The effects of three concentrations of carvacrol, the constituent of Zataria multiflora Boiss (a monoterpenoid phenol, C(10) H(14) O) and 10 nm atropine on muscarinic receptors were tested on: non-incubated (n = 7), incubated tracheal chains with propranolol and chlorpheniramine (n = 6) and incubated with propranolol (n = 5). The EC(50) of all three concentrations of carvacrol in incubated tissues with propranolol and chlorpheniramine was significantly greater than those of incubated tissues with propranolol and non-incubated trachea (p < 0.05 to p < 0.001). The EC(50) of two higher concentrations of carvacrol (0.2 and 0.4 µg/mL) in incubated tissues with propranolol was also significantly greater than those of non-incubated trachea (p < 0.01 to p < 0.001). The maximum response in the presence of all concentrations of carvacrol in non-incubated and incubated tissues with propranolol and chlorpheniramine and those of its two higher concentrations (0.2 and 0.4 µg/mL) in incubated tissues with propranolol were lower than saline (p < 0.05 to p < 0.001). There were parallel rightward shifts in the concentration-response curves in the presence of all concentrations of carvacrol in non-incubated and incubated tissues with propranolol and its lower concentration in incubated tissues with propranolol and chlorpheniramine. These results indicated an inhibitory effect of carvacrol on muscarinic receptors. A β-adrenoceptor stimulatory effect was also suggested for carvacrol.

The effects of three concentrations of aqueous-ethanolic extract, 10 nM atropine and saline on muscarinic receptors were tested on two groups of non-incubated (group 1; n = 7) and incubated tracheal chains with propranolol and chlorpheniramine (group 2; n = 6). The EC₅₀ of higher concentration of the extract (2 µg mL⁻¹) in group 2 was significantly greater than those of group 1 (p < 0.01). The maximum response obtained in the presence of all concentrations of extract in groups 1 and 2 were lower than saline (p < 0.05 to 0.001). There were parallel rightward shifts in the concentration response curves obtained for all concentrations of the extract in group 2. There was significant and positive correlation between the concentrations and the values of EC₅₀ in group 1 (p < 0.05) and group 2 (p < 0.001). These results indicate an anti-cholinergic effect of Zataria multiflora Boiss on the tracheal chains of guinea pigs. A β-adrenoceptor stimulatory effect for the plant was also suggested.

Context: Dracocephalum polychaetum Bornm. (Lamiaceae) is used in folk medicine and contains antioxidant agents. Objectives: The objective of this study is to investigate the antidiabetic, antioxidant, and antilipid peroxidative properties of methanol extract of D. polychaetum aerial parts. Materials and methods: The effect of extract (200, 300, and 400 mg/kg, b.w.) on oral glucose tolerance test (OGTT) was investigated. Also, extract (300 mg/kg) administered orally in diabetic rats for 14 d then, serum levels of some biochemical factors were evaluated. Pancreas samples were used for the determination of malondealdehyde (MDA) level, glutathione (GSH) content, superoxide dismutase, and catalase enzyme activities. Red blood cells (RBCs) and plasma were used for MDA estimation. Pancreatic a-amylase inhibition, DPPH (1,1-diphenyl-2-picrylhydrazyl), and FRAP (ferric reducing antioxidant power) assays were done. The total flavonoid content of the extract was determined by spectrophotometry. Results: Extract (300 mg/kg) decreased serum glucose level (27.1%) significantly at 120 min in OGTT. Serum levels of creatinine, triglycerides, cholesterol, alanine amino transferase and MDA levels in plasma, RBCs, and pancreas significantly decreased in treated (300 mg/kg) diabetic rats, while pancreatic GSH content, superoxide dismutase, and catalase enzymatic activities increased (p50.05). The IC 50 values for the extract and butyl hydroxyanisole were 5.6 and 1.15 mg/mL in DPPH and 0.155 and 0.062 mg/mL in the FRAP methods, respectively. The extract had no inhibitory effect on a-amylase activity. The total amount of flavonoids of the extract was estimated to be 1.8% (g/g) on the basis of quercetin content. Conclusion: Dracocephalum polychaetum shoot extract has antioxidant, antihyperlipidemic, and antilipid peroxidative properties.

Levisticum officinale (Apiaceae) has been identified as a medicinal plant in traditional medicine, with the anti-inflammatory, antioxidant, and anticholinesterase activities.

O. persica shoot extract has antihyperglycemic, antilipid peroxidation, and insulin secretory properties.