Quercetin as a nephroprotector after warm ischemia: histomorphometric evaluation in a rodent model

ABSTRACT Purpose: To quantitatively evaluate the possible long-term protective effects of quercetin during renal warm ischemia. Materials and Methods: Male rats were allocated into 4 groups: sham (S), sham quercetin (SQ), ischemia (I), and ischemia quercetin (IQ). Groups SQ and IQ received quercetin (50mg/kg) before and after surgery. Groups I and IQ had their left renal vessels clamped for 60 minutes. All animals were euthanized four weeks after the procedure, and serum urea and creatinine levels were measured. Renal weight and volume, cortex-non-cortex area ratio (C-NC), cortical volume (CV), glomerular volumetric density (Vv[glom]), volume-weighted glomerular volume (VWGV) and number of glomeruli per kidney (N[glom]) were evaluated by stereological methods. Results were considered statistically significant when p <0.05. Results: Serum urea levels in group I increased by 10.4% in relation to group S, but no differences were observed among the other groups. The C-NC of group I was lower than those of all other groups, and group IQ had similar results to sham groups. The Vv[glom] and N[glom] of group I were lower than those of group S (33.7% and 28.3%, respectively) and group IQ had no significant difference compared to the S group. Conclusions: Quercetin was effective as a nephroprotective agent in preventing the glomerular loss observed when the kidney was subjected to warm ischemia. This suggests that this flavonoid may be used preventively in kidney surgery, when warm ischemia is necessary, such as partial nephrectomy.

Inhibition of paracetamol-induced acute kidney damage in rats using a combination of resveratrol and quercetin / Inhibición de daño renal agudo inducido por paracetamol en ratas usando una combinación de resveratrol y quercetina

Paracetamol (also called acetaminophen, or APAP) overdose causes acute damage to the liver and kidneys in both humans and experimental animal models via the induction of the oxidative stress pathway. We sought to determine whether the combined antioxidants and anti-inflammatory compounds, resveratrol (RES) and quercetin (QUR) can protect against kidney injury induced by a toxic dose of APAP in a rat model of APAP-induced acute kidney injury. Rats were either received a single dose of APAP (2 g/kg) before being sacrificed after 24 hours or were pre-treated for 7 days with combined doses of RES (30 mg/kg) and QUR (50 mg/kg) before being given a single dose of APAP and then sacrificed 24 hours post APAP ingestion. Harvested kidney tissues were prepared for light microscopy staining, and tissue samples were assayed for (i) biomarkers of oxidative stress and antioxidant, malondialdehyde (MDA) and superoxide dismutase (SOD); and (ii) biomarkers of inflammation, tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). Hematoxylin and eosin (H&E) stained images showed that APAP overdose induced acute kidney injury as demonstrated by widening of glomeruli space (Bowman space), tubular dilatation, numerous cellular debris in the renal tubules with tubular epithelial degeneration, and vacuolization, which were effectively protected by RES+QUR except a partial protection of the glomeruli space was observed. In addition, APAP significantly (p<0.05) modulated tissue levels of MDA, SOD, TNF-α, and IL-6, which were protected by RES+QUR. Furthermore, a significant (p<0.0001) positive correlation was observed between glomeruli space and TNF-α, (r=0.8899), IL-6 (r=0.8986), and MDA (r=0.8552), whereas glomeruli space scoring versus SOD showed negative correlation (r= - 0.7870). We conclude that resveratrol plus quercetin substantially protects against APAP-induced acute kidney injury in rats, possibly via the augmentation of antioxidants and inhibition of oxidative stress and inflammation.

