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Aims: The aim of the study was to investigate the antihypertensive effect of L-Tartaric acid. Background: L-Tartaric acid (L-TA) is a well-known weak organic acid that naturally occurs in a wide range of fruits, most notably in grapes, tamarind, and citrus Objective: The present study aimed to assess the effect of acute and subchronic administration of L-TA on blood pressure parameters in normotensive and hypertensive rats as well as its vasorelaxant potency. Methods: In the current study, the antihypertensive activity of L-TA was pharmacologically studied. L-NAME-induced hypertensive and normotensive rats received L-TA (80 and 240 mg/kg) orally over six hours for the acute experiment and seven days for the subchronic treatment. Thereafter, systolic, diastolic, mean, mid arterial blood pressure, and pulse pressure as well as heart rate were evaluated. In the in vitro experiment, the vasorelaxant ability of L-TA was performed in rat-isolated thoracic aorta. Results: An important drop in blood pressure was recorded in L-NAME-induced hypertensives treated with L-TA. This molecule also produced a dose-dependent relaxation of the aorta precontracted with norepinephrine (NEP) and KCl. The study demonstrated that the vasorelaxant capacity of L-TA seems to be exerted through the activation of eNOS/NO/cGMP pathways. Conclusion: The results demonstrate the potential action of L-TA as a possible antihypertensive agent.

Aims: The study aimed to evaluate the glucose-lowering effect of Tetraclinis articulata. Background: Tetraclinis articulata is commonly used for the treatment of diabetes characterized by chronic hyperglycemia. Objective: This work aimed to evaluate the effect of Tetraclinis articulata (T. articulata) aqueous extract (TAAE) on glycaemia and lipid profile in normal and streptozotocin(STZ)-induced diabetic rats. Additionally, its acute toxicity, phytochemical composition, and antioxidant capacity were assessed. Methods: To highlight the effect of TAAE on plasma glucose levels and lipid metabolism, blood glucose levels were measured at 1, 2, 4, and 6 hours of treatment for the acute test and on days 2, 4 and 7 over the daily oral administration for the subchronic test at two selected doses (10 mg/kg and 20 mg/kg). Furthermore, Triglycerides (TGs), total cholesterol (TC), and High-density lipoprotein cholesterol (HDL-c) were measured after the treatment. The rats' liver, extensor digitorum longus (EDL), and soleus muscle were isolated from diabetic rats treated with TAAE at a dose of 20 mg/kg at the end of the experiment to measure glycogen content using a standard method. The acute toxicity of TAAE was examined according to the OECD guideline. In addition, body weight, signs of toxicity, and/or mortality were observed for 14 days. Besides, a preliminary phytochemical screening, quantification of phenolic, flavonoid, and tannin contents as well as the antioxidant activity were evaluated. Results: The results showed that TAAE at the doses of 10 and 20 mg/kg possesses a potent antihyperglycemic effect in STZ-treated diabetic rats and an acute hypoglycemic effect in normal rats, as well as, the extract provoked a decrease of blood glucose levels after glucose loading in the glucose tolerance test in a dose-dependent manner. TAAE at a dose of 20 mg/kg revealed a significant improvement of the lipid profile. However, treatment with TAAE at a dose of 20 mg/kg did not significantly modify the glycogen content. In the same way, the acute toxicity analysis revealed no death or signs of toxicity in rats, and the LD50 value was more than 2 g/kg. In addition, preliminary phytochemical screening revealed that TAAE revealed the presence of polyphenols, flavonoids, tannins, carbohydrates, saponins, quinones, sterols and terpenoids. Furthermore, TAAE exhibited a potent antioxidant activity which may be due to the richness in polyphenol content (756.21±6.72 mg GAE/1 g of extract). Conclusion: The current study demonstrates for the first time that aqueous Tetraclinis articulata extract has a potent the glucose-lowering effect.

Aims: This work assessed the antihyperglycemic effect of Euphorbia guyoniana. Background: Euphorbia guyoniana (Boss. and Reut.) is widely used in traditional medicine. Objective: This study was designed to confirm this traditional use by assessing its antihyperglycemic capacity in vivo. Methods: The effect of the aqueous extract of Euphorbia guyoniana (Boss. and Reut.) (60 mg/kg) on glycemia in both normal and diabetic rats was evaluated. The glycogen content in the liver and skeletal muscles (extensor digitorum longus and soleus) was measured. Furthermore, liver histopathological analysis was performed. Results: The findings showed that Euphorbia guyoniana (Boss. and Reut.) exhibited a significant decrease in glycaemia in diabetic rats (from 20±2 mmol/l to 5.5 mmol/l after 6 hours of oral administration; p<0.0001 and from 20±2 mmol/l to 4.5 mmol/l after 7 days of once-daily repeated oral administration of the aqueous Euphorbia guyoniana extract; p<0.0001). In addition, the extract increased the glycogen content in the liver (41±4 mg/g versus 70±5 mg/g in normal and diabetic rats respectively) and extensor digitorum longus (39±4 mg/g versus 60±1 mg/g in normal and diabetic rats, respectively), and partially restored corporal weight in diabetic rats. Furthermore, this aqueous extract has been shown to suppress hyperglycemia induced by glucose load in treated diabetic rats. Additionally, hepatic histology in diabetic rats has been improved. This plant revealed the presence of several phytochemical constituents and possessed antioxidant activity. Conclusion: The current study evidenced that Euphorbia guyoniana (Boss. and Reut.) has a beneficial effect on improving hyperglycemia and glycogen depletion in the diabetic state.

Aims: The study aimed to study the antihypertensive activity of Laurus nobilis. Background: Laurus nobilis L. is used to treat hypertension in Morocco. Objective: The study was designed to investigate the effect of the aqueous extract leaves of Laurus nobilis (AELN) on blood pressure. Materials and methods: The antihypertensive and vasorelaxant activities of AELN were pharmacologically investigated in normotensive and L-NAME-induced hypertensive rats. Thereafter, blood pressure was evaluated and the ex-vivo vasorelaxant activity of this extract was performed. Results: A considerable decrease of blood pressure parameters was observed in L-NAME-induced hypertensive rats treated with AELN. The extract induced a vasorelaxant effect on aorta precontracted with epinephrine or KCl through inhibition of extracellular Ca2+ entry. Conclusion: The study demonstrates that Laurus nobilis aqueous extract exhibits a potent antihypertensive and vasorelaxant activities via the inhibition of Ca2+ entry.