bacteria, and viruses. Extensive studies on aromatic and medicinal plants from Africa have led to the identification of many novel compounds as well as essentials oils. This review summarizes the research into the major constituents and biological activities of essential oils from aromatic and medicinal plants of Africa between the years 2007 and 2012.

Volatile Constituents of the Flowers, Leaves, Stems and Roots of Tithonia diversifolia (Hemsely) A. Gray

Abstract The chemical composition of the essential oils isolated by hydrodistillation from the flowers, leaves, stems and roots of Tithonia diversifolia have been studied by GC-MS. The identified components accounted for 96.7 %, 93.7 %, 88.9 %and 93.7 % of the flower, leaves, stems and roots oils, respectively. The major constituents of flowers, leaves, stems and roots oils were α-pinene (60.9 -75.7 %), δ-pinene (7.2–11.0 %) and limonene (0.9–4.3 %).

Cardioprotective potential of a lanosteryl triterpene from Protorhus longifolia.

Abstract Context: The current rapid increase in the incidence of cardiovascular events indicates a need for the discovery of more effective cardioprotective agents. Objective: This study evaluated the cardioprotective potential of a lanosteryl triterpene from Protorhus longifolia (Benrh.) Engl. stem bark. Materials and methods: Spectroscopic data analysis was used to confirm the structure of methyl-3β-hydroxylanosta-9, 24-dien-21-oate (RA-3). The cardioprotective effect of RA-3 in isoproterenol-induced myocardial injury in hyperlipidemic rats was investigated. Rats were divided into the normal diet (ND) fed and high fat diet (HFD) fed groups. The HFD rats were further subdivided into three groups. The experimental group was orally administered with RA-3 (100 mg/kg) for 15 days. The rats were then injected with isoproterenol (85 mg/kg) to induce myocardial injury. At the end of the experiment, hearts and blood tissues were collected and used for histology and biochemical assays, respectively. Results: RA-3 exhibited a cardioprotective effect as it minimized myocardial injury in HFD rats. Few lesions of acute hyaline degeneration and reduced fat deposition were observed in the heart tissue of the triterpene pretreated rats. Lactate dehydrogenase (LDH) activity was decreased in the blood of the RA-3 pretreated rats (44.1 mU/mL) compared to the untreated group (64.8 mU/mL). Increased glutathione (GSH) content and catalase (CAT) activity along with lower levels of malondialdehyde (MDA) in the triterpene pretreated animals (120.8 nmol/μL) than in the non-treated HFD fed rats (143.6 nmol/μL) were also observed. Discussion and conclusion: The cardioprotective effect exhibited by RA-3 indicates its potential use in the management of cardiovascular diseases (CVD) and related health problems.

Chemical Composition and Antibacterial Activity of Essential Oil from the Leaves of Aframomum melegueta (Roscoe) K. Schum from Nigeria

Abstract The essential oil obtained by hydrodistillation from the dry leaves of Aframomum melegueta was analyzed by GC and GC-MS. Twenty-six components representing 92.5 % of the oil were identified. The major constituents were sabinene (35.9 %), α-pinene (15.0 %) and β-caryophyllene (9.7 %). The in vitro antibacterial activity of the oil was assayed against twelve microorganisms using agar-disc diffusion and broth-microdilution methods. The oil exhibited significant inhibition on the growth of Bacillus cereus, Staphylococcus aureus, Streptococcus faecalis and Escherichia coli with zones of inhibition and MIC values ranging from (6.3–19.3) mm and (0.2–10.0) mg/ml, respectively.

Chemical Composition, Antibacterial and Cytotoxic Activities of Essential Oil from the Leaves of Helichrysum odoratissimum grown in South Africa

Abstract The chemistry of Helichrysum odoratissimum (L) Sweet., (family Asteraceae) volatiles grown in South Africa has been studied. The essential oil was obtained by hydrodistillation and analyzed by GC and GC-MS. The main compounds were β-pinene (51.6 %) and limonene (16.9 %) among the monoterpenes, while α-humulene (5.6 %) and β-caryophyllene (4.7 %) are the prominent among the sesquiterpenes. The abundance of β-pinene is not a common occurrence when compared with previously reported data on the oil constituents of H. odoratissimum. The volatile oil showed potential antibacterial activities towards some tested microorganisms with mean zones of inhibition and minimal inhibitory concentrations ranging from 14.0±1.3 -17.0±1.7 mm and 0.6-2.5 mg/mL, respectively. The oil exhibited moderate cytotoxicity against brine shrimp larvae with LC50 of 31.16 µg/mL.