La sobredosis de paracetamol (también llamado acetaminofen o APAP) causa un daño agudo en el hígado y los riñones, tanto en humanos como en modelos animales experimentales, a través de la inducción de la vía del estrés oxidativo. Intentamos determinar si los antioxidantes y los compuestos antiinflamatorios combinados, el resveratrol (RES) y la quercetina (QUR) pueden proteger contra la lesión renal inducida por una dosis tóxica de APAP en un modelo de rata de lesión renal aguda inducida por APAP. Las ratas recibieron una dosis única de APAP (2 g / kg) antes de ser sacrificadas después de 24 horas o se trataron previamente durante 7 días con dosis combinadas de RES (30 mg / kg) y QUR (50 mg / kg), antes de ser tratadas, se administró una dosis única de APAP y luego fueron sacrificadas 24 horas después de la ingestión. Los tejidos renales recolectados se tiñeron con H-E y fueron observados a través de microscopía óptica. Las muestras de tejido se analizaron para (i) biomarcadores de estrés oxidativo y antioxidante, malondialdehído (MDA) y superóxido dismutasa (SOD); y (ii) biomarcadores de inflamación, factor de necrosis tumoral alfa (TNF-α) e interleucina-6 (IL-6). Las imágenes teñidas con H & E mostraron que la sobredosis de APAP indujo daño renal agudo como lo demuestra la ampliación del espacio glomerular, la dilatación tubular, numerosos desechos celulares en los túbulos renales con degeneración epitelial tubular y la vacuolización, que se protegieron eficazmente con RES + QUR Se observó una protección parcial del espacio glomerular. Además, APAP modificó significativamente (p <0.05) los niveles tisulares de MDA, SOD, TNF-α e IL-6, que estaban protegidos por RES + QUR. Además, se observó una correlación positiva significativa (p <0,0001) entre el espacio glomerular y el TNF-α, (r = 0,8899), IL-6 (r = 0,8986) y MDA (r = 0,8552), mientras que la puntuación del espacio glomerular versus SOD mostró correlación negativa (r = - 0,7870). Concluimos que el resveratrol más quercetina protege sustancialmente contra la lesión renal aguda inducida por APAP en ratas, posiblemente a través del aumento de antioxidantes y la inhibición del estrés oxidativo y la inflamación.

Effect of taxifolin on oxidative gastric injury induced by celiac artery ligation in rats

Abstract Purpose: To examine the effect of taxifolin on I/R induced gastric injury in rats using biochemical and histopatholohical methods. Methods: Eighteen albino Wistar male rats equally grouped as; gastric I/R (I/R), 50 mg/kg taxifolin + gastric I/R (TAX+ I/R) and sham operation applied (SHAM). Ischemia induced for 1 hour, and reperfusion induced for 3 hours. Results: Oxidant parameters like, Malondialdehyde (MDA) and Hydroxyguanine (8-OHdG) were higher, whereas total glutathione (tGSH) was lower in the I/R group according to SHAM group, histopathological findings such as marked destruction, edema, and proliferated dilated congested blood vessels were observed severely in the I/R group, whereas there was not any pathological finding except mild dilated congested blood vessels in the TAX+ I/R group. Conclusion: The taxifolin can be clinically beneficial in the treatment of gastric injury due to I/R procedure.

Hyperin protects against cisplatin-induced liver injury in mice

Abstract Purpose: To evaluate the effect of hyperin in cisplatin-induced liver injury in mice. Methods: Mice were pretreated with hyperin at doses of 25 mg/kg and 50 mg/kg, respectively, for six days, and intraperitoneal injection of cisplatin (40 mg/kg) was administrated one hour after the final intragastrication of hyperin. Twenty-four hours later, blood and liver were collected for further research. Results: A single injection of cisplatin (40 mg/kg) for 24 h significantly increased serum alanine and aspartate aminotransferases (ALT/AST) and gamma glutamyl transferase (GGT) activities, whileas hyperin reversed cisplatin-induced such increases. Liver histopathological examination further demonstrated the protection of hyperin against cisplatin-induced liver injury. Further results showed hyperin reversed cisplatin-induced the increase in content of malondialdehyde (MDA) and the decrease in level of total antioxidant capacity (T-AOC) in liver. Moreover, hyperin increased the levels of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx), glutathione-s transferase (GST) in cisplatin-induced liver. Conclusion: Hyperin inhibits cisplatin-induced hepatic oxidative stress, which contributes greatly to the amelioration of cisplatin-induced liver injury in mice.

