Atrazine-induced toxicity in goat spermatozoa is alleviated to some extent by polyphenol-enriched feed.

Atrazine (ATZ) is one of the most extensively used herbicides to control growth of broadleaf and grassy weeds in crops. ATZ and its metabolites have deleterious effect on sperm quality. ATZ is also known for its ability to induce oxidative stress. Pistacia lentiscus (PL) is an evergreen shrub, with a high content of polyphenols in leaf extracts, with a known anti-inflammatory and antioxidant properties. The protective effect of PL or its extracts against ATZ-induced damage have not been yet evaluated. We examined the harmful effects of atrazine (ATZ) exposure on male reproductive system, using goat (Capra hircus) model spermatozoa and the protective effects of PL and PL ethanolic extract (PLE). In in-vivo experiments, male goats were fed a standard ration or one supplemented with 15 mg ATZ/kg body weight daily, for 6 months. Exposure to ATZ impaired the spermatozoa's morphology, viability, mitochondrial membrane potential and cell lipid composition. These alterations may in turn lead to reduced fertilization competence of the exposed spermatozoa. In an ex-vivo experiment, spermatozoa from male goats fed a standard ration or one supplemented with PL or PLE for 90 days and then were exposed to 1 µM ATZ or 10 µM of its major metabolite diaminochlorotriazine (DACT) through in-vitro capacitation. Prefeeding with PL or PLE partially attenuated the harmful effects of ATZ and DACT. Dietary supplementation with polyphenol-enriched feed can protect, to a certain extent, spermatozoa in males exposed to environmental toxicants.

Toxicity of phenolic compounds to entomopathogenic nematodes: A case study with Heterorhabditis bacteriophora exposed to lentisk (Pistacia lentiscus) extracts and their chemical components.

Insects show adaptive plasticity by ingesting plant secondary compounds, such as phenolic compounds, that are noxious to parasites. This work examined whether exposure to phenolic compounds affects the development of insect parasitic nematodes. As a model system for parasitic life cycle, we used Heterorhabditis bacteriophora (Rhabditida; Heterorhabditiade) grown with Photorhabdita luminescens supplemented with different concentrations of plant phenolic extracts (0, 600, 1200, 2400 ppm): a crude ethanol extract of lentisk (Pistacia lentiscus) or lentisk extract fractionated along a scale of hydrophobicity with hexane, chloroform and ethyl acetate; and flavonoids (myricetin, catechin), flavanol-glycoside (rutin) or phenolic acids (chlorogenic and gallic acids). Resilience of the nematode to phenolic compounds was stage-dependent, with younger growth stages exhibiting less resilience than older growth stages (i.e., eggs < young juveniles < young hermaphrodites < infective juveniles < mature hermaphrodites). At high concentrations, all of the phenolic compounds studied were lethal to eggs and young juveniles. The nematodes were able to survive in the presence of medium and low concentrations of all studied compounds, but very few of those treatments allowed for reproduction beyond the infective juvenile stage and, at low concentrations, the crude 70% ethanol extract, chloroform and hexane extracts, and myricetin were associated with some impaired reproduction. The ethyl-acetate fraction and gallic acid were extremely lethal to the young stages and allowed almost no development beyond the infective juvenile stage. We conclude that exposure of infective juveniles to phenolics before they infect insects and post-infection exposure of other nematode developmental stages may affect the initiation of the infection, suggesting that the chemistry of dietary phenolics may limit H. bacteriophora's infection of insects.

Effects of selected Palestinian plants on the in vitro exsheathment of the third stage larvae of gastrointestinal nematodes.

BACKGROUND: Gastrointestinal parasites are one of the main restrictions to small ruminant production. Their pathological importance is primarily related to the major production losses, in quantity or quality, induced by the direct action of worms. Control of these parasites is based exclusively on the frequent use of anthelmintic drugs. However, the resistance to anthelmintics in worm populations after commercialisation of chemical drugs is now widespread. Therefore, there is a need to find new natural resources to ensure sustainable and effective treatment and control of these parasites. The aim of this study was to evaluate the anthelmintic activity, as minimum inhibitory concentration (IC 50 mg/mL), of different plant extracts using larval exsheathment inhibition assay using a two-species but steady population of parasitic nematodes (ca. 20% Teladorsagia circumcinta and 80% Trichostrongylus colubriformis). RESULTS: The study showed that the ethanolic extracts of 22 out of the 48 plant extracts, obtained from 46 plant species, have an inhibitory effect >50% (at concentrations of 100 mg/mL) on the third stage larvae (L3) of the nematodes exhibited the strongest inhibition activity (94%) with IC 50 of 0.02 mg/mL, where other members of the Rhamnaceae family have shown to possess strong anthelmintic activity (70-89%). CONCLUSIONS: Plant extracts are potential rich resources of anthelmintics to combat helminthic diseases. Our results suggest that extracts from Rhamnus elaternus, Epilobium hirsutum, Leucaena leucocephala and Rhamnus palaestinus have promising anthelmintic activity, with potential applications in animal therapeutics and feed.

