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Effects of aqueous leaf extracts of bryophyllum pinnatum (AEBP) on

Tridax procumbens is commonly used in traditional medicine in southern part of Nigeria for the treatment of hypertension. However, the mechanism of its antihypertensive properties remains unclear. Attempts were made to investigate the properties of direct actions of aqueous extract of the leaves of T. procumbens on mechanical responses of smooth muscles in aortic ring preparations isolated from the rat. Endothelium-intact aortic rings, isolated from the normotensive rats, had been pre-contracted with noradrenaline, and cumulative addition of the aqueous extract (0.15-1.05 mg/mL) to the bathing fluid induced a concentration-dependent relaxation. Aqueous extract of T. procumbens also attenuated the contractile responses to KCl and shifted the concentration-response curve to the right. The contractile responses to serotonin were also attenuated and the concentration-response curve was shifted to the right in the presence of the extract. The results of this study indicated that aqueous leaf extract of T. procumbens possesses vasodilatory effects on the aortic smooth muscles isolated from the rat. Based on these results, a possible mechanism involved in the relaxing actions of the extract on vascular smooth muscle was discussed. The results of this study may provide a scientific basis for the use of this extract to the treatment of hypertension in Nigerian traditional medicine.

These results suggest that the vasorelaxant effect of T. procumbens leaf extract may be mediated by a non-specific, non-competitive inhibition of Ca2+ influx as well as by inhibition of Ca2+ mobilization from intracellular stores. This implies that it may contain vasorelaxant agents that may have calcium antagonistic potential.

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Background: Humans are exposed to identifiable multiple environmental stressors. However, there is paucity of studies assessing chronic variable stress (CVS) exposure together with antioxidant supplementation on reproductive function. This study investigates impact of vitamin C supplementation, during CVS exposure on contractile functions of testicular artery and sperm parameters. Twenty pubertal male Wistar rats (150-200 g) were grouped into four of five rats each consisting of control (normal saline), vitamin C treated (7 mg/kg bwt), chronic variable stress (CVS) + vitamin C, and CVS only. Animals were treated respectively for 8 weeks. Serum superoxide dismutase (SOD), catalase, malondialdehyde (MDA) activity, testosterone, and cortisol were assayed. Contractile responses of excised testicular artery to phenylephrine, potassium chloride, acetylcholine, and sodium nitroprusside were determined using Ugo Basile data acquisition system. Sperm parameters and histopathology of the testis were also determined. Statistical significance was taken at p < 0.05 Result: MDA activity was significantly increased in group exposed to chronic variable stress. However, groups supplemented with vitamin C during CVS exposure showed no significant increase. Serum SOD and catalase were enhanced in group exposed to CVS with vitamin C supplementation when compared to group exposed to chronic variable stress only. Chronic variable stress exposure increased serum cortisol level and this was attenuated with vitamin C supplementation. Vitamin C supplementation significantly increased serum testosterone level when compared to CVS only exposed group. Contraction responses of testicular arterial strips to phenylephrine and potassium chloride were attenuated in vitamin C supplemented groups when compared to CVS only exposed group. Vitamin C supplementation during CVS exposure also enhanced relaxation of testicular artery strip to sodium nitroprusside and acetylcholine. Sperm count and percentage motility were significantly reduced in CVS only exposed group when compared vitamin C supplemented group. Sperms cells with abnormal morphology were also significantly increased in chronic variable stress only exposed group when compared to control and vitamin C supplemented groups. Conclusion: Chronic variable stress adversely impacts contractility of testicular artery, sperm parameters, cortisol, and testosterone level. Vitamin C supplementation modulated these by suppressing MDA and enhancing antioxidant enzyme activity.

Asthma is a chronic inflammatory disorder of the airways. It is characterized by an inflammation of the airways causing dysfunction. Asthma is associated with widespread airflow obstruction and increase in airway responsiveness to a variety of stimuli. An asthma attack is accompanied by wheezing, shortness of breath, chest tightness and coughing. The anti-asthmatic and anti-cough activities of the essential oils and 1,8-cineole on rats were assessed. These activities were induced and challenged with histamine and acetylcholine using an ultrasonic nebulizer for asthma and exposure to ammonia for coughs. Anti-inflammatory activities of the essential oils and 1,8-cineole were determined using the cotton pellet granuloma test. Muscle contraction studies where carried out using the vascular reactivity on aortic smooth muscle. The oils exhibited concentration dependent anti-asthma and anti-cough activities. Significantly, 1,8-cineole isolated and purified from the essential oil showed a concentration dependent anti-inflammatory, anti-cough and anti-asthma activity and The essential oils showed vasorelaxant activity. The ability of the essential oils and 1,8-cineole to directly dilate smooth muscle and relieve the stress of bronchial contraction and obstruction of the airways passage validates the use of Eucalyptus grandis as an anti-asthmatic and anti-cough agent. It is concluded that the essential oils have the potential to be used as an anti-asthma and anti-cough therapy. This study also justifies its use by traditional healers in the treatment of asthma and coughs in Zulu folklore medicine.

RESULTS suggest that T. procumbens extract has a concentration-dependent relaxant effect on the isolated rat corpus cavernosum. The mechanism of action of T. procumbens extract is complex. A part of its relaxing effect is mediated directly by the release of NO from endothelium which may improve erectile dysfunction.