Chemical Constituents of Hypericum uralum and the Analgesic and Antimalarial Activities / 中国药学杂志

OBJECTIVE: To study the chemical constituents of Hypericum uralum were isolated and identified and test the analgesic activity and β-hematin formation inhibitory activity of some selected compounds. METHODS: The compounds were isolated and purified by column chromatography padded with the separating material including silica gel and Sephadex LH-20, and their structures were elucidated based on the analyses of modern spectrum technology. Analgesic and antimalarial activities of selected compounds from H. uralum were evaluated by acetic acid-induced writhing, hot water tail-flick test in mice, and β-hematin formation inhibition method, respectively. RESULTS: Thirteen compounds were isolated from ethyl acetate portion of 95% ethanol extract of H. uralum and identified as (-)-eriodictyol (1), 3,4,5-trihydroxyxanthone (2), 1,7-dihydroxyxanthone (3), 4-hydroxy-2,3-dimethoxyxanthone (4), toxyloxanthone B (5), 1,3,6,7-tetrahydroxyxanthone (6), 2,3-dimethoxyxanthone (7), 1,5,6-trihydroxy-3-methoxyxanthone (8), hyperielliptone HD (9), 3,3′,4,4′-tetrahydroxybiphenyl (10), shikimic acid (11), quercetin-3-O-(4″-methoxy)-α-L-rahmnopyranosyl (12), and proanthocyanidin A-2 (13). The analgesic activity test indicated that compounds 3 and 12 had certain peripheral analgesic activity, while compound 1 exhibited strong β-hematin formation inhibitory activity. CONCLUSION: All the compounds are obtained from this plant for the first time.The analgesic and antimalarial activities of H. uralum have corresponding material basis.

Antimalarial activity of Isodon yuennanensis / 中国药学杂志

OBJECTIVE: To evaluate the antimalarial activity of Isodon yuennanensis for the development of neo-style antimalarial drugs or lead compounds from plants. METHODS: The crude extract and compounds from I. yuennanensis were screened for antimalarial activities by β-hematin formation inhibition assay, and the results were expressed as IC50 values. RESULTS: The crude extract, as well as some compounds, showed β-hematin formation inhibition activities in different degrees. CONCLUSION: The ethyl acetate fraction derived from the 70% acetone extract of I. yuennanensis and the compounds 2, 12, and 13 obtained from the ethyl acetate fraction are worthy of deeper research due to their significant antimalarial activities.

Effect of exogenous carbon monoxide donor Hematin on photosynthesis parameters and chlorophyll fluorescence characteristics of Coptis chinensis seedlings under NaCl stress / 中草药

Objective: Using exogenous carbon monoxide (CO) donor Hematin (H) to study the changes of photosynthesis parameters and chlorophyll fluorescence characteristics in Coptis chinensis seedlings under NaCl stress and get the way for promoting the resistance ability of C. chinensis seedlings under NaCl stress. Methods: Under 100 mmol/L NaCl stress, the several physiological indexes of C. chinensis seedlings treated by H at the different concentration, such as the contents of photosynthetic pigment and the parameters of chlorophyll fluorescence and photosynthesis, were measured. Results: Under NaCl stress the photosynthetic physiology of C. chinensis seedlings was inhibited, but the contents of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids could be obviously increased after the treatment of H at different concentration. The levels of the net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (Tr) in C. chinensis seedlings were all decreased, which would gradually increase with the time and concentration increase of NaCl stress, while the concentration of CO2 (Ci) increased with the opposite tendency. These results indicated that the main influencing factor of decreasing Pn of C. chinensis was non-stomatal factors. After being treated with different exogenous substances, the Pn, Gs, and Tr were all increased in different degrees, but the level of Ci was decreased. And the maximum fluorescence (Fm), photochemical efficiency of photosystem II (Fv/Fm), potential photochemical efficiency (Fv/Fo), photochemical efficiency (Fv'/Fm'), PSII actual photochemical efficiency (ΦPSII), photochemical quenching coefficient (qP), electronic transfer rate (ETR), and photochemistry rate (PCR) were obviously increased, while the levels of minimal fluorescence (Fo), non-photochemical quenching coefficient (NPQ), and heat dissipation rate (HDR) were effectively decreased. Conclusion: Exogenous CO H with the appropriate concentration of 2.0 mmol/L could reduce the excess excitation dissipation, improve photochemical electron transport efficiency, and efficiently protect C. chinensis leaves from PSII damage by significantly alleviating the damages of salt stress to C. chinensis so that H could obviously promote the salt resistance to C. chinensis under salt stress.

