Bioactive phenolics from Carthamus lanatus L

Two flavonoid aglycons, eight flavonoid glycosides, chlorogenic acid and syringin were isolated from aerial parts of Carthamus lanatus. Isorhamnetin 3-O-beta-D-glucoside and chlorogenic acid were found for the first time in the genus Carthamus and respectively, quercimeritrin, astragalin, kaempferol 3-O-beta-D-sophoroside and syringin in the species. The ethyl acetate fraction of the methanol extract exhibited a higher antioxidant activity than the butanol fraction measured by the alpha,alpha-diphenyl-beta-picrazylhydrazyl (DPPH) free radical scavenging assay. Cytotoxicity and antioxidant activities of the main constituent, luteolin 7-O-beta-D-glucoside, were evaluated.

Effect of advanced oxidation processes on the toxicity of municipal landfill leachates

The aim of the present study was to assess the effect of advanced oxidation processes (AOPs) (oxidation ozone and peroxide/ozone) on the toxicity of leachates from municipal landfill for Warsaw, Poland, using a battery of tests. AOPs used to pre-treat leachates were carried out in laboratory conditions after their coagulation with the use of FeCl3. The effects of the pre-treatment of leachates using the method of coagulation with FeCl3 depended on the concentration of organic compounds and with optimal conditions of the process ranged from 40 to 70%. Further pre-treatment of the leachates after coagulation, involving the use of oxidation with 03 and H2O2/O3, did not cause significant decrease of leachate toxicity. The data of this study demonstrated the usefulness of the battery of tests using Daphnia magna, Artemia franciscana, Scenedesmus quadricauda and Vibrio fischeri for the toxicity evaluation of raw and pre-treated leachates.

Phenolic removal in a model olive oil mill wastewater using Pleurotus ostreatus in bioreactor cultures and biological evaluation of the process

Pleurotus ostreatus grown in bioreactor batch cultures in a model phenolic wastewater (diluted and sterilized olive oil mill wastewater-OMW), caused significant phenolic removal. Laccase, the sole ligninolytic enzyme detected in the growth environment, was produced during primary metabolic growth. The bioprocess was simulated with the aid of a mathematical model and the parameters of growth were determined. When the fungal biomass was increased in the reactor (during repeated batch experiments) the rate of reducing sugars consumption progressively increased, but a phenolic fraction seemed of being strongly resistant to oxidation. The toxicity of OMW against the seeds of Lepidium sativum and the marine Branchiopoda Artemia sp. was significantly decreased after biotreatment. On the contrary, the toxicity against the freshwater Branchiopoda Daphnia magna was not affected by the treatment, whereas on the soil and freshwater sediments Ostracoda Heterocypris incongruens was slightly decreased. Both treated and untreated OMWs, used as water for irrigation of lettuce and tomato plants, did not significantly affect the uptake of several nutrients by the cultivated plants, but resulted in a decrease in the plant yields, which was minimized when high OMW dilutions were used. As a conclusion, P. ostreatus is able to reduce phenolic content and toxicity of sterilized OMW, in bioreactor cultures. However, high OMW dilutions should be used, and/or additional treatment should be applied before use of the OMW in the environment, e.g. as water for irrigation. Further research should be done in order to transfer this technology under industrial conditions (e.g. by using unsterilized OMW).

Organophosphate nerve agent toxicity in Hydra attenuata

The toxicity for analogues of sarin (GB), soman (GD), and VX was evaluated using Hydra attenuata as a model organism. The organophosphate nerve agent analogue simulants used in this investigation included the following: isopropyl p-nitrophenyl methylphosphonate (for GB); pinacolyl p-nitrophenyl methylphosphonate (for GD); and diisopropyl S-(2-diisopropylaminoethyl)phosphorothioate, diethyl S-(2-diisopropylaminoethyl)phosphorothioate, and diethyl S-(2-trimethylaminoethyl)phosphorothioate (for VX). The toxicity of each organophosphate nerve agent was assessed quantitatively by measuring the minimal effective concentration within 92 h in H. attenuata. There is a positive correlation between the molecular hydrophobicity of the compound and its ability to cause toxicity. Results from this study indicate the potential for application of this assay in the field of organophosphate chemical warfare agent detection, as well as for the prediction of toxicity of structurally similar organophosphate compounds. The minimal effective concentration for two of the VX analogues was 2 orders of magnitude more toxic than the analogue for GD and 4 orders of magnitude more toxic than the analogue for GB.

