Open Access Original Research Article

Cyathula prostrata: A Potential Herbal Hope for Hypertensives, an Animal Model Study and Its Secondary Metabolites Assessment via GC-MS

Anthony B. Ojekale, Oladipupo A. Lawal, Malik O. Lasisi

European Journal of Medicinal Plants, Page 1-10
DOI: 10.9734/EJMP/2016/25007

Aim: The use of folkloric therapy in the management of ailments such a hypertension is a global phenomena. Extracts of Cyathula prostrata are used as alternate antihypertensive in Nigeria. This paper evaluated the scientific basis for such use.

Study Design: The study involved using rat model. High blood pressure was simulated in the rat via induction with adrenaline, while another group of rats was used without adrenaline administration. Aqueous and ethanolic extracts of the Cyathula prostrata were administered to the different rat sets. The work was carried out in Lagos, Nigeria in the second half of 2015.

Methodology: Cyathula prostrata extracts was administered in graded doses of 50, 100 and 150 mg/kg body weight to the different groups of animals. The presence of secondary metabolites in the extracts was assessed using standard phytochemistry techniques and verified using GC-MS.

Results: A total of 13 plant secondary metabolites were identified by GC-MS. Cyathula prostrata extracts effected a marked decrease in the measured blood pressure parameters of adrenaline induced hypertensive rats evaluated in this study.

Conclusion: In this study, orally administered Cyathula prostrata extracts reduced high blood pressure parameters in adrenaline induced hypertensive rats, with the most likely effectors being the secondary metabolites present in this extract. The outcome of this baseline study potentially validates the folkloric use of the extract as antihypertensives.

Open Access Original Research Article

Antimicrobial Effects of Leaves of Eucalyptus camaldulensis on Some Microbial Pathogens

Aleruchi Chuku, Abigail I. Ogbonna, Godwin A. Obande, Mwanret Namang, Iliyasu R. Ahmad

European Journal of Medicinal Plants, Page 1-8
DOI: 10.9734/EJMP/2016/25759

Background: Plants are important sources of medicinal materials and have been in use since ancient times. Although numerous plants have been explored for their medicinal properties, there still remains much to be studied.

Aim: To evaluate the phytochemical constituents of Eucalyptus camaldulensis extracted using ethanol, methanol and petroleum ether and the antimicrobial activity of the leaf extracts.

Place and Duration of Study: The study was conducted in Jos, Plateau State, Nigeria over a period of 18 months.

Methodology: Methanol, ethanol and petroleum ether extracts of E. camaldulensis leaves were obtained and phytochemical constituents were determined following standard procedures. The antimicrobial effect of the extracts obtained was tested against three bacterial species including Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and two fungi namely Penicillium expansum and Candida albicans using the agar well diffusion method, at concentrations of 400, 200, 100 and 50 mg/ml. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) were also determined.

Results: The phytochemical analysis of the leaf extracts revealed that they contained alkaloids, tannins, flavonoids, saponins, carbohydrates, steroids and cardiac glycosides. All the test organisms (both bacteria and fungi) were inhibited by each of the extracts at concentrations of 400, 200, 100 and 50 mg/ml with variations. The highest concentration (400 mg/ml) of ethanol extract showed the highest inhibition for C. albicans (27 mm) and B. subtilis (27 mm), while those of methanol and petroleum ether were most effective against C. albicans (27.7 mm) and B. subtilis (27 mm). The MIC ranged between 50 mg/ml and 200 mg/ml, while MBC and MFC ranged between 100 mg/ml and 400 mg/ml for all extracts. The inhibitory effects of the plant extracts were comparable to that of commercially available antibiotics used as controls.

Conclusion: The leaf extract of E. camaldulensis could be a better option in the treatment of infections caused by test organisms studied if properly processed and harnessed.

Open Access Original Research Article

Toxicity Studies on Anti-fungal Essential Oils Extracted from Selected Aromatic Plants from Mabira and Kakamega Forests, East Africa

Jesca Lukanga Nakavuma, Josphat Clement Matasyoh, Isabel Nyokabi Wagara, John Kalema, Lordrick Alinaitwe

European Journal of Medicinal Plants, Page 1-14
DOI: 10.9734/EJMP/2016/25185

Isabel Nyokabi Wagara3, John Kalema1 and Lordrick Alinaitwe1

Aim: In a bid to explore for grain bio-preservatives, essential oils extracted from Cymbopogon citratus, Rosmarinus officinalis, Monanthataxis littoralis and Aframomum angustifolium, that were earlier established to have anti-mold activity, were evaluated for their biosafety by determining the oral LD50.