A Novel Biomimetic Porphyrin Biosensor Based on Poly (3,4-ethylenedioxythiophene) and 1-Pyrenebutanoic Acid Decorated with Hematin and Its Application in Bioelectrical Catalysis of Catechol / 分析化学

A new biosensor was prepared based on conductive polymer poly ( 3 , 4-ethylenedioxythiophene ) ( PEDOT) and 1-pyrenebutanoic acid ( PBA) through π-π stacking, as well as hematin associated with PBA through coordinate bonds of Zr4+ and carboxyl group. Its stability and sensitivity were examined by cyclic voltammetry ( CV) , electrochemical impedance spectroscopy ( EIS) and current-time ( i-t) method. A pair of well defined and quasi-reversible redox peaks was observed when GCE/PEDOT/PBA/hematin was tested by CV in PBS without oxygen. The electron transfer rate constant was estimated to be 4. 8 s-1 . Results indicated that the PEDOT film enhanced the electron transfer process of hematin. When the i-t method was used to detect the response of biosensor to catechol with different concentrations, it displayed a linear response for the reduction of catechol in the range of 0. 5-200 μmol/L. The linear equation was i=0. 018C+0. 006 ( R=0. 9998), and the detection sensitivity was 0. 258 μA (μmol/L· cm2) with a detection limit of 0. 33 nmol/L (S/N=3). The results illustrate that the GCE/PEDOT/PBA/hematin biosensor is very sensitive and stable.

Modulation of the oxidative stress in malaria infection by clotrimazole

Antimycotic clotrimazole (CTZ) has demonstrated remarkable activity against Plasmodium falciparum in vitro and in vivo. Hemoglobin degradation by Plasmodium parasites makes amino acids available for protein synthesis, inducing oxidative stress in infected cells and producing free heme. These events represent biochemical targets for potential antimalarials. In this study, we have tested the ability of CTZ to modify the oxidative status in Plasmodium berghei-infected erythrocytes. After hemolysis, activities of superoxide dismutase (SOD), catalase (CAT), glutathione cycle and NADPH+H+-producing dehydrogenases were investigated using UV-visible spectrophotometry. Thiobarbituric acid reactive substances (TBARS) were evaluated as a marker of lipid damage. Results showed that CTZ significantly decreased the overall activity of 6-phosphagluconate dehydrogenase (6PGD) compared to infected and non-treated cells; consequently, the glutathione cycle was inhibited, leaving the parasite vulnerable to the oxidative stress originating from hemoglobin degradation. As a compensatory response, CTZ prevented some loss of SOD and CAT activities in infected cells. The infection triggered lipid peroxidation in erythrocytes, which was decreased by CTZ. These results suggest the presence of a redox unbalance in cells treated with CTZ, discussing a possible effect of this compound disturbing the oxidative status in a Plasmodium berghei-infection.

O antifúngico clotrimazol (CTZ) tem demonstrado notável atividade contra Plasmodium falciparum. A degradação da hemoglobina por Plasmodium para a obtenção dos aminoácidos necessários à síntese protéica induz estresse oxidativo em eritrócitos devido à liberação de hemos oxidantes. Estes eventos representam alvos bioquímicos para a produção de antimaláricos potenciais. Neste estudo, testamos a capacidade do CTZ para modificar o estado oxidativo em eritrócitos infectados com Plasmodium berghei. Depois da hemólise, as atividades da superóxido dismutase (SOD), catalase (CAT), desidrogenases produtoras de NADPH+H+ e do ciclo de glutationa (GSH) foram investigados. A produção das espécies reativas ao ácido tiobarbitúrico (TBARS) foi avaliada como marcador de dano lipídico. Os resultados mostraram que o CTZ diminuiu a atividade da 6-fosfogliconato desidrogenase (6PGD), em comparação com eritrócitos infectados e não tratados. Consequentemente, o ciclo da GSH foi inibido, tornando os parasitas vulneráveis ao estresse oxidativo resultante da degradação da hemoglobina. Como resposta compensatória, CTZ impediu a perda de atividade da SOD e CAT nas células infectadas. A infecção induz peroxidação lipídica nos eritrócitos, sendo esta diminuída pelo CTZ. Estes resultados sugerem a existência de desequilíbrio redox nas células tratadas com CTZ, interferindo, assim, com o estado oxidativo verificado durante a infecção malárica.

Evaluation of non cyanide methods for hemoglobin estimation.

