Trends in Phytochemical Research
Volume:3 Issue: 1, Winter 2019

Eighty-nine essential oil analyses carried out on Cameroonian plant material by gas chromatography are reviewed, and structures of sixty one main oil compounds are presented. Plant samples had been collected all over the rainforest area and further northwards, covering forty plant species belonging to ten families. For these plants, common names, traditional use as well as bioactivity and toxicity of their essential oils in vitro and in vivo are compiled. Data show that oils from leaves, bark, roots, fruit, rhizome or seeds display their own one to four main essential oil components. Each of them contributing more than 10% to over 90% of the oil´s volume, which sums up to species-unique essential oil fingerprints and decreasing similarity of these fingerprints with increasing phylogenetic distance between species. This review article shows that the environmental factor include, temperature, rainfall (Littoral region), humidity (Center, South, East and West regions) and solar radiation (Adamaoua, North and Far-north regions) as well as the soil nutrients influence the secondary metabolite composition of the plants. Bioassays valorized traditional use of a good number of oils, for example against the dermatophytic fungus Trichophyton rubrum being twice as effective as amphothericin B®; against the chloroquine resistant Plasmodium falciparum; against cancer cell lines; and against a variety of human pathogen bacteria, being up to ten times as effective as ciproxin®, lidaprim®, tetracycline hydrochloride® and lidaprim®. Importantly, in an experiment employing the stored product beetle Callosobruchus maculatus, the leaf oil of Lippia adoensis (Verbenaceae) indicated neurotoxicity, so that preparations should be applied with care. Follow up work may focus on bioassays with commercial pure compounds, with the goal to improve effectivity and doses calculation for traditional essential oil medicines and agricultural products.

This study deals with the identification of secondary metabolites of methanol extract of the roots of Mangifera indica L and the assessment of plant in vitro anti-inflammatory activity. High-performance liquid chromatography with electrospray ionization mass spectrometric detection (HPLC-ESI-MSn) using the negative ion mode was performed to establish the chromatographic fingerprint and identify various chemical components of the plant extract. The anti-inflammatory effect of the MeOH extract (3, 30 and 300 µg/mL) was assessed through cell viability and nitric oxide (NO) production on non-stimulated and LPS-stimulated peritoneal macrophages. Phytochemical analysis indicated the presence of a number of phenolic compounds where galloyl derivatives, mangiferin and its derivatives were the major constituents. The methanol extract exhibited significant concentration-dependent inhibitory effect on NO production, both on stimulated and non-stimulated macrophages. The concentration 300 µg/mL showed significant cell toxicity. The methanol extract of Mangifera indica is rich in phenolic compounds and possesses potent in vitro anti-inflammatory activity, but its higher concentrations are cytotoxic.

The antioxidant activities and reducing power capabilities of Veronica crista-galli and Veronica persica were evaluated using DPPH radical scavenging assay, total antioxidant activity and MTT assay at incubation times of 24, 48 and 72 hours. A water fraction of methanolic extract of V. crista-galli with the highest amount of total flavonoid (16.19 ± 0.001 mg of QE/g of dried plant) demonstrated stronger antioxidant effect than V. persica extract with the highest content of phenolic compounds (60.75 ± 0.0013 mg GAE/g of dried plant). The IC50 values of V. persica and V. crista-galli extracts were found to be 153.7 and 79.64 μg/mL, respectively. V. crista-galli possessed considerable inhibitory effect at lower concentrations on MCF-7 and Hela cell lines by increasing incubation time. There was no cytotoxic effect observed in the normal HDF cell line. This study recommends that the water fraction of the methanolic extracts of V. persica and V. crista-galli with in vitro antioxidant and selective anti-proliferative activities can support the popular uses of Veronica species in traditional medicine as effective natural remedies.

Naringin is a flavonoid abundantly found in Citrus L. spp. with diverse applications. The present review emphasizes on the ameliorative role of naringin against hepatotoxicity, neurotoxicity, renal toxicity and cardiotoxicity. Naringin has been found to be a strong antioxidant and beneficial in inflammation cases. Its supplementation revealed a drop in pathological changes in liver, brain and kidney tissues in hyperammonemia conditions. Naringin also regulates the expressions of glutamine synthetase, neuronal nitric oxide and soluble guanylate cyclase. It also inhibits some virus activities including herpes simplex. Treatment with naringin was found to be associated with controlled serum creatinine, blood urea nitrogen, bilirubin, aspartate transaminase, alanine transaminase and low-density lipoproteins. It has also been found to possess ameliorative properties against cardiac toxicity and hypertrophy. It improves myocardial fibrosis by modulating p38 and PKC-beta protein expressions. It also enhances oxidative enzyme activities and regulate the increase in malondialdehyde, protein carbonyls and tumour necrosis factor-alpha concentrations. Naringin, as one of the key flavonoids, possesses enormous potential to mitigate the effects of harmful drugs. It is a robust antitoxic agent revealing resilient action against hepato-, neuro-, renal and cardio-toxicity. Naringin may be used as a strong therapeutic agent to cure disease like herpes, diabetes, alcoholism and heart failure.

In the present study, the volatile compounds identified in the essential oil from the flowers of Terminalia ivorensis A. Chev (Combretaceae) collected from Kaduna, Northern Nigeria, are reported. Essential oils were obtained using hydrodistllation in a Clevengertype apparatus. The yield of the light yellow oil was found to be 0.22% (v/w, dry weight basis). The content and composition of the oil were analyzed by gas chromatography (GC-FID) and gas chromatography with electron impact mass spectrometry (GC-MS). The main compounds of the oil were δ-3-carene (29.4%) and α-pinene (20.9%). To the best of our knowledge, this is the first report on the essential oil constituents of any part of T. ivorensis