Methods: The essential oils were extracted by hydro-distillation from aromatic plants collected from Kakamega and Mabira forests in Kenya and Uganda, respectively. Acute oral toxicity was established using mice by determining the LD50; after which sub-acute toxicity studies were performed. The animals were observed for behavioural changes; and the gross and histopathological effects, if any, on the intestinal mucosa, spleen, lungs, liver, kidney and heart were noted.

Results: The oral LD50  for Cymbopogon citratus, Rosmarinus officinalis, Monanthataxis littoralis and Aframomum angustifolium essential oils were established as 7,046.90; 4,723.33; 13,335.82; and 17,539.82 (mg/kg body weight), respectively. In all cases, increased breathing rates were observed, however Rosemary also caused lethargy and convulsions. Grossly, no changes were seen in the liver, kidney, lungs, heart and spleen from both the control and the treated mice except for Monanthataxis littoralis where the lungs and liver seemed changed; and the urinary bladder distended. However, the latter effects were noted at higher doses than the established oral LD50. Histopathologically, thickened intestinal mucosa lining; tubular degeneration and proteinuria in the kidneys; vascular congestion, focal necrosis and hydropic degeneration of hepatocytes in the liver, were encountered.

Conclusion: Basing on the oral LD50 in mice, all oils were safe and can be explored further as anti-mold grain preservatives. However, Rosmarinus officinalis was marginally safe as per the OECD guidelines. The histopathological effects of Monanthataxis littoralis essential oil need to be investigated further.

Open Access Original Research Article

Antibacterial Activity of the Volatile Oil of Phyllanthus muellerianus and Its Inhibition against the Extracellular Protease of Klebsiella granulomatis

Adeola Adesegun, Folorunso Samuel, Oke Adesina

European Journal of Medicinal Plants, Page 1-10
DOI: 10.9734/EJMP/2016/24781

Aim: This study was carried out to evaluate the antimicrobial effect of the volatile oil of Phyllanthus muellerianus leaves against Klebsiella granulomatis and its inhibitory effect partially on the purified and characterized extracellular protease of this bacteria.

Study Design: This involved the use of medicinal plants and pathogenic bacteria.

Place and Duration of Study: Department of Biochemistry, Faculty of Science, Lagos State University, Ojo Lagos State Nigeria, between April, 2014 – September, 2014.

Methodology: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the hydrodistillated volatile oil against this bacterium were estimated by micro-dilution technique. The extracellular protease was partially purified with ammonium sulfate and Sephadex G-100 gel filtration and assayed using casein as substrate with the volatile oil as inhibitor.

Results: The MIC and MBC obtained were 0.5% and ≥0.7% respectively. Gel filtration produced two peaks each for total protein and enzyme activity.  Highest fold of 4.67 was achieved with specific activity of 83.3 μmol/min/mg protein as compared to the crude enzyme. The oil competitively inhibited the partially purified extracellular protease of this bacterium with Vmax = 500 μmol/min and Km = 0.2 mg/ml (no inhibitor) and Km´ = 0.8 mg/ml (inhibitor). Optimal activities of this protease were obtained at pH 7.5 and 35°C.  None of the metallic chloride salts tested significantly increased the activity of the enzyme. However, Pb2+, Mn2+, Zn2+, K+, Hg2+, Co2+, Ba2+ and Mg2+ generally inhibited the enzyme activity.

Conclusion: The volatile oil of Phyllanthus muellerianus possessed antimicrobial property and inhibited the extracellular protease of Klebsiella granulomatis. Further clarification and clinical verification of this oil will prove to be an effective match in combating burns and post-operative wound infections caused by Klebsiella granulomatis and similar species.


Open Access Original Research Article

Antimicrobial and Cytotoxicity Activity of Clausena anisata, Acokanthera shemperii and Olea europaea Growing in Tanzania

Winisia E. Makirita, Leonard J. Chauka, Musa Chacha

European Journal of Medicinal Plants, Page 1-9
DOI: 10.9734/EJMP/2016/23635

Aims: To evaluate antimicrobial and cytotoxicity activities of Clausena anisata, Acokanthera shemperii and Olea europaea against seven Gram negative bacteria and fungal species.

