Paracetamol (acetaminophen) hepatotoxicity increases in the presence of an added herbal compound.

Hepatotoxicity from paracetamol/acetaminophen has occasionally been reported at lower than expected doses. As herbal preparations may interact with pharmaceutical drugs the following in vitro study was undertaken to determine whether the toxic effects of paracetamol on liver cell growth in culture would be exacerbated by the addition of psoralen, a furanocoumarin compound that is present in Psoralea corylifolia, a common Chinese herb. The following study utilising a liver carcinoma cell line (HepG2) showed that Psoralea corylifolia was significantly toxic from 0.3 mg/ml to 5 mg/ml (p < 0.05), whereas paracetamol was not toxic below 50 mM (p = 0.0026). Interactions between previously non-toxic levels of 0.1 mg/ml of Psoralea corylifolia and increasing concentrations of paracetamol (0-50 mM), however, were observed, with a significant increase in toxicity compared to paracetamol alone (30% cell death vs. 72% cell death with Psoralea corylifolia). A significant synergistic interaction was observed at 40 mM paracetamol with 0.1 mg/ml of Psoralea (p = 0.038). This study has, therefore, shown significantly increased hepatotoxicity in cell cultures exposed to paracetamol when herbal compounds containing furanocoumarins were added. Fulminant acute liver failure occurring after the ingestion of low doses of paracetamol may not, therefore, always be due to an occult idiosyncratic response to paracetamol, but instead possibly to the combined effects of paracetamol and herbal preparations. Given the widespread use of both paracetamol and herbal preparations this possibility should be considered in cases of unexplained hepatic necrosis and liver failure that present for medicolegal investigation.

Chemical constituents from the fruits of Psoralea corylifolia and their protective effects on ionising radiation injury.

Two new flavonoids, corylifol F (1) and corylifol G (2), together with 19 known compounds, were isolated from the fruits of Psoralea corylifolia L.. The structures of these compounds were determined by interpretation of spectroscopic data and comparison with literature properties. The radioprotective effects of the isolated compounds against ionising radiation damage were also evaluated in vitro. The results showed that corylifol A exhibited radioprotective effects in both HBL-100 and MCF-7 cells, while psoralen, isopsoralen, corylifol C and bakuchiol showed obvious selective action to protect HBL-100 cells against damage caused by ionising radiation.

The ethanol extraction of prepared Psoralea corylifolia induces apoptosis and autophagy and alteres genes expression assayed by cDNA microarray in human prostate cancer PC-3 cells.

Prostate cancer is the most common male reproductive system cancer. The prevalence of prostate cancer in Europe and the United States is higher than that in the Asian region. However, the treatment of prostate cancer remains unsatisfactory. Psoralea corylifolia has been used to cure this disease as Chinese medicine in the Asian region. In this study, we analyzed the components of ethanol extraction of unprepared and prepared P. corylifolia by HPLC. Psoralen and isopsoralen content from the prepared P. corylifolia is twofold higher than that from unprepared, so we use the prepared extraction in this study. However, the effects of the ethanol extraction of P. corylifolia (PCE) on PC-3 human prostate cancer cells remain unclear. PC-3 cells were treated with PCE for different time periods and cells were examined for cell morphological change and total viable cells by using contrast phase microscopy and flow cytometer, respectively. Results indicated that PCE induced cell morphological changes and cytotoxic effect in PC-3 cells in dose-dependent manners. PCE induced chromatin condensation of PC-3 cells dose-dependently. PCE also induced apoptosis and autophagy in PC-3 by western blotting and acridine orange (AO) staining, respectively. Furthermore, a complementary DNA microarray analysis demonstrated that PCE treatment led to 944 genes upregulation and 872 genes downregulation. For example, the DNA damage-associated gene DNA-damage-inducible transcript 3 (DDIT 3) had a 62.1-fold upregulation and CDK1 2.68-fold downregulation. The differential genes were classified according to the Gene Ontology. Furthermore, GeneGo software was used for the key genes involved and their possible interaction pathways. Those genes were affected by P. corylifolia, which provided information for the understanding of the antiprostate cancer mechanism at the genetic level and provide additional targets for the treatments of human prostate cancer.

Polymeric monolith column composited with multiwalled carbon nanotubes-ß-cyclodextrin for the selective extraction of psoralen and isopsoralen.

