Dichrostachys cinerea (L.) Wight et Arn (Mimosaceae) hydro-alcoholic extract action on the contractility of tracheal smooth muscle isolated from guinea-pig

<p>Abstract</p> <p>Background</p> <p><it>Dichrostachys cinerea </it>(L.) Wight et Arn. (Mimosaceae) is largely used in ethno-medically across Africa, and mainly employed for the treatment of asthma in Ivory Coast and Gabon. The paper analyses the relaxation induced by the methanolic extract of <it>D. cinerea </it>(Edici) in the guinea-pig trachea preparations (GPTPs). Purpose: This study aimed to bring out the scientific basis to the use of this plant leading to the validation of this phytomedicine.</p> <p>Method</p> <p>The aorta obtained from guinea-pigs was immediately placed in a Mac Ewen solution. Experiments were performed in preparations suspended between two L-shaped stainless steel hooks in a 10 ml organ bath containing Mac Ewen solution. The isometric contractile force of the aorta strips of guinea-pig were recorded by using a strain gauge. The different drugs were directly administered into the organ bath and the magnitude of GPTPs was evaluated.</p> <p>Results</p> <p>Phytochemical analysis of the methanolic extract of Dichrostachys <it>cinerea </it>(Edici) using chemical methods revealed the presence of flavenoids, tannins, sterols, triterpenes and polyphenols. Pharmacological studies performed in GPTPs show that of <it>Dichrostachys cinerea </it>(0.1 mg/ml - 2 mg/ml) evoked a broncho-constriction in GPTPs. Whereas, at concentration up to 2 mg/ml, Edici induced a significant dose-dependent relaxation in the GPTPs. KCl-, ACh- or histamine-evoked contractions of isolated trachea was significantly inhibited by increasing concentrations of Edici (3.5-10 mg/ml). Edici (10 mg/ml) as well as promethazine (0.25 mg/ml) significantly inhibited contractions induced by increasing concentrations of histamine (1×10^-7-1×10^-4mg/ml). In the presence of atropine at a concentration of 10^-6mg/ml, contractile response curve (CRC) evoked by ACh (1×10^-5-1×10^-2mg/ml) was significantly abolished in concentration-dependent manner. Edici did not significantly reduced ACh evoked contraction (10^-5-10^-2mg/ml).</p> <p>Conclusion</p> <p>These observations suggest that Edici could act through two mechanisms: firstly by activation of β-adrenergic or histaminergic receptors; and secondly muscarinic receptors may not be greatly involved, that justifying the use of the extract in traditional Medicine in Africa.</p

Is there really a beauty premium or an ugliness penalty on earnings?

Purpose Economists have widely documented the “beauty premium” and “ugliness penalty” on earnings. Explanations based on employer and client discrimination would predict a monotonic association between physical attractiveness and earnings; explanations based on occupational self-selection would explain the beauty premium as a function of workers’ occupations; and explanations based on individual differences would predict that the beauty premium would disappear once appropriate individual differences are controlled. In this paper, we empirically tested the three competing hypotheses about the “beauty premium”. Design/Methodology/Approach We analyzed a nationally representative and prospectively longitudinal sample from the National Longitudinal Survey of Adolescent Health (Add Health). Findings Findings The results contradicted the discrimination and self-selection explanations and strongly supported the individual differences explanation. Very unattractive respondents always earned significantly more than unattractive respondents, sometimes more than average-looking or attractive respondents. Multiple regression analyses showed that there was very weak evidence for the beauty premium, and it disappeared completely once individual differences, such as health, intelligence, and Big Five personality factors, were statistically controlled. Implications Past findings of beauty premium and ugliness penalty may possibly be due to the fact that: 1) “very unattractive” and “unattractive” categories are usually collapsed into “below average” category; and 2) health, intelligence (as opposed to education) and Big Five personality factors are not controlled. It appears that more beautiful workers earn more, not because they are beautiful, but because they are healthier, more intelligent, and have better (more Conscientious and Extraverted, and less Neurotic) personality. Originality/Value This is the first study to show that: 1) very unattractive workers have extremely high earnings and earn more than physically more attractive workers, suggesting evidence for the potential ugliness premium; and 2) the apparent beauty premium and ugliness penalty may be a function of unmeasured traits correlated with physical attractiveness, such as health, intelligence, and personality