GC-MS analysis and bioactivity testing of the volatile oil from the leaves of the toothbrush tree Salvadora persica L

Upon GC-MS analysis of the volatile oil extracted from Salvadora persica L. leaves, we were able to identify benzyl nitrile, eugenol, thymol, isothymol, eucalyptol, isoterpinolene, and beta-caryophyllene. Toxicity of the aroma was evaluated using brine shrimp lethality test which gave an LC50 > 1,000 ppm. Using Disc Diffusion Test, it was found that the extract of the leaves has a considerable antibacterial effect on several different oral aerobic bacteria with comparable results to known antibiotics. The extract can be used effectively as a natural tool for teeth cleaning and as a natural analgesic for the disturbing toothache.

Variation of leishmanicidal activity in four populations of Urechites andrieuxii

Urechites andrieuxii Muell.-Arg. (Apocynaceae) is widely used in the Yucatan Peninsula for the treatment of cutaneous leishmaniasis. The influence of the environment in the variability of the leishmanicidal activity of the plant was evaluated using crude methanol extracts of roots from individuals belonging to four natural populations growing in the Yucatan Peninsula. The results of the growth inhibition test using three Leishmania spp. promastigotes showed a stronger leishmanicidal activity in populations of U. andrieuxii growing in more humid environments. Further evaluation against four human cancer cell lines and in the brine shrimp bioassay of both extracts from various parts of the plant and from the most active methanol root extracts, suggested that while the leaf extract appears to have selective toxicity against Leishmania parasites, the strong leishmanicidal activity detected in the root extracts of the plant might be due to its cytotoxicity.

Synthesis and biological evaluation of some new substituted naphthoquinones

Two novel series of 1,4-naphthoquinone derivatives have been synthesized namely; N-ethoxycarbonyl-2-ethoxycarbonyloxy-3- alkyl-1,4-naphthoquinon-1-substituted phenylhydrazones 3a-f and 2-chlorocetyloxy-3-alkyl-1,4-naphthoquinone-1-substituted phenylhydrazones 4a-d. The antimicrobial activity as well as anticancer activity of these compounds have been evaluated. The acute toxicity of the active compounds was determined.

Bioactivity of secoiridoid glycosides from Centaurium erythraea

As part of our on-going search for bioactive compounds from Scottish plants, two secoiridoid glycosides, swertiamarin and sweroside, have been isolated from the aerial parts of Centaurium erythraea Rafn (Family: Gentianaceae) by reversed-phase preparative HPLC coupled with a photo-diode-array detector. The structures of these compounds were elucidated unambiguously by UV, FABMS and extensive 1D and 2D NMR spectroscopic analyses and also by comparing experimental data with literature data. Antibacterial, free radical scavenging activities and general toxicity of these glycosides have been assessed. Both compounds inhibited the growth of Bacillus cereus, Bacillus subtilis, Citrobacter freundii and Escherichia coli. While swertiamarin was also active against Proteus mirabilis and Serratia marcescens, sweroside inhibited the growth of Staphylococcus epidermidis. Swertiamarin and sweroside exhibited significant general toxicity in brine shrimp lethality bioassay and the LD50 values were 8.0 microg/ml and 34 microg/ml, respectively, whereas that of the positive control podophyllotoxin, a well known cytotoxic lignan, was 2.79 microg/ml. Chemotaxonomic implications of these compounds in the family Gentianaceae have also been discussed briefly.

12alpha-hydroxystigmast-4-en-3-one: a new bioactive steroid from Toona ciliata (Meliaceae)

In a bioassay guided phytochemical investigation of Toona ciliata (Fam. Meliaceae), a new hydroxy steroidal ketone, 12alpha-hydroxystigmast-4-en-3-one (1) was isolated from the petroleum ether extract of the plant together with two known steroids and three C-methyl coumarins. The structure of 1 was established by means of spectroscopic analyses. Compound 1 was found cytotoxic in a brine shrimp lethality bioassay with LC50 of 9.9 microg/ml and it also showed significant antitumor activity with Ti50 value of 14.1 microg/ml in a potato disc bioassay.