Background: The hemoglobincyanide method (HiCN) method for measuring hemoglobin is used extensively worldwide; its advantages are the ready availability of a stable and internationally accepted reference standard calibrator. However, its use may create a problem, as the waste disposal of large volumes of reagent containing cyanide constitutes a potential toxic hazard. Aims and Objective: As an alternative to drabkin`s method of Hb estimation, we attempted to estimate hemoglobin by other non-cyanide methods: alkaline hematin detergent (AHD-575) using Triton X-100 as lyser and alkaline- borax method using quarternary ammonium detergents as lyser. Materials and Methods: The hemoglobin (Hb) results on 200 samples of varying Hb concentrations obtained by these two cyanide free methods were compared with a cyanmethemoglobin method on a colorimeter which is light emitting diode (LED) based. Hemoglobin was also estimated in one hundred blood donors and 25 blood samples of infants and compared by these methods. Statistical analysis used was Pearson`s correlation coefficient. Results: The response of the non cyanide method is linear for serially diluted blood samples over the Hb concentration range from 3gm/dl -20 gm/dl. The non cyanide methods has a precision of + 0.25g/dl (coefficient of variation= (2.34%) and is suitable for use with fixed wavelength or with colorimeters at wavelength- 530 nm and 580 nm. Correlation of these two methods was excellent (r=0.98). The evaluation has shown it to be as reliable and reproducible as HiCN for measuring hemoglobin at all concentrations. The reagents used in non cyanide methods are non-biohazardous and did not affect the reliability of data determination and also the cost was less than HiCN method. Conclusions: Thus, non cyanide methods of Hb estimation offer possibility of safe and quality Hb estimation and should prove useful for routine laboratory use. Non cyanide methods is easily incorporated in hemobloginometers by using very minute quantities of reagents and test sample; hence, these methods can be used to provide point of care testing in blood banks for hemoglobin (Hb) estimation in blood donors.

Disturbance in hemoglobin metabolism and in vivo antimalarial activity of azole antimycotics / Alteración en el metabolismo de la hemoglobina y actividad antimalárica in vivo de azoles antimicóticos

Plasmodium parasites degrade host hemoglobin to obtain free amino acids, essential for protein synthesis. During this event, free toxic heme moieties crystallize spontaneously to produce a non-toxic pigment called hemozoin or ß-hematin. In this context, a group of azole antimycotics, clotrimazole (CTZ), ketoconazole (KTZ) and fluconazole (FCZ), were investigated for their abilities to inhibit ß-hematin synthesis (IßHS) and hemoglobin proteolysis (IHbP) in vitro. The ß-hematin synthesis was recorded by spectrophotometry at 405 nm and the hemoglobin proteolysis was determined by SDS-PAGE 12.5 percent, followed by densitometric analysis. Compounds were also assayed in vivo in a malaria murine model. CTZ and KTZ exhibited the maximal effects inhibiting both biochemical events, showing inhibition of β-hematin synthesis (IC50 values of 12.4 ± 0.9 µM and 14.4 ± 1.4 µM respectively) and inhibition of hemoglobin proteolysis (80.1 ± 2.0 percent and 55.3 ± 3.6 percent, respectively). There is a broad correlation to the in vivo results, especially CTZ, which reduced the parasitemia ( percentP) of infected-mice at 4th day post-infection significantly compared to non-treated controls (12.4 ± 3.0 percent compared to 26.6 ± 3.7 percent, p = 0.014) and prolonged the survival days post-infection. The results indicated that the inhibition of the hemoglobin metabolism by the azole antimycotics could be responsible for their antimalarial effect.

Los parásitos del género Plasmodium degradan la hemoglobina hospedera obteniendo aminoácidos libres para su síntesis proteica. Durante este evento, unidades de hemo libre tóxicas cristalizan espontáneamente formando un pigmento no tóxico denominado ß-hematina. En este trabajo, se investigó la capacidad de un grupo de azoles antimicóticos: clotrimazol (CTZ), ketoconazol (KTZ) y fluconazol (FCZ), en inhibir la síntesis de ß-hematina y la proteólisis de la globina. La síntesis de ß-hematina se registro por espectrofotometría a 405 nm y la proteólisis de la hemoglobina se determino por SDS-PAGE 15 por ciento seguido por análisis densitométrico de las bandas de hemoglobina intactas. Los compuestos fueron también ensayados in vivo en un modelo de malaria murina. CTZ y KTZ inhibieron la síntesis de ß-hematina con CI50 entre 10 y 15 µM y bloquearon la proteólisis de la hemoglobina (80.01 ± 2.04 por ciento y 55.33 ± 3.57 por ciento, respectivamente). En relación directa con los resultados encontrados in vitro, el CTZ redujo la parasitemia de ratones infectados en forma significativa, así como prolongó lo días de sobrevivencia post-infección en comparación con animales controles no tratados. Se sugiere así que la inhibición del metabolismo de la hemoglobina por los antimicóticos azólicos pudiera ser el mecanismo responsable de su actividad antimalárica.

A Case of Porphyria Presented During Management of Acute Upper Respiratory Infection

A 34-year old woman visited the hospital complaining severe general pain which had onset on the way of improvement of sore throat, cough with sputum as symptoms of acute upper respiratory infection for 3 days. The facts that her younger sister also had a history of porphyria and the color of the patient's urine changed to dark black after it had exposed to sunlight made us to rule out porphyria strongly. Therefore, we measured the level of delta-ALA and porphobilinogen in the collected urine during 24 hours, and confirmed her diagnosis as acute intermittent porphyria. The SIADH was complicated and the sleep disturbance, disorientation and hallucination onset during the hospital days. She had taken high dose dextrose IV and hematin IV therapy for porphyria and improved gradually. Therefore, authors et al. report a case of acute intermittent porphyria with various clinical symptoms on the way of treatment of upper respiratory infection as well as review the previous literatures.