Past, present and future of Psoralea glandulosa Linn, Chilean medicinal plant, an inexhaustible resource: a literature review / Pasado, presente y futuro de Psoralea glandulosa Linn, planta medicinal chilena fuente inagotable de recursos: una revisión de la literatura

Culén is the popular term used in Chile for the only endemic species of the Fabaceae family, Psoralea glandulosaLinn. It is one of the most widely used medicinal plants in Chile and in some regions of South America, not only as a home remedy, but also recommended by medicine and widely used in the gastronomic industry. Many properties are known, supported by biological tests both in vitroand in vivo. Because it is so highly appreciated, it is included in the book "Medicamentos HerbariosTradicionales" (Traditional Herbal Medicines) of the Chilean Ministry of Health. Given the great interest in this plant since time immemorial, this review contains information on its history, popular uses and scientific studies, for a better knowledge, management and sustainable care of this Chilean natural resource.

Culén es el término popular utilizado en Chile para la única especie endémica de la familia Fabaceae, Psoralea glandulosaLinn. Se trata de una de las plantas medicinales más utilizadas en Chile y en algunas regiones de Sudamérica, no solamente como remedio curativo casero, sino también recomendada por la medicina y con amplia utilización en la industria gastronómica. De ella se conocen un gran número propiedades avaladas por ensayos biológicos tanto in vitrocomo in vivo. Por ser tan apreciada, se encuentra incluida en el libro "Medicamentos Herbarios Tradicionales" del Ministerio de Salud de Chile. Dado el gran interés que despierta esta planta desde tiempos inmemoriales, se recoge en este capítulo la información sobre su historia, usos populares y estudios científicos, para un mejor conocimiento, manejo y cuidado de manera sustentable de este recurso natural chileno.

Hypoglycemic mechanism of Psoraleae Fructus and its main chemical constituents / 中国中药杂志

With the rise of incidence, fatality rate, and number of young cases, diabetes mellitus has been one of the seven major diseases threatening human health. Although many antidiabetic drugs(oral or for injection) are available, the majority have serious side effects during the long-term use. Thus, it is of particularly vital to develop new drugs with low risk and definite effect. Psoraleae Fructus, a traditional medicinal widely used in the folk, has hypoglycemic, anti-osteoporosis, antitumor, estrogen-like, and anti-inflammatory effects. Thus, it has great clinical application potential. Chinese medicine and the active ingredients, characterized by multiple targets, multiple pathways, and multiple effects in the treatment of diabetes mellitus, have distinct advantages in clinical application. However, the safety of Chinese medicine remains to be a challenge, and one of keys is to clarifying the mechanism of a single Chinese medicinal and its active ingredients. With the method of literature research, this study summarized and analyzed the hypoglycemic mechanisms of Psoraleae Fructus and its main active ingredients over the last decade: regulating glucose metabolism, improving insulin resistance, and directly acting on pancreatic β-cells. The result is expected to serve as a reference for further research on the effects of Psoraleae Fructus and its main chemical constituents in lowering blood glucose and preventing diabetes mellitus and the clinical application.

Pharmacokinetic characteristics of psoralen,isopsoralen,psoralenoside and isopsoralenoside in rats after oral administration of Psoraleae Fructus extract / 中国中药杂志

Coumarins are the main active components in Psoraleae Fructus. To study the multi-component pharmacokinetics of Psoraleae Fructus, this study established a sensitive and rapid ultra-pressure liquid chromatography coupled to tandem mass spectrometry(UPLC-MS/MS) method for simultaneous determination of psoralen, isopsoralen, psoralenoside, and isopsoralenoside in rat plasma. After validation, the method was applied to the investigation of pharmacokinetics of psoralen, isopsoralen, psoralenoside, and isopso-ralenoside in rats after single and multiple administration of Psoraleae Fructus extract. The results revealed that the exposure of psoralen and isopsoralen in rat plasma was high after a single intragastric administration of Psoraleae Fructus extract, with an AUC_(0-∞) of 443 619-582 680 and 167 314-276 903 ng·mL~(-1)·h~(-1), respectively. Compared with these two compounds, the exposure of psoralenoside and isopsoralenoside was lower with marked gender difference. After 7-day administration of Psoraleae Fructus extract to rats, the AUC_(0-∞) of psoralen and isopsoralen was 29 701-81 783 and 39 234-89 914 ng·mL~(-1)·h~(-1), respectively, which was significantly lower than that at the first day(P<0.05), and that of psoralenoside and isopsoralenoside was 7 360-19 342 and 8 823-45 501 ng·mL~(-1)·h~(-1), respectively. There was no significant gender difference in exposure of psoralenoside and isopsoralenoside in male and female rats. However, the exposure of psoralenoside and isopsoralenoside in male rats was reduced(P<0.05), and the t_(1/2) and mean residence time(MRT) were shortened, suggesting that the removal of these two compounds from the body was accelerated.

