Advancement in Medicinal Plant Research

Number 4, 2016

106-115
Essential oil composition of Mentha spp. extracted seasonally and their effects against Candida yeast growth and biofilm formation

Authors: Simone Nataly Busato de Feiria, Priscilla de Laet Santana, Giovana Cláudia Boni, Paula Cristina Anibal, Marcelo Fabiano Gomes Boriollo, Glyn Mara Figueira, Ilza Maria de Oliveira Sousa, Benício Pereira, Mary ann Foglio and José Francisco Höfling

Abstract

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Studies with essential oil of Mentha spp. in the literature have shown potential antimicrobial activity against Candida spp. In this context, the aim of this study was to evaluate the antifungal activity, biofilm inhibition and disruption of Candida spp., and cytotoxic activity of essential oils from Mentha spp. extracted seasonally. The essential oils of Mentha spp. (Mentha aquatica, Mentha arvensis and Mentha piperita) were extracted monthly over a year, followed by the analysis of gas chromatography. The oils were tested against Candida spp. for obtainment of minimal inhibitory concentration determined by the broth microdilution test (MIC). The biofilm formation and mature biofilm were measured by a spectrophotometer of microplates after exposure to XTT. The cytotoxic activity was determined by the antiproliferative activity test of HaCat cells and analyzed by IC 50%. The Mentha spp. oils, harvested from April to September, showed growth inhibition in planktonic cells of Candida spp. at 2 mg/ml. Compounds of higher production in this period were: dihydrocarveol and carvotanacetone (Mentha aquatica); menthol (Mentha arvensis); menthofuran and menthyl acetate (Mentha piperita). EOs from the three species of Mentha were able to inhibit the formation of biofilm by C. albicans MYA 2876 and to deconstruct mature biofilm (24 h). All tested concentrations (initial 2 mg.ml-1) showed IC 50% below or equal to 50% for HaCat cell lineage. The antifungal activity and detection of essential oil components by Mentha spp. were related to seasonal weather conditions. The essential oil of Mentha spp. is a potential biofilm inhibitor for C. albicans, and exhibits low cytotoxicity in HaCat cells.

116-121
Antibacterial activity, phytochemical screening and cytotoxicity of Hibiscus sabdariffa (calyx)

Authors: Mohamed I. Garbi, Mahmmoud S. Saleh, Ali M. Badri, Ibrahim T. Ibrahim, Suha F. Mohammed, Muddathir S. Alhassan, Ahmed A. Elshikh and Ahmed S. Kabbashi

Abstract

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The purpose of the paper was to investigate the in-vitro antibacterial activity, preliminary phytochemical screening and cytotoxicity [3-(4,5-dimethyl thiazol-2-yl)-2, 5-diphenyltetrazolium bromide-MTT assay] of methanol extract of Hibiscus sabdariffa L. (calyxes). The methanol extract of H. sabdariffa was tested against 11 clinical isolates bacteria and 3 standard bacteria, that is: 5 Gram positive bacteria (Corynebacterium diphtheria, Staphylococcus aureus, Enterococcus faecalis, Listeria monocytogenes and Bacillus cereus), 9 Gram negative bacteria (Proteus mirabilis, Proteus vulgaris, Pseudomonas aeruginosa, Pseudomonas aeruginosa (ATCC 27853), Serratia marcescens, Escherichia coli, Escherichia coli (ATCC 25922), Klebsiella pneumonia and Klebsiella pneumoniae (ATCC 70063) using the cup-plate agar diffusion method, preliminary phytochemical screening and cytotoxicity (MTT assay) was also performed with different concentrations (500, 250 and 125 µg/ml) and compared to the reference control Triton-x100. The methanol extract of H. sabdariffa (calyxes) exhibited inhibitory effects against most of the tested organisms with the zone of inhibition ranging from 14 to 36 mm in length. The largest inhibition zone was obtained for the Gram-positive against bacteria L. monocytogenes (36 mm), E. faecalis (33 mm), B. cereus (28 mm), C. diphtheriae (26 mm) and S. aureus (24 mm) while in case of Gram negative highest inhibition was observed against P. aeruginosa (ATCC 27853) (28 mm), K. pneumoniae (ATCC 70063) (25 mm), P. aeruginosa (23 mm), E. coli (20 mm), E. coli (ATCC 25922) and P. vulgaris (19 mm), K. pneumonia (18 mm), S. marcescens (17 mm) and P. mirabilis (14 mm). Preliminary phytochemical screening investigation for the methanolic extracts showed the presences of alkaloids, glycosides, flavonoids, tannins, sterols triterpens and phenols, while saponins was absent. In addition cytotoxicity (MTT-assay) verified the safety of the examined extract with an IC50 less than 100 μg/ml. The study concluded that H. sabdariffa (calyxes) proved to have potent activities against antibacterial activity in vitro with verified safety evidence for use.