Ethanolic extracts of Inula viscosa, Salix alba and Quercus calliprinos, negatively affect the development of the entomopathogenic nematode, Heterorhabditis bacteriophora - A model to compare gastro-intestinal nematodes developmental effect.

Heterorhabditis bacteriophora can represent a model system for herbal medication against gastro-intestinal strongylid parasites in determining the recovery and development due to their unique parasitic infectious cycle. The fact that plant extracts impair nematode development is known but their differential impact on stages of the life cycle of H. bacteriophora has never been investigated. We examined the developmental stages resumed from eggs, young juveniles (J1-3), infective juveniles (IJs), young and adult hermaphrodites of H. bacteriophora upon exposure to crude ethanolic extracts of Inula viscosa, Salix alba, and Quercus calliprinos at concentrations of 600, 1200, and 2400ppm. Our results showed that plant extracts were highly toxic to the survival of the eggs and young juveniles J1 to J3 at all concentrations. The plant extracts inhibited their development and were associated with low reproduction parameters (i.e. fecundity and viability of eggs). The IJs, J4, young and developed hermaphrodites displayed concentration-dependent negative effect on development with less egg count, poor vulval muscle development, loss of egg laying capacity and progeny development by matricidal hatching. Plant extract of I. viscosa at low (600ppm) concentration did not impair vulval development. These results suggest that these plant extracts show potential for the control of parasitic rhabditids.

Identification of a New Antibacterial Sulfur Compound from Raphanus sativus Seeds.

Raphanus sativus L. (radish), a member of Brassicaceae, is widely used in traditional medicine in various cultures for treatment of several diseases and disorders associated with microbial infections. The antibacterial activity of the different plant parts has been mainly attributed to several isothiocyanate (ITC) compounds. However, the low correlation between the ITC content and antibacterial activity suggests the involvement of other unknown compounds. The objective of this study was to investigate the antibacterial potential of red radish seeds and identify the active compounds. A crude ethanol seed extract was prepared and its antibacterial activity was tested against five medically important bacteria. The ethanol extract significantly inhibited the growth of all tested strains. However, the inhibitory effect was more pronounced against Streptococcus pyogenes and Escherichia coli. Bioassay-guided fractionation of the ethanol extract followed by HPLC, 1H-NMR, 13C-NMR, 15N-NMR, and HMBC analysis revealed that the active fraction consisted of a single new compound identified as [5-methylsulfinyl-1-(4-methylsulfinyl-but-3-enyl)-pent-4-enylidene]-sulfamic acid, which consisted of two identical sulfur side chains similar to those found in ITCs. The minimal inhibitory concentration values of the isolated compound were in the range of 0.5-1 mg/mL. These results further highlight the role of radish as a rich source of antibacterial compounds.

Effects of tannin-rich host plants on the infection and establishment of the entomopathogenic nematode Heterorhabditis bacteriophora.

Parasitized animals can self-medicate. As ingested plant phenolics, mainly tannins, reduce strongyle nematode infections in mammalian herbivores. We investigated the effect of plant extracts known to be anthelmintic in vertebrate herbivores on the recovery of the parasitic entomopathogenic nematode Heterorhabditis bacteriophora infecting African cotton leafworm (Spodoptera littoralis). Nematode infective juveniles (IJs) were exposed to 0, 300, 900, 1200, 2400 ppm of Pistacia lentiscus L. (lentisk), Inula viscosa L. (strong-smelling inula), Quercus calliprinos Decne. (common oak) and Ceratonia siliqua L. (carob) extracts on growth medium (in vitro assay). In control treatments, 50-80% of IJs resumed development to J4, young and developed adult hermaphrodites, whereas all extracts, except for C. siliqua at 300 ppm, impaired IJ exsheathment and development. The highest concentration of I. viscosa extract (2400 ppm) had the strongest effect, killing 95% of exposed nematodes. Surviving nematodes did not recover, remaining at the IJ stage. Over the whole cycle, I. viscosa extract inhibited recovery to 25% or less, and did not allow full development to adulthood, whereas 65% of IJs in the control treatment recovered and resumed development, 12% reaching complete maturation within 72 h of incubation. When herbivorous S. littoralis larvae were fed with different plant extracts in vivo, I. viscosa had the strongest effect at concentrations above 300 ppm, with 90% of insect-invading IJs not developing to parasitic stages, whereas in the control treatment, 85% of IJs resumed development. Exposure to C. siliqua extract also inhibited exsheathment and development of 75% of the IJs. Half of those that resumed development reached full maturation. P. lentiscus and Q. calliprinos extracts also inhibited development of 50% IJs. Our results suggest that H. bacteriophora can be used to study herbal medication against parasites in animals.

