Effect of Aqueous Extract of Boscia senegalensis on Hyperglycemia, Hyperlipidemia and Oxidative Stress Induced in Rats

Boscia aqueous extract. senegalensis on hyperglycemia, hyperlipidemia and oxidative stress induced in rats. The aqueous extract was prepared from B. senegalensis seed powders under the extraction conditions: time (10 min), temperature (55˚C) and the ratio of mass of flour/volume of water (3/10 g/mL). Male wistar rats aged 6 to 8 weeks were acclimated and divided into 8 groups of 5 rats each: two normal control groups which received a normal standard diet (3810 kcal/kg), and six test groups which were subjected to a hyperlipidemic diet (5310 Kcal/kg). All groups of animals were fed in this manner for 8 weeks to induce hyperglycemia, hyperlipidemia and oxidative stress. After induction the animals were treated either with distilled water for the normal and negative control groups or with atorvastatin for the positive control group or with the extract of B. senegalensis. (125, 250 and 500 mg/kg) for the test groups. Fasting blood glucose was taken every 7 days during induction. After sacrifice, biochemical and oxidative stress parameters were measured. The aqueous extract of B. senegalensis significantly decreased (p B. senegalensis at a dose of 500 mg/kg has the capacity to reduce blood sugar, improve the quality of the lipid profile and reduce oxidative stress. Thus, the results reveal that the aqueous extract of B. senegalensis has powerful hypoglycemic, hypolipidemic and antioxidant properties.

Physicochemical Properties of the Seed Oil of Khaya senegalensis

The physicochemical characteristics of Khaya senegalensis seed oil were investigated. Iodine value, saponification value, percentage free fatty acid (FFA), acid value, and peroxide value were the chemical parameters examined in the oil analysis, while specific gravity and refractive index were examined as physical parameters. The results showed that the acid value was 1.18 ± 0.01, the saponification value was 191.76 ± 0.01 mgKOH/gm, and the iodine value was 102.79 ± 0.01. It contained 0.59 ± 0.01 percent free fatty acid. The value of peroxide was 6.83 ± 0.01 meq/kg. The results showed that the refractive index was 1.462 ± 0.02 and the specific gravity was 0.9194 ± 0.04. The established parameters fell within the worldwide and Nigerian vegetable oil industry standards.

Efficiency of Bio-Fertilizing as One of the Natural Alternatives to Improve the Growth of Khaya senegalensis and Swietenia mahagoni Trees and for Sustainability

A field experiment was carried out at Ismailia Research Station, Ismailia Governorate from 2020-2022 to improve the growth of Khaya senegalensis and Swietenia mahagoni by using a combination of mineral fertilizer (NPK) and biological fertilizer (Azotobacter chroococcum, Bacillus megatherium, and Bacillus circulant) as recommended dose under new sandy soils conditions. Split plot designed with four treatments (Control, (50% Mineral fertilizer (M.) + 50% Biological fertilizer (Bio.)), 100% M. and 100% Bio.) of each species. Vegetative growth, leaf area, tree biomass, stored carbon, basal area, tree volume, and in the soil both of microbial account and mineral content were determined. The experimental results showed no significant differences between studied species among the most studied parameters except for Khaya senegalensis which gave the highest significant difference in root biomass and below-stored carbon than Swietenia mahagoni. Evidently, the highest significant growth parameters were 100% mineral fertilizer followed by (50% M. + 50% Bio.) as compared with control. No significant difference between 100% M. and (50% M. + 50% Bio.) of shoot dry biomass (15.19 and 12.02 kg, respectively) and above-stored carbon (0.28 and 0.22 Mt, respectively). Microbial account and mineral content in soil were improved after cultivation of tree species compared to before planting and control, especially with 50% mineral fertilizer and 50% bio-fertilizer treatment. In conclusion, a treatment containing 50% mineral fertilizer and 50% bio-fertilizer has led to the ideal Khaya senegalensis and Swietenia mahagoni growth in sandy soil for cheaper and sustainable.