Analysis of standard decoction of salt-processed Psoraleae Fructus / 中国中药杂志

The traditional Chinese medicine standard decoction is prepared on the basis of the theory of traditional Chinese medicine and clinical application. With reference to the modern extraction method,the single decoction of traditional Chinese medicine is prepared by the standardized process,and the establishment of its quality standards is conducive to standardizing clinical medication. This research is to set an evaluation standard for the quality of salt-processed Psoraleae Fructus standard decoction. Twelve batches of salt-processed Psoraleae Fructus standard decoctions were prepared. The contents of psoralen and isopsoralen were determined,the transfer and extract rates were calculated,and the pH value was measured; HPLC fingerprint method was established for analysis. The results of the 12 batches of samples revealed that the transfer rates of psoralen and isopsoralen were 17. 10%-26. 40%,14. 70%-22. 70%,respectively; the extract rate was between 14. 7%-27. 0%,and the pH value was between 5. 4-6. 9. Moreover,7 common chromatographic peaks were determined based on fingerprint by using similarity evaluation system for chromatographic fingerprint of traditional Chinese medicine( 2012 A).The similarities of the 12 batches of samples were analyzed and compared,and the results showed that the similarities were all higher than0. 9. In this study,the preparation method for salt-processed Psoraleae Fructus decoction was standard,with high similarities in fingerprint. This study build a convenient and reliable method of comprehensive quality evaluation,with a high precision,stability and repeatability,which can provide a reference for the quality control of salt-processed Psoraleae Fructus dispensing granules.

Toxicokinetics of bakuchiol, hepatic and renal toxicity in rats after single oral administration of Psoraleae Fructus and combination with Glycyrrhizae Radix et Rhizoma / 中国中药杂志

To study the toxicokinetics of bakuchiol, hepatic and renal toxicity in rats after single oral administration of Psoraleae Fructus and combined with Glycyrrhizae Radix et Rhizoma, in order to provide scientific evidences for clinical safe medication use. A total of 35 SD rats were randomly divided into seven groups: vehicle (distilled water) control group, Glycyrrhizae Radix et Rhizoma group, positive control (aristolochic acid A) group, Psoraleae Fructus (40 g x kg(-1)) group( both male and female rats), Psoraleae Fructus and Glycyrrhizae Radix et Rhizoma (40 +20) g x kg(-1) group (both male and female rats). HPLC-UV method was used to determine the concentration of bakuchiol in rat plasma at different time points after single oral administration. Plasma alanine transaminase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), plasma creatinine (Cr), N-acetyl-β-D-glucosaminidase (NAG) and kidney injury molecule 1 (Kim-1) were measured after administration for 24 h. The main toxicokinetics parameters of bakuchiol in rats exert significantly gender difference. When Psoraleae Fructus combination with Glycyrrhizae Radix et Rhizoma, the total area under the plasma concentration-time curve( AUC), C(max), and plasma clearance (CL) of bakuchiol were increased, respectively; CL, half-life (t½) were decreased, and T(max) were prolonged. The biochemical indicators (including ALT, AST, BUN, Cr and KIM-1 level) in different dose of Psoraleae Fructus groups, were found no statistically significant difference when compared with vehicle control group. The level of NAG in both Psoraleae Fructus and compatibility with Glycyrrhizae Radix et Rhizoma groups were significant increased (P < 0.05). There are obvious effects on toxicokinetics of bakuchiol in rats when Psoraleae Fructus combined with Glycyrrhizae Radix et Rhizoma. Renal toxicity induced by Psoraleae Fructus at high dose was observed after single oral administration and no liver damage in rats was found.

