Adel M. Mahasneh

Antimicrobial activity of extracts of herbal plants used in the traditional medicine of Jordan

Petroleum ether, ethanol, butanol, and aqueous crude extracts of the whole aerial parts of nine plants exhibited variable degrees of antimicrobial activity against four bacterial and three fungal species. Methanol and hexane extracts did not show any activity. Compared with standard antibiotics, extracts had low to moderate activity. The activity spectrum is wide against gram-positive and negative bacteria as well as fungi tested. However, the butanol extracts at 4 mg/disc of Ononis spinosa (OS), Bryonia syriaca (BS) had high moderate antifungal activity against Aspergillus flavus, Fusarium moniliforme and Candida albicans relative to miconazole nitrate at 40 microg/disc. Furthermore, higher antibacterial activity was observed though low to moderate compared with streptomycin and very comparable with chloramphenicol. Cyclaman persicum (CP) petroleum ether extracts only exhibited pronounced antibacterial activity.

Antiproliferative Activity of Plant Extracts Used Against Cancer in Traditional Medicine

Forty four extracts from sixteen plants used traditionally as anticancer agents were evaluated in vitro for their antiproliferative activity against Hep-2, MCF-7, and Vero cell lines. Plants were fractionated using ethanol, methanol, chloroform, n-hexane, distilled water, and butanol. The antiproliferative activity was measured by MTT assay. TLC was used to identify active fractions. The apoptotic activity of active fractions was determined using TUNEL colorimetric assay. 20 of these extracts demonstrated significant antiproliferative activity against one or more of the cell lines. These extracts were prepared from Ononis hirta, Inula viscosa, Salvia pinardi, Verbascum sinaiticum and Ononis sicula. Methanol fractions of Ononis hirta (aerial parts) and Inula viscosa (flowers) were the most active fractions against MCF-7 cells with IC50 of 27.96 and 15.78 μg/ml respectively and they were less toxic against other cell lines. Other extracts showed lower activity against cancer cell lines. TLC analysis showed the presence of flavonoids and terpenoids in active plants while alkaloids were detected in Ononis hirta (aerial parts) extracts. Ononis hirta (aerial parts) and Inula viscosa (flowers) extracts exerted their antiproliferative activity by inducing apoptosis in cancer cell lines. Further studies are necessary for detailed chemical characterization and more extensive biological evaluation of the most active ingredients.

Antimicrobial, Cytotoxicity and Phytochemical Screening of Jordanian Plants Used in Traditional Medicine

Antimicrobial activity and cytotoxicity of fifty one extracts of different parts of 14 plants were studied. Ethanol, methanol, aqueous, butanol, and n-hexane extracts were tested against three Gram negative, two Gram positive bacteria, and two fungi. Cytotoxicity and phytochemical screening were determined using MTT and TLC assays, respectively. Of the fifty one extracts, twenty two showed activities against different microorganisms with MICs ranging from 62.5 to 1000 µg/mL. The highest activity (100% inhibition) was for a butanol extract of Rosa damascena receptacles against Salmonella typhimurium and Bacillus cereus (MIC of 62.5 and 250 µg/mL) respectively. Butanol extract of Narcissus tazetta aerial parts and aqueous extract of Rosa damascena receptacles were both active against Candida albicans (MIC of 125 µg/mL). Methicillin-resistant Staphylococcus aureus was inhibited by butanol, aqueous extracts of Rosa damascena receptacles and butanol extract of Inula viscosa flowers (MIC of 500, 500, and 250 µg/mL) respectively. Rosa damascena receptacles and Verbascum sinaiticum flowers ethanol extract showed lowest cytoxicity against Vero cell line (IC50 of 454.11and 367.11). Most toxic was the ethanol extract of Ononis hirta aerial parts (IC50 72.50 µg/mL). Flavonoids and terpenoids were present in all plants. Ononis hirta and Narcissus tazetta contained alkaloids. The results validate the use of these plants and report for the first time bioactivity of Rosa damascena receptacles and further justifies the use of such screening programs in the quest for new drugs.

Microbial growth and quorum sensing antagonist activities of herbal plants extracts.

Antimicrobial and antiquorum sensing (AQS) activities of fourteen ethanolic extracts of different parts of eight plants were screened against four Gram-positive, five Gram-negative bacteria and four fungi. Depending on the plant part extract used and the test microorganism, variable activities were recorded at 3 mg per disc. Among the Gram-positive bacteria tested, for example, activities of Laurus nobilis bark extract ranged between a 9.5 mm inhibition zone against Bacillus subtilis up to a 25 mm one against methicillin resistant Staphylococcus aureus. Staphylococcus aureus and Aspergillus fumigatus were the most susceptible among bacteria and fungi tested towards other plant parts. Of interest is the tangible antifungal activity of a Tecoma capensis flower extract, which is reported for the first time. However, minimum inhibitory concentrations (MICs) for both bacteria and fungi were relatively high (0.5-3.0 mg). As for antiquorum sensing activity against Chromobacterium violaceum, superior activity (>17 mm QS inhibition) was associated with Sonchus oleraceus and Laurus nobilis extracts and weak to good activity (8-17 mm) was recorded for other plants. In conclusion, results indicate the potential of these plant extracts in treating microbial infections through cell growth inhibition or quorum sensing antagonism, which is reported for the first time, thus validating their medicinal use.

