Thymus Schimperi Research Articles

Acute oral toxicity study of <i>Thymus serrulatus</i> and <i>Thymus schimperi</i> from Ethiopia

Thymus serrulatus and Thymus schimperi both endemic to Ethiopia are used by the public as tea and food additives. They are claimed to have some sort of toxicity. However, no toxicity test has been conducted to date. So the present study aimed to test the acute oral toxicities of their Essential Oils (EOs). T. serrulatus was collected from Ofla (Ofl), Alamata (Ala), and Yilmana Densa (Yil) and T. schimperi from Tarmaber (Tar), Butajira (Buta), and Bale (Bal). The control group (Group I) mice were administered with calculated amounts of 0.1% Tween-80 in normal saline. Experimental group (Groups II to VI), on the other hand, were delivered with 2000 μL/Kg body weight of Ofl, Ala, Yil, Tar, Buta and Bal EOs respectively. Treated and control mice were observed, and changes were recorded for 14 days. On the 14th day, after mice were humanely killed by heart puncture method, their organs were weighed, organ to body weight ratios were calculated and packed cell volumes (PCVs) were determined. Growth rate decrease was observed in mice treated with Yil and Buta EOs (carvacrol chemotypes) than in those treated with the thymol chemotypes (Ofl, Ala, Tar, and Bal). The organ to body weight ratios of the control group were either significantly higher than or comparable to that of the treatment groups implying that the EOs had no any inflammatory effects on the organs. The % PCVs of mice treated with the EOs were either significantly higher than or comparable to the control mice. The median lethal dose (LD50) of each EO was between 2000 μL/kg to 5000 μL/kg body weight. The LD50 values of the dry weights of thyme were calculated based on their EO yields that were approximated to be around 278g /kg bw (Bal), 313g /kg bw (Yil, Tar, and Buta) and 500g /kg bw (Ofl and Ala). Since the aerial parts, not the EOs, of thyme are used in the form of tea and food additives (not their EOs), this value is so high that these plants are not toxic. However, cautions should be taken for vulnerable groups.Key words: Acute Toxicity, Thymus serrulatus, Thymus schimperi, Essential oils

Flavone polyphenols dominate in Thymus schimperi Ronniger : LC–ESI–MS/MS characterization and study of anti-proliferative effects of plant extract on AGS and HepG2 cancer cells

Thymus schimperi is a highly localized and a rare plant endemic to Ethiopia. An optimized and validated high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) method was applied to characterize 23 polyphenolic compounds found in ethyl acetate extracts of the plant. From those, flavones dominated and luteolin was the major component contributing 21.83% of the total composition (or 46.05±0.59g/kg of fresh sample weight). Validation data showed a determination coefficient (R2)≥0.997. Limits of detection (LOD) and quantification (LOQ) were 0.03-0.97 and 0.11-3.23mg/L, while recovery values spiked at 5 and 50mg/L were between 70.89-115.39 and 67.65-120.19%, respectively. Except for caffeic acid and epicatechin gallate, the relative standard deviations (%RSDs) were far below 15%, showing acceptable precision values. The plant extracts inhibited cell proliferation and induced cell death in human gastric adenocarcinoma (AGS) and liver hepatocellular carcinoma (HepG2) cancer cells. This is the first report of polyphenolic components from T. schimperi being characterized using HPLC-ESI-MS/MS. Being components of many edible vegetables, fruits, and spices, the identified polyphenols suggest that T. schimperi could be a potential food with promising health benefits.

An Ethno Botanical Review on Medicinal Plants Used for the Management of Hypertension

Hypertension has become one of the most principal growing health problems in developing countries, and is an important cause of cardiovascular death in the world. It is also called the silent killer as it usually shows no direct symptoms and many people die of the disease without understanding its. Despite their availability and effectiveness, the conventional drugs used for the treatment of hypertension have caused adverse side effects and increased the risks of developing new diseases. Herbal medicines, therefore, are gaining great demand and more importance in the treatment of hypertension because of their wide biological and medicinal activities, higher safety margins and lesser cost. Accordingly this review article mainly focuses on medicinal plants used for the management of hypertension in Ethiopia and provides a list of sixty six anti-hypertensive plants obtained from various sources. Furthermore, the review briefly describes the photochemistry and pharmacological properties of Moringa stenopetala, Thymus serrulatus, Thymus schimperi, Syzygium guineense and Calpurnea aurea. The purpose of this review is to create baseline data for future pharmacological and phytochemical investigations involving traditional medicinal plants used for treating hypertension and to preserve the traditional knowledge.