Effect of Psoraleae Fructus and Myristicae Semen in "Ershen pill" on serum metabonomics in spleen-kidney Yang deficiency diarrhea rats before and after processing / 中国中药杂志

The metabonomics method was used to study the intervention effect of Psoraleae Fructus and Myristicae Semen in "Ershen pill" on the changes in serum endogenous metabolites in spleen-kidney Yang deficiency diarrhea rats before and after processing, screen out differentiated metabolites related to spleen-kidney Yang deficiency diarrhea and explore the metabolic patterns related to spleen-kidney Yang deficiency diarrhea and the processing synergy mechanism of Psoraleae Fructus and Myristicae Semen in "Ershen pill". Efforts were made to detect SOD and MDA of each group, test rat serum metabolic fingerprints in different stages by using GC-MS, analyze by PCA and PLS-DA methods and screen out potential biomarks through VIP and t test. The results revealed that "Ershen pill" could enhance the level of SOD and decrease the level of MDA and identified 10 differentiated metabolites related to spleen-kidney Yang deficiency diarrhea. Compared with the model group, all of metabolites recovered to varying levels after being intervened with "Ershen pill", with the best effect shown in the "Ershen pill" IV group (salt-processed Psoraleae Fructus + bran-roasted Myristicae Semen). It is speculated that that Psoraleae Fructus and Semen Myristicae in "Ershen pill" show a synergistic effect by inhibiting peroxide, improving aglucolipid, amino acids and energy metabolism, with multiple target sites.

Study of the chemical composition of the resinous exudate isolated from Psoralea glandulosa and evaluation of the antioxidant properties of the terpenoids and the resin / Estudio de la composición química del exudado resinoso aislado de Psoralea glandulosa y la evaluación de las propiedades antioxidantes de la resina y sus terpenoides

Otholobium glandulosum (L.) J.W. Grimes (= Psoralea glandulosa L.) (Fabaceae) is a resinous bush that grows in Chile. The chemical composition of its resinous exudate was determined for the first time. Three meroterpenic: bakuchiol (8), 3-hydroxybakuchiol (11), 12-hydroxyisobakuchiol (12) and a new compound kuchiol (13) were isolated and their structures were determined. The antioxidant activity of the terpenic compounds and resin was evaluated using the bleaching of DPPH radical, Ferric Reducing Antioxidant Power (FRAP) and Total Reactive Antioxidant Properties (TRAP) assays.

Otholobium glandulosum (L.) J.W. Grimes (= Psoralea glandulosa L.) (Fabaceae) es un arbusto resinoso que crece en Chile. La composición química de su exudado resinoso fue determinada por primera vez. Tres meroterpenos: bakuchiol (8), 3-hidroxibakuchiol (11), 12-hidroxiisobakuchiol (12) y un nuevo compuesto kuchiol (13) fueron aislados y sus estructuras fueron determinadas espectroscópicamente. La actividad antioxidante de los compuestos terpénicos y la resina se evaluó mediante tres métodos antioxidantes DPPH, Poder Reductor de Hierro III (FRAP) y Capacidad Antioxidante Total (TRAP).

Study on tissue distribution of psoraleae fructus decoction in rats / 中国中药杂志

Advanced technologies are used to clarify the meridian tropism theory of traditional Chinese medicine is an important part of theoretical studies of traditional Chinese medicine. In this article, modern pharmacokinetic method was used to investigate tissue distribution characteristics of psoralen and isopsoralen of Psoraleae Fructus decoction in rats, in order to provide research ideas and experimental basis for the meridian tropism theory. In this study, various tissue samples such as heart, liver, spleen, lung, kidney, brain and spermary were collected at different times after oral administration with FP decoction, in order to determine concentration of psoralen and isopsoralen by HPLC. Pharmacokinetic parameters were calculated by DAS 2.0 software. The study results showed that HPLC indexes of psoralen and isopsoralen in various tissues of rats met the determination requirements of biological samples. Both components were distributed in all of the tissues, with AUC(0-t) order of liver > lung approximately kidney > heart > brain approximately spleen > spermary. There was significant difference between liver, kidney, lung and other tissues (P < 0.05). MRT(0-t) of both psoralen and isopsoralen were about 10 h. Therefore, psoralen and isopsoralen showed stronger targeting selection in liver, kidney and lung.

