scholarly journals Endothelium/Nitric Oxide Mediates the Vasorelaxant and Antihypertensive Effects of the Aqueous Extract from the Stem Bark ofMammea africanaSabine (Guttiferae)

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Elvine Pami Nguelefack-Mbuyo ◽  
Alain Bertrand Dongmo ◽  
Télesphore Benoît Nguelefack ◽  
Albert Kamanyi ◽  
Pierre Kamtchouing ◽  
...  

This study evaluates the vasorelaxant and antihypertensive effects of the aqueous extract from the stem bark ofM. africana(AEMA). AEMA was testedin vitroon intact or endothelium-denuded rats’ aorta rings precontracted with KCl or norepinephrine in absence or in presence of L-NAME or glibenclamide. The effect of a single concentration (300 μg/mL) of AEMA was also examined on the concentration-response curve of KCl.In vivo, the antihypertensive effects of AEMA (200 mg/kg/day) were evaluated in male Wistar rats treated with L-NAME (40 mg/kg/day) for 4 weeks. AEMA relaxed aorta rings precontracted with NE or KCl with respective EC50 values of 0.36 μg/mL and 197.60 μg/mL. The destruction of endothelium or pretreatment of aorta rings with L-NAME shifted the EC50 of AEMA from 0.36 μg/mL to 40.65 μg/mL and 20.20 μg/mL, respectively. The vasorelaxant activity ofM. africanawas significantly inhibited in presence of glibenclamide. AEMA also significantly inhibited the concentration-response curve of KCl. Administered orally, AEMA induced acute and chronic antihypertensive effects and normalized renal NO level. These results show that the vasorelaxant activity of AEMA might be mediated by the activation of the NO-cGMP-ATP-dependent potassium channels pathway and might predominantly account for its antihypertensive effect.

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jyoti Kaushik ◽  
Simran Tandon ◽  
Rishi Bhardwaj ◽  
Tanzeer Kaur ◽  
Surinder Kumar Singla ◽  
...  

Abstract Modern treatment interventions for kidney stones are wrought with side-effects, hence the need for alternative therapies such as plant-based medicines. We have previously documented through in vitro studies that statistically optimized aqueous extract of Tribulus terrestris (Zygophyllaceae family) possesses antiurolithic and antioxidant potential. This provides strong scientific foundation to conduct in vivo efficacy and preclinical safety studies to corroborate and lend further proof to its ability to prevent and cure kidney stones. The preventive and curative urolithiatic efficacy in experimentally induced nephrolithiatic Wistar rats, along with preclinical toxicity was evaluated following oral administration of statistically optimized aqueous extract of T. terrestris. Treatment showed augmented renal function, restoration of normal renal architecture and increase in body weight. Microscopic analysis of urine revealed excretion of small sized urinary crystals, demonstrating that treatment potentially modulated the morphology of renal stones. Tissue enzymatic estimation affirmed the antioxidant efficacy of treatment with reduced free radical generation. Significant upregulation of p38MAPK at both the gene and protein level was noted in hyperoxaluric group and interestingly treatment reversed it. Acute oral toxicity study established the Median Lethal Dose (LD50) to be greater than 2000 mg/kg body weight (b.wt.) No observed adverse effect level (NOAEL) by repeated oral toxicity for 28 days at 750 mg/kg b.wt. was noted. This study lends scientific evidence to the safe, preventive and curative potential of statistically optimized aqueous extract of T. terrestris at a dose of 750 mg/kg b.wt. and suggests that the extract shows promise as a therapeutic antiurolithic agent.


1988 ◽  
Vol 235 (1279) ◽  
pp. 139-144 ◽  

Male Wistar rats were heparinized and killed with pentobarbital. The upper and lower ends of the aortae were cannulated and the blood was washed out with saline until the washings contained calcium and sialic-acid-reacting material at minimal concentrations. The aortae were perfused with neuraminidase for 15 min. This caused the appearance of calcium as well as of sialic acids in the perfusate in total amounts of about 5.3 nmol and about 3.6 nmol per aorta respectively. The molar ratio of about 1.5 is sufficiently close to that determined for the association of calcium with sialic acids in vitro to suggest that their association is similar in vivo .


2017 ◽  
Vol 56 (4) ◽  
Author(s):  
Ismat Fatima ◽  
Munawar A. Munawar ◽  
Waqar Nasir ◽  
Misbahul A. Khan ◽  
Affia Tasneem ◽  
...  