Desenvolvimento e avaliação de eficácia de nanoemulsão catiônica bioativa na proteção capilar aos danos foto-oxidativos / Development and evaluation of the effectiveness of bioactive cationic nanoemulsion in protecting hair photo-oxidative damage

A radiação solar, composta por radiação ultravioleta (UV), visível (Vis) e infravermelho, é responsável por acelerar os processos de alteração de cor e do conteúdo proteico da fibra capilar. Visando contornar este problema, este trabalho propõe a incorporação do flavonoide quercetina, de reconhecida atividade antioxidante, em uma nanoemulsão catiônica de aplicação capilar. Para tanto, foram desenvolvidas formulações contendo quercetina a 0,5% (p/p) pelo método de baixa energia sub-PIT. A formulação de menor índice de polidispersão (IPD) foi selecionada e submetida à Avaliação de Estabilidade Normal. Neste ensaio, a nanoemulsão foi armazenada em diferentes condições de temperatura por 90 dias, sendo analisados: características organolépticas, valor de pH, atividade antioxidante, conteúdo de quercetina, diâmetro médio de gotícula e potencial zeta. A fotoestabilidade da nanoemulsão envolveu a determinação do perfil de absorção e da sua atividade antioxidante após períodos de exposição à radiação UV/Vis. Posteriormente, a nanoemulsão foi caracterizada quanto aos seguintes parâmetros: eficiência de encapsulamento, perfil reológico, morfologia das gotículas por Microscopia Eletrônica de Transmissão Criogênica e Microscopia de Força Atômica (AFM). A possível interação entre a quercetina e os demais tensoativos presentes na nanoemulsão foi avaliada por Microscopia Confocal de Fluorescência e Análise térmica. A segurança da nanoemulsão foi determinada pelo método in vitro HET-CAM e por biocompatibilidade cutânea, em voluntários. A eficácia da nanoemulsão catiônica na fotoproteção das características da fibra capilar descolorida tratada com tintura cores loiro (12.0) ou ruivo (6.66) foi determinada avaliando-se os parâmetros cor, tração à ruptura, penteabilidade, fricção, perda proteica, morfologia das cutículas e nível de melanina radical por Espectroscopia de Ressonância Paramagnética Eletrônica (EPR), sendo calculado o Fator de Proteção Radicalar (FPR). As mechas de cabelo tingidas foram expostas à radiação UV/Vis artificial (500 W/m2) por até 180 h, sendo os parâmetros analisados antes e após o período de exposição. A nanoemulsão selecionada pelo reduzido IPD apresentava diâmetro médio de gotícula e potencial zeta iguais a 24,97±0,30 nm e 19,6±2,19 mV, respectivamente. Na Avaliação de Estabilidade Normal, a nanoemulsão armazenada a 45,0±2,0° C apresentou alterações significativas de todos os parâmetros avaliados, exceto