Optimization of preparation of salt-processed psoraleae fructus medicines with multi-index orthogonal method / 中国中药杂志

<p><b>OBJECTIVE</b>To optimize the preparation of salt-processed Psoraleae Fructus by the orthogonal test method.</p><p><b>METHOD</b>With the 12 components such as coumarin, flavone and phenolics as study indexes, a L9 (3(4)) orthogonal test was adopted to compare the effect of different factors on salt-processed Psoraleae Fructus.</p><p><b>RESULT</b>According to the finalized optimal process, 100 g Psoraleae Fructus was added with 2 g salt, moistened for 2 hours, and then fried for 10 min at 150 degrees.</p><p><b>CONCLUSION</b>The orthogonal test is so reasonable and reliable that it can provide basis for the preparation of salt-processed Psoraleae Fructus.</p>

Effects of Xanthium stramarium and Psoralea corylifolia Extracts Combined with UVA1 Irradiation on the Cell Proliferation and TGF-beta1 Expression of Keloid Fibroblasts

BACKGROUND: Xanthium stramarium (XAS) and Psoralea corylifolia (PSC), phototoxic oriental medicinal plants, has been used in traditional medicines in Asian countries. OBJECTIVE: The effects of highly purified XAS or PSC extract combined with ultraviolet A1 (UVA1) irradiation on cell proliferation and transforming growth factor-beta1 (TGF-beta1) expression of the keloid fibroblast were being investigated to define potential therapeutic uses for keloid treatments. METHODS: The keloid fibroblasts were treated with XAS or PSC alone or in the combination with UVA1 irradiation. The cell viability, apoptosis, and expression of TGF-beta1 and collagen I were investigated. RESULTS: XAS and PSC in combination with UVA1 irradiation suppressed cell proliferation and induced apoptosis of keloid fibroblasts. Furthermore, the XAS and PSC in combination with UVA1 irradiation inhibited TGF-beta1 expression and collagen synthesis in keloid fibroblasts. CONCLUSION: These findings may open up the possibility of clinically used XAS or PSC in combination with UVA1 irradiation for keloid treatments.

Effects of Xanthium stramarium and Psoralea corylifolia Extracts Combined with UVA1 Irradiation on the Cell Proliferation and TGF-beta1 Expression of Keloid Fibroblasts

BACKGROUND: Xanthium stramarium (XAS) and Psoralea corylifolia (PSC), phototoxic oriental medicinal plants, has been used in traditional medicines in Asian countries. OBJECTIVE: The effects of highly purified XAS or PSC extract combined with ultraviolet A1 (UVA1) irradiation on cell proliferation and transforming growth factor-beta1 (TGF-beta1) expression of the keloid fibroblast were being investigated to define potential therapeutic uses for keloid treatments. METHODS: The keloid fibroblasts were treated with XAS or PSC alone or in the combination with UVA1 irradiation. The cell viability, apoptosis, and expression of TGF-beta1 and collagen I were investigated. RESULTS: XAS and PSC in combination with UVA1 irradiation suppressed cell proliferation and induced apoptosis of keloid fibroblasts. Furthermore, the XAS and PSC in combination with UVA1 irradiation inhibited TGF-beta1 expression and collagen synthesis in keloid fibroblasts. CONCLUSION: These findings may open up the possibility of clinically used XAS or PSC in combination with UVA1 irradiation for keloid treatments.

Chemical constituents from Psoralea corylifolia and their antioxidant alpha-glucosidase inhibitory and antimicrobial activities / 中国中药杂志

Twelve compounds were isolated from Psoralea corylifolia and their structures were identified as isopsoralen (1), psoralen (2), 8-methoxypsoralen (3), psoralidin (4), corylin (5), bavachin (6), daidzein (7), corylifolinin (8), bavachinin (9), neobavaisoflavone (10), daidzin (11) and astragalin (12). The results showed that psoralidin had the activity of scavenging DPPH free radicals activity (IC50 43.85 mg x L(-1)). Psoralidin (IC50 1.32 mg x L(-1))c, oryfolin (IC50 4.97 mg x L(-1)), daidzin (IC50 10.47 mg x S(-1)), daidzein (IC50 34.22 mg) x L(-1)) and astragalin (IC50 31.27 mg x L(-1)) had the activity of scavenging ABTS free radical. Psoralidin (IC50 40.74 mg x L(-1)), coryfolin (IC50 45.73 mg x L(-1)) and daidzein (IC50 49.44 mg x L(-1)) had alpha-glucosidase inhibitory activity. Corylifolinin and neobavaisoflavone had significantly effect of inhibiting SA, MRSA and ESBLs-SA (MIC 0. 781 3, 1.562, 5, 0.781 25 microg x disc(-1) and 6.25, 6.25, 6.25 microg x disc(-1).

