Evaluation of wound healing activity of Thunbergia laurifolia supercritical carbon dioxide extract in rats with second-degree burn wounds.

Thunbergia laurifolia Lindl (TL) has been traditionally used as an antidote, anti-inflammatory, and anti-drug addiction. This study investigated the burn wound healing activity of TL leaf extract (TLL) from supercritical CO2 extraction in rats. The extract was prepared to 2.5%, 5%, and 10% gel (TLL gel). Rats were induced to second-degree burn wounds. They were randomly divided into six groups (six rats/group), which five groups were topically applied gel base, 1% silver sulfadiazine gel, 2.5%, 5%, and 10% TLL gel, respectively, for 14 days. Six untreated burn rats were used as the control group. The rats in each group were evaluated for wound healing rate, histological parameters, and wound collagen content. Rats treated with 10% TLL gel had a higher wound healing rate than rats in the control and untreated groups. An increase in collagen content, which indicates good regeneration of wound skin, was observed in the TLL treated rats from a pathological study by Masson's trichrome and collagen content assay. The results from this study suggest that T. laurifolia leaf extract obtained by supercritical CO2 extraction promotes the recovery of wound skin by shortening the inflammation phase, increasing collagen content, and stimulating fibroblasts proliferation and migration in wound healing.

Clinical pharmacokinetic of celecoxib in healthy Thai volunteers.

BACKGROUND: Celecoxib, a nonsteroidal antiinflammatory drug exhibits its antiinflammatory effect by selective inhibition of cyclooxygenase-2 (COX-2) enzyme. Its efficacy has been accepted for the treatment of arthritic pain with superior gastrointestinal side effect profile compared with other conventional NSAIDs. OBJECTIVE: To elucidate clinical pharmacokinetic of celecoxib following an oral dose administration. MATERIAL AND METHOD: Eighteen healthy Thai male volunteers were enrolled in the present study. Their mean age was 20.94 +/- 1.21 years and their mean weight was 63 +/- 5.17 kg. They were orally administered 200 mg celecoxib after an over night fasting, serial blood samples were drawn before and at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 8, 10, 12, 24 and 48 hours after dosing. Plasma celecoxib was analysed by reversed-phase HPLC. RESULTS: Following a 200 mg celecoxib oral administration, the drug was absorbed into the systemic circulation and reach maximum concentration (Tmax) within 2.50 +/- 1.22 hrs by average with the mean peak concentration (Cmax) of 686.83 +/- 211.35 ng/ml. The extent of absorption (area under the curve, AUC) was approximately 5157.12 +/- 1499.46 and 5911.48 +/- 1363.51 ng hr/ml for AUC(0-->t) and AUC(0-->infinity) respectively. The apparent volume of distribution (Vd) was found to be 458.93 +/- 323.28 L/hr. Celecoxib was eliminated after biotransformation and the metabolites were excreted in both urine and feces. The elimination half-life (t(1/2)) of celecoxib appeared to be 8.79 +/- 5.49 hrs with the apparent clearance (CL) of 35.91 +/- 9.85 L. The elimination rate constant for celecoxib obtained from this present study was about 0.11 +/- 0.05 hr(-1). CONCLUSION: Pharmacokinetic parameters following an oral dose of 200 mg celecoxib administration were characterized, including Cmax, Tmax, Vd, kel, CL, AUC. These parameters reflected absorption, distribution, biotransformation and excretion of celecoxib in healthy Thai volunteers.

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.