Open Access Original Research Article

Effect of Harvest Time on Yield, Chemical Composition, Antimicrobial and Antioxidant Activities of Thymus vulgaris and Mentha pulegium Essential Oils

Said Zantar, Driss El Garrouj, Rafael Pagán, Mohammed Chabi, Amin Laglaoui, Mohammed Bakkali, Mounir Hassani Zerrouk

European Journal of Medicinal Plants, Page 69-77
DOI: 10.9734/EJMP/2015/17513

Aims: This work aims to study the effect of the harvest time (pre-flowering and full-flowering) on the yield, chemical composition, antimicrobial and antioxidant activities of Thymus vulgaris and Mentha pulegium essential oils (EOs).

Study Design: Leaves and flowers from each period (pre and full-flowering) were used for EOs extraction. EO yield, chemical composition, antimicrobial and antioxidant activities were determined for each plant at the two harvest times studied.

Place and Duration of Study: The studied plants (T. vulgaris and M. pulegium) were collected during the period of April 2011 (Pre-flowering) to June 2011 (Full-flowering). Experiments were conducted at the chemistry and microbiology laboratory of the National Institute of Agronomic Research of Tangier (Morocco).

Methodology: The EOs were extracted via steam distillation. Chemical composition has been determined by a GC/MS analysis. Antimicrobial activity against Escherichia coli (SCTC 471), Salmonella Senftenberg 775W (ATCC 43845), Listeria monocytogenes (SCTC 4031) and Staphylococcus aureus (SCTC 976) was determined by paper disc agar plates. Antioxidant activity were determined by the radical scavenging activity assay.

Results: The greatest yield for T. vulgaris (3.6%) and for M. pulegium (3.5%) EOs was obtained during the full-flowering period. The chromatographic analysis showed that the studied EOs were constituted mainly by carvacrol for T. vulgaris and pulegone for M. pulegium. Harvest time affected quantitatively but not qualitatively the chemical composition of both EOs. T. vulgaris EO showed a greater antimicrobial and antioxidant activity than that of M. pulegium. The antimicrobial and antioxidant activities were maximal during the full-flowering period for T. vulgaris EO whereas they were greater in the pre-flowering period for M. pulegium EO.

Conclusion: The full-flowering period would be the best time to harvest T. vulgaris plants to obtain EOs with better yield, antimicrobial and antioxidant activity. In contrast, the pre-flowering stage would allow producers to obtain a M. pulegium EO with higher antimicrobial and antioxidant activities although with a lower yield.


Open Access Original Research Article

Hypoglycemic and Hypolipidemic Potentials of Extract of Vernonia calvoana on Alloxan-Induced Diabetic Albino Wistar Rats

I. A. Iwara, G. O. Igile, F. E. Uboh, E. U. Eyong, P. E. Ebong

European Journal of Medicinal Plants, Page 78-86
DOI: 10.9734/EJMP/2015/16058

Objective: Investigations were carried out to evaluate the therapeutic potentials of extract of Vernonia calvoana as herbal medicines.

Methods: In this study, the hypoglycemic and hypolipidemic potentials of extract of Vernonia calvoana was evaluated by using normal and alloxan-induced diabetic rats at a dose of 400 mg/kg b.w. daily for 14 days. Fasting Blood glucose levels and body weight were monitored at 7 days intervals, and different biochemical parameters, serum glucose, serum cholesterol, serum triacylglycerol, high density lipoprotein, low density lipoprotein and very low density lipoprotein were also assessed in the experimental animals.

Results: It was found that extract of Vernonia calvoana showed significant hypoglycemic and hypolipidemic activity (P<0.01).

Conclusion: Extracts of Vernonia calvoana showed significant hypoglycemic and hypolipidemic activity, which provides the scientific proof for their traditional claims.


Open Access Original Research Article

Pharmacognostic Evaluation of Spigelia anthelmia Linn (Loganiaceae)

O. Taiwo Elufioye, A. Omolola Olaifa

European Journal of Medicinal Plants, Page 87-96
DOI: 10.9734/EJMP/2015/16490

Aims: To establish the pharmacognostic standard for S. anthelmia with a view to assisting in the standardization and quality control of medicinal products from the plant.

Study Design: Pharmacognostic assessment of Spigelia anthelmia.

Place and Duration of Study: Department of Pharmacognosy laboratory, University of Ibadan, Nigeria. Between 2013 and 2014.

Methodology: Chemo microscopic evaluation and determination of physicochemical properties (moisture content, ash values, extractive values) of the powdered whole plant as well as studies of the macroscopic and anatomical sections of the leaf were carried out using standard methods.

Results: Evaluation of the macro and microscopic characters showed that the stem is greyish green with smooth bark, the leaves are opposite, simple and entire. The leaf epidermis is straight with numerous starch grains and calcium oxalate crystals. The stomata are anomocytic while the trichome is uniserate. The physichochemical parameters for the whole plant are: Moisture content 11.0±0.05%, total ash 14.67±0.05%, acid insoluble ash 3.33±0.01%, sulphated ash 11.0±0.05%, alcohol soluble extractive 0.25±0.06% and water soluble extractive 0.69±0.02%.  

