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Objective: The goal of the present study was to assess the antidepressant-like action of Withania qaraitica in two behavioral animal models, the forced-swimming test (FST) and tail suspension test (TST) in mice. Methods: Withania qaraitica methanolic extract was prepared by the maceration. The antidepressant activity was measured by the forced-swimming test (FST) using C57BL/6 mice and the tail suspension test (TST) using BALB/c mice. Mice were divided into three groups: control (DMSO), standard (citalopram and desipramine), and Withania qaraitica methanolic extract (n = 6 per group). Drugs were injected (1 ml/100 g) intraperitoneally (i. p.). Data were evaluated using analysis of variance, followed by LSD post-hoc tests, where *p

The current study was conducted to prepare different polarities extracts and evaluate their antimicrobial and cytotoxic activities from the aerial parts of Cleome austroarabica (C. austroarabica) which was collected from the initial campus of the University of Nizwa. The coarse powder was extracted with direct methanol by using a maceration method. The extract residue was fractionated by using various organic solvents with increasing polarity. The agar disc and brine shrimp lethality (BSL) bioassays were used to assess the antimicrobial and cytotoxic activities of the aerial extracts of C. austroarabica. Four concentrations (2000, 1000, 500, 250 µg/ml) of each extract were used to determine the antimicrobial activity against two Gram (+) bacteria: Staphylococcus aurous (S. aurous), Enterococcus faecalis (E. aurous) and two Gram (−) bacteria: Haemophilus Influenza (H. Influenza), and Escherichia coli (E. coli). Brine shrimp organisms were used to assess the cytotoxic activities of various polarities aerial extracts and the fractions of chloroform extract. The antimicrobial activity results showed that all polarities extracts at different concentrations did not give any activity against the tested bacteria. The cytotoxic activity of all polarities aerial extracts displayed activity within the value of LC50 385.25–640.25 μg/ml in the order of chloroform > hexane > hydro alcoholic > ethyl acetate > methanol extract. However, the isolated all chloroform fractions showed high LC50 activity compared to control. The further extensive study will be needed to confirm the antimicrobial and cytotoxic activities of the crude extracts and to isolate the active ingredients from the highest activity aerial extracts. Keywords: Cleome austroarabica, Muqabil al shams, Antimicrobial, Cytotoxicity, Oman

Cancer is considered a major health issue all over the world for its high morbidity and mortality. Naturally obtained anticancer compounds have comparatively less side-effects, thus it remains a major focus for research. Hyoscyamus gallagheri (H. gallagheri), is one of the plants which have a useful source of bioactive metabolites. The present study is based on preparing plant extracts from the aerial parts of the herbal drug H. gallagheri with various polarities, determining their cytotoxicity and isolating the major cytotoxic compound from the highest active extract. A methanol extract was prepared by the Soxhlet extraction method. Then, it was processed with solvents of increasing polarities. Later, the extracts were evaluated for their cytotoxic activity by brine shrimp lethality assay (BSLA). The highest mass obtained was ethyl acetate and the highest cytotoxicity activity was observed in the ethyl acetate extract, While the lowest was water extract. Ethyl acetate extract was processed for isolation of cytotoxic compounds by different chromatographic methods to give nine fractions which were evaluated by BSLA. Among all, fractions No. 2, 3 and 4 showed significant activity against BSLA and the fractions were purified using preparative thin-layer chromatography (PTLC) to give four compounds (1–4). Only compound 1 showed high purity and appropriateness for NMR analysis. The compound was identified, and the structure was elucidated using 1D and 2D spectroscopy and was found to be 5,7,2′,3′,4′ pentahydroxyflavanone (1). In conclusion, the isolated bioactive compound could be used as an anticancer agent.

