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Allovahlkampfia spelaea (A. spelaea) is a free-living amoeba, proved to cause Acanthamoeba-like keratitis with quite difficult treatment. This study aimed to evaluate the amoebicidal effect of Allium cepa (A. cepa) on A. spelaea trophozoites and cysts both in vitro and in vivo using Chinchilla rabbits as an experimental model of this type of keratitis. Chemical constituents of the aqueous extract of A. cepa were identified using Liquid Chromatography-mass Spectrometry (LC-MS). In vitro, A. cepa showed a significant inhibitory effect on trophozoites and cysts compared to the reference drug, chlorhexidine (CHX) as well as the non-treated control (P < 0.05) with statistically different effectiveness in terms of treatment durations and concentrations. No cytotoxic effect of A. cepa on corneal cell line was found even at high concentrations (32 mg/ml) using agar diffusion method. The in vivo results confirmed the efficacy of A. cepa where the extract enhanced keratitis healing with complete resolution of corneal ulcers in 80% of the infected animals by day 14 (post infection)pi compared to 70% recovery with CHX after 20 treatment days. The therapeutic effect was also approved at histological, immune-histochemical, and parasitological levels. Our findings support the potential use of A. cepa as an effective agent against A. spelaea keratitis.

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Trypanosomosis is a worldwide disease that affects human and livestock populations with limited availability and high cost of trypanocides. The study aims to evaluate the possible in vitro and in vivo anti-trypanosomal activity of Thymus vulgaris (thyme), Mentha piperita (mint) and Elettaria cardamomum (cardamom) aqueous extracts against Trypanosoma evansi in experimentally infected rats using Intropar as a reference drug. The crude extracts of the selected plants were used in three concentrations (2500, 2000, and 1000 µg/ml). The in vitro trypanocidal activities were assessed regarding parasite motility, count, and infectivity. The in vivo susceptibility of T. evansi was evaluated by assessing the level of parasitemia in the experimental rats. The packed cell volume (PCV) was also monitored. Both the in vitro and in vivo experiments showed trypanocidal activity, of all the tested extracts, higher than that of Intropar. The in vitro trypanocidal effects were dose-dependent and represented by a significant reduction of the parasite count together with immobilizing effect within 3 hours incubation period, compared to the negative and positive controls (p< 0.05). The in vivo trypanocidal effects of the different concentrations of all the tested extracts were represented by the significantly lowered levels of parasitemia, compared to the negative control (NC) group with varying degrees; in a dose-dependent manner concerning the time. They exhibited also a significantly higher level in PCV recovery compared to the NC group (p < 0.05). This study initially confirmed the potent in vitro and in vivo trypanocidal effect of the three extracts, with a potentially promising future for the treatment of trypanosomosis.

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Giardiosis is one of the common parasitic diarrhoea in humans, especially in children, worldwide. Many drugs are used for its treatment, but there is evidence of drug resistance, insufficient efficacy and unpleasant side effects. Natural products are good candidates for discovering more effective anti-giardial compounds. This study evaluated the activity of extracts of Zingiber officinale (ginger) and Curcuma longa (curcumin) against Giardia lamblia in vitro and in vivo. Giardia cyst suspension was prepared from children faecal specimens. For the in vitro experiment, 1, 10 and 50 mg/mL dichloromethane extracts of ginger and curcumin separately were incubated with Giardia cysts for 5, 10, 30 and 60 min. The viability was distinguished by 0.1 % eosin and a haemocytometer. For the in vivo experiments, Balb/c mice were infected with Giardia cyst suspension containing 10,000 cysts/mL. Infected mice were administered 10 and 20 mg kg(-1) day(-1) ginger and curcumin extracts separately for 7 days post-infection. The effectiveness of the extracts was evaluated by faecal cyst and intestinal trophozoite counts and histopathological examination of the small intestine. In vitro ginger extract had a higher significant effect on cyst viability than curcumin, in a dose- and time-dependent manner. In vivo ginger (more effective) and curcumin extracts significantly treated infected mice, and this was evidenced by the faecal cyst and intestinal trophozoite counts reduction, in addition to evident improvement of intestinal mucosal damages induced by Giardia infection. Z. officinale and C. longa extracts may represent effective and natural therapeutic alternatives with low side effects and without drug resistance in the treatment of giardiosis.