A polymeric column that contains multiwalled carbon nanotubes-ß-cyclodextrin composite was developed. The composite was wrapped into the poly(butyl methacrylate-ethylene dimethacrylate) monolith column (0.76 mm id and 10 cm in length). The column was then applied for the online solid-phase microextraction of psoralen and isopsoralen from Fructus Psoraleae. Following microextraction, the coumarins were quantified by high-performance liquid chromatography with C18 separation column and UV detection. The effects of sample flow rate, sample volume, and pH value were optimized. The method showed low limits of detection (20 pg/mL, S/N = 3) for both psoralen and isopsoralen. Finally the method was successfully applied to the determination of psoralen and isopsoralen in spiked herb extracts and rat plasma where it gave recoveries that ranged between 93.2 and 102.1%. The empty hydrophobic cavities of ß-cyclodextrin and the hydrophobicity of multiwalled carbon nanotubes provided specific extraction capability for psoralen and isopsoralen.

Phytochemical study of Bituminaria basaltica aerial parts, an Italian endemism.

The first phytochemical investigation of the aerial parts of Bituminaria basaltica, an endemic species from the Aeolian Islands, led to the isolation and identification of eight compounds including plicatin B (3), two furanocoumarins: angelicin (1), psoralen (2), three pterocarpans: erybraedin C (4), 3,9-dihydroxy-4-isoprenyl-pterocarpan (5), bitucarpin A (8) and two flavonoid glycosides: isoorientin (6), daidzin (7). Their structures were elucidated by spectroscospic techniques and compared with data reported in the literature. Sesquiterpenes characterised the essential oil composition of the title plant where ß-caryophyllene and germacrene D were the main constituents.

Antioxidant, antilipidemic and antidiabetic effects of ficusin with their effects on GLUT4 translocation and PPARγ expression in type 2 diabetic rats.

In this study, the antioxidant, antilipidemic and antidiabetic effects of ficusin isolated from Ficus carica leaves and their effects on GLUT4 translocation and PPARγ expression were evaluated in HFD-STZ induced type 2 diabetic rats. Ficusin (20 and 40 mg/kg b. wt.) lowered the levels of fasting blood glucose, plasma insulin and body weight gain, in HFD-STZ induced diabetic rats. Ficusin also significantly lowered the serum antioxidant enzymes (SOD, CAT and GPx) and lipids (TC, TG and FFA) levels to near normal. Ficusin significantly enhanced the PPARγ expression and improved the translocation and activation of GLUT4 in the adipose tissue. Molecular docking analysis exhibited promising interactions of GLUT4 and PPARγ into their active sites. This study suggests that ficusin improved the insulin sensitivity on adipose tissue and it can be used for the treatment of obesity related type 2 diabetes mellitus.

Two nematicidal furocoumarins from Ficus carica L. leaves and their physiological effects on pine wood nematode (Bursaphelenchus xylophilus).

The ethanol extract of the Ficus carica L. leaves was tested to show strong nematicidal activity against pine wood nematode (PWN), Bursaphelenchus xylophilus, causing 90.93% corrected mortality within 72 h at 1.0 mg/mL. From the ethyl acetate soluble fraction of the F. carica L. leaves extract, the main nematicidal constituents were obtained by bioassay-guided isolation and identified as linear furocoumarins bergapten (1) and psoralen (2) by mass and NMR spectral data analysis. Bergapten and psoralen had significant nematicidal activity against PWN with the LC50 values of 97.08 aKSnd 115.03  µ g/mL within 72 h, respectively. The two furocoumarins could inhibit the activities of amylase, cellulase and acetylcholinesterase (AchE) from PWN. The morphologies of PWNs changed much after they were treated by bergapten and psoralen. The physiological effects of bergapten and psoralen on PWN might provide helpful clues to elucidate their nematicidal mechanisms.

In vitro enhancement of psoralen as an important anticancer compound in Psoralea corylifolia through precursor feeding.