Evaluation of Diuretic and Antihypertensive Activity of Leaf Extracts of <em>Thymus Schimperi</em> in Rats

The present study was performed to evaluate diuretic activity of aqueous and essential oil extract and antihypertensive activity of the aqueous extract of Thymus Schimperi leaves against salt-sucrose induced hypertension in rats. Aqueous extract of T. Schimperi leaves at the doses of 250, 500, 750 and 1000 mg/kg and the essential oil at 1.0 and 1.5 mL/kg were administered orally with normal saline to male wistar rats (n = 6). Normal saline and hydrochlorothiazide were used as negative and positive control, respectively. Urine volume and its electrolyte contents (Na+, K+ and Cl-) were measured to study diuretic activity of T. Schimperi leaves. On the other hand, for antihypertensive study, rats were randomly divided into control and treatment groups (n = 6). Treatment groups were given daily aqueous extracts (250 and 500 mg/kg) orally with 2% NaCl and 10% sucrose solution. Whereas, positive, negative and normal control received captopril (20 mg/kg/day with 2% NaCl and 10% sucrose solution), only 2% NaCl and 10% sucrose solution ad libitum and water ad libitum for 6 weeks, respectively. The blood pressure was measured every week using tail cuff blood pressure analyzer and after 6 weeks the blood was sampled to evaluate effect on serum lipid profile (TC, TG and BG) and liver function indicator enzymes (ALT & ALP) using clinical chemistry analyzer. The oral administration of aqueous extract of T. Schimperi leaves (500 mg/Kg/day) for six weeks produced significant (p<0.05) prevention in systolic blood pressure increment. The oral administration of aqueous extract of T. Schimperi (250, 500, 750 and 1000 mg/kg) showed positive diuretic activity at 5 h. The aqueous extract of T. Schimperi (750 and 10000 mg/kg, orally) significantly increased Na+, K+ and Cl- excretion in 5 h and additionally essential oil of T. Schimperi (1 and1.5 mL/kg) showed significant kaliuretic effect. The results of the present study revealed the antihypertensive and diuretic activity of aqueous extract of T. Schimperi leaves. These effects might be attributed to the presence of the potassium or phenolic components of the thymus leaves.

&lt;i&gt;Thymus&lt;/i&gt; species in Ethiopia: Distribution, medicinal value, economic benefit, current status and threatening factors

The genus Thymus is one of the genera in the family Lamiaceae . In Ethiopia, it is represented by two endemic species namely Thymus serrulatus and Thymus schimperi . The aims of this study were to identify the types of species from six geographically distant localities in Ethiopia, assess the ethnobotanical and socioeconomic information of these species in these localities and gather information about the current status and threatening factors of these species in the six localities. The plant specimens from these localities were authenticated by experts in the National Herbarium of Addis Ababa University as Thymus serrulatus and Thymus schimperi . The plants were rated by local informants as treatments for ailments like blood pressure (30.7%), general pain syndrome (10%), influenza (10%), abdominal pain (10%), ascariasis (2.9%), and intestinal parasites (2.9%). The informants rated the economic value of these plants as animal forage (71.5%), bee forage (71.5%), condiments (68%), and washing and fumigation (46%). According to the informants, the status of Thymus species is declining from time to time due to overgrazing (80.7%), agricultural expansion (64.2%), overharvesting (48.57%), uprooting during harvesting (14.2%), and lack of recognition (13.6%) Keywords: Ethiopia, Thymus schimperi , Thymus serrulatus , threatening factors

Assessment of Hematological, Biochemical and Histopathological Effects of Acute and Sub-chronic Administration of the Aqueous Leaves Extract of Thymus schimperi in Rats