Some novel derivatives of 2-(9<em>H</em>-Purin-6-ylsulfanyl)acetohydrazide were synthesized by reacting it with respective aldehydes in ethanol. The antithyroid effect of these compounds was ascertained <em>in vitro</em> by studying their complexation with iodine spectrophotometrically. <em>In vivo</em>, the hormonal as well as histological variations in male Wistar rats demonstrated significant antithyroid potential (p ≤ 0.05) of these compounds.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Mariscal Brice Tchatat Tali ◽  
Cedric Derick Jiatsa Mbouna ◽  
Lauve Rachel Yamthe Tchokouaha ◽  
Patrick Valere Tsouh Fokou ◽  
Jaures Marius Tsakem Nangap ◽  
...  

Background. Terminalia mantaly is used in Cameroon traditional medicine to treat malaria and related symptoms. However, its antiplasmodial efficacy is still to be established. Objectives. The present study is aimed at evaluating the in vitro and in vivo antiplasmodial activity and the oral acute toxicity of the Terminalia mantaly extracts. Materials and Methods. Extracts were prepared from leaves and stem bark of T. mantaly, by maceration in distilled water, methanol, ethanol, dichloromethane (DCM), and hexane. All extracts were initially screened in vitro against the chloroquine-resistant strain W2 of P. falciparum to confirm its in vitro activity, and the most potent one was assessed in malaria mouse model at three concentrations (100, 200, and 400 mg/kg/bw). Biochemical, hematological, and histological parameters were also determined. Results. Overall, 7 extracts showed in vitro antiplasmodial activity with IC50 ranging from 0.809 μg/mL to 5.886 μg/mL. The aqueous extract from the stem bark of T. mantaly (Tmsbw) was the most potent (IC50=0.809 μg/mL) and was further assessed for acute toxicity and efficacy in Plasmodium berghei-infected mice. Tmsbw was safe in mice with a median lethal dose (LD50) higher than 2000 mg/kg of body weight. It also exerted a good antimalarial efficacy in vivo with ED50 of 69.50 mg/kg and had no significant effect on biochemical, hematological, and histological parameters. Conclusion. The results suggest that the stem bark extract of T. mantaly possesses antimalarial activity.


2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Carine Flore Adjouzem ◽  
Ateufack Gilbert ◽  
Marius Mbiantcha ◽  
William Yousseu Nana ◽  
Vanessa Matah Marthe Mba ◽  
...  

Among the most exploited species in Cameroon, Alstonia boonei is widely used in African medicine for the relief of several pathologies including gastrointestinal disorders. This study was conducted in order to assess the effects of aqueous and methanol stem-bark extracts of Alstonia boonei on DSS- (dextran sodium sulfate-) induced intestinal colitis and to determine its antioxidant potential. The classes of secondary metabolites present in these extracts were determined by chemical screening. The production of TNF-α, IL-6, IL-1β, and PGE2 was performed by in vitro ELISA analysis. Anticolitis effects were determined using an in vivo model of ulcerative colitis induced by DSS. The colitis was induced with a double dose of DSS (3% and 1%), and the aqueous and methanol extracts were administered orally from the 6th day after commencement of induction. The phytochemical screening revealed the presence of six classes of secondary metabolites in these crude extracts: tannins, saponins, alkaloids, steroids, flavonoids, and phenols. Methanol and aqueous extracts of Alstonia boonei significantly (P<0.001) inhibited TNF-α, IL-6, IL-1β, and PGE2 production stimulated by LPS. Both extracts at all doses significantly reduced (P<0.01, P<0.001) the signs of DSS-induced colitis in the Wistar rats by decreasing inflammation and chronic colon damage. In addition, the extracts significantly (P<0.001) reduced malondialdehyde and nitric oxide levels in the colon and significantly (P<0.01) increased superoxide dismutase and catalase and reduced glutathione (P<0.05). Both extracts showed greater activity than the reference substance (prednisolone 4 mg/kg) used in this study. This study has demonstrated that aqueous and methanol extracts of Alstonia boonei stem bark have healing properties against colitis experimentally induced by DSS in rats.