Synergistic antibacterial effects of polyphenolic compounds from olive mill wastewater.

Polyphenols or phenolic compounds are groups of secondary metabolites widely distributed in plants and found in olive mill wastewater (OMW). Phenolic compounds as well as OMW extracts were evaluated in vitro for their antimicrobial activity against Gram-positive (Streptococcus pyogenes and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae). Most of the tested phenols were not effective against the four bacterial strains when tested as single compounds at concentrations of up to 1000 µg mL(-1). Hydroxytyrosol at 400 µg mL(-1) caused complete growth inhibition of the four strains. Gallic acid was effective at 200, and 400 µg mL(-1) against S. aureus, and S. pyogenes, respectively, but not against the gram negative bacteria. An OMW fraction called AntiSolvent was obtained after the addition of ethanol to the crude OMW. HPLC analysis of AntiSolvent fraction revealed that this fraction contains mainly hydroxytyrosol (10.3%), verbascoside (7.4%), and tyrosol (2.6%). The combinations of AntiSolvent/gallic acid were tested using the low minimal inhibitory concentrations which revealed that 50/100-100/100 µg mL(-1) caused complete growth inhibition of the four strains. These results suggest that OMW specific fractions augmented with natural phenolic ingredients may be utilized as a source of bioactive compounds to control pathogenic bacteria.

Traditional Arabic and Islamic Medicine, a Re-emerging Health Aid.

Complementary medicine is a formal method of health care in most countries of the ancient world. It is expected to become more widely integrated into the modern medical system, including the medical curriculum. Despite the perception of modern medicine as more efficacious, traditional medicine continues to be practiced. More than 70% of the developing world's population still depends primarily on the complementary and alternative systems of medicine (CAM). In rural areas, cultural beliefs and practices often lead to self-care, home remedies or consultation with traditional healers. Herbal medicine can be broadly classified into four basic systems as follows: Traditional Chinese Herbalism, Ayurvedic Herbalism, Western Herbalism-which originally came from Greece and Rome to Europe and then spread to North and South America and Traditional Arabic and Islamic Medicine (TAIM). There is no doubt that today the concept of Arabic traditional herbal medicine is a part of modern life in the Middle East, and it is acquiring worldwide respect, with growing interest among traditional herbalists and the scientific community. TAIM therapies have shown remarkable success in healing acute as well as chronic diseases and have been utilized by people in most countries of the Mediterranean who have faith in spiritual healers. TAIM is the first choice for many in dealing with ailments such as infertility, epilepsy, psychosomatic troubles and depression. In parallel, issues of efficacy and safety of complementary medicine have become increasingly important and supervision of the techniques and procedures used is required for commercial as well as traditional uses. More research is therefore needed to understand this type of medicine and ensure its safe usage. The present review will discuss the status of traditional Arab medicine (particularly herbal medicine), including the efficacy and toxicity of specific medicinal preparations, with an emphasis on the modern in vitro and in vivo techniques.

Maintaining a physiological blood glucose level with 'glucolevel', a combination of four anti-diabetes plants used in the traditional arab herbal medicine.