Removal of Methyl Violet in Aqueous Solution on Activated Carbon Based on Saba senegalensis Shell Residues

Adsorption on activated carbon is one of the most widely used methods for the removal of dyes. The objective of this study is to valorize the shells of Saba senegalensis from local product in Senegal in the form of activated carbon and to test its effectiveness for the removal of methyl violet. The study was carried out in batch mode for a maximum duration of one hour with 100 mL of solution treated at 600 rpm. The results reveal that the granulometry 500 μm gives the best yield with an adsorption rate of 95%, a mass of adsorbent of 0.2 g gives an adsorption capacity of 20 mg/g, the contact time of one hour with a capacity of 5 mg/g. The study also showed that the adsorption process of methyl violet is described by the pseudo-second order kinetic model with correlation coefficient of 0.99. Two adsorption isotherms were studied, and the results revealed that the Freundlich model better describes the adsorption of methyl violet on Saba senegalensis shell residue-based activated carbon (SSSRAC). The results indicate that SSSRAC could be used as a low-cost alternative for the removal of textile dyes such as methyl violet.

Gastroprotective effect of the aqueous leaf extract of Guiera senegalensis in Albino rats

Objective:To evaluate the effect of aqueous leaf extract of Guiera senegalensis(G.senegalensis)on gastric mucosal damage using different ulcer models.Methods:Considering the above claims,the present study was undertaken to validate the gastroprotective potential of the aqueous leaf extract of this plant against ethanol,water immersion and Aspirin induced ulcer models.Results:The leaf extract(50,100 and 200 mg/kg,p.o.)significantly(P<0.05)decreased the ulcer index in all assays used.Conclusions:The results obtained,provide strong evidence of antiulcer activity of the leaf extract of G.senegalensis and support the traditional uses of the plant for the treatment of ulcer.

Evaluation of the acute and sub acute toxicity of Annona senegalensis root bark extracts

Objective:To investigate the safety profile of Annona senegalensis（A.senegalensis）.Methods: Dried powdered root-bark of A.senegalensis was prepared by Sohxlet extraction using methanolmethylene chloride（1:1） solution and concentrated to obtain the methanol-methylene chloride extract（MME）.MME was fractionated to obtain the n-hexane（HF）,ethylacetate（EF） and methanol（MF） fractions.Acute toxicity(LD50) test was performed with MME,HF,EF and MF in mice by oral route.The sub acute toxicity studies were performed in rats after 14 days of MME administration while haemalological and biochemical parameters were monitored.Results: Medium lethal（LD-（50）） values of 1 296.3 808.1 265 and 2 154 mg/kg were obtained for the MME.MF, HF and EF,respectively.The sub-acute toxicity studies indicated a significant（P【0.05） increase in the body weight of both the treated rats and the control.The haematological tests indicated no change in the packed cell volume values but a significant（P【0.05） increase in the total WBC count at 100 and 400 mg/kg doses.The differential analysis showed a decrease in the nutrophils and a non-significant increase in the lymphocyte counts.The liver transaminase enzymes, alanin transaminase and aspartate transaminase showed no significant increase compared to the control.Histopathological examination of the liver sections also indicted no obvious signs of hepatotoxicity except with the 400 mg/kg dose that showed degeneration and necrosis of the hepatocytes.Conclusions:These results indicated that the root bark extracts of A.Senegalensis are safe at the lower doses tested,and calls for caution in use at higher doses in treatment.

Chemical Profile of the Sulphated Saponins from the Starfish Luidia senegalensis Collected as by-Catch Fauna in Brazilian Coast

The by-catch fauna of the shrimp fishery includes a number of marine invertebrates that are discarded because they do not have commercial value.In order to try to add some value to these materials,we analyzed the chemical composition of the starfish Luidia senegalensis collected in the Brazilian coast as a consequence of the trawling fishery method.In order to access their chemical composition,we used a combination of solid phase extraction(SPE)followed by ultra-high performance liquid chromatography coupled to electrospray ionization ion trap tandem mass spectrometry(UPLC-ESI-IT-MSn).Luidia sene-galensis contains asterosaponins,which are sulphated glycosilated steroids,containing five and six sugar moieties,in addition to polyhydroxysteroids.This study helped us to support the presence of important and potentially bioactive compounds in invertebrates associated to the by-catch fauna of the shrimp fishery,using a fast and efficient method.