Using bioassays for testing seawater quality in Greece

The objective of this work was the assessment of seawater quality in Thermaikos Gulf, Pagassitikos Gulf and Skiathos island in Northern Aegean Sea by the use of bioassays. Two bioassays using marine organisms as indicators of seawater quality were applied in this study; the invertebrate Artemia franciscana and the marine bioluminescent bacterium Vibrio fischeri. Bioassays are required for the integrated evaluation of water pollution, as physical and chemical tests alone are not sufficient enough for the assessment of potential effects on aquatic organisms. According to the result of this study, improvement in coastal water quality of Thermaikos Gulf was observed between September 1997 and April-May 2000. However, coastal water quality of Pagassitikos Gulf varied during the test period; it was generally good during April-May 2000, while in October 1999 it was generally poor. Between the two bioassays that have been applied in this study, the Microtox test, where the marine bacterium V. fischeri was used as a test organism, was more sensitive in detecting toxicity in seawater.

Antihypertensive, antiatherosclerotic and antioxidant activity of triterpenoids isolated from Olea europaea, subspecies africana leaves

For the first time a biossay-directed study of triterpenoids isolated from the leaves of Olea europaea from Greece, from wild African olive and from a cultivar of O. europaea grown in Cape Town was reported. The experiment was undertaken since our preliminary analyses showed that the African wild olive leave is rich in triterpenoids and contain only traces of the glycoside oleuropein, which is typical for the European olive leaves. The isolate of the African wild olive leaves (AO) used in the experiments was found to contain 0.27% 1:1 mixture of oleanolic acid and ursolic acid, named oleuafricein. The isolate of Greek olive leaves (GO) was found to contain 0.71% oleanolic acid, and the Cape Town cultivar (CT) contained 2.47% oleanolic acid. No ursolic acid was found in either GO or CT. The antihypertensive, diuretic, antiatherosclerotic, antioxidant and hypoglycemic effects of authentic oleanolic and ursolic acid and the three isolates (GO, AO and CT) were studied on Dahl salt-sensitive (DSS), insulin-resistant rat genetic model of hypertension. All three isolates, in a dose 60 mg/kg b.w. for 6 weeks treatment, prevented the development of severe hypertension and atherosclerosis and improved the insulin resistance of the experimental animals. GO, OA and CT isolates could provide an effective and cheap treatment of this particular, most common type of salt-sensitive hypertension in the African population.

Cytotoxic activities of some mono and bis Mannich bases derived from acetophenone in brine shrimp bioassay

Some mono Mannich bases (1-phenyl-3-amino-1-propanone salts) and bis Mannich bases (1-phenyl-3-amino-2-amino-methyl-1-propanone salts) derived from acetophenone and a few representative quaternary derivatives were synthesised and their cytotoxicity was tested using the brine shrimp bioassay. This assay may serve as an intermediate test before further in vivo animal experiments in large scale, since brine shrimp nauplii as whole organisms were used in this test. Mono Mannich bases were generally more cytotoxic than their corresponding bis Mannich bases. Mannich bases synthesised were cytotoxic in both brine shrimp bioassay in this study and cell culture tests using Jurkat and Renca cells in a previous study. However, the order of the cytotoxic potency of the compounds were reverse, which may result from faster deamination of bis derivatives than optimal level, and different species and test media used in the two test systems. Faster deamination of bis derivatives might have led to elimination of active metabolites before reaching its target. The cytotoxicity of the compounds might have been altered by amino acids and proteins present in cell culture medium but not in sea water used in brine shrimp bioassay affecting their transport through the cell membrane and metabolism in the cell by binding with the compounds. With higher cytotoxic activity compared with 5-fluorouracil (CAS 51-21-8) in brine shrimp bioassay, mono Mannich base 1 and its quaternary derivative 4 and quaternary bis derivative 8 seem to be candidate compounds for further drug design.