Safety and anti-diabetic effects of Glucolevel, a mixture of dry extract of leaves of the Juglans regia L, Olea europea L, Urtica dioica L and Atriplex halimus L were evaluated using in vivo and in vitro test systems. No sign of toxic effects (using LDH assay) were seen in cultured human fibroblasts treated with increasing concentrations of Glucolevel. Similar observations were seen in vivo studies using rats (LD50: 25 g/kg). Anti-diabetic effects were evidenced by the augmentation of glucose uptake by yeast cells (2-folds higher) and by inhibition of glucose intestinal absorption ( approximately 49%) in a rat gut-segment. Furthermore, treatment with Glucolevel of Streptozotocin-induced diabetic rats for 2-3 weeks showed a significant reduction in glucose levels [above 400 +/- 50 mg/dl to 210 +/- 22 mg/dl (P < 0.001)] and significantly improved sugar uptake during the glucose tolerance test, compared with positive control. In addition, glucose levels were tested in sixteen human volunteers, with the recent onset of type 2 diabetes mellitus, who received Glucolevel tablets 1 x 3 daily for a period of 4 weeks. Within the first week of Glucolevel consumption, baseline glucose levels were significantly reduced from 290 +/- 40 to 210 +/- 20 mg/dl. At baseline, a subgroup of eleven of these subjects had glucose levels below 300 mg% and the other subgroup had levels >/= 300 mg%. Clinically acceptable glucose levels were achieved during the 2-3 weeks of therapy in the former subgroup and during the 4th week of therapy in the latter subgroup. No side effect was reported. In addition, a significant reduction in hemoglobin A1C values (8.2 +/- 1.03 to 6.9 +/- 0.94) was found in six patients treated with Glucolevel. Results demonstrate safety, tolerability and efficacy of herbal combinations of four plants that seem to act differently but synergistically to regulate glucose-homeostasis.

Safety of traditional arab herbal medicine.

Herbal remedies are widely used for the treatment and prevention of various diseases and often contain highly active pharmacological compounds. Many medicinal herbs and pharmaceutical drugs are therapeutic at one dose and toxic at another. Toxicity related to traditional medicines is becoming more widely recognized as these remedies become popular in the Mediterranean region as well as worldwide. Most reports concerning the toxic effects of herbal medicines are associated with hepatotoxicity although reports of other toxic effects including kidney, nervous system, blood, cardiovascular and dermatologic effects, mutagenicity and carcinogenicity have also been published in the medical literature. This article presents a systematic review on safety of traditional Arab medicine and the contribution of Arab scholars to toxicology. Use of modern cell biological, biochemical, in vitro and in vivo techniques for the evaluation of medicinal plants safety is also discussed.

Phytoremediation of selenium using subsurface-flow constructed wetland.

The potential of two plant species, Phragmites australis (common reed) and Typha latifolia (cattail), in the phytoremediation process of selenium (Se) was studied in subsurface-flow constructed wetland (SSF). Se was supplemented continuously at a concentration of 100 microg Se L(-1) in the inlet of the cultivation beds of the SSF. Water samples collected from the outlet of the Phragmites bed after 1, 3, 6, 9, and 12 wk of treatments showed that Se content was under detectable limits. Water samples collected from the Typha bed at the same five periods showed that Se concentrations in the outlet were 55, 47, 65, 76, and 25 microg/L, respectively. The results of bioaccumulation in the biomass of both species after 12 wk of treatment indicated that Typha plants accumulated Se mainly in fine roots. Phragmites accumulated Se mainly in leaves and rhizomes, and moderate levels were found in stems and fine organic materials. The results indicate that common reed is a very good species for Se phytoextraction and phytostabilization (immobilization) and that cattail is only a phytostabilization species. The use of common reed and cattail for Se phytoremediation in a SSF system and in constructed wetland models are discussed.

Aqueous extracts of Teucrium polium possess remarkable antioxidant activity in vitro.

Teucrium polium L. (Lamiaceae) (RDC 1117) is a medicinal plant whose species have been used for over 2000 years in traditional medicine due to its diuretic, diaphoretic, tonic, antipyretic, antispasmodic and cholagogic properties. The therapeutic benefit of medicinal plants is often attributed to their antioxidant properties. We previously reported that an aqueous extract of the leaves and stems of this plant could inhibit iron-induced lipid peroxidation in rat liver homogenate at concentrations that were not toxic to cultured hepatic cells. Others have reported that organic extracts of the aerial components of this plant could inhibit oxidative processes. Against this background, we felt further investigation on the antioxidant action of the extract of T. polium prepared according to traditional Arab medicine was warranted. Accordingly, we assessed (i) its ability to inhibit (a) oxidation of beta-carotene, (b) 2,2'-azobis(2-amidinopropan) dihydrochloride (AAPH)-induced plasma oxidation and (c) iron-induced lipid peroxidation in rat liver homogenates; (ii) to scavenge the superoxide (O2*-) radical and the hydroxyl radical (OH(*)); (iii) its effects on the enzyme xanthine oxidase activity; (iv) its capacity to bind iron; and (v) its effect on cell glutathione (GSH) homeostasis in cultured Hep G2 cells. We found that the extract (i) inhibited (a) oxidation of beta-carotene, (b) AAPH-induced plasma oxidation (c) Fe(2+)-induced lipid peroxidation in rat liver homogenates (IC(50) = 7 +/- 2 mug ml(-1)); (ii) scavenged O2*-(IC(50) = 12 +/- 3 mug ml(-1)) and OH(*) (IC(50) = 66 +/- 20 mug ml(-1)); (iii) binds iron (IC(50) = 79 +/- 17 mug ml(-1)); and (iv) tended to increase intracellular GSH levels resulting in a decrease in the GSSG/GSH ratio. These results demonstrate that the extract prepared from the T. polium possesses antioxidant activity in vitro. Further investigations are needed to verify whether this antioxidant effect occurs in vivo.