potencial zeta, sendo que a elevação do diâmetro médio de gotícula acarretou em perda da transparência. A oxidação da quercetina e a instabilidade do tipo Ostwald ripening (ω3) foram as responsáveis pelas modificações observadas. No armazenamento a 5,0±2,0° C, a nanoemulsão manteve todos os parâmetros inalterados, mas a 25±2,0° C houve elevação discreta do diâmetro médio de gotícula, sem perda da funcionalidade. A nanoemulsão apresentou elevada fotoestabilidade, sem alteração da atividade antioxidante após exposição ao UV/Vis. A caracterização da nanoemulsão mostrou que a eficiência de encapsulamento foi de 99,8%, no mínimo, a formulação apresentou típico comportamento newtoniano e as gotículas apresentavam formato esférico. As imagens obtidas por Microscopia Confocal de Fluorescência e o ensaio de Análise térmica mostraram que a quercetina se encontra dentro das gotícula atuando, também, como co-tensoativo, por interagir com os tensoativos, além de exercer sua função antioxidante. A nanoemulsão foi classificada como levemente irritante (método HET-CAM), sendo esse baixo potencial de irritação corroborado pelo teste de biocompatibilidade cutânea. Na avaliação de eficácia, observou-se que a nanoemulsão protegeu a cor total (dE*) do cabelo tingido de loiro em 54%, e elevou a alteração da cor do cabelo tingido de ruivo em 47% (t = 180 h) em comparação à mecha controle. Além disso, a nanoemulsão melhorou a penteabilidade e reduziu os coeficientes de fricção. A radiação UV/Vis provocou elevada perda proteica e redução da espessura das cutículas em aproximadamente 50%. Concluiu-se, pelos resultados obtidos, que as moléculas que compoem a tintura capilar, principalmente os pigmentos mais escuros, atuaram como filtros solares, pois elas protegeram as estruturas proteicas da fibra. A nanoemulsão apresentou FPR igual a 3,31 e 4,14, para as mechas tingidas de loiro e ruivo, respectivamente. O FPR indica a capacidade de uma formulação em reduzir o nível de radicais livres formados por indução da radiação UV/Vis, um dos fatores que induzem alterações na fibra capilar tingida. Assim, considerando que a radiação UV/Vis atua tanto por mecanismos diretos quanto indiretos, e que alterações significativas de cor foram observadas mesmo quando o nível de radicais livres foi reduzido pela ação da quercetina, deve ser incorporada à formulação fotoprotetora capilar filtros solares associados a antioxidantes nanoestruturados. Tais filtros devem ficar aderidos à cutícula, de modo a protegê-la da degradação proteica e reduzir a entrada de radiação para o interior da fibra capilar, local onde os antioxidantes nanoestruturados devem atuar como uma segunda linha de defesa