Toxicity of some bis Mannich bases and corresponding piperidinols in the brine shrimp (Artemia salina) bioassay

Some acetophenone-derived bis Mannich bases were synthesized: bis[beta-benzoylethyl]ethylamine hydrochloride (IIa), bis[beta-(p-methylbenzoyl)ethyl]ethylamine hydrochloride (IIb), bis[beta-(p-chlorobenzoyl)ethyl]ethy- lamine hydrochloride (IId), bis[(2-thienylcarbonyl)ethyl]ethylamine hydrochloride (IIe); some corresponding piperidinol derivatives: 3-benzoyl-1-ethyl-4-phenyl-4-piperidinol hydrochloride (IIIa), 1-ethyl-3-(p-methyl- benzoyl)-4-(p-methylphenyl)-4-piperidinol hydrochloride (IIIb), 1-ethyl-3-(p-methoxybenzoyl)-4-(p-methoxy- phenyl)-4-piperidinol hydrochloride (IIIc), 1-ethyl-3-(p-chlorobenzoyl)-4-(p-chlorophenyl)-4-piperidinol hydrochloride (IIId), 1-ethyl-4-(2-thienyl)-3-(2-thienylcarbonyl)-4-piperidinol hydrochloride (IIIe); and some representative quaternary piperidinols: 3-benzoyl-1-ethyl-4-hydroxy-1-methyl-4-phenylpiperidinium iodide (IIIf), 1-ethyl-4-hydroxy-1-methyl-3-(p-methylbenzoyl)-4-(p-methylphenyl)piperidinium iodide (IIIg). Toxicity was tested by the brine shrimp bioassay as an intermediate test before further in vivo animal experiments. Piperidine derivatives were found to be more potent than bis Mannich bases. Quaternary piperidine derivatives IIIf and IIIg and also non-quaternary piperidine derivatives IIIb, IIIe, IIIc and IIId were more toxic than 5-fluorouracil in brine shrimp bioassay. Except for IIe, bis Mannich bases were not effective. Quaternization and conversion of bis Mannich bases to corresponding piperidines improved the toxicity. The lipid solubility of the compounds may not affect the toxicity. From these findings the quaternary piperidine derivatives IIIf and IIIg could be used in further drug development and also for in vivo experiments.

The potential use of constructed wetlands in a recirculating aquaculture system for shrimp culture

A pilot-scale constructed wetland unit, consisting of free water surface (FWS) and subsurface flow (SF) constructed wetlands arranged in series, was integrated into an outdoor recirculating aquaculture system (RAS) for culturing Pacific white shrimp (Litopenaeus vannamei). This study evaluated the performance of the wetland unit in treating the recirculating wastewater and examined the effect of improvement in water quality of the culture tank on the growth and survival of shrimp postlarvae. During an 80-day culture period, the wetland unit operated at a mean hydraulic loading rate of 0.3 m/day and effectively reduced the influent concentrations of 5-day biochemical oxygen demand (BOD5, 24%), suspended solids (SS, 71%), chlorophyll a (chl-a, 88%), total ammonium (TAN, 57%), nitrite nitrogen (NO2-N, 90%) and nitrate nitrogen (NO3-N, 68%). Phosphate (PO4-P) reduction was the least efficient (5.4%). The concentrations of SS, Chl-a, turbidity and NO3-N in the culture tank water in RAS were significantly (P<or=.05) lower than those in a control aquaculture system (CAS) that simulated static pond culture without wetland treatment. However, no significant difference (P<or=.05) in BOD5, TAN and NO2-N was found between the two systems. At the end of the study, the harvest results showed that shrimp weight and survival rate in the RAS (3.8 +/-1.8 g/shrimp and 90%) significantly (P<or=.01) exceeded those in the CAS (2.3+/-1.5 g/shrimp and 71%). This study concludes that constructed wetlands can improve the water quality and provide a good culture environment, consequently increasing the shrimp growth and survival without water exchange, in a recirculating system.

The toxicity of cationic surfactants in four bioassays

The purpose of this study was to investigate the toxicity of 15 quaternary ammonium compounds (QACs) in a battery of four bioassays comprising the bacterium Vibrio fischeri, two ciliated protozoa Spirostomum ambiguum and Tetrahymena thermophia, and the anostracean crustacean Artemia franciscana. The compounds were prepared by Professor Pernak's group at Poznań University of Technology (Poland). The toxicity of the test compounds was very high, with EC(LC)(50) values varying from 0.11 to 70 micromol/L. Microtox was the most sensitive bioassay, while the crustacean test was the least sensitive. Among the protozoa T. thermophila was 5-30 times less sensitive than S. ambiguum. The toxicity of the QACs depended on their structure, but no simple correlation was found for all the bioassays applied.