Study Design: Bioassay of antimicrobial assay was done using 96-well micro-dilution method.

Place and Duration of Study: School of Life Science and Bioengineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania, from April 2014 to June 2014.

Methodology: 96-well micro dilution method was used in antimicrobial assay. Extracts were loaded in the wells of the first row, followed by serial dilution and 50 μl of the bacterial suspensions (0.5 MacFarland standard turbidity) were added in each well. The first concentration which showed no bacterial growth was considered as minimum inhibition concentration. Method developed by Meyer et al 1982 was adopted in cytotoxicity activities.

Results: All extracts indicated antibacterial activity on at least three to five of the tested seven bacteria and two fungi species with MIC value ranging 0.7812 - 12.5 mg/mL. The highest activity was demonstrated by Olea europaea leaf methanolic, Acokanthera shemperii stem bark and Clausena anisata twigs ethyl acetate extracts with MIC value of 0.7812 mg/mL against Pseudomonas aeruginosa while the same MIC value was exhibited by Olea europaea stem bark methanol against Proteus mirabilis. However the Olea europaea root methanolic extract inhibited the growth of Pseudomonas aeruginosa and Salmonella kisarawe with MIC value of 0.7812 mg/mL. Olea europaea leaf methanolic and stem bark methanolic which demonstrated high antimicrobial activity were non toxic against brine shrimp larvae with LC50 value of 369.8272 and 226.1566 µg/mL, while Clausena anisata twigs ethyl acetate, Acokanthera shemperii stem bark ethyl acetate and Olea europaea root methanolic extracts were toxic with LC50 value of 6.21276, 67.4179 and 92.3089 µg/mL respectively.

Conclusion: This study has unveiled antimicrobial and cytotoxicity properties of Clausena anisata, Acokanthera shemperii and Olea europaea.

Open Access Review Article

Acute Hypotensive, Diuretic and Antioxidant Activities Induced by Urtica circularis

A. Rodríguez Basso, C. Marrassini, C. Anesini, S. Gorzalczany

European Journal of Medicinal Plants, Page 1-9
DOI: 10.9734/EJMP/2016/25661

Aims: The aim of this study was to investigate the possible hypotensive and diuretic effects of ethanolic extract of Urtica circularis (Hicken) Sorarú (Urticaceae) using preclinical methods.

Place and Duration of Study: Department of Pharmacology, School of Pharmacy and Biochemistry, Universidad de Buenos Aires, from July 2015 to January 2016.

Methodology: Effect on blood pressure and heart rate on anaesthetized normotensive and hypertensive rats were measured using Statham Gould P23ID pressure transducer coupled to a Grass 79D polygraph. Rats were placed in metabolic cages in order to collect urine. Urinary volume was measured and sodium and potassium concentration was estimated from each urine sample using indirect ion-selective electrode potentiometry. The vasorelaxant activity of major compound was studied using isolated aortic rings. Antioxidant activity was estimated measuring 2,2 diphenyl 2 picryl hydrazyl hydrate radical scavenging activity.

Results: The intravenous administration of the extract of U. circularis (0.1–30 mg/kg) in anaesthetized normotensive and hypertensive rats caused a dose-dependent reduction in the mean arterial pressure without affecting the heart rate. The greater reduction of blood pressure induced by U. circularis was observed in hypertensive rats (30 mg/kg: Spontaneously Hypertensive Rat: -34.7±3.3 mmHg, Spague Dawley: -18.3±3.9 mmHg). Cumulative urinary excretions 24 h after treatment with the extract 100 and 300 mg/kg were 18.2±1.2 and 14.9±1.5 mL respectively, significantly higher than the control group (9.0±1.3 mL). The addition of cumulative concentrations of vicenin-2 (10-7-10-4M) generated relaxation in endothelium-intact aortic rings pre-contracted with 10–7M Phenylephrine (Emax = 66.2±3.5%). Extract showed antioxidant activity reaching 45% of DPPH scavenging activity at 1000 μg/mL, meanwhile the flavonoid reached 20% of scavenger capacity.

Conclusion: U. circularis, has a diuretic, antioxidant and hypotensive effect. Vicenin-2, the major component of this extract showed vasorelaxant activity, potentially responsible for the properties of the extract.