Chemical composition and mechanisms underlying the spasmolytic and bronchodilatory properties of the essential oil of Nepeta cataria L.

AIM OF THE STUDY: The study was aimed to investigate the chemical composition and pharmacological basis for traditional use of essential oil of Nepeta cataria L. (Limiaceae) (Nc.Oil) in gastrointestinal and respiratory disorders. MATERIALS AND METHODS: Chemical analysis was carried out through GC-EIMS, 13C NMR and Kovats Retention Indices while pharmacological study was carried out in isolated tissues preparations. RESULTS: Four major components; 1,8-cineol (21.00%), alpha-humulene (14.44%), alpha-pinene (10.43%) and geranyl acetate (8.21%) were identified among the 27 compounds in Nc.Oil. In isolated rabbit jejunum, Nc.Oil, papaverine and verapamil inhibited spontaneous and high K+(80 mM) precontractions, as well as shifted the Ca++ concentration-response curves (CRCs) to right, indicating calcium channel blocking activity. In isolated guinea-pig trachea, Nc.Oil and papaverine inhibited carbachol (1 microM) and K+ precontractions with similar potency, while verapamil was more potent against K+. Nc.Oil also potentiated isoprenaline inhibitory CRCs, similar to papaverine, indicating papaverine-like PDE inhibitor activity. In isolated guinea-pig atria, Nc.Oil caused cardiodepression at around 25-80 times higher concentrations, similar to papaverine. CONCLUSIONS: These data indicate that Nepeta cataria possesses spasmolytic and myorelaxant activities mediated possibly through dual inhibition of calcium channels and PDE, which may explain its traditional use in colic, diarrhea, cough and asthma.

Perceptions about the cause of schizophrenia and the subsequent help seeking behavior in a Pakistani population - results of a cross-sectional survey.

BACKGROUND: There is a cultural variability around the perception of what causes the syndrome of schizophrenia. Generally patients with schizophrenia are considered dangerous. They are isolated and treatment is delayed. Studies have shown favorable prognosis with good family and social support, early diagnosis and management. Duration of untreated psychosis is a bad prognostic indicator. We aimed to determine the perceptions regarding the etiology of schizophrenia and the subsequent help seeking behavior. METHODS: This cross-sectional study was carried out on a sample of 404 people at the out patient departments of Aga Khan University Hospital Karachi. Data was collected via a self-administered questionnaire. Questions were related to a vignette of a young man displaying schizophrenic behavior. Data was analyzed on SPSS v 14. RESULTS: The mean age of the participants was 31.4 years (range = 18-72) and 77% of them were males. The majorities were graduates (61.9%) and employed (50%). Only 30% of the participants attributed 'mental illness' as the main cause of psychotic symptoms while a large number thought of 'God's will' (32.3%), 'superstitious ideas' (33.1%), 'loneliness' (24.8%) and 'unemployment' (19.3%) as the main cause. Mental illness as the single most important cause was reported by only 22%. As far as management is concerned, only 40% reported psychiatric consultation to be the single most important management step. Other responses included spiritual healing (19.5%) and Sociachanges (10.6) while 14.8% of respondents said that they would do nothing. Gender, age, family system and education level were significantly associated with the beliefs about the cause of schizophrenia (p < 0.05). While these variables plus 'religious inclination' and 'beliefs about cause' were significantly associated with the help seeking behavior of the participants. CONCLUSION: Despite majority of the study population being well educated, only a few recognized schizophrenia as a mental illness and many held superstitious beliefs. A vast majority of Pakistanis have non-biomedical beliefs about the cause of schizophrenia. Their help seeking behavior in this regard is inappropriate and detrimental to the health of schizophrenic patients. Areas for future research have been identified.