Author(s):  
Devang Y. Shelat ◽  
Sanjeev R Acharya

<p><strong>Objective: </strong>Curcumin, is widely studied as a potential drug in treating various disorders but lacks applicability due to poor water solubility and tissue bioavailability. The main objective of the study was to develop a formulation of curcumin that has enhanced water solubility and brain bioavailability.</p><p><strong>Methods: </strong>A curcumin concoction was prepared using solvent evaporation technique taking casein and glutathione as vectors. Various process parameters were identified namely time, temperature, pH and vector while formulation parameters included drug entrapment, anti-oxidant activity, and water solubility. The concoctions were evaluated for <em>in vitro</em> release kinetics at three pH i.e. 1.2, 4.5 and 6.2 at six-time intervals i.e. 10, 20, 30, 40, 60, 120 min using dialysis bag membrane. The same kinetics was further validated using same time points with wistar rats and giving concoction at a single dose of 2 g/kg via the oral route.</p><p><strong>Results: </strong>A concoction i.e. CUR-CA-THIONE having significant entrapment efficiency (77.83%, 97.75%, 90.19%), water solubility (40, 350 and 45 times than normal curcumin) and DPPH activity (IC<sub>50</sub>: 28.91, 25.07 and 27.89) was evaluated in concoctions CUR-CA-THIONE-T.1, CUR-CA-THIONE-T.2 and CUR-CA-THIONE-T.3 respectively. These formulations were then carried out for <em>in vitro</em> release profile at different pH with average release obtained between 20-30 min. <em>In vivo</em> kinetics was studied by isolating tissues like brain, liver, lung, kidney and spleen in male wistar rats and maximum brain bioavailability was observed for CUR-CA-THIONE-T.3 at 30 min with 75 ng/g of brain tissue.</p><p><strong>Conclusion: </strong>The experiment helps in concluding that CUR-CA-THIONE has improved its water solubility and is able to by-pass systemic circulation to targeted activity.</p>


Author(s):  
Paulin Nyadjeu ◽  
Alain Dongmo ◽  
Télesphore Benoît Nguelefack ◽  
Albert Kamanyi

The present study was undertaken to evaluate the antihypertensive and vasorelaxant effects of Cinnamomum zeylanicum Blume stem bark aqueous extract in rats. The in vivo activities of the extract were evaluated on normotensive and three rat models of hypertension while the in vitro tests were assayed on rat isolated aorta rings. Acute intravenous injection of the extract (5, 10 and 20mg/kg) induced a significant reduction in mean arterial blood pressure in anaesthetised normotensive Wistar rats, salt-loaded hypertensive, L-NAME hypertensive and spontaneously hypertensive rats. Pre-treatment of rats with either propranolol or atropine significantly inhibited the hypotensive effects of the plant extract suggesting its possible action through the interferences with both cholinergic and sympathetic transmissions. Moreover, pre-treatment of rats with L-NAME inhibited the sustained plant antihypertensive effects, suggesting a possible active vasodilatation, which might be partly mediated by an endothelial l-arginine/nitric oxide pathway. In isolated rat aortic rings pre-contracted with KCl (60mM), the extract exhibited cumulative vasodilating effects, which were attenuated with either L-NAME, vascular endothelium removal or both tetraethylammonium and glibenclamide pre-treatments. The vasorelaxant effects may be involved in the extract antihypertensive mechanism, partially by increasing the endothelial nitric oxide and by activating the KATP channels in vascular smooth muscle.


Author(s):  
MARWA ABDALLAH ◽  
DEMIANA I. NESEEM ◽  
OMAIMA N. ELGAZAYERLY ◽  
ALY A. ABDELBARY

Objective: To design topical Quercetin (Qc)-loaded transfersomes (TFs) for wound treatment. Methods: Qc-loaded TFs were prepared by thin-film hydration technique using 2241full factorial design and the optimum formula was selected. In vivo skin, deposition and cutaneous wound induction studies were performed for four groups of male wistar rats. At the end of the experiment, biochemical parameters were measured in the healed tissues (total proteins (TP), total antioxidant capacity (TAC), glutathione reductase (GSH), nitric oxide (NO), and malonaldehyde (MDA). Two in vivo histopathological experiments using male wistar rats were performed; the first study was done for the healed tissues of the above experiment and the second was to confirm the safety of formulations. Results: Qc optimum TFs (F6) showed EE% of 91.1%, PS of 695.35 nm, PDI of 0.592, and ZP of-11.1 mV, and spherical shape. In vivo skin deposition study showed that drug percentage retained in the skin from Qc optimum TFs was significantly higher than that from Qc suspension and Qc liposomes (p<0.05). There was no significant difference in the values of TP, TAC and MDA between the treated groups (p>0.05). GSH in TFs treated groups was significantly higher than the other groups (p<0.05) while NO in TFs treated groups was significantly lower than the other treated groups (p<0.05). Histopathological experiments showed that wounds treated by TFs healed better than those treated by both liposomes and Qc suspension. Conclusion: Qc-loaded TFs can be used as successful drug-delivery system for wound healing.


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