CONTEXT: Psoralea corylifolia L. (Fabacese) is rich source of bioactive compounds, which endows the plant with immense value for its use in pharmaceuticals, health, and body-care products. OBJECTIVE: The current study was designed (i) for the determination of psoralen from callus derived from different plant parts, and (ii) for the enhancement of psoralen in in vitro condition with the treatment of various psoralen pathway precursors. MATERIALS AND METHODS: B5 media were employed for raising the cultures from different plant parts such as leaf, node, root, and green seeds. Cotyledons' calluses were derived from cotyledon of green seeds that were elicited on MS + 10 µM BA + 5 µM IBA medium supplemented at 0.1, 1, 2.5, 5, 25, and 50 mg/L of various psoralen pathway precursors such as umbelliferone, cinnamic acid, and NADPH. The method for extraction of psoralen was modified from the Singh method and the content of psoralen was measured using HPLC. RESULTS: HPLC analysis of callus derived from different parts of P. corylifolia revealed that a maximum of psoralen (2601.8 µg/g fresh wt.) was recorded in cotyledons' callus. Cotyledonary callus was chosen for the enhancement of psoralens because of higher amount of psoralen in it. In vitro evaluation showed that all the precursors enhanced the psoralen amount dramatically so that the optimum amount of psoralen (2518.8 µg/g fresh wt.) was obtained at 2.5 mg/L cinnamic acid. DISCUSSION AND CONCLUSION: The results obtained indicate that cinnamic acid is one of the important precursors of psoralen pathway that induced a maximum amount of psoralen with in vitro conditions.

Isolation and purification of psoralen and isopsoralen and their efficacy and safety in the treatment of osteosarcoma in nude rats.

BACKGROUND: Modern studies have shown that psoralen has a significant inhibitory effect on tumor growth in a variety of animals and humans. OBJECTIVE: To obtain coumarin compounds - psoralen and isopsoralen - from traditional Chinese medicine Psoralea corylifolia L. using chromatographic techniques and isolation and purification methods, and to observe the transplanted tumor growth inhibitory effects and adverse reactions of psoralen and isopsoralen in nude rats with osteosarcoma. METHODS: Dried ripe fruits of Psoralea corylifolia L. were taken as the raw material to prepare crude extract of Psoralea corylifolia L. by ethanol reflux method. Column chromatography was used to isolate the crude extract; compounds were structurally identified based on (1)H-NMR, (13)C-NMR spectra, the two compounds were identified as psoralen andisopsoralen, and their contents were 99.7% and 99.6, respectively. Nude rat model of osteosarcoma was established; the rats were randomized into: normal saline group, psoralen low- and high-dose groups, isopsoralen low- and high-dose groups, and cisplatin group. Osteosarcoma volume and weight inhibition rates in nude rats in each group were observed; radioimmunoassay was used to determine the serum alkaline phosphatase activity; peripheral blood cell and bone marrow nucleated cell counts were determined; light microscopy was used to observe heart, liver, spleen, lung, kidney, and tumor histopathology; and electron microscopy was used to observe the fine structure of tumor cells. RESULTS: Tumor volume inhibition rates were 43.75% and 40.18%, respectively, in the psoralen and isopsoralen low-dose groups, and tumor weight inhibition rates were 38.83% and 37.77%. Tumor volume inhibition rates were 67.86% and 66.96%, respectively, in the psoralen and isopsoralen high-dose groups, and tumor weight inhibition rates were 49.47% and 47.87%. Psoralen and ispsoralen markedly lowered serum AKP level. Psoralen and isopsoralen induced apoptosis or necrosis of osteosarcoma. After administration of high doses of psoralen and isopsoralen, toxic reactions such as writhing, lassitude, and hypoactivity were seen. Kidney histopathology showed tubulointerstitial dilatation and congestion, and inflammatory cell aggregation in the renal intercellular space. Psoralen and isopsoralen did not cause any significant toxic side effects to the bone marrow, or other organs such as heart, lung, liver, and spleen. CONCLUSION: Psoralen and isopsoralen have growth inhibitory effects on transplanted tumor in nude rats with osteosarcoma, and can induce tumor cell apoptosis or necrosis, without significant toxic effects.

Effects of Psoraleae fructus and its major component psoralen on Th2 response in allergic asthma.

