Accumulation of the Major Components from Polygoni Multiflori Radix in Liver and Kidney after Its Long-Term Oral Administrations in Rats

Although Polygoni Multiflori Radix (PMR) has been widely used as a tonic and an anti-aging remedy for centuries, the extensively reported hepatotoxicity and potential kidney toxicity hindered its safe use in clinical practice. To better understand its toxicokinetics, the current study was proposed, aiming to evaluate the biodistributions of the major PMR components including 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucopyranoside (TSG), emodin, emodin-8-O-β-D-glucopyranoside (EMG) and physcion as well as their corresponding glucuronides following bolus and multiple oral administrations of PMR to rats. Male Sprague-Dawley rats received a bolus dose or 21 days of oral administrations of PMR concentrated granules at 4.12 g/kg (equivalent to 20.6 g/kg raw material). Fifteen minutes after bolus dose or the last dose on day 21, rats were sacrificed and the blood, liver, and kidney were collected for the concentration determination of both parent form and glucuronides of TSG, emodin, EMG, and physcion by HPLC-MS/MS. Among all the tested analytes, TSG, EMG, EMG glucuronides in liver and TSG, EMG, as well as all the glucuronides of these analytes in the kidney demonstrated the most significant accumulation after multiple doses. Moreover, the levels of the parent analytes were all significantly higher in liver and kidney in comparison to their plasma levels. Strong tissue binding of all four analytes and accumulation of TSG, EMG, and EMG glucuronides in the liver and TSG, EMG, as well as the glucuronides of all four analytes in the kidney after multiple dosing of PMR were considered to be associated with its toxicity.

Variation in quality of the different prepared formulation granules of rhubarb was evaluated by quantitative analysis of multicomponents with single marker

Rhei Radix et Rhizoma formula granule (RRFG) , Winy Rhei Radix et Rhizoma formula granule(WRFG) and Rhubarb charcoal formula granules (RCFG) are the three most popular and effective formula granules of rhubarb in China and anthraquinone components are their main active ingredients. In order to discuss the difference in anthraquinone components of these three drugs, a simultaneous quantitative analysis method of multicomponents by single-marker (QAMS) was developed. Emodin was chosed as the internal reference standard, the relative correction factors (RCFs) of aloe-emodin, rhein, chrysophanol and physcion were established and the contents of the four components were calculated based on the RCFs, respectively. Meanwhile, the contents of these components was determined by external standard method (ESM) and compared with QAMS to verify its rationality, feasibility and repeatability. The results showed that there were no significant difference between QAMS and ESM (RSDs≤2.26%). The contents of anthraquinone components showed a wide variation in these three drugs. All of 5 components were higher in RRFG than that in the others and RCFG had the lowest content. This method was successfully applied for the evaluation on difference of these drugs and the wide variation in anthraquinone components indicated there were different pharmacodynamic basis.

Identification and action mechanism of lipid regulating components from Rhei Radix et rhizoma

ETHNOPHARMACOLOGICAL RELEVANCE

Rhei Radix et Rhizoma is widely used in Traditional Chinese Medicine to attack stagnation, clear damp heat, relieve fire, cool blood, remove blood stasis and detoxify recorded in Chinese Pharmacopoeia. Modern pharmacological research has showed the extract of Rhei Radix et Rhizoma has the effect of lowering blood lipids, but the main active components and their mechanisms are still not clear.

AIM OF THE STUDY

To reveal the lipid regulating components from Rhei Radix et Rhizoma and preliminarily explore their related action mechanisms.

MATERIALS AND METHODS

A rat model of dyslipidemia was established by administration of a high-fat emulsion via gavage, and the intervention effect of different polar fractions of Rhei Radix et Rhizoma on rat blood lipids as well as their related action mechanisms were preliminarily investigated. The effective components were inferred based on the above tests and identified by high performance liquid chromatography in comparison with reference substances, their UV absorption and high resolution mass spectra characteristics.