As a herbal medicine, essential oil is used for the treatment of several chronic diseases, however, the clinical evidence of essential oil is insufficient. In this context, we have made an effort to quantify its percentage of chemical composition and the biological potency of essential oil of the leaves of Psidium guajava. The content of essential oil was found in 0.38% (v/w) and the oil was isolated by using hydro distillation from the leaves of the selected plant. The isolated oil was analyzed by using gas chromatography–mass spectrometry (GC–MS) equipped with a HP-5MS fused silica capillary column (30 m × 0.25 i.d., film thickness 0.25 μm). The antimicrobial and cytotoxic activities of the isolated leaves oil at different concentrations were determined by agar gel diffusion and brine shrimp lethality bioassay. The antimicrobial activity of the essential oil at various concentrations was determined against three Gram (+) Enterococcus faecalis, Staphylococcus aureus and Streptococcus aureus and three Gram (−) Escherichia coli, Haemophilus influenzae, and Pseudomonas aeruginosa bacterial strains. A total of 54 chemical compounds were detected by using GC–MS which is representing 98.172% of the total oil. The dominating ingredients in the leaves oil were iso-caryophyllene (33.53%), veridiflorene (13.00%), farnesene (11.65%), dl-limonene (9.84%), δ-cadinene (1.75%), α-copaene (2.80%), α-humulene (3.74%) and τ-cadinol (0.08%). The oil showed significant antimicrobial activity against both Gram (+ and −) bacterial strains with an inhibition range of 0–13 mm. However, the isolated leaves oil did not show any activity at any concentration against brine shrimp lethality bioassay. The isolated oil showed significant antimicrobial activity and it could be used as natural antibiotics.

The design of this study was to investigate and compare the total phenols content and antioxidant activity of various crude extracts of lemon peels collected from local farmers and imported one from the local supermarket. Investigation of the total phenol content and antioxidant activity of various polarity peel extracts were performed by modifying Folin-Ciocalteu reagent (FCR) and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) bioassay. The maximum total phenol content in locally grown lemon was found in methanol extract and the minimum was obtained in butanol extract. However, the maximum concentration of total phenol content in imported lemon was also found in the methanol crude extract and the minimum was found in chloroform extract. The high antioxidant activity among the six prepared extracts of local lemon peels was found in the ethyl acetate extract and the lowest was found in chloroform extract. Similar antioxidant activity result was found in the imported lemon collected from the supermarket. Our results show that both lemon peels have the considerable concentration of total phenols content and antioxidant activity, respectively. The lemon peels are cheap and available globally and may find extensive use in medicine, food and perfume industries as vital sources of natural antioxidants.

Graphical abstract, Highlights • Rubus fruticosus is an indigenous plant used traditionally in Oman to treat different disorders. • Antimicrobial activity of crude extracts and isolated fractions of the selected plant was determined by diffusion method. • Cytotoxic activity of crude extracts and isolated fractions of the selected plant was determined by brine shrimp method. • Hydro alcoholic extract showed the highest activity and it could be used as folk medicine to treat diseases., Medicinal plant as herbal medicine is widely used to cure infectious diseases. Rubus fruticosus L (R. fruticosus) has been studied for its antimicrobial and cytotoxic activities. Different polarity leave extracts were prepared by using hexane, chloroform, ethyl acetate and hydro alcoholic solvents. Agar diffusion method has been used to assess the antibacterial activity against two gram-positive Enterococcus faecalis and Staphylococcus aureus and two gram-negative Escherichia coli and Haemophilus influenza bacterial strains. Cytotoxic activity was carried out against brine shrimp using the nauplii method (BSL). The results so obtained for various experiments demonstrates the total number of extracts produces moderate to strong antibacterial activity against the gram (+ and -). The best activity was discovered within hydro alcoholic upon all concentrations, whereas the inhibition zone exists within the range of 6−11 mm. In addition to that, the cytotoxic activity test confirms that hydro alcoholic extracts the maximum toxicity for values LC50 (4.68–6.96 μg/ml), where the LC50 values for all extracts be located within the range of 4.68–6.96 μg/ml. Finally, the plant itself and its derived extracts have been used as a folk medicine to treat serious infectious diseases.

Thymus vulgaris L. belongs to the Lamiaceae family and has a pleasant smell. It is native to the Westren Mediterranean region and southern Italy. The fresh plant material was collected in the month of April from Al Jabal Al Abyadh in Sharqiya region of Oman. The aerial parts of T. vulgaris were separated from fresh plant material and essential oil was isolated by steam distillation method using Clevenger's apparatus. The oil was analyzed by GC-MS. A total of eighteen constituents were identified, the major constituent was durenol (56.2 %). Other main constituents were thymol (15.04 %), p-cymene (8.69 %), δ-terpinene (5.24 %), and α-pinene (2.65 %).