This study is aimed to evaluate the effects of Psoraleae fructus (PF) on Th2 responses in a rat model of asthma in vivo and psoralen, a major constituent in PF, on Th2 responses in vitro. A rat model of asthma was established by sensitization and challenged with ovalbumin (OVA). Airway hyperresponsiveness was detected by direct airway resistance analysis. Lung tissues were examined for cell infiltration and mucus hypersecretion. Bronchoalveolar lavage fluid (BALF) was assessed for cytokine levels. In vitro study, Th2 cytokine production was evaluated in the culture supernatant of D10.G4.1 (D10 cells) followed by the determination of cell viability, meanwhile Th2 transcription factor GATA-3 expression in D10 cells was also determined. The oral administration of PF significantly reduced airway hyperresponsiveness (AHR) to aerosolized methacholine and decreased IL-4 and IL-13 levels in the BALF. Histological studies showed that PF markedly inhibited inflammatory infiltration and mucus secretion in the lung tissues. In vitro study, psoralen significantly suppressed Th2 cytokines of IL-4, IL-5 and IL-13 by ConA-stimulated D10 cells without inhibitory effect on cell viability. Furthermore, GATA-3 protein expression was also markedly reduced by psoralen. This study demonstrated that PF exhibited inhibitory effects on hyperresponsiveness and airway inflammation in a rat model of asthma, which was associated with the suppression of Th2 response. Psoralen, a major constituent of PF, has immunomodulatory properties on Th2 response in vitro, which indicated that psoralen might be a critical component of PF for its therapeutic effects.

Psoralea corylifolia L. seed extract ameliorates streptozotocin-induced diabetes in mice by inhibition of oxidative stress.

Pancreatic beta-cell death is known to be the cause of deficient insulin production in diabetes mellitus. Oxidative stress is one of the major causes of beta-cell death. In this study, we investigated the effects of Psoralea corylifolia L. seed (PCS) extract on beta-cell death. Oral administration of PCS extract resulted in a significant improvement of hyperglycemia in streptozotocin-induced diabetic mice. PCS extract treatment improved glucose tolerance and increased serum insulin levels. To study the mechanisms involved, we investigated the effects of PCS extract on H2O2-induced apoptosis in INS-1 cells. Treatment with PCS extract inhibited cell death. PCS extract treatment decreased reactive oxygen species level and activated antioxidative enzymes. Among the major components of PCS extract, psoralen and isopsoralen (coumarins), but not bakuchiol, showed preventive effects against H2O2-induced beta-cell death. These findings indicate that PCS extract may be a potential pharmacological agent to protect against pancreatic beta-cell damage caused by oxidative stress associated with diabetes.

[Study on the chemical constituents of aerial part of Ligusticum jeholense].

OBJECTIVE: To study the chemical constituents of the aerial part of Ligusticum jeholense. METHODS: The constituents were isolated by sillica gel column chromatography, Sephadex LH-20 column chromatography and their structures were elucidated by spectral analysis. RESULTS: Seven compounds were separated from the EtOH extracts. Their structures were identified as psoralen (1), beta-sitosterol (2), daucosterol (3), kaempferol-3-O-(2",4"-di-E-p-coumaroyl)-alpha-L-rhamnoside (4), kaempferol-3-O-beta-D-galactoside (5), quercetin-3-O-beta-D-galactoside (6), sucrose (7). CONCLUSION: Compounds 1, 4, 5 and 6 are isolated from the genus for the first time. Compounds 2, 3 and 7 are isolated from the aerial part of the plant for the first time.

In vitro isolation, elicitation of psoralen in callus cultures of Psoralea corylifolia and cloning of psoralen synthase gene.

Psoralen, an important furanocoumarin occurring abundantly in seeds of Psoralea corylifolia is used as an anticancerous compound against leukemia and other cancer cell lines. Evaluation and isolation of psoralen from the calluses derived from different plant parts, viz. cotyledons, nodes, leaves and roots have been done in the present case for the first time. Amongst all, a maximum of 1934.75 µg/g f.w. of psoralen was recorded in callus derived from cotyledons, followed by 1875.50 and 1465.75 µg/g f.w. of psoralen in node and leaf derived calluses, respectively. Amount of psoralen enhanced further when cotyledonary calluses were exposed to different concentrations of organic elicitors (yeast extract, proline, inositol, casein hydrolyzate (CH), glycine, glutamine and sucrose) and precursors of psoralen (umbelliferone, cinnamic acid and NADPH). Isolation of psoralen was done using methanol as solvent through column chromatography and TLC. FT-IR and NMR further characterized and confirmed the structure of psoralen. In addition, the putative gene, psoralen synthase involved in psoralen synthesis pathway has been isolated, cloned and sequenced which comprised 1237 bp length. BLAST analysis of the gene sequence of psoralen synthase revealed that its nucleotide sequence showed 93% homology with psoralen synthase isolated from Ammi majus. This is the first report of isolation, cloning and characterization of psoralen synthase from Psoralea corylifolia.