RESULTS

The extract with dichloromethane fraction (DF) containing rhubarb free anthraquinones (aloe-emodin, rhein, emodin, chrysophanol and physcion) significantly regulated the disordered blood lipids, lowered TC and LDLC, reversed TG and increased HDLC level in dyslipidemic rats and also showed lipid-lowering effect on lipid abnormalities in HepG2 cells. DF could alter the signaling pathways such as PPARα and AMPK implicated in lipid metabolism, and it down-regulated the mRNA expression of liver APOA2, SCD-1, HMGCR, SREBP-2 and PCSK9, but up-regulated the expressions of liver APOE, LPL and intestinal ABCG8. Besides, it could change the composition of Firmicutes, Bacteroidetes and Proteobacteria in dyslipidemic rat feces samples.

CONCLUSIONS

Rhubarb free anthraquinones have a significant regulating effect on the levels of serum TC, LDLC and HDLC, and probably possess a bidirectional regulatory effect on TG level in dyslipidemic rats. These effects may be achieved by regulating the expressions of the liver PPARα and SREBP target genes, PCSK9 and the intestinal ABCG8 genes, which are involved in blood cholesterol transport, liver lipid metabolism and intestinal cholesterol excretion. Rhubarb free anthraquinones may also affect energy metabolism by changing the composition of gut microflora related to lipid metabolism in dyslipidemic rats.

Multi-material basis and multi-mechanisms of the Dahuang Zhechong pill for regulating Treg/Th1 balance in hepatocellular carcinoma

BACKGROUND

Dahuang Zhechong pill (DHZCP) improves the inhibitory immune status of mice with hepatocellular carcinoma (HCC) by regulating Treg/Th1 balance.

HYPOTHESIS/PURPOSE

To study the multi-material basis and multi-mechanisms of DHZCP against HCC by regulating Treg/Th1 balance in vitro and in vivo.

METHODS

UPLC-MS/MS was used to detect the dynamic changes in 29 characteristic components of different polar parts of DHZCP. H&E and TUNEL were used to check pathological condition in HCC mice. The number of CD4⁺T, CD8⁺T, Treg, Th1, and Th1-like Treg cells was counted by flow cytometry. TGF-β, IL-10, IFN-γ, and TNF-α content were detected by ELISA. α-Ketoglutarate and glutamine levels were detected by Trace1310/TSQ8000 GC-MS/MS. p-Smad2, and p-Smad3 protein levels were detected by WB, mRNA expression of Smad2, alanine-serine-cysteine transporter-2, glutaminase, and glutamate dehydrogenase were detected by RT-PCR. Simca-p multivariate data analysis software was used to evaluate the relationship between the different polar parts of DHZCP and the proportion of Treg cells.

RESULTS

Water-soluble (PW) and ethyl acetate (PE) polar parts of DHZCP affected the HCC immune system by inhibiting the differentiation of Tregs, reversing the balance of Treg/Th1, and significantly reduced the tumor volume and weight. However, petroleum ether and n-butanol polar parts had no above actions. The changes in emodin, chrysophanol, aloe vera emodin, emodin-8-O-β-D-glycoside, gallic acid, naringenin, baicalein, wogonin, norwogonin, apigenin, chrysin, glycyrrhizin, formononetin, and palmitic acid were closely related to the changes of Treg cells, which is the main material basis of DHZCP inhibition of Treg differentiation. Additionally, PW mainly inhibit the differentiation of Treg cells by affecting the metabolism of hepatoma cells, improving tumor microenvironment acidity, and glutamine depletion. However, PE inhibited the differentiation of Treg cells mainly by regulating the TGF-β/Smad pathway.

CONCLUSION

In this study, accurate analysis of multi-component was combined with pharmacodynamic evaluations to identify the pharmacodynamic substances of DHZCP in regulating Treg/Th1 balance, and clarified the multi-target mechanism of DHZCP to improve tumor immunity. The study style offers a novel approach for pharmacological research on TCM.