Objective To determine the total phenolics and flavonoids and to evaluate antioxidant and antimicrobial activities of different extracts from fruits of Datura metel (D. metel). Methods Different crude extracts from the fruits of D. metel were subjected to determination of total phenolics, flavonoids, antioxidant and antimicrobial activities by established methods. Resutls The total phenolics results showed that ethyl acetate extract was the most efficient (60.26%) compared to hexane, chloroform, butanol and methanol extracts which had phenolic contents of 50.08, 35.50, 52.54 and 26.49%, respectively. Almost similar results were obtained from the fruits crude extracts for total flavonoids and results found that methanol crude extract was the highest (1.71%) compared to other crude extracts. The antioxidant activity results showed that methanol extract acted the highest activity compared to other extracts and in the order of methanol>ethyl acetate>hexane>chloroform>butanol extract. All extracts were displayed moderate antibacterial potential against the tested bacteria such as Staphylococcus aureus, Escherichia coli and Pseudomonus aeruginosa in the range of 0%–10%. Conclusions The results of this present study clearly showed that the crude extracts of D. metel demenstrated antimicrobial and antioxidant activities and it may act as potential antioxidant sources for human biological system.

Objective: To prepare different polarities leave crude extracts of Juniperus excels (J. excels) and to determine their phytochemical screening, antioxidant, antimicrobial and cytotoxic activities. Methods: The phytochemical screening of different crude extracts was determined by well-established methods. The antioxidant activity was determined by free radical scavenging (2,2-diphenyl-1-picrylhydrazyl, DPPH) method. The antimicrobial activity was evaluated by agar disc diffusion method and cytotoxic activity was determined through brine shrimp lethality assay. Results: The phytochemical tests showed that alkaloids, flavonoids, saponins, steroide, triterpenoids and tannins are present in all leave crude extracts except chloroform crude extract do not contain tannins. The antioxidant results of crude extracts were found to be in the order of hydro alcoholic > chloroform> ethyl acetate >hexane. All leave crude extracts showed moderate antibacterial against gram positive and gram negative food borne pathogen bacteria. The cytotoxicity results revealed that hexane and chloroform extracts have killed all the shrimp larvae at the concentration of 500 μg/mL. Conclusion: More in-vivo and in-vitro studies along with detailed phytochemical investigations are needed in order to potentially use this plant in the prevention and therapies of some oxidative damage related diseases.

Objective To analyze three essential oils isolated from three different brands' clove samples collected from Gulf region and tested their antimicrobial activities. Methods The essential oils were isolated from powder clove samples by water distillation method and analyzed and identified by gas chromatography-mass spectrometry. Antimicrobial activities of the three isolated essential oils were calculated on the diameter inhibition zone by disc diffusion method against three bacterial strains with amoxicillin standard. Results Twenty-eight, twenty-two and twenty-six chemical ingredients with high percentage were characterized based on gas chromatography retention time from clove essential oils collected from Saudi Arabia, United Arab Emirate and Jordan. The highest antimicrobial activity was obtained from Saudi Arab against Escherichia coli, Pseudomonus aeruginosa and Staphylococcus aureus and the lowest was from Jordan and the order of antimicrobial activity was Saudi Arabia>United Arab Emirate>Jordan. Conclusions All three essential oils from Gulf region are containing very portent chemical ingredients and it could be used as medicine or antibiotics for different aliments.

Juniperus excelas is an important flowering medicinal plant belonging to the Cupressaceae family. Essential oil was obtained from fresh fruit of J. excelas by hydro-distillation in a Clevenger apparatus and analysed by gas chromatography–mass spectrometry (GC–MS). The chemical constituents of the essential oil were identified by their mass spectra, retention time and retention indices. The yield was 0.27%. We identified 48 chemical compounds accounting for 89.74% of the composition. The major chemical components were α-terpinene (23.85%), limonene (23.42%), fenchene (6.57%), camphene (6%), δ-3-carene (4.17%), 4-terpineol (2.93%), germacrene B (2.21%), myrcene (1.96%), α-pinene (1.77%), β-pinene (1.53%) and abietatriene (1.13%). The antimicrobial activity of the essential oil of J. excelas was determined against one Gram-positive and two Gram-negative foodborne pathogenic bacteria, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. No activity was detected.