New saponins from the starfish Certonardoa semiregularis

Ten new saponins designated as certonardosides A-J (1-5, 7-11) and the known halityloside D (6) were isolated from the brine shrimp active fraction of the MeOH extract of the starfish Certonardoa semiregularis. The structures were determined on the basis of spectral analysis and chemical manipulation. The compounds were evaluated for antiviral activity against HIV, HSV, CoxB, EMCV, and VSV and displayed insignificant activity within the range of noncytotoxic concentrations.

Biological activity of common mullein, a medicinal plant

Common Mullein (Verbascum thapsus L., Scrophulariaceae) is a medicinal plant that has been used for the treatment of inflammatory diseases, asthma, spasmodic coughs, diarrhea and other pulmonary problems. The objective of this study was to assess the biological activity of Common Mullein extracts and commercial Mullein products using selected bench top bioassays, including antibacterial, antitumor, and two toxicity assays--brine shrimp and radish seed. Extracts were prepared in water, ethanol and methanol. Antibacterial activity (especially the water extract) was observed with Klebsiella pneumonia, Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli. Agrobacterium tumefaciens-induced tumors in potato disc tissue were inhibited by all extracts. Toxicity to Brine Shrimp and to radish seed germination and growth was observed at higher concentrations of the extracts.

New biologically active marine sesquiterpenoid and steroid from the okinawan sponge of the genus Axinyssa

A new bisabolane-type sesquiterpenoid, (E)-3-isocyanobisabolane-7,10-diene (1), and a new epidioxyergostane-type steroid, 9(11)-dehydroaxinysterol (2), were isolated from the Okinawan sponge of the genus Axinyssa. Their structures were elucidated based on the results of spectroscopic analysis and chemical conversion. Epidioxysterol 2 was found to show significant growth inhibitory effects against human cancer cell lines.

Toxicity of tannins towards the free-living nematode Caenorhabditis elegans and the brine shrimp Artemia salina

Toxicities of gallo- and condensed tannins towards the free-living nematode Caenorhabditis elegans is dependent on the tannins' molecular sizes. In the present paper we investigate the toxicity of ellagitannins to C elegans and the toxicity of ellagi-, gallo-, and condensed tannins to the brine shrimpArtemia salina. Ellagitannins 1 and 2 were isolated from Euphorbia supina and identified as tellimagrandin I and rugosin A methyl ester, respectively. An ellagitannin preparation from Cornus officinalis was chromatographically fractionated into ellagitannins A through H, having different molecular weights and specific rotations. Three of the ten ellagitannins, 2, G, and H produced significant toxicity towards C. elegans, showing the presence of an activity-structure relationship, as opposed to the results from tests of gallo- and condensed tannins. Ellagi-, gallo-, and condensed tannins also produced toxicity in A. salina.

Syntheses, antibacterial, cytotoxic and antifungal effects of new 3-carboxy-l-phenacylpyridinium salts

Thirteen pyridine-3-carboxylic acid salt derivatives with various substituted phenacyl residues were prepared and their cytotoxicity, antibacterial and antifungal activities tested. Compounds 5 and 11 proved to be active in the brine shrimp bioassay, compounds 7, 9-12 and 14 showed promising antibacterial activities, whereas none of the compounds tested against 15 fungal cultures proved to be active. Extensive spectroscopic techniques were employed to confirm the structure of the synthetic products.

Ultrastructure of a novel eurytele nematocyst of Carybdea alata Reynaud (Cubozoa, Cnidaria)

The ultrastructural characteristics of nematocysts from the cubozoan Carybdea alata Reynaud, 1830 (Hawaiian box jellyfish) were examined using light, scanning and transmission electron microscopy. We reclassified the predominant nematocyst in C. alata tentacles as a heterotrichous microbasic eurytele, based on spine, tubule and capsule measurements. These nematocysts exhibited a prominent and singular stylet, herein referred to as the lancet. Discharged nematocysts from fixed tentacle preparations displayed the following structures: a smooth shaft base, lamellae, a hemicircumferential fissure demarking the proximal end of a stratified lancet, and a gradually tapering tubule densely covered with large triangularly shaped spines. The lancet remained partially adjoined to the shaft base in a hinge-like fashion in rapidly fixed, whole-tentacle preparations. In contrast, this structure was not observed in discharged nematocyst preparations which involved multiple transfer steps prior to fixation. Various approaches were designed to detect this structure in the absence of fixative. Detached lancets were located in proximity to discharged tubules in undisturbed coverslip preparations of fresh tentacles. In addition, examination of embedded nematocysts from fresh tentacles laid on polyacrylamide gels revealed still-attached lancets. To examine the function of this structure in prey capture, Artemia sp. laden tentacles were prepared for scanning electron microscopy. While carapace exteriors exhibited structures proximal to the lancet, i.e., the nematocyst capsule and shaft base, neither tubule nor lancet structures were visible. Taken together, the morphological data suggested a series of events involved in the discharge of a novel eurytele from C. alata.