[Therapeutic effect of Shengjiang Powder on experimental autoimmune encephalomyelitis mice through IL-6/JAK2/STAT3 signaling pathway:based on HPLC]

A high performance liquid chromatography(HPLC) method was established to analyze the components in Shengjiang Powder(SJP) such as emodin and curcumin and explore its therapeutic effect on experimental autoimmune encephalomyelitis(EAE) mice. To be specific, HPLC was performed to determine the content of compounds in SJP such as emodin and curcumin. A total of 72 female SPF C57 BL/6 mice were randomized into control group(equivalent volume of ultrapure water, ig), model group(equivalent volume of ultrapure water, ig), low-, medium-, and high-dose SJP groups(SJP, ig), and positive control group(prednisone acetate, ig), 12 each group. EAE was induced in mice except the control group. Administration began from the first day after immunization. The general conditions, symptom score, and body weight of the mice were recorded. On the 21 st day, mouse brain tissues were separrated. Then hematoxylin-eosin(HE) staining and Luxol Fast Blue(LFB) staining were used to detect the pathological changes of brain tissues. Immunohistochemistry(IHC) was employed to determine the myelin basic protein(MBP) level, and Western blot the expression of occludin and claudin-5, as well as the levels of interleukin-6(IL-6) and proteins in the Janus kinase 2(JAK2)/signal transducer and activator of transcription 3(STAT3) pathway and their phosphorylation levels. The mRNA expression of IL-6, JAK2, and STAT3 was detected by real-time quantitative polymerase chain reaction(qPCR). Finally, molecular docking of six main active components in SJP, including emodin and curcumin, with IL-6, JAK2 and STAT3 was performed, and the binding affinity was evaluated. The results showed that the established HPLC method demonstrated high precision, reproducibility, stability, and high recovery of samples. Compared with the model group, SJP reduced the clinical symptom score and alleviate the inflammatory infiltration of brain white matter and demyelination of EAE mice. At the same time, SJP increased the expression of occludin and claudin-5, down-regulated the mRNA expression of IL-6, JAK2, and STAT3, as well as the levels of IL-6/JAK/STAT3 proteins and the phosphorylation levels, with significant difference. Molecular docking suggested that the six active components in SJP had high binding energy with IL-6, JAK2, and STAT3 proteins. The established HPLC method is simple, accurate, and highly sensitive, which can simultaneously determine the content of emodin and curcumin in SJP. SJP may alleviate the clinical symptoms of EAE by inhibiting IL-6/JAK2/STAT3 signaling pathway, protecting the blood-brain barrier, and relieving the inflammatory response and demyelinization of brain tissue.

Characterization and Structural Analysis of Emodin-O-Methyltransferase from Aspergillus terreus

All O-methylated derivatives of emodin, including physcion, questin, and 1-O-methylemodin, show potential antifungal activities. Notably, emodin and questin are two pivotal intermediates of geodin biosynthesis in Aspergillus terreus. Although most of the geodin biosynthetic steps have been investigated, the key O-methyltransferase (OMT) responsible for the O-methylation of emodin to generate questin has remained unidentified. Herein, through phylogenetic tree analysis and in vitro biochemical assays, the long-sought class II emodin-O-methyltransferase GedA has been functionally characterized. Additionally, the catalytic mechanism and key residues at the catalytic site of GedA were elucidated by enzyme-substrate-methyl donor analogue ternary complex crystal structure determination and site-directed mutagenesis. As we demonstrate, GedA adopts a typical general acid/base (E446/H373)-mediated transmethylation mechanism. In particular, residue D374 is also crucial for efficient catalysis through blocking the formation of intramolecular hydrogen bonds in emodin. This study will facilitate future engineering of GedA for the production of physcion or other site-specific O-methylated anthraquinone derivatives with potential applications as biopesticides.

pH-responsive and CD44-targeting polymer micelles based on CD44p-conjugated amphiphilic block copolymer PEG-b-HES-b-PLA for delivery of emodin to breast cancer cells