Background: Thymus species are widely used herbal medicinal plants for various ailments throughout the developing world Thymus schimperi. T. schimperi is one of the species that is used as spices and traditional medicine for various ailments in Ethiopia. Objective: This study was designed to assess the acute and subchronic toxic effects of the aqueous leaves extract of T. schimperi on blood parameters, histopathology and biochemicals of liver and kidney of rats. Methods: The aqueous leaves extract of T. schimperi was tested for toxicity study. Wistar rats were randomly divided into control and treatment groups. The doses for acute toxicity study were single doses of 300, 2000, 5000 and 10,000 mg/kg body weight of animal. Whereas, subchronic toxicity study daily administration of doses of 200 and 600 mg/kg of the aqueous extract were used for 90 consecutive days. Biomarkers and hematological parameters, microscopic examination of liver and kidney tissue and body weight of rats were evaluated following the test period besides recording the signs of toxicity. Results: Acute toxicity study did not reveal any signs of toxicity; hence the LD50 was higher than 10,000 mg/kg. There was no significant change (p>0.05) in general body weight and most of evaluated hematological and biochemical parameters after 90 days of sub-chronic treatment. The kidneys and liver of treatment group appear normal in their texture, shape, size or color compared to the control in gross and histopathological examination. However, the light microscopic examination reveals that there was localized mononuclear lymphocytic infiltration and mild blood congestion within the hepatic portal and central veins in liver at higher dose (600 mg/kg). Conclusion: The findings revealed that the aqueous leaves extract of T. schimperi relatively nontoxic in rats.

Antimicrobial potential of the Ethiopian Thymus schimperi essential oil in comparison with others against certain fungal and bacterial species.

BackgroundTo evaluate the in vitro activities of Ethiopian Thymus schimperi with other three hydro distilled essential oils against Dermatophytes (Tricophyton spp. and Microsporum spp.) and other pathogenic micro organisms.MethodsThe studies were carried out using Agar disk diffusion method for screening the most effective essential oils and Agar dilution to determine Minimum Inhibitory Concentration (MIC) of the essential oils.ResultsEssential oils of T. schimperi and Cinnamomum zeylanicum were highly active against tested organisms. The MIC were in the range of 0.08 μl/ml to 0.31 μl/ml for T. schimperi, 0.31 μl/ml to 0.16 μl/ml for C. zeylanicum, 2.5 μl/ml to1.25 μl/ml for Citrus limon and 5 μl/ml to 2.5 μl/ml for Eucalyptus camaldulensis against Tricophyton spp. and Microsporum spp. T. schimperi and C. zeylanicum oils also showed antimicrobial effect against Candida albicans, Aspegilus niger, Rhodotorula rubra, Escherichia coli, Shigella spp., Bacillus spp. and Streptococci.ConclusionsThe Ethiopian T. schimperi oil had pronounced antifungal and antibacterial activities against all the tested microbes. Therefore, it is required further investigation in order to identify the active compounds and their clinical applications for treatment of tested organisms.

English

Thymus schimperi Ronniger is a wild endemic herb to Ethiopia, and is traditionally used as food flavoring, preservative as well as medicinal ingredient. This paper reports the total phenolic and flavonoid contents, antioxidant capacity and α-amylase inhibition activity of various solvent extracts of the dried leaves. The acetone extracts contained the highest total phenolic content (122.0±11.6 mg GAE/g). Total flavonoid content was the highest in methanol extract (45.1±2.9 mg QRE/g). The aqueous methanol extract showed the highest 2,2-diphenylpicrylhydrazyl (DPPH) radical scavenging ability (IC50 =11.0±1.0 µg/ml), iron reducing power (60.1±1.0 mg AAE/g), and total antioxidant capacity (1.1±0.1 mg BHTE/g). The water extract exhibited the highest iron chelating activity (IC50 = 65.4±1.1 µg/ml) while the methanol extract exhibited the highest percentage of α-amylase inhibition activity (IC50 = 335. 6±90.4 µg/ml). Except for iron chelating activity, all antioxidant activities were positively correlated with total phenolic and flavonoid contents. The study revealed that antioxidant and α-amylase inhibitory activities of the crude extract were variable when extracted by different solvents indicating a high potential to be used as natural antioxidants in food preservation as well as for preventing oxidative stress mediated human disorders. Key words: Antioxidant activity, α-amylase, BHT, phenolic, Thymus schimperi Ronniger, thyme.