Stable life predection for Psoralea corylifolia by initial average rate stability test / 中国中药杂志

<p><b>OBJECTIVE</b>To study the total content change of psoralea and isopsoralea in Psoralea corylifolia under different temperature, and predict its term of validity by initial average rate stability test in order to provide the basis for assessing its quality.</p><p><b>METHOD</b>The reaction rate constant K was replaced by initial velocity V. According to Arrhenius rule, storage period was obtained at room temperature.</p><p><b>RESULT</b>The stable life of P. corylifolia has been determined as 0.53 years.</p><p><b>CONCLUSION</b>The high temperature is not conducive to the stability of the P. corylifolia, which need to store in a dark and cool place.</p>

Rapid analysis of psoralen and isopsoralen in Psoralea corylifolia by microwave-assisted extraction / 中国中药杂志

<p><b>OBJECTIVE</b>To establish a convenient and rapid method of microwave-assisted extraction (MAE) for the extraction of psoralen and isopsoralen in Psoralea corylifolia.</p><p><b>METHOD</b>The effects of various parameters on the MAE were investigated with several single-factor tests, and compared with the traditional extraction.</p><p><b>RESULT</b>The optimal conditions of MAE were as follows: the extractine time was 3 min, and the ratio of solvent to material was 400 mL x g(-1) by using methanol as the solvent. Compared with soxhlet extraction, heat reflux extraction, and ultrasound-assisted extraction, MAE needed only 3 min to give the highest yield of psoralen and isopsoralen, while the other extraction methods needed several hours and gave lower yield.</p><p><b>CONCLUSION</b>The proposed method has greatly shortened extraction time and improved extraction yield, so it provides a neotype, simple and rapid measure for the separation of psoralen and isopsoralen from P. corylifolia.</p>

Variation of 4 kinds of compounds in Psoralea corylifolia processed by different methods / 中国中药杂志

<p><b>UNLABELLED</b>OBJECITVE: To established an efficient method for simultaneous quantification of 7 compounds belonging to 4 chemical types in Psoralea corylifolia processed by different methods, and to elucidate variations of 4 kinds of compounds in different processed P. corylifolia.</p><p><b>METHOD</b>The chromatographic separation was performed on an ACUITY C18 column using acetonitrile and 0.1% formic acid aqueous solution in the gradient elution at 0.4 mL x min(-1). Detection wavelength was set at 246 nm. Column temperature was fixed at 50 degrees C.</p><p><b>RESULT</b>The 4 kinds of compounds including psoralenoside, isopsoralenoside (benzofuran glycosides), psoralen, isopsoralen, psoralidin (coumarins), bavachin (flavonoids), and bakuchiol (meroterpenes) were separated in 25 min. The correlation coefficients of those compounds were over 0.9993 in the tested range. The intra- and inter-day precisions were below 1.5%. The average recoveries ranged from 99.2% to 106%.</p><p><b>CONCLUSION</b>This method is simple, rapid and accurate, which can be used for the determination of the 4 kinds of compounds in different processed P. corylifolia. In P. corylifolia processed by different methods, the contents of benzofuran glycosides, flavonoids, and meroterpenes in P. corylifolia processed by Leigong's method decrease obviously, while the contents of psoralen and isopsoralen increase significantly.</p>

Vitro antitumor activity and synthesis of the key intermediate of bakuchiol / 药学学报

The in vitro antitumor activity of bakuchiol was exploited, compared with tamoxifen. The result of biological activities showed that bakuchiol could inhibit human breast cancer and the IC50 values were 2.89 x 10(-5) mol L(-1) and 8.29 x 10(-3) mol L(-1) against the cells line T-47D and MDA-MB-231 respectively. On the other hand, the key intermediate to synthesize bakuchiol was obtained by the method of Ireland-Claisen rearrangement. Comparing with traditional Claisen rearrangement, the reaction conditions are milder and the reaction reagents are safer.

Two new compounds from Psoralea corylifolia L / 药学学报

To study the chemical constituents of the fruits of Psoralea corylifolia L., the constituents were isolated and purified by chromatography. Two new compounds were isolated from the ethyl acetate-soluble fraction of the ethanol extract. On the basis of chemical and spectroscopic data 1D and 2D NMR, they were identified as 2-(3, 4-dihydroxyphenyl)-8, 8-dimethyl-8H-pyrano[2, 3-h]chromen-4-one (1) and 5-(2-hydroxyl-1-methyl)-ethyl-4, 5-dihydrofurano[2, 3-h](4'-hydroxyl-3', 5'-dimethoxy)-isoflavone (2), and named as coryfolia D and bavarigenin separately.