Herein, an amphiphilic block copolymer CD44-targeting peptide-conjugated polyethylene glycol-block-hydroxyethyl starch-block-poly (L-lactic acid) (CD44p-conjugated PEG-b-HES-b-PLA) are synthesized, which could self-assemble into the pH-responsive and CD44-targeting polymer micelles against breast cancer cells MDA-MB-231. Emodin (Emo) is a natural anthraquino with pharmacological activities in anti-tumor effects. However, Emo suffers from poor water solubility, low biocompatibility, rapid systemic elimination, and off-target side effects, resulting in unsatisfactory treatment outcomes. Nanotechnology-based drug delivery systems have proven great potential for cancer chemotherapy. The constructed polymeric micelles Emo@CD44p-PM have exhibited an average size of 154.5 ± 0.9 nm characterized by DLS and TEM. Further, the Emo@CD44p-PM have effective Emo-loading capacity, good thermal stability, and pH responsiveness. Intracellular uptake study shows the enhanced cellular internalization of Emo@CD44p-PM due to the increased exposure of CD44p enhances the cellular internalization of Emo@CD44p-PM effectively. Furthermore, thein vitroresults showed Emo@CD44p-PM has been observed good biocompatibility and anti-tumor effects. Therefore, the polymeric micelles Emo@CD44p-PM provide a promising delivery strategy of targeted therapy for breast cancer.

[Formulation optimization of emodin nanostructured lipid carriers by Box-Behnken response surface method and in vitro quality evaluation]

Emodin nanostructured lipid carriers(ED-NLC) were prepared and their quality was evaluated in vitro. Based on the results of single-factor experiments, the ED-NLC formulation was optimized by Box-Behnken response surface method with the dosages of emodin, isopropyl myristate and poloxamer 188 as factors and the nanoparticle size, encapsulation efficiency and drug loading as evaluation indexes. Then the evaluation was performed on the morphology, size and in vitro release of the nanoparticles prepared by emulsification-ultrasonic dispersion method in line with the optimal formulation, i.e., 3.27 mg emodin, 148.68 mg isopropyl myristate and 173.48 mg poloxamer 188. Under a transmission electron microscope(TEM), ED-NLC were spherical and their particle size distribution was uniform. The particle size of ED-NLC was(97.02±1.55) nm, the polymer dispersion index 0.21±0.01, the zeta potential(-38.96±0.65) mV, the encapsulation efficiency 90.41%±0.56% and the drug loading 1.55%±0.01%. The results of differential scanning calorimeter(DSC) indicated that emodin may be encapsulated into the nanostructured lipid carriers in molecular or amorphous form. In vitro drug release had obvious characteristics of slow release, which accorded with the first-order drug release equation. The fitting model of Box-Behnken response surface methodology was proved accurate and reliable. The optimal formulation-based ED-NLC featured concentrated particle size distribution and high encapsulation efficiency, which laid a foundation for the follow-up study of ED-NLC in vivo.

Abscisic acid and aloe-emodin against NS2B-NS3A protease of Japanese encephalitis virus

There are no specific drugs for the treatment of Japanese Encephalitis. Thus, new chemical entities or exploration of existing molecules is required. We have tested the antiviral potential of abscisic acid and aloe-emodin against protease of the Japanese encephalitis virus (JEV) using the computational and target-based assay. Maestro Schrödinger glide suite 2019 was used for molecular docking and dynamic studies, and NS2B-NS3A JEV protease kit was used to confirm protease inhibitory activity of abscisic acid and aloe-emodin. The abscisic acid and aloe-emodin have shown optimum binding affinity towards NS2B-NS3A protease of JEV. Furthermore, molecular dynamic simulation results have also shown the stability of abscisic acid and aloe-emodin within the binding pocket of NS2B-NS3A protease. The ADME parameters of both compounds were also found in an acceptable range. The IC50 values were found to be 100 μg/ml and 7.3 μg/ml for abscisic acid and aloe-emodin respectively which indicate more potency of aloe-emodin over the abscisic acid. However, the toxicity prediction results have shown a good safety profile of abscisic acid as compared to aloe-emodin. Thus, further, more detailed experimental studies are required to develop abscisic acid and aloe-emodin as a specific protease inhibitor of JEV.