Evaluation of the anticonvulsant and muscle relaxant effects of the methanol root bark extracts of Annona senegalensis

Objective:To investigate the potentials of the root bark of Annona（A.） senegalensis in the control of seizure and related hypnotic and motor incoordination effects in mice using experimental models.Methods:The methanol extract（ME） of the root bark of A.senegalensis was studied in mice using pentylenetetrazole（PTZ） induced convulsions,phenobarbitone induced sleeping time and motor coordination test on rota-rod performance.Acute toxicity and lethality（LD50） lest as well as phytochemical analysis were also carried out.Results:The extract（200,400,800 mg/ kg） exhibited a non- dose dependent significant（P【0.05） delay in the onset of both tonic and clonic phases of seizure induced by PTZ（60 mg/kg,s.c.） as well as offered a 100%protection （200 mg/kg） in mice from PTZ induced seizures.The extract significantly（P【0.05） decreased the latency and increased the duration of phenobarbitone induced sleeping time.At 200 mg/kg, the extract exhibited a significant（P【0.05） motor incoordination.The acute toxicity test revealed an oral LD50 of 1 2%mg/kg,while the phytochemical studies showed the presence of alkaloids, resins,glycosides,carbohydrate,reducing sugar,flavonoids,terpenoids,saponins and tannins. Conclusion:The extract of A senegalensis possessed anticonvulsant activity with pronounced hypnotic and muscle relaxant effects.

Anthelmintic activity of Saba senegalensis(A.DC.) Pichon (Apocynaceae) extract against adult worms and eggs of Haemonchus contortus

Objective: To evaluate the anthelmintic property of Saba senegalensis(A.DC) Pichon(Apocynaceae)(S. senegalensis) on Haemonchus contortus that is traditionally used in Burkina Faso for its gastrointestinal parasites treatment.Methods: The lyophilized aqueous decoction of leaves of S. senegalensis at concentrations of 0.10, 1.00, 3.00, 10.00 and 15.00 mg/m L was used on eggs and adult worms of Haemonchus contortus collected from gastrointestinal tract of small ruminant.Results: The LC_(50) on adult worms was 6.79 mg/m L and 3.25 mg/m L for the leaves of S. senegalensis and the levamisole(reference drug), respectively. Inhibition of hatching assay showed a concentration-dependent manner with an inhibition of 93.63% at the concentration of 15.00 mg/m L of S. senegalensis.Conclusions: These results indicate that the aqueous extract of S. senegalensis possesses an anthelmintic property and may justify its use in traditional medicine for the treatment of gastrointestinal parasites.

<i>Saba senegalensis</i>: Key Features and Uses

Native of West Africa, Saba senegalensis belongs to the family of Apocynaceae, and is a wild plant that is mainly exploited in the diet. It grows mainly along riverbanks, in wooded savannah areas in humid areas, in gallery forests and in rocky ravines and hills. Saba senegalensis is a large woody liana with white latex, dark gray bark, can reach more than 40 m high and a trunk that can measure up to 47 cm in diameter. The fruit is a globose shell, 7 to 10 cm long, 6 to 8 cm wide. The leaves are opposite, elliptical, dark green in color, about 8 to 15 cm long and 4 to 6 cm wide. This fruit is characterized by its richness in antioxidant molecules especially vitamin C (480 mg/100 g) and total polyphenols (945.83 mg/100 g). The fruit contents 41.43 until 80% water with a low pH (2.24). In Senegal, the fruit is eaten as it or transformed into puree, nectar, syrup, canned etc. It is a plant that has enormous therapeutic virtues, from the fruit to the roots through the leaves, bark, and latex. Despite its high nutritional potential, its many therapeutic virtues and its economic potential, Saba senegalensis remains under-exploited. Further researches on the nutritional and therapeutic properties deserve to be conducted.

Effect of the Ethanolic Extract of Khaya senegalensis on Some Biochemical Parameters on Rabbit’s in Glucose Overload Condition

The effect of the ethanolic extract Khaya senegalensis on some biochemical parameters was tested in rabbits with normal glucose and glucose overload. Phytochemical screening after three batches of 6 rabbits race (TBD) were treated with the extract in oral doses of respectively 10, 25 and 50 mg/kg body weight for 30 days;three other groups receiving respectively these doses of the extract were placed under a priori temporary overload of glucose;a control group received instead distilled water treatment. Blood glucose, triglycerides and total cholesterol were measured by spectrophotometry and weight gain of the animals was performed at the beginning of the experiment and every 2 weeks during the study period. The phytochemical screening revealed the presence of polyphenolic compounds (majority) of saponins of anthracene derivatives and steroids in the extract. The test results indicate that under the dose of 50 mg/kg body weight (BW) there was a significant decrease (p < 0.05) in blood glucose after 24 hours. The extract had no effect on the lipid profile or body weight of rabbits.