Azadirachta indica (neem) belonging to Meliaceae family is very important medicinal plant which is traditionally used to treat different diseases. The objective of this study was to evaluate in vitro antioxidant activity and characterize the chemical constituents in different crude extracts of the leaves of Azadirachta indica (neem) by using modern sensitive gas chromatography–mass spectrometry (GC–MS). The evaluation of antioxidant activity of different crude extracts was determined by DPPH (2,2-diphenyl-1-picrylhydrazyl) method. GC–MS analyses showed that majority of these identified compounds in various crude extracts contain normal hydrocarbons, phenolic compounds, terpeniods, alkaloids and glycosides. The high percentage of compounds that were identified in the crude extracts are chemically and biologically important. The evaluation of antioxidant capacity of different crude extracts was in the order of chloroform > butanol > ethyl acetate extract > hexane extract > methanol extract. The important chemical constituents were present in the leaf crude extracts of neem that can be endorsed to cultivation on a domestic plantation. The appropriate crude extracts for selective bioactive organic compounds can be chosen on the basis of GC–MS analysis. Therefore the identified good number of chemical compounds from various extracts of neem might have some ecological benefit for different aliments. Result from this study suggested that the chloroform crude extracts of neem could be used as a natural antioxidant.

Datura metel is considered as medicinal plants worldwide. Locally it is used as a traditional medicine due to its medicinal values. The objective of this present work is to identify the chemical ingredients and evaluation of total phenolics contents of different crude extracts from the locally grown D. metel . In vitro evaluation of total phenolics contents of different crude extracts was measured by established Folin–Ciocalteu reagents method. The identification of chemical ingredients was carried out in various crude extracts of D. metel by using sensitive gas chromatography–mass spectrometry (GC–MS). The results showed from different chromatogram that high percentage ingredients are high molecular weight ingredients such as polyphenolics and their derivatives, flavonoids, triterpeniods, hydrocarbons etc. The identified high percentage chemical ingredients present in the crude extracts are biologically active. The phenolic contents of crude extracts as gallic acid equivalents were found to be highest in chloroform followed by the order methanol > butanol > ethyl acetate > hexane extract. The identification of good number of chemical ingredients by spectrometry method in various crude extracts of D. metel fruits might have some ecological significance. In conclusion, chloroform crude extract contains highest phenolics content could be used as antibiotics.

Tecurium is a plant which belongs to the family Lamiaceae (Labiataea). This study was conducted in order to investigate the phytochemical composition of the leaves of Tuecrium mascatenses grown in Oman. The volume of the isolated oil was 1.2 m10.5 % w/w. Thirty two compounds were detected. The main constituents were limonene (17.2 %), linalool (12.4 %), α-pinene (10.1 %), β-eudesmol (10.1 %), unknown (7.6 %), linalyl acetate (4.3 %) bergamotene (4.3 %), β-pinene(3.5 %) and β-selinene (2.5 %).

Objective: The aim of this present study was to isolate and analyze the chemical composition of essential oils from two different imported brands of Syzigium caryophyllatum (clove) samples using gas chromatography-mass spectrometry (GC-MS). Methods: The two essential oils were isolated by hydrodistillation from two different brands of Syzigium caryophyllatum (clove) such as Guzal and Shahi clove samples using Clevenger type apparatus. Results: Eleven chemical components were identified in the essential oil isolated from Guzal clove imported from Indonesia. The isolated components representing 99.03% of the Guzal clove oil were identified as eugenol (51.51%), caryophyllene (36.20%), 毩- caryophyllene (4.26%), acetyleugenol (2.64%), carvacrol (2.42%), 毩-cubebene (0.77%) and thymol (0.42%) were the major components with some other minor components isolated from the same. About twenty two components representing 99.73% were identified within the essential oil isolated from the Shahi brand clove which was imported from India with the main components being eugenol (46.53%), caryophyllene (43.03%), 毩-caryophyllene (4.61%), aceteugenol (2.54%), copaene (0.80%), 毩-farnesene (0.72%), germacrene (0.43%) and 毮-cadinene (0.27%). Conclusions: Both the isolated essential oils were found to be rich in eugenol and caryophyllene. The clove essential oil from Guzal and Shahi was found to be comparable in terms of its eugenol and caryophyllene contents. According to the above findings, it is suggested that both brands of clove are of similar quality.

