Effects of Corchorus olitorius and protacatechuic acid on diabetic rat testis tissue / Efectos de Corchorus olitorius y ácido protocatéquico en el tejido testicular de rata diabética

SUMMARY: The aim of this study is to investigate the effects of Protocatechuic acid and Corchorus olitorius on streptozotocin (STZ) induced diabetic rat testis tissue. Randomly selected Wistar Albino rats were divided into five groups as; Diabetes Mellitus, Diabetes Mellitus treated with Corchorus Olitorus (STZ+CO), Diabetes Mellitus treated with Protacatechuic acid (STZ+PCA), Corchorus olitorius (CO), Protocatechuic acid (PCA) and Control. Diabetic model was generated by intraperitoneal injection of 60 mg/kg Streptozotosin. After 48 hours of the STZ injection, blood samples were collected from tail vein in order to measure blood glycose levels. Over 250 mg/dL accepted as diabetic subjets and fed with 250 mg/kg Corchorus olitorius or 20 mg/kg PCA by oral gavage for three weeks. At the end of the experiment, right testes were removed and fixed in 10 % neutral formaldehyde for paraffine embedding. Sections were stained by HE, Masson trichrome, PAS and TUNEL for microscopic evaluation. Control, PCA-only and Corchorus olitorius-only treated group testes tissues showed a normal tissue organization, when degeneration in seminiferous tubules, the vacuolization, seperations in spermatogenic cell series, outpouring of cell groups in the lumen, vesicular body formation, liquid accumulation in the interstitial region and edema were observed in STZ induced diabetic models and untreated groups. Besides, higher amount of TUNEL (+) stained cells were determined in STZ group. On the other hand, blood glucose level and number of TUNEL (+) stained cells were decreased as a result of PCA and Corchorus olitorius treatment. Because of the reduction of blood glucose level and apoptotic cell numbers, PCA and Corchorus olitorius decreace the complications of diabetes mellitus induced rat testis.

RESUMEN: El objetivo de este estudio fue investigar los efectos del ácido protocatéquico y Corchorus olitorius sobre el tejido testicular de rata diabética inducida por estreptozotocina (STZ). Las ratas Wistar Albino fueron seleccionadas al azar y se dividieron en cinco grupos; Diabetes Mellitus, Diabetes Mellitus tratada con Corchorus olitorius (STZ + CO), Diabetes Mellitus tratada con ácido protocatéquico (STZ + PCA), Corchorus olitorius (CO), ácido protocatéquico (PCA) y Control. El modelo diabético se generó por inyección intraperitoneal de 60 mg/kg de estreptozotosina. Después de 48 horas de la inyección de STZ, se recogieron muestras de sangre de la vena de la cola para medir los niveles de glucosa. Niveles mayores a 250 mg/dL fueron considerados como especímenes diabéticos y alimentados con Corchorus olitorius de 250 mg/kg o PCA de 20 mg/kg por sonda oral durante tres semanas. Al final del experimento, se extirparon los testículos derechos y se fijaron en formaldehído neutro al 10 % para la inclusión en parafina. Las secciones se tiñeron con HE, tricromo de Masson, PAS y TUNEL para evaluación microscópica. Los tejidos de los testículos de los grupos control, tratados solo con PCA y con Corchorus olitorius mostraron una organización tisular normal. En cambio en modelos diabéticos inducidos por STZ y grupos no tratados se observó degeneración en los túbulos seminíferos, vacuolización, separaciones en series de células espermatogénicas, efusión de grupos celulares en la luz, formación del cuerpo vesicular, acumulación de líquido en la región intersticial y edema. Además, se determinó una mayor cantidad de células teñidas con TUNEL (+) en el grupo STZ. Por otro lado, el nivel de glucosa en sangre y el número de células teñidas con TUNEL (+) disminuyeron como resultado del tratamiento con PCA y Corchorus olitorius. Debido a la reducción del nivel de glucosa en sangre y el número de células apoptóticas, se observó que PCA y Corchorus olitorius disminuyen las complicaciones de los testículos de rata inducidos por diabetes mellitus.

Pesticidal and pest repellency activities of rhizomes of Drynaria quercifolia (J. Smith) against Tribolium castaneum (Herbst)

BACKGROUND: Tribolium castaneum (Herbst) is a harmful pest of stored grain and flour-based products in tropical and subtropical region. In the present study, rhizome of Drynaria quercifolia (J. Smith) was evaluated for pesticidal and pest repellency activities against T. castaneum, using surface film method and filter paper disc method, respectively. In addition, activity of the isolated compound 3,4-dihydroxybenzoic acid was evaluated against the pest. RESULTS: Chloroform soluble fraction of ethanol extract of rhizome of D. quercifolia showed significant pesticidal activity at doses 0.88 to 1.77 mg/cm² and significant pest repellency activity at doses 0.94 to 0.23 mg/cm². No pesticidal and pest repellency activity was found for petroleum ether, ethyl acetate and methanol soluble fractions of ethanol extract as well as for 3,4-dihydroxybenzoic acid. CONCLUSION: Considering our findings it can be concluded that chloroform soluble fraction of rhizome of D. quercifoliais useful in controlling T. castaneum of stored grain and flour-based products.

The mechanism of gentisic acid-induced relaxation of the guinea pig isolated trachea: the role of potassium channels and vasoactive intestinal peptide receptors

We examined some of the mechanisms by which the aspirin metabolite and the naturally occurring metabolite gentisic acid induced relaxation of the guinea pig trachea in vitro. In preparations with or without epithelium and contracted by histamine, gentisic acid caused concentration-dependent and reproducible relaxation, with mean EC50 values of 18 æM and Emax of 100 percent (N = 10) or 20 æM and Emax of 92 percent (N = 10), respectively. The relaxation caused by gentisic acid was of slow onset in comparison to that caused by norepinephrine, theophylline or vasoactive intestinal peptide (VIP). The relative rank order of potency was: salbutamol 7.9 > VIP 7.0 > gentisic acid 4.7 > theophylline 3.7. Gentisic acid-induced relaxation was markedly reduced (24 + or - 7.0, 43 + or - 3.9 and 78 + or - 5.6 percent) in preparations with elevated potassium concentration in the medium (20, 40 or 80 mM, respectively). Tetraethylammonium (100 æM), a nonselective blocker of the potassium channels, partially inhibited the relaxation response to gentisic acid, while 4-AP (10 æM), a blocker of the voltage potassium channel, inhibited gentisic acid-induced relaxation by 41 + or - 12 percent. Glibenclamide (1 or 3 æM), at a concentration which markedly inhibited the relaxation induced by the opener of ATP-sensitive K+ channels, levcromakalim, had no effect on the relaxation induced by gentisic acid. Charybdotoxin (0.1 or 0.3 æM), a selective blocker of the large-conductance Ca2+-activated K+ channels, caused rightward shifts (6- and 7-fold) of the gentisic acid concentration-relaxation curve. L-N G-nitroarginine (100 æM), a NO synthase inhibitor, had no effect on the relaxant effect of gentisic acid, and caused a slight displacement to the right in the relaxant effect of the gentisic acid curve at 300 æM, while methylene blue (10 or 30 æM) or ODQ (1 æM), the inhibitors of soluble guanylate cyclase, all failed to affect gentisic acid-induced relaxation. D-P-Cl-Phe6,Leu17[VIP] (0.1 æM), a VIP receptor antagonist, significantly inhibited (37 + or - 7 percent) relaxation induced by gentisic acid, whereas CGRP (8-37) (0.1 æM), a CGRP antagonist, only slightly enhanced the action of gentisic acid.