The state of the art of traditional arab herbal medicine in the eastern region of the mediterranean: a review.

Historical and current studies indicate that the Eastern region of the Mediterranean has been distinguished from other regions by a rich inventory of complementary alternative medicine (CAM), in particular herbal medicine. Data collected from several surveys and studies indicate that there is a flourishing and well-developed trade of herbs. These surveys also reveal that 200-250 herbs are used in treating human diseases and are sold or traded in market places in the Mediterranean region or internationally. In addition, some of these herbs are rare or even endangered species. In regard to the status of the know-how of herbalists, unfortunately, herbal medicine in our region is mostly prescribed by ethnopharmacologists symptomatically-based on signs and symptoms alone, rather than as a result of a full understanding of the underlying disease. In some cases, herbs used today may not even correspond to the plants described originally in the old literature, as the former are cultivated from herbs that went through different breeding procedures throughout several centuries. This article presents a systematic review of both the state of the art of traditional Arab herbal medicine and the status of the know-how of Arab herbalists.

Tradition and perspectives of arab herbal medicine: a review.

Complementary and Alternative Medicine (CAM), including herbal medicine, are popular in the general population worldwide. Parallel to the increasing interest in 'modern' CAM therapies and the historical importance of Arab medicine, there is also a similar trend in research activities dealing with the efficacy and safety of medicinal plants in our region. Historical and current studies and surveys indicate that the Eastern region of the Mediterranean has been distinguished throughout the generations with a rich inventory of natural medicinal herbs. It is well documented that indigenous Arab medicine has contributed greatly to the development of modern medicine in Europe and remains one of the closest forms of original European medicine. The rapid increase in consumption of herbal remedies worldwide has been stimulated by several factors, including the notion that all herbal products are safe and effective. This article presents a systematic review on traditional Arab medicine including historical background, medical innovations introduced by Arab physicians in the field of safety and efficacy of herbal medicine and a state-of-the-art description of traditional Arab herbal medicine in the Mediterranean region.

Fertilization-induced changes in growth parameters and antioxidant activity of medicinal plants used in traditional Arab medicine.

In response to increased popularity and greater demand for medicinal plants, a number of conservation groups are recommending that wild medicinal plants be brought into cultivation systems. We collected four medicinal herbs Cichorium pumilum, Eryngium creticum, Pistacia palaestina and Teucrium polium used in traditional Arab medicine for greenhouse cultivation to assess the effects of different fertilization regimes on their growth and antioxidant activity. Wild seedlings were collected and fertilized with either 100% Hoagland solution, 50% Hoagland solution, 20% Hoagland solution or irrigated with tap water. Plant height was measured and the number of green leaves and branches counted weekly. Thereafter, the aboveground parts of plants were harvested for preparing a water-soluble powder extracts of which antioxidant activity was measured by their ability to suppress the oxidation of beta-carotene. Of the fertilization regimes, we found either 20 or 50% Hoagland solution produced the most consistent response of the plant growth parameters. All powders prepared from the four wild growing plants inhibited oxidation of beta-carotene. Increasing the amount of fertilizer caused a significant concentration-dependent increase in antioxidant activity of the cultivated T. polium compared with the wild type. In contrast, increasing the amount of fertilizer caused a significant concentration-dependent reduction in the antioxidant activity of powders prepared from the cultivated E. creticum when compared with wild plants. Our results showed that cultivation success should not rely solely on parameters of growth but should incorporate assessment related to indices of therapeutic potential.

The effects of aqueous extracts prepared from the leaves of Pistacia lentiscus in experimental liver disease.