Dendrochronological Potential and Impact of Climate Factors on Radial Growth of Two Species in the Sahelian Zone: <i>Boscia senegalensis</i>(Pers.) Lam. ex Poir and <i>Sclerocarya birrea</i>(A. Rich) Hoscht (Ferlo Nord/Senegal)

The objective of this study is to analyze the dendrochronological potential of two Sahelian species (B. senegalensis and S. birrea) and to evaluate the relationships between their growth rings and the climate. The study was conducted in 2016 in the Ferlo area of Senegal. The biological material consists of wood slices, taken from the trunks of these adult woody species at 0.30 m and 1.30 m from the ground after they have been felled. The technique used to examine the slices consists in identifying their rings, establishing their structures, inter-dating them and studying the relationship between the identified rings and climatic factors. The results showed that the species had thin, clear, highly visible and sharp rings. The limit of growth is marked by a line of parenchyma. Intradatation series carried out on the chronologies made it possible to estimate the ages of the individuals, which vary from 10 to 38 years for B. senegalensis and from 29 to 50 years for S. birrea. Their average growth rates are estimated at 0.906 mm/year and 0.89 mm/year respectively. The chronological sequences are 29 years (1987-2016) for B. senegalensis and 38 years (1964-2012) for S. birrea. The results revealed that there is no significant correlation between the growth chronologies of B. senegalensis and the climatic regressors (temperature and precipitation). In contrast, the ring-climate relationship shows that in S. birrea winter precipitation positively influences ring growth while temperature has no effect on ring growth in this species. This study provides a better understanding of the response of forest ecosystems to possible climate change, particularly in the current context of sustainable forest management.

Intake Nutritional Variabilities of Saba senegalensis Fruits

Saba senegalensis is a popular wild fruit;which is consumed as such or transformed into various products. Despite its economic potential, its nutritional potential is unknown. The objective of this study is to characterize its fruits according to Senegal’s main production areas. The study included five samples from five geographical areas of Senegal. Parameters measured include pH, protein, lipids, ash, moisture, vitamin C, carotenoids, polyphenols, minerals, and sugars. The results showed that for moisture, proteins, lipids, pH and reducing sugars did not differ significantly (p 0.05%) for all accessions. Vitamin C content varies between 32.86 and 198.22 mg·100g-1, carotenoids with a content of between 5.05 and 9.12 mg·100g-1;polyphenol contents are between 1.17 and 2.56 g·100g-1. The nutritional value of Saba fruits appears to be homogeneous in Senegal. A thorough study of the functional molecules seems necessary for a better appreciation of the potential of this fruit.

Development of a Performant Method for Glucocapparin Determination in Boscia senegalensis Lam Ex. Poir.: A Study of the Variability

This study describes a glucocapparin determination method. Based on rapeseed determination of glucosinolate (GSL), the equation of the average straight regression line is Y = 100.42X – 0.03 (R2 = 0.9998). Enzymatic hydrolysis of glucocapparin extracted from leaves and fruits of B. senegalensis, analyzed by SPME-GC-MS confirmed the presence of methylisothiocyanate as the main hydrolysis glucocapparin product. Monitoring glucocapparin contents in B. senegalensis leaves and fruits collected in 4 localities in Senegal showed differences between organs according localities and periods of harvest. Glucocapparin content was very high in dry season particularly in January and the lowest rates were recorded during the rainy period between August and November.