The solar radiation, comprising ultraviolet (UV), visible (VIS) and infrared, is responsible for accelerating color and protein content changes in the hair fiber. In order to avoid this problem, this work proposes the incorporation of the flavonoid quercetin, a recognized antioxidant molecule, in a cationic nanoemulsion for hair application. For this, formulations containing quercetin 0.5% (w/w) were developed by the low-energy sub-PIT method. The formulation with a lower polydispersity index (PDI), which had HLB value (Hydrophilic-Lipophilic Balance) equal to 12.5 was selected and subjected to the Normal Stability Test. In this assay, the nanoemulsion was stored under different temperature conditions for 90 days, and the following parameters were analyzed: organoleptic properties, pH, antioxidant activity, quercetin content, average droplet diameter and zeta potential. The photostability of the nanoemulsion involved the determination of the absorption profile and its antioxidant activity after periods of exposure to UV/Vis radiation. Subsequently, the nanoemulsion was characterized according to the following parameters: encapsulation efficiency, rheological profile, morphology of the droplets by Cryogenic Transmission Electron Microscopy and Atomic Force Microscopy (AFM). The possible interaction between quercetin and other surfactants present in the nanoemulsion was evaluated by Confocal Fluorescence Microscopy and thermal analysis. The safety of the nanoemulsion was assessed by the in vitro HET-CAM method and by cutaneous biocompatibility in volunteers. The photoprotection effectiveness of the bioactive cationic nanoemulsion was evaluated in blond (color 12.0) and auburn (color 6.66) dyed hair fibers by assessing the parameters: color, tensile break, combing, friction, protein loss, morphology of cuticles and level of melanin radical by Electron Paramagnetic Resonance Spectroscopy (EPR). The Radical Hair Protection Factor (RHF) was calculated. Dyed hair tresses were exposed to UV/Vis artificial radiation (500 W/m2) for 180 h. The parameters were analyzed before and after the exposure period. The nanoemulsion selected due to its reduced PDI had an average droplet diameter and zeta potential equal to 24.97±0.30 nm and 19.6±2.19 mV, respectively. In the Normal Stability Test, the nanoemulsion stored at 45.0 ± 2.0º C showed significant changes in all parameters except zeta potential, and the increase in the average droplet diameter resulted in the loss of transparency. Oxidation of quercetin and Ostwald ripening instability (ω3) were responsible for the changes. At 5.0 ± 2.0º C, the nanoemulsion kept all parameters unchanged, but at 25.0±2.0º C there was a slight increase in the average droplet diameter without loss of functionality. The nanoemulsion showed high photostability since antioxidant activity was not altered after UV/Vis exposure. The characterization of the nanoemulsion showed that the encapsulation efficiency was 99.8% at least, the formulation showed typical Newtonian behavior and droplets were spherical. The images obtained by Confocal Fluorescence Microscopy and thermal analysis showed that quercetin was within the droplet acting, also, as a cosurfactant, due to the interaction with the surfactants. The nanoemulsion was classified as slightly irritating (HET-CAM method), and this low irritation potential was supported by the cutaneous biocompatibility assay. The photoprotective effectiveness evaluation showed that the nanoemulsion protected the total color (dE*) of blond dyed hair in 54%, but raised the color change of auburn dyed hair in 47% (t = 180 h). In addition, the nanoemulsion improved combability and reduced coefficients of friction. UV/Vis radiation caused high protein loss and reduced cuticle thickness by approximately 50%. It was concluded that the molecules that compose hair dye, especially the darker pigments, acted as sun filters because they protected the protein structures of the hair fiber. The nanoemulsion showed RHF equal to 3.31 and 4.14 for blond and auburn dyed hair, respectively. The RHF indicates the ability of a formulation to reduce the level of free radicals formed by UV/Vis induction, one of the factors that induce changes in the dyed hair fibers. Thus, considering that the UV/Vis radiation acts by direct and indirect mechanisms and that significant changes in color were observed even when the level of free radicals has been reduced by the quercetin, chemical filters should be incorporated into hair formulations associated with nanostructured antioxidants in order to fully protect hair fiber. Such filters must be attached to the cuticle, protecting it from protein degradation and reducing the radiation input into the hair fiber, where the nanostructured antioxidants must act as a second line of defense