[Study on the Antioxidant Activity of Aloe-Emodin Metal Complex]

OBJECTIVE

To synthesize three kinds of metal complexes of aloe-emodin and compare the antioxidant activities of the ligands and the complexes.

METHODS

Three kinds of aloe emodin metal complex, the aloe-emodin-iron (Ⅱ), the aloe-emodin-copper (Ⅱ) and the aloe-emodin-magnesium (Ⅱ) complexes, were synthesized by dissolving and stirring in anhydrous ethanol solvent, and their structures were characterized. The Fe 2+-H 2O 2-methylene blue method, the diphenyl bitter hydrazine radical method (DPPH method) and other assays were used to determine the clearance effect of ligands and complexes on superoxide radicals (O 2 －•), hydroxyl radicals (•OH) and phenyl bitter hydrazine radical (DPPH•).

RESULTS

Three kinds of aloe emodin metal complex, the aloe-emodin-iron (Ⅱ), the aloe-emodin-copper (Ⅱ) and the aloe-emodin-magnesium (Ⅱ) complexes, were successfully synthesized. According to the results of structural characterization, we speculated that the aloe-emodin metal complexes were formed at the site between the two molecules of aloe-emodin and one molecule of metal ions (Fe 2+, Mg 2+, Cu 2+) via the 9 th carbonyl and 8 th hydroxyl groups of the aloe-emodin molecules. Both the complex and the ligand have clearance effects on three kinds of free radicals, and the complex showed stronger effects than its ligand ( P<0.05).

CONCLUSION

Coordination of aloe-emodin with metal ions, such as Fe 2+, Cu 2+, and Mg 2+, could enhance the antioxidant activity of the ligand itself.

[Emodin ameliorates the peritoneal dialysis-related peritoneal fibrosis via inhibiting the activation of Notch pathway]

Long term peritoneal dialysis (PD) is often associated with peritoneal fibrosis. The aim of this study was to explore the effect of emodin on PD-related peritoneal fibrosis and its related cellular and molecular mechanism. PD-related peritoneal fibrosis rats and cultured rat peritoneal mesothelial cells were recruited in the experiment. PD-related peritoneal fibrosis was induced by intraperitoneal injection of lactate-buffered solution containing 4.25% glucose. The peritoneal equilibrium test (PET) was performed at the end of 2 weeks, 4 weeks, and 6 weeks, respectively. HE staining and Masson staining were used for histopathological evaluation. Enzyme linked immunosorbent assay (ELISA) was used to measure the plasma N-terminal procollagen III propeptide (PIIINP) level. Real-time PCR technique was used to detect the mRNA levels of Notch1, Jagged-1, and Hes-1 in peritoneal tissue. Western blot was applied to identify the protein levels of Notch1, Jagged-1, Hes-1, and Notch intracellular domain (NICD). In vitro, Notch1 overexpressing or knockdown rat peritoneal mesothelial cells were established and Western blot was used to examine the effect of emodin on the expressions of Hes-1 and Hey. Compared with the control group, HE staining revealed that PD rats suffered from decreasing in mesothelial cells, or detaching from surface of parietal peritoneum, accompanied by infiltration of inflammatory cells; Masson staining result showed thickened peritonea (P < 0.01), and the collagen deposition in the parietal peritoneum was increased; also, PIIINP level in plasma was elevated (P < 0.01). Treatment of the PD rats with emodin increased mesothelial cells in peritoneal tissue, and decreased the peritoneal thickness (P < 0.01), collagen depositions, as well as the plasma PIIINP level (P < 0.05). The expressions of Notch1, Jagged-1, Hes-1 and NICD in peritoneal tissue were also attenuated (P < 0.05 or P < 0.01). In cultured rat peritoneal mesothelial cells, compared with emodin group, emodin further inhibited the expressions of Hes-1 and Hey induced by Notch1-overexpression (P < 0.05), but not the expressions of Hes-1 and Hey induced by Notch1-knockdown (P > 0.05). Therefore, the activation of Notch pathway may be involved in the pathological process of PD-induced peritoneal fibrosis. Emodin may ameliorate the PD-related peritoneal fibrosis through inhibiting the activation of Notch pathway.