English

Thymus schimperi Ronninger (Lamiaceae) locally known as Tosign, is a multipurpose endemic plant that has been used for various remedies as constituents of traditional medicine in Ethiopia. The objective of this study is to evaluate antibacterial activity of water, ethanol, methanol and chloroform extracts of T. schimperi using agar well diffusion and broth dilution methods against human pathogenic bacterial strains. Amongst the solvents used for this study, chloroform extract possess the highest potential of inhibiting the growth of all bacteria under study at concentrations of 50 mg/ml while ethanol and methanol extract fail to inhibit three gram negative bacteria, namely: Escherichia coli (ATCC 25922), Klebsiella pneumoniae (clinical isolate) and Shigella flexneri (ATCC 12022) at the same concentration. Water extract did not show any zone of inhibition on all test bacteria as compared to other solvents. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were performed only for chloroform extracts that showed inhibition against all test organisms. This study revealed that, the highest inhibition with chloroform extract was exhibited against Methicillin-Resistant S. aureus (MRSA) with mean zones of inhibition of 22.6+2.5 mm whilst the minimum inhibition zone was observed for E. coli with mean zone of inhibition of 14.6+2.3 mm. The MIC value ranged from 6.25 to 12.5 mg/ml while the MBC value ranged from 6.25 mm to 25 mg/ml. This study clearly indicates that the crude chloroform extract of T. schimperi showed highest antibacterial activity against all studied bacterial strains as compared to the three solvents used in this study. Thus, further study and characterization of active compounds of chloroform extract of this plant is required. Key words: Antibacterial activity, MBC, MIC, Thymus schimperi, Tosign, zone of inhibition.

Growth Inhibition of Grain Spoilage Fungi by Selected Herbs and Spices Essential Oils

Natural plant extracts are promising alternatives for chemical food additives and synthetic pesticides. In this study, essential oils of selected herbs and spices were tested for their antimicrobial activities against Aspergillus flavus and Aspergillus niger, two of the most common food spoilage microorganisms. Agar disk diffusion assay was used for screening of the most effective essential oils, agar dilution assay was used to determine Minimum Inhibitory Concentration (MIC) of the essential oils and broth dilution assay was employed to the spore germination inhibition assay. Tests were also conducted to examine the effects of the essential oils for sorghum kernel protection against the tested fungi, and the optimal protective dosages on the sorghum grains were also determined. From the preliminary tests, essential oils of Cinnamomum zeylanicum (Cinnamon) and Thymus schimperi (thymus) were found to be the most effective. However piper nigrum (black pepper) had no effect on the test organisms. In MIC, spore germination inhibition and grain protection assay, cinnamon essential oil was found to be superior where its MIC on the isolates was found to be 0.0156% and its optimum protective dosage on the sorghum grain was 5%. It inhibited spore germination at a concentration of 3iL/mL. The effect of thymus oil was also very much comparable to these results (no significant difference at P>0.05). Finally, it was concluded that essential oil extracts of cinnamon and thymus can be a useful source of antifungal agents for protection of grain spoilage by fungi.

Antioxidant Activity and Preservative Effect of Thyme (Thymus schimperi R.)

Aims: To evaluate antioxidant activity and preservative effects of Thyme (Thymus Schimp eri R.)on soybean oil, butter and meat. Study design:Complex factorialdesign.