122-128
Antibacterial activity of clove oil against some microorganisms at Khartoum State

Authors: Zahra O. Fagere and Aisha Zoheir Al Magboul

Abstract

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Microorganisms have increased and that may cause some health problems, so it has become necessary to find out new antibacterial agents. This is a descriptive cross-sectional study aiming to evaluate the antibacterial activity of the essential oil of Syzygium aromaticum against selected bacteria at Khartoum State, Sudan. The essential oil of S. aromaticum was obtained by hydrodistillation technique using Clevenger’s apparatus and was screened for in vitro antibacterial activity against four standard bacteria two Gram positive: Bacillus subtilis (NCTC 8236) and Staphylococcus aureus (ATCC 25923) and two Gram negative: Eschericia coli (ATCC 25922) and Psuedomonas aeruginosa (ATCC 27853), using the cup plate agar diffusion method and the micro-dilution method. The essential oil of S. aromaticum dissolved in methanol (1:10) showed high activity (28 and 22 mm) against Gram positive bacteria (S. aureus and B. subtilis) and (26 and 21 mm) against Gram negative bacteria (E. coli and P. aeruginosa). The minimum inhibitory concentration of the essential oil of S. aromaticum against Gram positive (Bacillus subtilis and Staphylococcus aureus) was 0.78 mg/ml and against the Gram negative (Escherichia coli and Pseudomonas aeruginosa) was 1.5 mg/ml. The minimum bactericidal concentrations of the essential oil of S. aromaticum against (B. subtilis, S. aureus and E. coli were 3.125 mg/ml and P. aeruginosa) was 6.25 mg/ml. The result of antibacterial activity of the essential oil was compared with the activity of reference drugs. The essential oil of the S. aromaticum possessed antibacterial activity against the Gram positive and Gram negative organisms which are responsible for several diseases. It is recommended that pharmacological, toxicological and clinical studies be carried out on the essential oils of the clove Syzygium aromaticum to assess its safety, therapeutic efficacy and potential for commercial utilization.

129-134
Amelioration of gastric mucosal lesions induced by multiple stressors in rats treated with garlic (Allium sativum L.) suspension

Authors: Saleh Alqasoumi

Abstract

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Garlic (Allium sativum L.), renowned for its pleiotropic medicinal value in traditional medicine, is a popular culinary item consumed worldwide. The present study aimed to justify the use of garlic in Arab traditional medicine for the treatment of acute gastric ulcer. The plethora of its beneficial effects has been ascribed to its multiple bioactive constituents including organosulfur compounds. Nutraceutical products containing garlic-derived compounds are known to possess a myriad of pharmacological effects such as hepatoprotective, nephroprotective, cardioprotective, hypolipidemic, anti-microbial, anti-tumor effects. Studies in animal models and humans have shown a beneficial effect of garlic on the gastrointestinal system. Herein, using a rat model of gastric mucosal injury, simulating gastric ulcer disease of humans, we show that garlic suspension (250 and 500 mg/kg) dose-dependently mitigates gastric ulceration (evaluated as ulcer index) triggered by hypothermic restraint, pyloric ligation (Shay rats), indomethacin and necrotizing agents (80% ethanol, 0.2 mol/L NaOH and 25% NaCl). The results of this study show that the acute administration of garlic suspension significantly thwarted gastric acid secretion in pylorus-ligated rats and enhanced mucus secretion following the administration of 80% ethanol. Mechanistically, rats pretreated with garlic suspension showed a slight alteration in non-protein sulfhydryl and malondealdehyde levels of gastric tissue following treatment with 80% ethanol; this data points to a subtle antioxidant activity of the suspension. Taken together, these findings unravel gastroprotective effects of garlic suspension in rats subjected to multiple stress conditions. Dietary consumption of garlic and garlic-based supplements may have a beneficial impact on digestive health by alleviating the development and/or progression of gastric mucosal damage.