Anti-Obesity Effect of Boscia senegalensis in Rabbits

Introduction: Obesity is defined as excessive and abnormal accumulation of fatty tissue with significant somatic, psychological and social consequences on quality of life. Obesity has long been considered a simple aesthetic problem linked to excessive gluttony. It is however recognized today as a real pathology, so much so that the WHO has declared it as “the first non-infectious epidemic in history and a major problem of the century”. In addition, many studies have been carried out aimed at the production of less fatty foods and, scientifically, at the development of anti-obesity drugs. Thus, the objective of this study is to evaluate the anti-obesity effect of the extract of Boscia senegalensis (Capparaceae) used in Chad to fight against type II diabetes and metabolic syndrome. Methodology: A bromatological study of Boscia senegalensis extract was carried out at the Food Quality Control Centre (CECOQDA) in Ndjamena (Chad), followed by an in vivo study of rabbits carried out at the IRED Biotechnop&#244;le laboratory (Chad). Results: The results obtained from the 100 g bromatological study of the dry extract of Boscia senegalensis are as follows: protein content (20.24% ± 0.007%), fat content (5.92% ± 0.21%), carbohydrate content (35.16% ± 1.05%), fibre content (2.11% ± 0.26%), moisture content (5.7% ± 0.14%) and ash content (2.90% ± 0.03%). No aflatoxin was detected in the dry extract of Boscia senegalensis. A significant decrease (p = 0.04) in body weight was observed in rabbits treated with Boscia senegalensis extract compared to controls. In addition, histological sections of the various organs (liver, spleen, kidneys) of treated rabbits showed no lesions following the incorporation of the extract of Boscia senegalensis. Conclusion: This study showed the anti-obesity effect of Boscia senegalensis. It also made it possible to verify the harmlessness of the product with regard to the results on chronic toxicity.

Aqueous Extract of Erythrina senegalensis Exhibits Dose-Dependent Hepatoprotective Activity on Paracetamol-Induced Liver Damage in Wistar Rats

Erythrina senegalensis is utilized in the treatment of liver diseases in folklore medicine in most of northern Nigeria, but sufficient pharmacological-based and peer-reviewed scientific literature is not available to authenticate its use in the treatment of liver ailments. This research is aimed at assessing the hepatoprotective effects of Erythrina senegalensis against paracetamol-induced (PCM-induced) hepatotoxicity in wistar albino rats. This was evaluated by estimating the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) as compared with the control group. The extract was concentrated and then desired concentrations of extracts were made by dissolving in normal saline. Four different doses of aqueous extracts Erythrina senegalensis (200, 300, 400 and 500 mg/kg) were administered orally for 6 consecutive days after the 72 hrs administration of paracetamol (1500 mg/kg) per body weight. Paracetamol significantly induced oxidative stress in the liver, ultimately leading to increased serum levels of liver enzyme markers like alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase. Administration of the extracts showed significant (p 0.05) and dose-dependent hepatoprotective activity resulting in decrease in the activity of ALT, AST and ALP. These data revealed that Erythrina senegalensis aqueous extracts possess significant hepatoprotective activity against PCM-induced toxicity attributable to its constituent phytochemicals. The mechanism of hepatoprotection seems to be through the modulation of antioxidant enzyme systems.

Micropropagation from Juvenile Material of Annona senegalensis Pers.

Annona senegalensis is a savannah species present in the wild in tropical and sub-tropical African regions. It is used by the local populations for its many economic, pharmacological, nutritional and ecological interests. However, the strong pressure exerted on this species as well as the increasing degradation of the ecosystems, in which it evolves, seriously compromise its sustainability and development. Conventional methods of vegetative propagation are not sufficient to ensure its durable regeneration and the renewal of endemic populations in Senegal. In this context, it was undertaken in vitro propagation, from 30 days old juvenile seedlings. Thus, axillary, cotyledonary and apical nodes were in vitro cultured in Murashige and Skoog (1962) medium (MS), with different concentrations of cytokinins and/or auxins. BAP used alone at 2 mg•L−1 proved to be more beneficial for micropropagation of different types of explants compared to Kinetin used alone or in combination with BAP, especially for axillary and cotyledonary nodes. The BAP-NAA combination allowed to have a better elongation of newly formed shoots. For shoots of apical and cotyledonary nodes origin, a rhizogenic induction of 5 days, with IBA at 25 mg•L−1, resulted in a better rooting rate with, respectively, 75% (for 2.22 roots) and 66.67% (for 4.17 roots). For newly formed shoots of axillary origin, a 24-hour rooting induction with IBA at 50 mg•L−1 gave a rooting rate of 58.33% (for 2.4 roots). After 30 days of acclimatization, the survival rate was 75% for the young plants from the apices and 83.33% for those originating from the cotyledonary and axillary nodes. This protocol can therefore be adopted for the in vitro clonal propagation of A. senegalensis juvenile material.