[Comparative Study on Boiling Powder and Traditional Herbal Pieces of Rhubarb]

OBJECTIVE

To optimize the particle size of rhubarb boiling powder, to determine decoction process of rhubarb boiling powder through the comparative study with traditional herbal pieces.

METHODS

Three kinds of particle size of rhubarb boiling powder were prepared. The content of aloe emodin,rhein, emodin, chrysophanol and emodin monomethyl ether were detected by HPLC,and to determine particle size of rhubarb boiling powder according to the content of total chemical ingredients and dry extract rate in water decoction. The effect of the amount of water and decocting time on decoction of boiling powder and traditional herbal pieces of rhubarb were systematically investigated by using single factor test.

RESULTS

Firstly, the content of 2 mm to 0. 18 mm particles in rhubarb boiling powder can not be less than 80%. Total anthraquinone content and dry extract rate had no significant difference in the decoction of boiling powder in the amount of water between 14 ~ 20 times; decocting time had no significant effect on total anthraquinone and dry extract rate; the content of combined anthraquinone decreased significantly, while the decocting time was more than 20 min. The decocting time had great influence on the herbal pieces, with ten times of water,and decocting 5 ~ 50 min each time, the compound content and dry extract rate of boiling powder were 3. 23 ~ 9. 48 times and 1. 61 ~ 3. 44 times than that of traditional herbal pieces, and with the extension of the decocting time, the gap was narrowing.

CONCLUSION

Preparation process of rhubarb boiling powder is simple and suitable for industrial production, boiling powder can save more than half of the amount of traditional herbal pieces with ten times of water, decocting one times, decoction time of 10 ~ 15 min.

[Effects of emodin-8-O-β-D-glucoside on cell apoptosis and expression of Bcl-2/Bax in cervical cancer SKOV3 cells]

OBJECTIVE

To explore the effect of emodin-8-O-β-D-glucoside (EG) on cell apoptosis and expression levels of Bcl-2 family proteins in human ovarian cancer SKOV3 cells.

METHODS

SKOV3 cells were cultured and divided into two groups (control group and experimental group). Cell viabilities were determined by the methyl thiazolyl tetrazolium (MTT) method; apoptosis and cell cycle were analyzed by flow cytometry; the changes of protein expression of cleaved caspase-3, cleaved caspase-9, Bcl-2 and Bax were detected by Western blot.

RESULTS

From the data of MTT, the cell proliferation of human ovarian cancer SKOV3 cells was inhibited by EG (20, 40, 80 mg/L) in a dose- and time-dependent manner. Flow cytometry assays showed that EG significantly induced apoptosis in SKOV3 cells. 48 h after treated with EG (20, 40, 80 mg/L), the apoptosis rate of the experimental group were increased gradually, and they were 23.8%, 35.5%, 59.6%, respectively, which were higher than these of the control group significantly. The data of Western blot showed that EG down-regulated Bcl-2 and up-regulated cleaved caspase-3, cleaved caspase-9, Bax in a dose-dependent manner.

CONCLUSIONS

EG can inhibit the proliferation of SKOV3 cells and promote apoptosis, and the anticancer effect of EG may be associated with the down regulation of Bcl-2 expression and up regulation of Bax expression, as well as the increase of relative activity of caspase 3 and caspase 9. EG may be a promising antitumor agent for cancer treatment.

The Quantitative Conversion of Barbaloin to Aloe-Emodin and its Application to the Evaluation of Aloes

Barbaloin can be quantitatively converted into aloe-emodin by heating a solution in 4 N hydrochloric acid, containing 4 per cent ferric chloride, for 4 hr. in a boiling water bath under reflux. Each of these numerical conditions can be varied ±10 per cent without significantly altering the yields. The reaction has been successfully applied to the assay of commercial samples of aloes.