Additional cytotoxic diacetylenes from the stony coral Montipora sp

Three new diacetylenes (1, 4, 6) have been isolated as cytotoxic constituents from the methanolic extract of the stony coral Montipora sp. The structures have been elucidated on the basis of spectroscopic evidence. The compounds were evaluated for cytotoxicity against a small panel of human tumor cell lines and showed moderate to significant activity.

Small heat shock protein p26 associates with nuclear lamins and HSP70 in nuclei and nuclear matrix fractions from stressed cells

The small heat shock/alpha-crystallin protein p26 undergoes nuclear translocation in response to stress in encysted embryos of the brine shrimp Artemia franciscana. About 50% of total p26 translocates to nuclei in embryos treated with heat shock or anoxia, and in embryo homogenates incubated at low pH. Nuclear fractionation shows that the majority of nuclear p26 and a nuclear lamin are associated with the nuclear matrix fraction. To further explore the roles of p26 and other HSPs in stabilizing nuclear matrix proteins (NMPs), nuclear matrices from control, and heat-shocked embryos were disassembled in urea and evaluated by one and two-dimensional (2-D) gel electrophoresis and Western immunoblotting after reassembling. Nuclear lamins were present only in reassembled fractions and, in the case of heat shock, p26 and HSP70 were also present. HSP90 was not detected in any nuclear fraction. Confocal microscopy on isolated nuclei and nuclear matrix preparations from control and heat-shocked embryos showed that the majority of p26 and a nuclear lamin share similar nuclear distributions. The combination of microscopy and fractionation results suggests that p26 and HSP70 play a role in the protection of nuclear lamins within the nuclear matrix.

Feeding and wounding responses in Hydra suggest functional and structural polarization of the tentacle nervous system

The nervous system of Hydra, a freshwater cnidaria, occurs as dispersed, or diffuse, nerve net throughout the animal. It is widely accepted that in a diffuse nervous system an external stimulus is conducted in all directions over the net. Here I report observations that hydra tentacles respond to feeding and wounding stimuli in a unidirectional manner. Upon contact of a tentacle with a brine shrimp larva during feeding, tissue on the proximal side of the point of contact contracted strongly, whereas tissue on the distal side contracted only very weakly. Feeding a tentacle to which a second tentacle was grafted to the proximal end in the reversed orientation showed that unidirectional conduction, once initiated, was blocked by the reversal of polarity, demonstrating that the distal to proximal polarity of tissue is crucial for unidirectional conduction. Unidirectional conduction was obtained also by mechanically pinching the tissue. The response of tentacles devoid of neurons examined was bidirectional, demonstrating that the nervous system is responsible for the unidirectional responses. These observations suggest that polarized property of the nerve net in hydra tentacles is responsible for the unidirectional tentacle contraction.

Cytotoxic, hypoglycemic activity and phytochemical analysis of Rubus imperialis (Rosaceae)

Rubus imperialis, Artemia salina, 3-O-methylellagic-4'-O-alpha-rhamnose Acid Screening of different extracts, fractions and compounds from Rubus imperialis Chum. Schl. (Rosaceae) has been conduced using the brine shrimp microwell cytotoxicity assay. Three parts of the plant (methanolic extract from leaves, roots and stems), three fractions from roots (hexane, ethyl acetate and butanol) and three isolated compounds (niga-ichigoside F1, 23-hydroxytormentic acid, ellagic acid derivative) were tested. The most promising material (LC50 <1000 microg/ml) were the methanolic extract and ethyl acetate fraction from roots. However, there was little correlation observed in the degree of toxicities observed between the isolated compounds. On the other hand, the cytotoxicity and in vivo assays confirmed the hypoglycemic activity of methanolic extract and validated the Brazilian popular use of R. imperialis as an antidiabetic agent.