Effects of psoralen from Psoralea corylifolia on quinone reductase, ornithine decarboxylase, and JB6 cells transformation promotion.

The cancer chemopreventive effect of psoralen isolated from the seeds of Psoralea corylifolia was investigated in the induction of quinone reductase (QR) activity, intracellular detoxification enzyme, inhibition of 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced ornithine decarboxylase (ODC) activity, a key regulatory enzyme for polyamine metabolism, and tumor promotion in mouse epidermal JB6 cells, sensitive to tumor promoters (clone 415a P+ cells), which are related to suppress multistage carcinogenesis including initiation and promotion. Psoralen was isolated and identified from the ethyl acetate-soluble fraction of the methanolic extract from the seeds. Psoralen was active in induction of QR activity, the concentration of psoralen required to induce 1.5 fold QR activity was 14.8 µg/mL. Also, this pure compound inhibited TPA-induced ODC activity by 50% (designated IC(50)) at the concentration 15.6 µg/mL and exhibited inhibition of TPA-induced tumor promotion in mouse epidermal JB6 cells with an IC(50) value of 17.1 µg/mL. Therefore, it is extrapolated that psoralen has the potential capable of inhibiting the initiation and/or promotion stage of carcinogenesis by induction of QR activity, inhibition of TPA-induced ODC activity and mouse epidermal JB6 cells tumor promotion.

[Study on the chemical constituents of Psoralea corylifolia].

OBJECTIVE: To study the chemical constituents of Psoralea corylifolia. METHODS: Column chromatography was used in the isolation procedure. The structures of isolated compounds were elucidated by spectral data. RESULTS: Seven compounds were isolated and their structures were identified as isopsoralen (1), psoralen (2), bavachalcone (3), 4", 5"-dehydroisopsoralidin (4), methyl 4-hydroxybenzoate (5), psoralidin (6), corylin (7). CONCLUSION: Compounds 4 and 5 are obtained from Psoralea for the first time.

Simultaneous and sensitive determination of xanthotoxin, psoralen, isoimpinellin and bergapten in rat plasma by liquid chromatography-electrospray ionization mass spectrometry.

A sensitive, specific and rapid liquid chromatography-mass spectrometry (LC-MS) method has been developed and validated for the simultaneous determination of xanthotoxin (8-methoxypsoralen), psoralen, isoimpinellin (5,8-dimethoxypsoralen) and bergapten (5-methoxypsoralen) in rat plasma using pimpinellin as an internal standard (IS). The plasma samples were pretreated by protein precipitation with methanol and chromatographic separation was performed on a C(18) column with a mobile phase composed of 1 mmol ammonium acetate and methanol (30:70, v/v). The detection was accomplished by multiple-reaction monitoring (MRM) scanning via electrospray ionization (ESI) source operating in the positive ionization mode. The optimized mass transition ion-pairs (m/z) for quantitation were 217.1/202.1 for xanthotoxin, 187.1/131.1 for psoralen, 247.1/217.0 for isoimpinellin, 217.1/202.1 for bergapten, and 247.1/231.1 for IS. The total run time was 6 min between injections. The calibration curves were linear over the investigated concentration range with all correlation coefficients higher than 0.998. The lower limits of quantitation (LLOQ) of these analytes were less than 1.21 ng/ml. The intra- and inter-day RSD were no more than 9.7% and the relative errors were within the range of -8.1% to 4.5%. The average extraction recoveries for all compounds were between 90.7% and 106.2%. The proposed method was further applied to the determination of actual plasma samples from rats after oral administration of Radix Glehniae extract.

Phytoestrogens from Psoralea corylifolia reveal estrogen receptor-subtype selectivity.

