Quantification of chlorogenic acid, rosmarinic acid, and caffeic acid contents in selected Thai medicinal plants using RP-HPLC-DAD

The chlorogenic acid, rosmarinic acid, and caffeic acid contents in 100 selected plants were determined using reversed phase high performance liquid chromatography equipped with diode array detector. The optimum condition was 0.2% phosphoric acid in water (solvent A) and methanol (solvent B) as the mobile phase, which was set at 45% B for 20 minutes at a flow rate of 1.2 mL/min. The column temperature was maintained at 30 ºC and the detection wavelength was 325 nm. Among 100 selected plants, 39.64% contained all 3 compounds, 40.54% contained 2 compounds, 14.41% contained only 1 compound, and 5.41% could not detect any of the 3 compounds. The highest contents of chlorogenic acid, rosmarinic acid, and caffeic acid were found in Lonicera japonica flowering buds, Melissa officinalis leaves, and Coffea canephora seeds at the concentration of 9.900 ± 0.004, 19.908 ± 0.171, and 1.233 ± 0.003 g/100 g of dried plant, respectively.

Antispasmodic effects of curcuminoids on isolated guinea-pig ileum and rat uterus.

Curcuminoids, a yellow constituent isolated from Curcuma longa Linn. rhizomes was studied for its antispasmodic activity in isolated guinea-pig ileum and rat uterus. Curcuminoids at the concentration of 12 microg/ml significantly inhibited the ileum pre-contracted with acetylcholine (ACh) 5 x 10(-7) M and histamine 5 x 10(-7) M. (Force of contraction was 62.84 +/- 4.66% and 75.60 +/- 4.66% respectively) and the effects were prominently observed when the concentration of curcuminoids was increased to 36 microg/ml. (Force of contraction was 44.93 +/- 4.33% and 42.79 +/- 1.98%). In potassium depolarizing Tyrode solution, curcuminoids 4 microg/ml and 20 microg/ml reduced the contraction induced by calcium chloride (CaCl2) 1.8 mM. (The contraction was 63.31 +/- 1.80% and 36.87 +/- 3.25%). In rat uterus smooth muscle preparation, curcuminoids 8 microg/ml and 16 microg/ml significantly reduced force and frequency of contraction induced by oxytocin 1 x 10(-2) IU/ml. Curcuminoids 8 microg/ml produced 54.68 +/- 3.34 per cent force of contraction and 79.09 +/- 2.29 per cent frequency of contraction. Curcuminoids 16 microg/ml caused more relaxation of rat uterus smooth muscle. (Force of contraction was 43.38 +/- 3.56%, frequency of contraction was 49.96 +/- 5.20%). Curcuminoids 8 and 16 microg/ml significantly reduced force of contraction induced by KCl 50 mM. (Force of contraction was 54.10 +/- 4.92% and 36.60 +/- 2.99%). The results obtained from this study concluded that curcuminoids produced a smooth muscle, relaxation effect on isolated guinea-pig ileum and rat uterus by receptor-dependent and independent mechanism.

Chemical compositions and pharmacological effects of essential oil from the fruit of Zanthoxylum limonella.

Examination of chemical compositions of essential oil distilled from the fruit of Zanthoxylum limonella Alston (Rutaceae) revealed the presence of 33 chemical components. Evaluation of the oil composition was achieved by GC/MS analysis. Limonene (31.09%), terpin-4-ol (13.94%) and sabinene (9.13%) were found to be the major components. Effects of essential oil have been performed in isolated guinea pig ileum, rat thoracic aorta and conscious mice. The essential oil at the concentration of 7.68 x 10(-5)-1.92 x 10(-3) microl/25 ml, produced dose-dependent contraction of the isolated rat thoracic aorta. These contractions were significantly reduced by pretreatment with prazosin (1 x 10(-7) M) and verapamil (1 x 10(-7) M). Its contraction was abolished in calcium free Krebs solution. Contractile response to the volatile oil (2 x 10(-6)-5.12 x 10(-4) microl/25 ml) was examined in isolated guinea pig ileum, it evoked ileal contraction in concentration-dependent manner and the contractions were suppressed after exposure to chlorpheniramine (1 x 10(-7) M) cypoheptadine (1 x 10(-7) M) atropine (1 x 10(-7) M) and verapamil (1 x 10(-7) M). Therefore, it could be concluded that the essential oil from the fruit of Zanthoxylum limonella possessed stimulation effect on different smooth muscle preparations by non-specific mechanisms. It involved the non receptor and receptor-mediated mechanism. Gastrointestinal stimulant effect of the essential oil was confirmed in intact mice since the oil significantly increased black ink movement from the stomach to ileo-caecal junction after oral feeding.