Analysis of Otolith Shape as a Tool for Discriminating Stocks of Cassava Croaker (Pseudotolithus senegalensis) in Beninese Waters

This study examined the right and left otoliths of 174 individuals of Pseudotolithus senegalensis from the Porto-Novo lagoon, Lake Nokoué and the Atlantic coast. The results show a significant variation in the population according to geographic location. Mixed-effects linear analysis showed no significant variation by site, side or sex (p > 0.05). Analysis of otolith shape using ANOVA showed significant differences for length, width and area (p 0.05). Canonical discriminant analysis revealed significant differences between sites (p < 0.05). Finally, shape analyses showed significant differences between sites (p = 0.0001) and between right and left sides (p = 0.007), but no difference by sex (p = 0.395). The study of otolith morphology is therefore proving to be a valuable tool for differentiating stocks and understanding ecological variations.

Atomic force microscopy correlates antimetastatic potentials of HepG2 cell line with its redox/energy status: effects of curcumin and Khaya senegalensis

OBJECTIVE： The fatality of cancer is mostly dependent on the possibility of occurrence of metastasis. Thus, if the development of metastasis can be prevented through novel therapeutic strategies targeted against this process, then the success of cancer treatment will drastically increase. In this study, therefore, we evaluated the antimetastatic potentials of an extract of Khaya senegalensis and curcumin on the metastatic liver cell line HepG2, and also assessed the anticancer property of the extract. METHODS： Cells were cultured and treated with graded concentrations of test substances for 24, 48, or 72 h with provisions made for negative controls. Treated cells were assessed as follows： nanotechnologically--atomic force microscopy （AFM） was used to determine cell stiffness; biochemically--cell cytotoxicity, glutathione level and adenosine triphosphate status, caspase activation and mitochondrial toxicity were considered; and microbiologically--a carrot disk assay was used to assess the anticancer property of the extract of K. senegalensis. RESULTS： Curcumin and K. senegalensis increased the cell stiffness by 2.6- and 4.0-fold respectively, indicating their antimetastatic effects. Corresponding changes in redox （glutathione level） and energy （adenosine triphosphate） status of the cells were also demonstrated. Further mechanistic studies indicated that curcumin was not mitotoxic in HepG2 cells unlike the K. senegalensis extract. In addition the extract potently inhibited the Agrobacterium tumefaciens-induced genetic transformation based on carrot disk assay. CONCLUSION： Cell elasticity measurement data, using AFM, strongly suggested, for the first time, that both curcumin and the extract of K. senegalensis exhibited antimetastatic properties on HepG2 cells.

Stress-preventing effects of the anaesthetic agents 2-phenoxyethanol, MS-222, clove oil and metomidate in the Senegalese sole Solea senegalensis

Objective: To determine the effectiveness of the anaesthetic agents 2-phenoxyethanol, MS-222, clove oil and metomidate in attenuating acute handling stress in juvenile specimens of Solea senegalensis subjected to two routine stressful events specific to aquaculture and/or fish research. Methods: The stress-preventing effects of four anaesthetic agents (2-phenoxyethanol, 600 mg/L;metomidate, 5 mg/L;clove oil, 30 mg/L and MS-222, 75 mg/L) were evaluated in juvenile specimens of Senegalase sole (Solea senegalensis) subjected to two different types of acute (handling-related) stress: air exposure and net handling (chasing). To assess the stress-preventing effects of the four anaesthetic agents, diverse blood and plasma parameters (haematocrit, haemoglobin, glucose, lactate and cortisol levels) were determined as stress indicators. Fish were treated with the anaesthetic agents before being subjected to the different types of acute stress, and they were sacrificed 30 min, 2 and 24 h later. Control fish were processed in the same way without pretreatment with the anaesthetic agents. Results: The net handling stress was of sufficient intensity to cause a significant increase in the levels of most of the stress indicators considered. By contrast, air exposure stress only induced significant increases in cortisol and haemoglobin levels. Conclusions: The stress-preventing effects of the anaesthetic agents tested were ranked on the basis of their capacity to prevent increases in the haematocrit, haemoglobin, glucose, lactate and cortisol levels, as follows: metomidate (5 mg/L) > clove oil (30 mg/L) > MS-222 (75 mg/L)> 2-phenoxyethanol (600 mg/L).