The seed of Psoralea corylifolia L. (PCL), a well-known traditional Chinese medicine, has been applied as a tonic or an aphrodisiac agent and commonly used as a remedy for bone fracture, osteomalacia and osteoporosis in China. In our study, the estrogen receptor subtype-selective activities of the extracts and compounds derived from PCL were analyzed using the HeLa cell assay. The different fractions including petroleum ether, CH(2)Cl(2) and EtOAc fractions of the EtOH extract of PCL showed significant activity in activating either ERalpha or ERbeta whereas the n-BuOH fraction showed no estrogenic activity. Further chromatographic purification of the active fractions yielded seven compounds including the two coumarins isopsoralen and psoralen, the four flavonoids isobavachalcone, bavachin, corylifol A and neobavaisoflavone, and the meroterpene phenol, bakuchiol. In reporter gene assay, the two coumarins (10(-8)-10(-5)M) acted as ERalpha-selective agonists while the other compounds (10(-9)-10(-6)M) activated both ERalpha and ERbeta. The estrogenic activities of all compounds could be completely suppressed by the pure estrogen antagonist, ICI 182,780, suggesting that the compounds exert their activities through ER. Only psoralen and isopsoralen as ERalpha agonists promoted MCF-7 cell proliferation significantly. Although all the compounds have estrogenic activity, they may exert different biological effects. In conclusion, both ER subtype-selective and nonselective activities in compounds derived from PCL suggested that PCL could be a new source for selective estrogen-receptor modulators.

Furanocoumarins: novel topoisomerase I inhibitors from Ruta graveolens L.

Topoisomerase I inhibitors from Ruta graveolens are reported for the first time. Potent topoisomerase I inhibitory activity from in vitro culture extracts R. graveolens were observed. Stabilization of DNA-topoisomerase covalent complex was observed in all the tested extracts. The mechanism of topoisomerase inhibition was determined by preincubation studies. The irreversible topoisomerase I mediated relaxation of plasmid in enzyme-substrate preincubation study, indicated that the observed inhibitory activity of extract constituents was not mediated through conformational changes in the DNA. Furthermore, the affinity of inhibitors with the enzyme was tested by enzyme-extract preincubation study. Increase in inhibition of topoisomerase activity and promotion of DNA-enzyme complex was observed after enzyme-extract preincubation. The activity could be assigned to furanocoumarins-psoralen, bergapten and xanthotoxin, identifying them as novel, potent topoisomerase I inhibitors.

[Chemical constituents of antibacterial activity fraction of Angelica polymorpha].

OBJECTIVE: To study chemical constituents of antibacterial activity fraction of Angelica polymorpha. METHODS: Compounds were isolated by repeatedly silica gel column chromatography and recrystallization. Their structures were identified by physical and chemical evidences and spectral methods. RESULTS: Seven compounds were obtained from the antibacterial activity fraction, their structures were elucidated as: bisabolangelone(I), isoimperatorin (II), oxypeucedanine(III), isooxypeucedanine(IV), oxypeucedanin hydrate(V), bergapten(VI), pabulenol(VII). CONCLUSION: Bisabolangelone(I) is obtained from this plant for the first time. Compound (II)-(VII) belong to linear furanocourmarins.

Antipsoriatic microemulsion gel formulations for topical drug delivery of babchi oil (Psoralea corylifolia).

The aim of this study was to investigate and evaluate a microemulsion gel-based system of babchi oil (Psoralea corylifolia) for the treatment of psoriasis, which could provide improved permeation of the drug through the skin and increased patient compliance. Babchi oil is used because its chief constituent psoralen is a photoactive furocoumarin that binds to DNA when exposed to UV light to form photoproducts with pyrimidine base. This action inhibits DNA synthesis and causes decrease in cell proliferation. Moreover, babchi oil, in addition to providing psoralen, also acts as an oily phase for microemulsion system. The presence of surfactant and cosurfactant increases the permeation. On the basis of qualitative and quantitative estimation of all eight brands of babchi oil, Bakuchi Tail was selected for microemulsion formulation. Microemulsions were prepared by aqueous phase-titration method. Pseudoternary phase diagrams were constructed for the identification of microemulsion existence zones. Prepared microemulsions were subjected to different thermodynamic stability tests and characterized for droplet size, viscosity and refractive index. In vitro skin permeation of babchi oil through rat abdominal skin was determined by the Franz diffusion cell. The in vitro skin permeation profile of formulation F2, which consisted of 1.67% v/v of babchi oil, 8.33% v/v of oleic acid, S(mix) 55% v/v of Tween 80 Transcutol-P (S/Co ratio 1:1) and 35% v/v of distilled water, was significant when compared with other microemulsion formulations (p < 0.05). Formulation F2 was converted into microemulsion gel by adding 1% Carbopol-940 and coded as MGF2. Formulation MGF2 was selected for its in vivo antiinflammatory effects determined by footpad edema. The results suggested that microemulsion gel is a potential vehicle for improved topical delivery of psoralen and that microemulsion gels are potential vehicles for improved topical delivery of babchi oil.