In a previous study, we identified Pistacia lentiscus was worthy for further laboratory evaluation because an aqueous extract of the plant suppressed iron-induced lipid peroxidation in rat liver homogenates without affecting mitochondrial respiration in cultured HepG2 and PC12 cells. The present study was undertaken to evaluate the efficacy of an aqueous extract prepared from the dried leaves of Pistacia lentiscus in a rat model of hepatic injury caused by the hepatotoxin, thioacetamide. We assessed the impact of daily dosing on biochemical and morphological indices and the extent of oxidative stress in the livers of healthy and thioacetamide-treated rats. In healthy rats, long-term administration of the extract induced hepatic fibrosis and an inflammatory response, mild cholestasis and depletion of reduced glutathione associated with an increase in its oxidized form. In thioacetamide-treated rats, long-term administration of extract aggravated the inflammatory and fibrotic and glutathione depleting responses without affecting the extent of lipid peroxidation. Although our previous in vitro study established that extracts prepared from the leaves of Pistacia lentiscus had antioxidant activity, this in vivo study establishes these extracts also contains hepatotoxins whose identity may be quite different from those compounds with antioxidant properties. The results of this study suggest complementing in vitro experiments with those involving animals are essential steps in establishing the safety of medicinal plants. Furthermore, these data confirm that complete reliance on data obtained using in vitro methodologies may lead to erroneous conclusions pertaining to the safety of phytopharmaceuticals.

Antioxidant activity of Crataegus aronia aqueous extract used in traditional Arab medicine in Israel.

BACKGROUND: The medicinal use of extracts prepared from plant parts of the genus Crataegus dates back to ancient times. Furthermore, it has been proposed that its antioxidant constituents account for its beneficial therapeutic effects. A decoction of leaves and unripe fruits from Crataegus aronia syn. azarolus (L) (Rosaceae), the indigenous Israeli hawthorn, is used to treat cardiovascular diseases, cancer, diabetes and sexual weakness in Arab traditional medicine. PURPOSE: Because laboratory data on the bioactivity of extracts prepared from the indigenous Israeli hawthorn is lacking, we evaluated the antioxidant and cytotoxic potentials of an extract prepared from leaves and unripe fruits in a variety of cell and cell-free in vitro assays. METHODS: The antioxidant assays measured: (a) its ability to inhibit (i) oxidation of beta-carotene, (ii) 2,2'-azobis(2-amidino-propan) dihydrochloride (AAPH)-induced plasma oxidation and (iii) iron-induced lipid peroxidation in rat liver homogenates; (b) its ability to scavenge the superoxide (O2-) radical; (c) its effects on the enzyme xanthine oxidase (XO) activity; (d) its effect on the redox state of glutathione (GSH) in cultured Hep G2 cells. In addition, we also evaluated the effects of the extract on cell membrane integrity and mitochondrial respiration in cultured Hep G2 cells. RESULTS AND CONCLUSIONS: Water-soluble extracts inhibited (1) oxidation of beta-carotene, (2) AAPH-induced plasma oxidation and (3) Fe(2+)-induced lipid peroxidation in rat liver homogenates. In addition, the extract (4) is an efficient scavenger of the O2- (5) increases intracellular GSH levels and (6) is not cytotoxic. Accordingly, we propose that the therapeutic benefit of Crataegus aronia can be, at least in part, attributed to its effective inhibition of oxidative processes, efficient scavenging of O2- and possible increasing GSH biosynthesis.

Antioxidant activity and cytotoxicity of eight plants used in traditional Arab medicine in Israel.

Ethnopharmacological surveys conducted among herbal practitioners of traditional Arab medicine in Israel and the Palestinian area have revealed a large number of indigenous plant species are used as sources of their herbal therapies. Some of these herbal therapies are used to treat liver disease, jaundice or diabetes, conditions in which oxidative stress is prominent. No laboratory data on the bioactivity of herbal medicines in these settings exist in traditional Arab medicine. We hypothesized that the beneficial effect of these plants might be due to their antioxidant properties. Accordingly, we selected eight plants used to treat these two conditions and assessed their antioxidant potential by measuring their ability to suppress the extent of iron-induced lipid peroxidation in rat liver homogenates and their potential toxicity by evaluating their effects on mitochondrial respiration and cell membrane integrity in cultured PC12 and HepG2 cells. We found that all the extracts can suppress iron-induced lipid peroxidation and are not toxic. Of these extracts, those prepared from Teucrium polium and Pistacia lentiscus were the most effective in suppressing iron-induced lipid peroxidation. Further investigations are now needed to establish the exact mechanism of action and identify the active bio-ingredient(s) of each extract in order to explain their therapeutic efficacy.