Conclusion: The results of this research provided information which can be included in official monograph of the plant for its proper identification.

Open Access Original Research Article

Antibacterial Activity of Vitex negundo L. against a Multidrug Resistant Pathogenic Bacterium

Md. Mahfuz-Al-Mamun, Md. Monirul Islam, Rejoana Afrin Neera, Md. Rashed Nejum, G. M. Sala Uddin

European Journal of Medicinal Plants, Page 97-106
DOI: 10.9734/EJMP/2015/17378

Aims: The aim of this present study is to investigate antibacterial activity of extracts and/or essential oils of Vitex negundo L. leaves to an unknown pathogenic bacterium have been resistant to various groups of antibiotics

Study Design: The study was design followed by previously studied and manuals of antimicrobial susceptibility test.

Methodology: For antimicrobial susceptibility test disks diffusion method were used according to the guideline of European Committee on Antimicrobial Susceptibility Testing followed by McFarland standards. Various groups of antibiotics were used for conforming resistant of this unknown pathogen. The zone of inhibition and MIC was compared and measures with National Committee for Clinical Laboratory Standards (NCCLS) guidelines and reference data of previously studied.

Results: According to NCCLS and data to our study revealed that UB201201 (unknown) was a multidrug resistant bacterium. Molecular identification discloses the bacterium were Bacillus cereus group. All extracts of Vitex negundo L. leaves (ethanol, chloroform, ethyl acetate and hexane) and essential oils were responsible for antibacterial susceptibility with inhibition zone of 29±0.7, 9±0.5, 8±0.3, 12±0.7, and 25±0.2 mm respectively.

Conclusion: This study signifies ethanolic extract of Vitex negundo L. leaves as moderate antimicrobials and can be used for pharmaceutical and medicinal purpose. Therefore, isolation and identification of bioactive compounds from this plant will be an interest for human being.


Open Access Original Research Article

Phytochemical and Antioxidant Properties of Stem Bark Extracts of Anthocleista nobilis

K. G. Ngwoke, I. A. Anusi, P. M. Eze, U. M. Okezie, C. C. Abba, D. O. Abonyi

European Journal of Medicinal Plants, Page 107-111
DOI: 10.9734/EJMP/2015/16107

Aim: This study was carried out to determine the phytochemical and antioxidant properties of extracts of Anthocleista nobilis.

Methodology: Acetone and methanol stem bark extracts of A. nobilis were investigated for their free radical scavenging activity in the presence of 1,1-diphenyl-2-picrylhydrazyl (DPPH) using ascorbic acid as positive control. The phytochemical evaluation of the plant extracts was carried out using standard methods.

Results: In the phytochemical screening of the plant extracts, both extracts showed the presence of alkaloids, tannins, flavonoids, and glycosides. The acetone and methanol stem bark extracts of A. nobilis exhibited reasonable free radical scavenging activity in the DPPH assay with the acetone extract recording better activity. The antioxidant activity of the two extracts was however, lower than that recorded by the positive control-ascorbic acid.

Conclusion: The results suggest that the extracts of A. nobilis have potential antioxidant properties which could be exploited in medicine.


Open Access Original Research Article

Antiplasmodial Properties, Toxicity and Novelty-Induced Behavior of a Formulation from Picralima nitida and Alstonia boonei

A. T. Falodun, C. O. Ajayi, E. M. Obuotor, A. O. Adepiti, M. A. Akanmu, A. A. Elujoba

European Journal of Medicinal Plants, Page 112-120
DOI: 10.9734/EJMP/2015/17211

Aims: This study aimed at investigating the antiplasmodial activities of the combination of Alstonia boonei De Wild (Apocynaceae) stem-bark and Picralima nitida (Stapf) T.&H.Dur. (Apocynaceae) seed, which is currently being produced as MAMA Syrup (MS) for malaria treatment in Nigeria. The study has also provided information on the CNS and sub-chronic toxicity effects of MS. This is to justify the folkloric use of the mixture of the two plants as an antimalarial remedy as well as the safety of MS.

Methodology: Swiss albino mice of both sexes, (18-22 g), were used for the antiplasmodial experiments with the freeze-dried extractive from the decoction of the 1:1 mixture of the two plants against chloroquine-sensitive Plasmodium berghei NK65 strain. For the toxicity and novelty-induced behavioral (NIB) studies, twenty four rats were divided into four groups (n=6 per group) for three dose (150, 300 and 600 mg/kg) levels of MS and the vehicle (distilled water). The NIB was observed on days 1 and 30 of administration of MS and the vehicle. The animals were sacrificed on day 30 and blood harvested for biochemical assays.

Results: The results of the antiplasmodial investigation showed that 12.5 mg/kg extractive of the plant mixture gave antiplasmodial activity equivalent to 82% of the activity of chloroquine (5 mg/kg). The NIB results showed that acute oral administration of MS had no significant effects while the sub-chronic administration caused a significant (P<0.05) increase in rearing but decrease in grooming behaviours, dose-dependently. The biochemical parameters were not affected by the administration of MS at all doses used.

Conclusion: The extractive of the plant mixture possessed antiplasmodial activity while the oral sub-chronic administration of MAMA Syrup had central excitatory effects but no significant toxicity potentials in rats.