Chemical Constituents of Essential Oils from Catharanthus roseus (L.) G. Don Grown in Nigeria

Abstract The characterization of the leaves and flowers essential oils of periwinkle, Catharanthus roseus (L.) G. Don (Apocyanaceae) was performed by means of gas chromatography-flame ionisation detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS) techniques. The pink flower C. roseus has its leaf oil consisting mainly of linolenic acid ethyl ester (43.9 %), stearic acid (10.6 %), phytol (7.3 %) and hexadecanoic acid (6.8 %), while the flower was made up of limonene (34.1 %), phytol (29.6 %) and linolenic acid ethyl ester (14.0 %). The main constituents of the white flower C. roseus were limonene (23.2 %), dodecyl alcohol (9.8 %), geraniol (7.3 %) and citral (7.0 %) from the leaf, with limonene (37.2 %) and dotriacontane (16.1 %) being the main compounds of the flower.

Chemical Composition and Insecticidal Activity of Essential Oils of Four Varieties of Codiaeum variegatum (L.) from Nigeria

Abstract Essential oils obtained by hydrodistillation of the air-dried leaves of four varieties of Codiaeum variegatum were analyzed by GC and GC-MS. The main constituents of C. variegatum (L.) Blume f. lobatum cv. Disraeli were caryophyllene oxide (58.2 %) and (Z)-β-farnesene (19.6 %). All the four compounds present in C. variegatum var. pictum ‘Congo’ namely linalool (39.3 %), 1,2,4-trimethylbenzene (21.0 %), β-pinene (21.6 %) and α-pinene (17.9 %) were present in significant amounts. Phytol (17.8 %), β-bisabolene (9.6 %) and linalool (8.9 %) were the major components of C. variegatum (L.) Blume f. taeniosum cv. Gold Sun, while, C. variegatum (L.) ‘Dreadlocks’ was dominated by β-ionone epoxide (29.7 %), γ-muurolene (20.5 %), naphthalene (16.3 %) and (E)- α-ionone (14.8 %). The chemical constituents of the studied essential oils were being reported for the first time. The essential oil displayed mortality (fumigant toxicity) against Sitophilus zeamais adults at tested concentration with lethal concentrations (LC50) of 72.07, 73.50, 47.43 and 44.04 μg/mL air respectively. The chemical constituents and insecticidal activity of essential oils of C. variegatum were being reported for the first time.

Croton gratissimus Leaf Essential Oil Composition, Antibacterial, Antiplatelet Aggregation, and Cytotoxic Activities

ABSTRACT Essential oil hydrodistilled from the leaves of Croton gratissimus was analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) to identify the constituents by comparison of their mass spectra (MS) data and linear retention indices (LRI) with literature. Forty constituents corresponding to 96.7% of the total oil content were identified from the oil sample. The major compounds were sabinene (14.6%), α-phellandrene (12.3%), β-phellandrene (10.7%), α-pinene (6.05%), and germacrene D (5.9%). The essential oil exhibited stronger antibacterial activity with minimum inhibitory concentration (MIC) of 0.6 mg.mL–1 (Staphylococcus aureus), 0.2 mg.mL–1 (S. faecalis), and 1.3 mg.mL–1 (Escherichia coli and Bacillus cereus). In the antiplatelet aggregation inhibitory activity, the oil displayed action against the induced platelet aggregation in the order collagen (IC50 < 1) > thrombin (IC50 1.18) > Adenosine diphosphate (IC50 2.32) > epinephrine (IC50 3.65). The lethal concentration (LC50) of the oil at 8.52 mg.mL–1 was toxic to Artemia salina.

Study on essential oils from the leaves of two Vietnamese plants: Jasminum subtriplinerve C.L. Blume and Vitex quinata (Lour) F.N. Williams

Abstract The essential oil constituents of the leaves of Jasminum subtriplinerve (Oleaceae) and Vitex quinata (Verbanaceae) cultivated in Vietnam were analysed by gas chromatography – flame ionisation detector (GC–FID) and gas chromatography – mass spectrometry (GC–MS) techniques. The main constituents identified in J. subtriplinerve were mainly oxygenated monoterpenes represented by linalool (44.2%), α-terpineol (15.5%), geraniol (19.4%) and cis-linalool oxide (8.8%). The quantitative significant components of V. quinata were terpene hydrocarbons comprising of β-pinene (30.1%), β-caryophyllene (26.9%) and β-elemene (7.4%). The chemical compositions of the essential oils are being reported for the first time. Graphical abstract