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A new long chain fatty alcohol acetate identified as 17-hydroxypentacosanyl acetate, (1) together with a new xanthone identified as 1,8-Dihydroxy-3,6-dimethoxy-xanthone-5-O-[α-L-rhamnopyranosyl-(1''→2')]-ß-D-glucopyranoside (3), as well as two new lignans identified as (+)-Lyoniresinol-3a-O-[α-L-rhamnopyranosyl-(1'''→6'')]-ß-D-glucopyranoside (4) and (+)-Isolariciresinol-3a-O-[α-L-rhamnopyranosyl-(1'''→2'')-α-L-rhamnopyranosyl-(1''''→6'')]-ß-D-glucopyranoside (5), in addition to ß-sitosterol-3-O-acetate (2) were isolated from the methanolic extract of the aerial parts of Polygonum bellardii growing in Egypt. Their structures were elucidated on the basis of different chemical and spectroscopic evidences. The total extract and its fractions, in addition to compounds (3, 4 and 5) showed significant antioxidant potential by DPPH(·) scavenging activity technique.

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A radical scavenging guided phytochemical study on the stem bark of Tecoma mollis afforded seven active phenylpropanoid glycosides (1-7), including a new one (4), and one iridoid (8). The structures of the isolated compounds were elucidated on the basis of spectroscopic evidences and correlated with known compounds. Compounds (1-7) displayed promising antioxidant activity (DPPH assay) in relation to ascorbic acid (positive control). The antimicrobial activity for compounds (1-8) was evaluated against five bacterial and five fungal strains. The isolated compounds exhibited nonselective weak to moderate antimicrobial activity. The highest antileishmanial activity against Leishmania donovani was observed for compound (7) with an IC50 value of 6.71 µg/ml, using pentamidine and amphotericin B as drug controls. Compound (5) exhibited moderate antimalarial activity (45% inhibition) against chloroquine sensitive (D6) clones of Plasmodium falciparum.

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The present work evaluated the effects of alcoholic extracts of salvia (Salvia officinalis), thyme (Thymus vulgaris), and 2 pure compounds (thymol and menthol) on the viability of Echinococcus granulosus protoscolices in vitro. Four different concentrations of each extract (2,500, 1,500, 1,000, and 500 µg/ml) and 3 different concentrations each of thymol and menthol (50, 10, and 1 µg/ml) were used. Concentration of 2,500 µg/ml of both extracts showed a significant protoscolicidal activity on the 6th day. Complete loss of viability of protoscolices occurred with 500 µg/ml concentration of both extracts at day 6 and day 7 post-treatment (PT), respectively. Pure compounds, i.e., menthol and thymol, showed potent effects with 50 µg/ml concentration at day 2 and day 5 PT, respectively. These effects were compared with those of albendazole sulfoxide (800 µg/ml), a commonly used treatment drug for hydatidosis. Krebs-Ringer solution and the hydatid cystic fluid at a ratio of 4:1 was a good preservative solution which kept the protoscolices viable for 15 days.

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Chromatographic fractionation of the alcoholic extract of the dried fronds of Adiantum capillus-veneris L. (Adiantaceae) yielded seven compounds: four triterpenoidal compounds belonging to adiantane and filicane groups were isolated from the hexane fraction and identified as isoadiantone (1); isoadiantol-B (2); 3-methoxy-4-hydroxyfilicane (3) and 3,4-dihydroxyfilicane (4) and three flavonoids were isolated from the ethyl acetate fraction and identified as: quercetin (5), quercetin-3-O-glucoside (6) and quercetin-3-O-rutinoside (rutin) (7). The identification of the isolated compounds has been established through their physical, chemical and spectroscopic methods including IR, (1)H NMR, (13)C NMR, HSQC, HMBC, NOESY and MS. Biological studies of the total alcoholic extract, hexane fraction and some of the isolated compounds showed an anti-inflammatory activity while the hypoglycemic study of the total alcoholic extract showed a significant activity.

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From the saponin fraction of the total methanolic extract of the dried root and stem barks of Taverniera aegyptiaca Boiss, six new triterpenoidal saponins of oleanane type were isolated and identified as 28-methyl serratagenate-3-beta-O-beta-xylopyranosyl (1-->2)-beta-glucopyranoside (2), 28-methyl serratagenate 3-beta-O-alpha-rhamnopyranosyl (1-->2)-beta-glucopyranoside (3), 3beta-O-alpha-rhamnopyranosyl (1-->2) beta-glucopyranosyl-olean-11,13(18)-dien-1beta, 3beta, 22beta-triol (4), 3beta-O-beta-glucopyranosyl (1-->2)-beta-glucuronopyranosylolean-11,13(18)-dien-1beta,3beta,22beta-triol (5), 3beta-O-beta-xylopyranosyl(1-->2)-beta-glucuronopyranosylolean-11,13(18)-dien-1beta,3beta,22beta-triol (6), 3beta-O-alpha-rhamnopyranosyl (1-->2)-beta-glucuronopyranosylolean-11,13(18)-dien-1beta, 3beta, 22beta-triol (7) together with the known oleanolic acid 3-beta-O-beta-glucoside (1). The identification of the isolated compounds was done on the basis of chemical and spectral evidences.

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