Gastroprotective activity of the hydroethanolic extract and ethyl acetate fraction from Kalanchoe pinnata (Lam. ) Pers

ABSTRACT Peptic ulcers are an important pathology, and the search for safer and more effective treatment methods is of paramount importance. In this study, we assess the gastroprotective effects of the hydroethanolic extract (HE) and ethyl acetate fraction (EAF) from Kalanchoe pinnata leaves against an ethanol/HCl-induced ulcer model in rats. The HE reduced gastric lesions by approximately 47% (400 mg/kg). A significant inhibition of the gastric lesions by 50% was observed after pretreatment with the EAF (200 mg/kg). Quercetrin and quercetin 3-O-α-L-arabinopyranosyl-(1→2)-α-L-rhamnopyranoside were isolated and identified in the flavonoid fraction (EAF) by HPLC and NMR analyses because this fraction showed the highest gastroprotective effect. This fraction demonstrated high antioxidant activities (CE50=41.91 µg/mL) by DPPH in comparison with Trolox(r) and 11.33 mmol Trolox(r) equivalent by ORAC. In conclusion, the HE and FAE from K. pinnata displayed gastroprotective activity in rats, most likely due to the presence of flavonoids.

A combination of methylprednisolone and quercetin is effective for the treatment of cardiac contusion following blunt chest trauma in rats

Cardiac contusion is a potentially fatal complication of blunt chest trauma. The effects of a combination of quercetin and methylprednisolone against trauma-induced cardiac contusion were studied. Thirty-five female Sprague-Dawley rats were divided into five groups (n=7) as follows: sham, cardiac contusion with no therapy, treated with methylprednisolone (30 mg/kg on the first day, and 3 mg/kg on the following days), treated with quercetin (50 mg·kg−1·day−1), and treated with a combination of methylprednisolone and quercetin. Serum troponin I (Tn-I) and tumor necrosis factor-alpha (TNF-α) levels and cardiac histopathological findings were evaluated. Tn-I and TNF-α levels were elevated after contusion (P=0.001 and P=0.001). Seven days later, Tn-I and TNF-α levels decreased in the rats treated with methylprednisolone, quercetin, and the combination of methylprednisolone and quercetin compared to the rats without therapy, but a statistical significance was found only with the combination therapy (P=0.001 and P=0.011, respectively). Histopathological degeneration and necrosis scores were statistically lower in the methylprednisolone and quercetin combination group compared to the group treated only with methylprednisolone (P=0.017 and P=0.007, respectively). However, only degeneration scores were lower in the combination therapy group compared to the group treated only with quercetin (P=0.017). Inducible nitric oxide synthase positivity scores were decreased in all treatment groups compared to the untreated groups (P=0.097, P=0.026, and P=0.004, respectively). We conclude that a combination of quercetin and methylprednisolone can be used for the specific treatment of cardiac contusion.

Efeitos da quercetina na lesão pulmonar induzida por bleomicina: um estudo preliminar / Effects of quercetin on bleomycin-induced lung injury: a preliminary study

OBJETIVO: Investigar os efeitos da quercetina em um modelo de inflamação pulmonar e fibrose induzidas por bleomicina. MÉTODOS: Setenta e nove hamsters machos adultos foram randomizados para aplicação de injeções pelas vias intratraqueal (IT) e intraperitoneal (IP) em quatro configurações: veículo IP/salina IT (grupo VS, n = 16); salina IT/quercetina IP (grupo QS, n = 16); bleomicina IT/veículo IP (grupo VB, n = 27); e bleomicina IT/quercetina IP (grupo QB, n = 20). A quercetina e a bleomicina foram aplicadas em doses de 30 mg/kg/dia e 10 U/kg, respectivamente.A quercetina foi iniciada/suspensa 3 dias antes/14 dias depois das injeções IT. RESULTADOS: A taxa de mortalidade do grupo VB foi significantemente superior à dos demais grupos (44 por cento vs. VS: 0 por cento; QS: 0 por cento; QB: 15 por cento). O grupo VB exibiu níveis pulmonares de substâncias reativas ao ácido tiobarbitúrico (× 10-2 nmol/mg) significativamente maiores (6,6 ± 1,3 vs. VS: 5,5 ± 0,8; QS: 2,5 ± 0,6; e QB: 5,8 ± 0,6).Os grupos VB/QB mostraram níveis pulmonares de glutationa reduzida (× 10-2 nmol/mg) significativamente menores que os dos grupos VS/QS (28,9 ± 13,8/28,6 ± 14,8 vs. 43,9 ± 16,0/51,1 ± 20,3) e níveis de hidroxiprolina (mg/g) significativamente maiores (201,6 ± 37,3/177,6 ± 20,3 vs. 109,6 ± 26,1/117,5 ± 32,0). CONCLUSÕES: Em um modelo animal de lesão pulmonar, a quercetina exibiu efeitos antiinflamatórios que são relacionados, pelo menos em parte, a suas propriedades antioxidantes.

