GC/MS analysis, anti-leishmanial and relaxant activity of essential oil of Chenopodium ambrosioides (L.) from Malakand region.

Chenopodium ambrosioides is abundantly available in Malakand region. As constituents and concentrations of essential oils vary based on its geographical location, we carried our current study to extract and evaluate its possible relaxant activity in rabbits' jejunum and anti-leishmanial activity against promastigotes of Leishmania tropica. The essential oil was obtained from aerial fresh parts through steam distillation followed by GC/MS analysis. Antispasmodic activity was performed on spontaneous and KCl induced contractions. Curves for calcium concentration response (CCRCs) were prepared with and without different concentrations of essential oils and verapamil - a standard calcium channel blocker as per our reported procedures. GC/MS analysis indicated that the essential oil contains 4-carene (56.59%) and o-cymene (41.46%), the two most abundant compounds previously reported from this species. The LD50 value for acute toxicity is 279.66±2.2mg/kg. The essential oil have significant antileishmanial activity with LC50 of Log10 (1.83±0.0026) ×10-6mg/ml, potent relaxant activity on rabbits' jejunal preparations with respective EC50 = 1.46±0.15mg/ml for spontaneous activity. For KCl (80mM) induced contractions, EC50=0.26±0.02mg/ml. In CCRCs, the oil produced a right shift as exhibited by verapamil. More, its relaxant activity, which is mediated through calcium channel blocking mechanism, proves a rationale for its traditional use in gut spasm.

Azithromycin induced contractile responses of intestinal smooth muscles: A mechanistic approach.

The current work is documented to investigate the actions of azithromycin on intestinal smooth muscles as there are reports of gastrointestinal upsets with use of azithromycin. Azithromycin was tested on rabbit's jejunal and rat's ileal preparations in test concentrations (µM) of 0.01, 0.03, 0.1, 0.3, 1, 3, 5, 10 and 15µM. After mounting the tissues in organ bath containing Tyrode's solution, spasmogenic activity of azithromycin was observed. To explore its possible mechanisms, response of azithromycin was noted in the presence of 0.3µM atropine, 3µM loratadine, 0.3µM ondansetron, 10µM metoclopramide, 0.3µM verapamil, 1µM propranolol, 3µM amiodarone and combination of 0.3µM each atropine, ondansetron, verapamil and propranolol (AOVP). Mean % Emax for azithromycin was 67.6±1.6 and 54.0±2.1 (% of ACh max) for rabbit's jejunal and rat's ileal preparations, respectively. The Mean % Emax for azithromycin in the presence of various antagonists for rabbit's jejunal and rat's ileal preparations was as: 2.4±0.1 and 11.4±1.3 with atropine; 67.9±2.0 and 50.7±1.9 with loratadine; 27.5±0.5 and 34.0±2.9 with ondansetron; 88.4±1.2 and 79.1±3.8 with metoclopramide; 13.6±1.2 and 22.3±2.5 with verapamil; 10.2±2.1 and 15.6±1.4 with propranolol; 68.4±1.3 and 58.0±3.4 with amiodarone. Results reveal that the spasmogenic response of azithromycin is mainly mediated through muscarinic receptors. However, we found involvement of mixed pathway including serotonergic receptors, voltage gated calcium channels and voltage gated sodium channels.