Opportunities for Bioprospecting Genetic Resources in Ethiopia

Bioprospecting involves the search of biodiversity for valuable genetic or biochemical resources/information or both for purely scientific or commercial purposes. Objective:The aim of the study was to identify potential genetic resources for bioprospecting and assess opportunities for future bioprospecting in Ethiopia. Methods: Ethno-biological data and sector-based data were collected from the local and scientific community respectively by using preference ranking, direct matrix ranking, paired comparison, semi-structured interviews and field observations. Results: Local people obtained medicinal plant species more from wild vegetation (52.5%) than homegardens (40%) and market (7.5%). Stephania abyssinica, Ensete ventricosum and Urtica simensis were ranked as priority species among the potential genetic resources which were identified by the key informants. Arundinaria alpine (94), Hypericumre volutum (85) and Ensete ventricosum (102) were ranked first as multi-purpose genetic resources from each study area. Yushania alpine, Urtica simensis, Thymus schimperi and some mushrooms were identified with bioprospecting potential for commercialization by the key informants. Conclusion: The results in the present study indicate that the studied woredas (districts) in Ethiopia possess rich medicinal plant species, and the local people have rich ethno-biological knowledge. The results can be used as opportunities for bioprospecting.

Identification and characterisation of human pathogenic filamentous fungi and susceptibility to Thymus schimperi essential oil

Twenty-eight clinical fungal isolates were characterised by morphological (macro- and micro-features and growth response at 25, 30 and 37°C) and molecular (nuclear rDNA-internal transcriber spacer, calmodulin, cytochrome c oxidase 1 and the largest subunit of RNA polymerase II) analyses. The clinical fungal isolates were ascribed to the following taxa: Penicillium chrysogenum, Verticillium sp., Aspergillus tubingensis, Aspergillus minutus, Beauveria bassiana and Microsporum gypseum. In addition, in vitro susceptibility testing of the isolates to conventional antifungal agents and to two chemically well-defined chemotypes of Thymus schimperi essential oil was performed. Most of the isolates were resistant to amphotericin B (except A. minutus), and itraconazole, while terbinafine was quite active on these fungi. T. schimperi essential oil showed antifungal activity against all of the tested fungal isolates with minimal inhibitory concentration values similar or lower than those of terbinafine. Transmission electron microscopy analyses revealed that fungal growth inhibition by essential oil was accompanied by marked morphological and cytological changes.

Potential genotoxicity of plant extracts used in Ethiopian traditional medicine

Aim of the study Although traditional herbal medicines are widely used in Ethiopia, no information is available on their potential genotoxicity. In the present study, hydroalcoholic extracts of Glinus lotoides, Plumbago zeylanica, Rumex steudelii and Thymus schimperi were evaluated for their DNA damaging effects using the comet assay. Material and methods Mouse lymphoma L5178Y cells were exposed to different concentrations of the extracts for 3 h with and without metabolic activation (S9-mix) using 4-nitroquinoline-N-oxide and benzo(a)pyrene as positive controls, and vehicles as negative controls. Results In the absence of S9, all extracts were found to induce significant DNA damage without affecting the cell viability. T. schimperi and R. steudelii were the most potent DNA-damaging extracts, and G. lotoides and P. zeylanica the least potent. The addition of S9 had different effects on the DNA damage induced by the extracts: it lowered the DNA damaging effect of P. zeylanica, did not affect the DNA damaging effect of T. schimperi, and increased the DNA damaging effects of R. steudelii and G. lotoides. Conclusion The findings of the present study suggest that all extracts evaluated have a genotoxic potential in vitro which needs to be substantiated by further studies.

Volatile oil constituents of twoThymus species from Ethiopia

The volatile oils from Thymus schimperi Ronninger and T. serrulatus Hochst. ex Benth. (Lamiaceae) grown in Ethiopia, have been examined by means of GC and GC–MS. The main constituents of the essential oils of T. schimperi from four regions — Bale, Gonder, Shewa, and Wello — were identified as p-cymene (9–23%), γ-terpinene (8–17%), thymol (6–38%) and carvacrol (5–63%). The oil from T. serrulatus was found to contain p-cymene (13%), γ-terpinene (13%) and thymol (49%) as major components. Both species belong to the thymol–carvacrol chemotypes. Copyright © 2000 John Wiley & Sons, Ltd.

Constituents of the essential oil of &lt;i&gt;Thymus schimperi.&lt;/i&gt;

Constituents of the essential oil of &lt;i&gt;Thymus schimperi.&lt;/i&gt;