Variations of trace metal concentrations in seawater and pearl oyster Pinctada radiata from Bahrain (Arabian Gulf)

Abstract Concentrations of seven trace metals in oysters ( Pinctada radiata ) and paired seawater samples from two stations in Bahrain (Arabian Gulf) were determined every 6–8 weeks during the period March 1991–March 1992. The measured annual means in oysters were higher for Pb (7.64 μg g −1 ) and Cd (2.48 μg g −1 ) at an offshore Station 2, while Ni was higher in oysters at a nearshore Station 1. For Cu and Mn no differences were observed between oysters of both stations, however, Fe and Zn were higher in oysters of Station 1. No significant difference was observed in concentrations of trace metals in seawater of the nearshore or offshore stations or between individual metals. Seasonal distribution of metals in oysters and water indicated a tendency to increase towards the hot summer months (June, July-September). Generally, metal concentrations were higher in oysters irrespective of the station and the levels of Pb and Cd exceeded the WHO limits.

Antiproliferative, Antimicrobial and Apoptosis Inducing Effects of Compounds Isolated from Inula viscosa

The antiproliferative and antimicrobial effects of thirteen compounds isolated from Inula viscosa (L.) were tested in this study. The antiproliferative activity was tested against three cell lines using the MTT assay. The microdilution method was used to study the antimicrobial activity against two Gram positive bacteria, two Gram negative bacteria and one fungus. The apoptotic activity was determined using a TUNEL colorimetric assay. Scanning electron microscopy was used to study the morphological changes in treated cancer cells and bacteria. Antiproliferative activity was observed in four flavonoids (nepetin, 3,3′-di-O-methylquercetin, hispidulin, and 3-O-methylquercetin). 3,3′-di-O-Methylquercetin and 3-O-methylquercetin showed selective antiproliferative activity against MCF-7 cells, with IC50 values of 10.11 and 11.23 µg/mL, respectively. Both compounds exert their antiproliferative effect by inducing apoptosis as indicted by the presence of DNA fragmentation, nuclear condensation, and formation of apoptotic bodies in treated cancer cells. The antimicrobial effect of Inula viscosa were also noticed in 3,3′-di-O-methylquercetin and 3-O-methyquercetin that inhibited Bacillus cereus at MIC of 62.5 and 125 µg/mL, respectively. Salmonella typhimurium was inhibited by both compounds at MIC of 125 µg/mL. 3,3′-di-O-Methylquercetin induced damage in bacterial cell walls and cytoplasmic membranes. Methylated quercetins isolated from Inula viscosa have improved anticancer and antimicrobial properties compared with other flavonoids and are promising as potential anticancer and antimicrobial agents.

Herbal plants in the traditional medicine of Bahrain

Plant samples collected in Bahrain and data reported in the literature indicate the flora of Bahrain to contain 52 species (49 genera; 20 families) of medicinal interest. Of these plant species 20 appear to be indigenous and are being used in traditional herbal remedies for numerous afflictions. Preparation of such remedies appears to be simple and includes boiling, infusions, extraction of milled dry or fresh leaves, flowers, seeds or whole plants. Direct consumption of plant parts, raw or cooked, is also practiced. None of these plants has been studied systematically to evaluate their medicinal potential.

Antimicrobial Activity of Extracts of Herbal Plants used in the Traditional Medicine of Bahrain

Petroleum ether, methanol, hexane, butanol and aqueous crude extracts of the whole aerial parts of Suaeda vermiculata, Prosopis farcta, Capparis spinosa and Salsola villosa exhibited variable degrees of antimicrobial activity. Extracts had low to moderate actvity against four bacterial and two fungal species compared with that exerted by antibiotics. The petroleum ether extract of S. vermiculata and the butanol extract of S. villosa had high antifungal activity against Candida albicans and Fusarium oxysporum comparable to the antifungal miconazole nitrate.

Some aspects of decomposition of leaf litter of the seagrass Halophila stipulacea from the gulf of Aqaba (Jordan)

Decomposition of the seagrass Halophila stipulacea (Forsk.) Aschers. followed in situ over 340 days showed that the plant lost 40.8% of its initial weight during the first 85 days and only 21.2% over the remaining 255 days of the incubation period. The observed overall rate of decay of 0.18% day−1 indicates the high resistance of Halophila tissue to decomposition. An exponential model showing a regularly decreasing decay coefficient was fitted to the data of weight loss. The correlation between observed and calculated weight remaining was highly significant (r = 0.9881, P < 0.0001). The samples of decomposing leaf litter harboured 2.2 × 1011 bacteria g−1 dry wt. on average and consumed 0.25−1.07 mg O2 −1 dry wt. h−1. The early colonizing bacteria of the detritus were mostly non-sporogenous forms. The most prominent genera involved in decomposition were Actinomyces, Arthrobacter, Bacillus and Pseudomonas, all of which are capable of degrading structural carbohydrates.

Heterotrophic bacteria attached to leaves, rhizomes and roots of three seagrass species from Aqaba (Jordan)

Abstract Significant differences in viable counts of heterotrophic bacteria attached to the seagrasses Halophila ovalis (R. Brown) Hook. f., Halophila stipulacea (Forsk.) Aschers. and Halodule uninervis (Forsk.) Aschers. were found between the species as well as between their various vegetative parts. Bacterial densities were highest on the leaves and showed a seasonal pattern with maxima in summer. Of the nine genera found, three were gram-negative. Most common were the gram-positive genera Actinomyces, Arthrobacter and Bacillus. Vibrio and Micrococcus occured on Halodule uninervis only, whereas Acinetobacter, Staphylococcus and Streptococcus occurred on Halophila ovalis only. The variation in the distribution pattern of the bacterial genera may be related partly to inhibiting substances such as flavones, phenolic acids and tannins, and partly to differences in the quantity and quality of soluble organic exudates released by the plants.