Vegetable Purgatives Containing Anthracene Derivatives: Part XI. Further Work on the Aloin-like Substance ofRhamnus purshiana DC

The aloin-like substance formerly referred to as Compound A1, has been resolved into four closely allied anthraquinone derivatives by paper chromatographic and countercurrent techniques. Two of these substances have been isolated in pure form and their general properties, melting point, optical rotation, RF values and ultra-violet light absorption curves are recorded. Treatment with ferric chloride yields aloe-emodin from both, and each on mild hydrolysis, produces barbaloin. The names Cascaroside A and Cascaroside B are proposed. Preliminary work on the other two components has shown that they are based on a compound similar to barbaloin but a derivative of chrysophanol instead of aloe-emodin; the name chrysaloin is suggested for this substance.

Pest-managing activities of plant extracts and anthraquinones from Cassia nigricans from Burkina Faso

Insecticidal activity of eight plants collected from Burkina Faso was studied using mosquito (Ochlerotatus triseriatus), Helicoverpa zea and Heliothis virescens larvae and adult white fly (Bemisia tabaci). The n-hexane, ethyl acetate and methanol extracts of Pseudocedrela kotschyi, Strophantus hispidus, Securidaca longepedunculata, Sapium grahamii, Swartzia madagascariensis, Cassia nigricans, Jatropha curcas and Datura innoxia were used in this study. Extracts were tested at 250 microg/mL concentration. All three extracts of C. nigricans, J. curcas (skin and seeds) and D. innoxia exhibited 100% mortality on fourth instar mosquito (O. triseriatus) larvae. In addition, the n-hexane and ethyl acetate extracts of S. hispidus, S. longepedunculata, S. grahamii showed 100% mortality. The ethyl acetate extract of S. madagascariensis was the most active on adult white fly and exhibited 80% mortality. Extracts of all other plants exhibited 30-50% mortality on B. tabaci. In the antifeedant assays against H. zea and H. virescens, the MeOH extracts of C. nigricans, S. madagascarensis and S. hispidus were more effective against H. zea as indicated by 74% larval weight reduction as compared to the control. Since C. nigricans is commonly used in West Africa to protect grain storage from insects, we have characterized the insecticidal components present in its extract. Bioassay directed isolation of C. nigricans leaf extract yielded anthraquinones emodin, citreorosein, and emodic acid and a flavonoid, luteolin. Emodin, the most abundant and active anthraquinone in C. nigricans showed approximately 85% mortality on mosquito larvae Anopheles gambiaea and adult B. tabaci at 50 and 25 microg/mL, respectively, in 24 h. These results suggest that the extract of C. nigricans has the potential to be used as an organic approach to manage some of the agricultural pests.

Evaluation of the potential carcinogenic activity of Senna and Cascara glycosides for the rat colon

Anthraquinone glycosides of Senna and Cascara were investigated for their ability to induce aberrant crypt foci (ACF) in the rat colon mucosa, which are considered putative preneoplastic lesions. Dietary exposure to high doses of these glycosides for 56 successive days did not cause the appearance of ACF or increase in incidence of ACF induced by 1,2-dimethyl-hydrazine (DMH). However, in rats treated with both DMH and the highest dose of glycosides, the average number of aberrant crypts per focus, considered a consistent predictor of tumor outcome, was higher than in rats given DMH alone. These findings suggest that Senna and Cascara glycoside might behave as weak promoters in rat colon carcinogenesis.

Gastrointestinal toxicity of melos conquer mixture in rats

GIT effects of Melos Conquer Mixture were investigated - using albino wister rats. Conquer Mixture was administered orally at different concentrations whereas the control group received water. The experiment lasted from 3 to 21 days. Pathological examination was carried out on the dead animals. The animals showed (1) loss of weight and appetite (2) weakness (3) faeces was soft (4) out of 10 animals which received 1.20 ml/kg died on day 5(5) the Glt of the dead rats was virtually empty except in the colon, (6) pieces from various parts of GIT revealed evidence of acute and sub acute inflammatory cellular reactions. The results indicate that Conquer Mixture may be toxic to the gastrointestinal tract and suggest that a re-evaluation of the therapeutic usefulness of the drug in the management of malaria is warranted.