To prepare various crude extracts using different polarities of solvent and to quantitatively evaluate their total phenol, flavonoids contents and phytochemical screening of Thymus vulgaris collected from Al Jabal Al Akhdar, Nizwa, Sultanate of Oman.The leave sample was extracted with methanol and evaporated. Then it was defatted with water and extracted with different polarities organic solvents with increasing polarities. The prepare hexane, chloroform, ethyl acetate, butanol and methanol crude extracts were used for their evaluation of total phenol, flavonoids contents and phytochemical screening study. The established conventional methods were used for quantitative determination of total phenol, flavonoids contents and phytochemical screening.Phytochemical screening for various crude extracts were tested and shown positive result for flavonoids, saponins and steroids compounds. The result for total phenol content was the highest in butanol and the lowest in methanol crude extract whereas the total flavonoids contents was the highest in methanol and the lowest hexane crude extract.The crude extracts from locally grown Thymus vulgaris showed high concentration of flavonoids and it could be used as antibiotics for different curable and uncurable diseases.

To isolate and analyse the chemical composition in the essential oils and free radical scavenging activity of different crude extracts from the fresh and dry leaves of vegetable plants of Lactuca sativa L. (L. sativa).The essential oils and volatile chemical constituents were isolated from the fresh and dry leaves of L. sativa (lettuce) grown in Sultanate of Oman by hydro distillation method. The antioxidant activity of the crude extracts was carried out by well established free radical scavenging activity (DPPH) method.About 20 chemical compounds of different concentration representing 83.07% and 79.88% respectively were isolated and identified by gas chromatography-mass spectroscopy in the essential oils isolated from the fresh and dry leaves as α-pinene (5.11% and 4.05%), γ-cymene (2.07% and 1.92%), thymol (11.55% and 10.73%), durenol (52.00% and 49.79%), α-terpinene (1.66% and 1.34%), thymol acetate (0.99% and 0.67%), caryophyllene (2.11% and 1.98%), spathulenol (3.09% and 2.98%), camphene (4.11% and 3.65%), limonene (1.28% and 1.11%) representing these major chemical compounds. However, some other minor chemical constituents were also isolated and identified from the essential oil of lettuce including β-pinene, α-terpinolene, linalool, 4-terpineol, α-terpineol, o-methylthymol, L-alloaromadendrene and viridiflorene.The chemical constituents in the essential oils from the locally grown lettuce were identified in the following classes or groups of chemical compounds such as monoterpenes, sesquiterpenes volatile organic compounds and their oxygenated hydrocarbons. Therefore, the essential oils and the crude extracts from Omani vegetable species of lettuce are active candidates which would be used as antioxidant, antifungal or antimicrobial agents in new drugs preparation for therapy of infectious diseases.

Objective: To isolate and analyze the chemical composition in different crude extracts of from the leaves of locally grown of Thymus vulgaris L (T. vulgaris) by gas chromatographymass spectrometry (GC-MS). Methods: The shade dried leaves powder was extracted with methanol by using Soxhlet extractor. Methanol crude extracts of T. vulgaris and the derived fractions of hexane, chloroform, ethyl acetate and butanol were obtained. Results: Qualitative analyses of various organic crude extracts of T. vulgaris by using GC-MS showed that there were different types of high and low molecular weight compounds. Most of the isolated and identified compounds by GC-MS in the crude extracts are basically biologically important. Further, the T. vulgaris leaf possessed certain characteristics that can be ascribed to cultivation on a domestic plantation. The crude extracts were prepared from the powder leaves of T. vulgaris for respective compounds can be chosen on the basis of above GC-MS analysis. Conclusions: All the major compounds were identified and characterized by spectroscopic method in different organic crude extracts of T. vulgaris are biologically active molecules. Thus the identification of a good number of compounds in various crude extracts of T. vulgaris might have some ecological role.