OBJECTIVE: The aim of this study was to identify the best experimental model in which to observe the pulmonary alterations characterizing hepatopulmonary syndrome (HPS). METHODS: Male Wistar rats, with mean weight of 250 g, were used in four experimental models: inhaled carbon tetrachloride; intraperitoneal carbon tetrachloride; partial portal vein ligation; and bile duct ligation (BDL). The animals in all groups were divided into control and experimental subgroups. The following variables were measured: transaminase levels; blood gases; lipoperoxidation, using thiobarbituric acid reactive substances (TBARS) and chemiluminescence; and levels of superoxide dismutase (SOD) anti-oxidant activity. Anatomopathological examination of the lung was also performed. RESULTS: There were statistically significant differences between the BDL control and BDL experimental groups: aspartate aminotransferase (105.3 ± 43 vs. 500.5 ± 90.3 IU/L); alanine aminotransferase (78.75 ± 37.7 vs. 162.75 ± 35.4 IU/L); alkaline phosphatase (160 ± 20.45 vs. 373.25 ± 45.44 IU/L); arterial oxygen tension (85.25 ± 8.1 vs. 49.9 ± 22.5 mmHg); and oxygen saturation (95 ± 0.7 vs. 73.3 ± 12.07 percent). Lipoperoxidation and antioxidant activity also differed significantly between the two BDL groups (control vs. experimental): TBARS (0.87 ± 0.3 vs. 2.01 ± 0.9 nmol/mg protein); chemiluminescence (16008.41 ± 1171.45 vs. 20250.36 ± 827.82 cps/mg protein); and SOD (6.66 ± 1.34 vs. 16.06 ± 2.67 IU/mg protein). The anatomopathological examination confirmed pulmonary vasodilatation in the BDL model. In the other models, there were no alterations that were characteristic of HPS. CONCLUSIONS: The data obtained suggest that the BDL model can be used in future studies involving hepatic alterations related to oxidative stress and HPS.

Nephrotoxicity induced by long-term administration of paraquat in rats: protective effects of quercetin and extracts of malt and green tea

Paraquat [PQ], a well-known herbicide, causes nephrotoxicity mediate by redox-cycling and extensive production of superoxide anions in the kidney. The possible protective effects of three natural products namely; green tea extract [I mg/kg], malt extract [625 mg/kg] and quercetin [50 mg/kg], against nephrotoxicity induced by long-term administration of PQ in rats were examined. PQ was intraperitoneally injected once weekly [20 mg/kg] with or without oral daily treatment with any of the three agents for 6 consecutive weeks. Nephrotoxicity was assessed by measuring serum creatinine level, histological examination of kidney sections and calculation of percentage kidney-to-body weight of rats. In addition changes in enzymatic activities of superoxide dismutase [SOD], lactate dehydrogenase [LDH] and myeloperoxidase [MPO], as well as reduced glutathione [GSH], protein thiols [Pr-SHs] and total nitrate/nitrite [NOx] contents of renal tissues were determined. Renal lipid peroxidation was also assessed by measurement of the levels of thiobarbituric acid reactive substances [TBARS]. PQ administration resulted in marked nephrotoxicity manifested by severe increase in serum creatinine level accompanied by changes in renal oxidant status of rats demonstrated by elevated TBARS level and increased activities of MPO and SOD. PQ also resulted in depletion of renal GSH and NOx contents as well as reduced activity of cytosolic LDH. On the other hand, no significant effect was noted on percentage kidney-to-body weight of rats or on renal Pr-SHs contents. Six weeks of regular daily treatment with any of the chosen agents significantly protected against most of PQ-induced biochemical changes. Histological examinations of kidney morphological changes revealed marked lesions with PQ especially in renal proximal tubules and variable degrees of protection by the test agents with the best results produced by malt extract and quercetin and to lesser extent by green tea extract. It could be concluded that malt extract and quercetin offered remarkable protection against PQ-induced nephrotoxicity in rats. Green tea extract produced some beneficial effects on the biochemical events associated with PQ-induced nephrotoxi city

Hepatoprotective studies on Phyllanthus emblica Linn. and quercetin.

Phyllanthus emblica is a constituent of many hepatoprotective formulations available in market. 50% alcoholic extract of P. emblica and quercetin isolated from it were studied for hepatoprotective effect against country made liquor (CML) and paracetamol challenge in albino rats and mice respectively. The extract at the dose of 100 mg/100 g [corrected], po and quercetin at the dose of 15 mg/100 g, po, produced significant hepatoprotection.