Identification of compounds in fruits of Psoralea corylifolia by HPLC-MS / 中国中药杂志

<p><b>OBJECTIVE</b>To identify the compounds in fruits of Psoralea corylifolia by high performance liquid chromatography-mass spectrometry.</p><p><b>METHOD</b>The chromatographic separation was carried out at 30 degrees C on a Diamonsil C18 column (4.6 mm x 250 mm, 5 microm) eluted in the gradient program. The mobile phase consisted of acetonitrile (A) and water containing 0.05% formic acid (B). The detection wavelength was at 246 nm and the on-line UV spectra was recorded in the range of 190-400 nm. The mass spectra were obtained by Finnigan LCQ Deca XP(plus) ion trap mass spectrometer in the positive ion mode with ion spray voltage 4.5 kV, sheath gas (N2), 60 arbitrary units, auxiliary gas (N2), 20 arbitrary units; capillary temperature, 350 degrees C, capillary voltage 19 V, tube lens offset voltage 25 V, mass range recorded, m/z 90-800.</p><p><b>RESULT</b>Two coumarin glycosides, three coumarins, eight flavonoids and one meroterpene were identified by HPLC-MS method.</p><p><b>CONCLUSION</b>The method is simple and rapid for the identification and quality control for the fruits of P. corylifolia.</p>

Induction of nitric oxide & tumour necrosis factor-alpha by Psoralea corylifolia.

BACKGROUND & OBJECTIVES: Psoralea corylifolia (PC) is an herb widely used in medicine for the treatment of a variety of ailment. PC is also known to have immunomodulatory activity. However, its mechanism of action is not known. In the present study we investigated effect of PC on nitric oxide (NO) and tumour necrosis factor-alpha (TNF-alpha) production in mouse peritoneal macrophages and also examined the mechanism by which PC regulates NO production. METHODS: MTT assay performed for cell viability test and nitrite concentration was measured by using Griess reagent. The amount of TNF-alpha secreted by the cells was measured by a modified enzyme-linked immunosorbent assay (ELISA). Expression of iNOS was investigated by western blot analysis. RESULTS: PC in combination with recombinant interferon-gamma (rIFN-gamma) showed a marked co-operative induction of NO production, with no effect on NO production by itself. The increased production of NO from rIFN-gamma plus PC-stimulated cells was almost completely inhibited by pre-treatment with pyrrolidine dithiocarbamate (PDTC), an inhibitor of nuclear factor kappa B (NF-kappaB). Furthermore, treatment of peritoneal macrophages with rIFN-gamma plus PC caused a significant increase in tumour necrosis factor-alpha (TNF-alpha) production. PDTC also decreased the effect of PC on TNF-alpha production significantly. INTERPRETATION & CONCLUSION: As NO and TNF-alpha play an important role in immune function and host defense, PC treatment could modulate several aspects of host defense mechanisms due to stimulation of the inducible nitric oxide synthase.

Ontogenetic changes in foliar features and psoralen content of Psoralea corylifolia Linn. exposed to SO2 stress.

Field-grown Psoralea corylifolia plants were exposed to 0.5 ppm and 1.0 ppm concentrations of sulphur dioxide gas and sampled for observation at the pre-flowering, flowering and post-flowering stages of plant ontogeny. One ppm SO2 concentration caused a significant decline in leaf number and leaf area per plant, total leaf dry weight, and the size and amount of midrib vasculature. The density and size of stomata decreased and many stomata were damaged. Interestingly new epidermis developed oversome of the damaged leaf stomata, thus showing a unique defence strategy against SO2 stress through dedifferentiation of the epidermal cells. Decline in the concentrations of leafchlorophylls and carotenoids in treated plants were up to 20% and 29% respectively. Stomatal conductance, intercellular CO2 content and net photosynthetic rate lowered byover 52%, 20% and 35%, respectively under the SO2 stress. Concentration of psoralen, a basic linear furanocoumarin known for its use in the treatment of dermal diseases, was highest (5.32%) in seeds and lowest (0.28%) in roots. It was heavily reduced in SO2 treated plants, the maximum decline occurring in seeds (86.70%) and leaves (56.27%). In the roots and shoots of the treated plants, it was low in pre-flowering stage, compared with the control, but showed a recovery during the post-flowering phase of plant growth.