The availability of a sensitive analytical assay for the simultaneous quantitation of pargyline (PARG) and four of its major metabolites have made possible a detailed study on the metabolism of the drug in rat liver microsomes with emphasis put on comparisons between optional N -dealkylation reactions and N -oxide formation. Pargyline is a lipophilic amine with a low p K a -value of 6.6 and undergoes extensive metabolism. The conversion of the substrate is rapid and comprizes three N -dealkylation and one N -oxidation reactions, yielcling N -benzylpropargylamine (BPA), N -methyl-propargylamine (MPA), N -benzylmethylamine (BMA) and pargyline N -oxide (PNO), respectively. Phenobarbital (PB) pretreatment of the rats causes a pronounced increase in the metabolism with about 90% of the substrate being consumed within the first minute of incubation at 100 μM substrate concentration. At this substrate concentration the most pronounced induction is seen in the formation of BPA and also in its further metabolism, while levels of BMA and MPA remain fairly constant. Pargyline N -oxide is the most abundant metabolite in microsomes from untreated rats and its formation is not increased by PB induction. Moreover, the inhibition of PNO formation by typical cytochrome P-450 inhibitors is marginal, while that of BPA, BMA and MPA formation is not. N -Debenzylation, yielcling MPA, is the least important of the N -dealkylation reactions and the effect of PB induction on this reaction becomes noticeable only at high substrate concentrations. The studies suggest that various cytochrome P-450 enzymes are involved in the N -dealkylation reactions of PARG while N -oxidation appears to occur mainly by a cytochrome P-450-independent pathway. As propiolaldehyde, a potential hepatotoxin, is formed concomitant to BMA, and as PNO, under certain conditions, can decompose to acrolein, another well-known hepatotoxin, both these quantitatively important metabolic routes have to be considered in evaluating the toxicity of pargyline.

Pargyline (I) and four of its major amine metabolites, N-benzylpropargylamine (II), N-methylpropargylamine (IV), N-benzylmethylamine (VI) and pargyline N-oxide (VIII), were determined by g.l.c. after reaction with isobutyl chloroformate in a two-phase system. Pargyline and metabolite IV which form the same derivative, were separated quantitatively by liquid-liquid distribution before derivatization with isobutyl chloroformate. Also, metabolites VI and VIII form identical derivatives, and as they could not be easily separated, VIII was reduced to I before derivatization. The analytical method was applied in studies of the metabolism of pargyline in microsomes from phenobarbitone pretreated rats. The metabolism was rapid, leading mainly to the formation of II, IV, VI and VIII. 92% of the substrate was consumed during the first min of incubation at an initial substrate concentration of 100 μM (32 nmol mg−1 protein), and II, IV, VI and VIII accounted for 83% of formed metabolites. The metabolite II was further metabolized while the levels of IV, VI and VIII remained constant after 5 min. It was possible to determine 0.5 μM of pargyline, II and VI in microsomal incubations, with an r.s.d. of

1. The hydrogen peroxide-supported oxidation of pargyline in rat-liver microsomes was investigated and compared to that promoted by cytochrome P-450 in the presence of an NADPH-generating system.2. The metabolic conversions promoted by hydrogen peroxide and cytochrome P-450 comprised N-demethylation, N-depropargylation, N-debenzylation and N-oxidation.3. For the hydrogen peroxide-cytochrome P-450-promoted oxidation, cyanide, but not carbon monoxide, was an effective inhibitor of all the reactions. Similarly, 2,4-dichloro-6-phenyl phenoxyethylamine (DPEA) inhibited all reactions, particularly N-demethylation and N-oxidation more extensively than the NADPH-dependent microsomal oxidation.4. Using microsomes from rats pretreated with phenobarbital caused no increase in the metabolites above the levels seen with microsomes from untreated animals.5. Various other peroxidase systems which were investigated were essentially unable to promote oxidation of pargyline.

Organic extracts from five medicinal plants collected in Oman were assayed for in vitro cytotoxic property. Dried samples from latex, leaves, roots and stem bark of these species were macerated in ethanol to give crude extracts which were Kupchan's partitioned into hexane, chloroform and ethyl acetate fractions. Six different concentrations of each fraction were subjected to brine shrimp test to determine their lethality values. Percent mortalities from each fraction were then converted to LC50 values by Finney probit analysis. Chloroform and ethyl acetate extracts from Calotropis procera latex and aerial part of Rhazya stricta were the most active. LC50 values for C. procera latex were 3.0 and 8.2μg/ml, respectively, while that of R. stricta were 18.1 and 13.9μg/ml, respectively. C. procera and R. stricta growing in Oman are good sources of cytotoxic compounds.