Potentiating effect of acetaminophen and carbon tetrachloride-induced hepatotoxicity is mediated by activation of receptor interaction protein in mice.

When multiple drugs or chemicals are used in combination, it is important to understand the risk of their interactions and predict potential additive effects. The aim of the current study was to investigate the molecular mechanism(s) accounting for the additive/synergistic effect of combination treatment with acetaminophen (APAP) and carbon tetrachloride (CCl4). Mice were intraperitoneally administered vehicle or 100 mg/kg (5 mL/kg) APAP and 30 min after vehicle or 15 mg/kg (5 mL/kg) CCl4. Sixteen hours after treatment, mice from each group were sacrificed and the livers were removed. CCl4 administration caused slight glycogen depletion; this effect was more pronounced following co-administration of APAP and CCl4. ATP and NADPH levels showed the same trend as glycogen levels. The levels of receptor interacting protein 1 and 3 increased following combination treatment with APAP and CCl4. In contrast, levels of the glutamate cysteine ligase catalytic subunit and glutamate cysteine ligase modifier subunits were not significantly affected by combination treatment. APAP and CCl4 co-administration potentiated the phosphorylation of c-Jun N-terminal kinase and p38 kinases, although phosphorylated activation of extracellular signal-regulated kinase was not changed. Our results suggest that APAP and CCl4 co-administration potentiates hepatotoxicity in an additive/synergistic manner via receptor interacting protein activation.

Sasa veitchii extract protects against carbon tetrachloride-induced hepatic fibrosis in mice.

BACKGROUND: The current study aimed to investigate the hepatoprotective effects of Sasa veitchii extract (SE) on carbon tetrachloride (CCl4)-induced liver fibrosis in mice. METHODS: Male C57BL/6J mice were intraperitoneally injected with CCl4 dissolved in olive oil (1 g/kg) twice per week for 8 weeks. SE (0.1 mL) was administered orally once per day throughout the study, and body weight was measured weekly. Seventy-two hours after the final CCl4 injection, mice were euthanized and plasma samples were collected. The liver and kidneys were collected and weighed. RESULTS: CCl4 administration increased liver weight, decreased body weight, elevated plasma alanine aminotransferase, and aspartate aminotransferase and increased liver oxidative stress (malondialdehyde and glutathione). These increases were attenuated by SE treatment. Overexpression of tumor necrosis factor-α was also reversed following SE treatment. Furthermore, CCl4-induced increases in α-smooth muscle actin, a marker for hepatic fibrosis, were attenuated in mice treated with SE. Moreover, SE inhibited CCl4-induced nuclear translocation of hepatic nuclear factor kappa B (NF-κB) p65 and phosphorylation of mitogen-activated protein kinase (MAPK). CONCLUSION: These results suggested that SE prevented CCl4-induced hepatic fibrosis by inhibiting the MAPK and NF-κB signaling pathways.

Non-toxic Level of Acetaminophen Potentiates Carbon Tetrachloride-Induced Hepatotoxicity in Mice.

A wide range of medications are routinely used to maintain and improve human health. Hence, it is essential that we understand and predict adverse effects caused by the combined use of multiple medications. In the present study, we investigated whether the combination of carbon tetrachloride (CCl4) and acetaminophen (APAP) had a detrimental effect on the liver. Mice injected with APAP (100 mg/kg) showed no significant changes in hepatic injury markers (alanine aminotransferase and aspartate aminotransferase), histopathological findings, pro-inflammatory cytokine levels, or hepatic oxidative stress. In contrast, a single injection of CCl4 (15 mg/kg) led to a significant increase in hepatic injury, in addition to an increase in pro-inflammatory cytokine levels and oxidative stress. Co-administration of APAP and CCl4 resulted in exacerbation of these hepatic injuries. Our results suggest that a non-toxic dose of APAP has the potential to increase CCl4-induced liver damage and oxidative stress.

Suppressive Effect of Kampo Formula "Juzen-taiho-to" on Carbon Tetrachloride-Induced Hepatotoxicity in Mice.

The aim of the present study was to investigate whether pretreatment with the Japanese herbal medicine, "Juzen-taiho-to" (JTX), had an ameliorative effect on carbon tetrachloride (CCl4)-induced hepatotoxicity through anorexia prevention. Mice injected with CCl4 exhibited severe anorexia. Moreover, CCl4 increased the plasma levels of hepatic injury markers (i.e., alanine aminotransferase and aspartate aminotransferase), lipid peroxidation, and hepatic Ca(2+) levels. Pretreatment with JTX recovered the CCl4-induced anorexia. In addition, JTX pretreatment decreased CCl4-induced plasma levels of hepatic injury markers. Increased Ca(2+) is a known indicator of the final progression to hepatocyte death, and CCl4-induced hepatotoxicity is mainly caused by oxidative stress. The present study indicated CCl4-induced lipid peroxidation and hepatic Ca(2+) content decreased with JTX pretreatment. Our results suggest that JTX has potential to protect of CCl4-induced anorexia, and the modulation of oxidative stress.

Kampo formula "Hochu-ekki-to" suppressed carbon tetrachloride-induced hepatotoxicity in mice.

OBJECTIVE: The aim of this study was to investigate whether pretreatment with the Japanese herbal medicine "Hochu-ekki-to" (TJ-41) has an ameliorative effect on carbon tetrachloride (CCl4)-induced hepatotoxicity through anorexia prevention. METHODS: Twenty-four hours before CCl4 injection, TJ-41 or saline solution was intraperitoneally administered. Furthermore, 24 h after TJ-41 injection, mice were intraperitoneally administered 1.6 g/kg CCl4 or olive oil. Moreover, 24 h after CCl4/olive oil injection, mice from each group were euthanized and bled for plasma analysis. RESULTS: Mice injected with CCl4 exhibited severe anorexia. Moreover, CCl4 increased the plasma levels of hepatic injury markers (i.e., alanine aminotransferase and aspartate aminotransferase) as well as lipid peroxidation and hepatic Ca levels. Pretreatment with TJ-41 recovered the CCl4-induced anorexia and plasma levels of the hepatic injury markers. Moreover, CCl4-induced lipid peroxidation and hepatic Ca levels decreased upon TJ-41 pretreatment. In addition, hepatic metallothionein levels in the TJ-41 + CCl4-treated group were decreased by >50 % compared with the levels in the TJ-41-treated group, implying that metallothionein was consumed by CCl4-induced radicals. CONCLUSION: Our results suggest that TJ-41 attenuates CCl4-induced hepatotoxicity, presumably by the induction of metallothionein, which in turn scavenges radicals induced by CCl4 exposure.

Retinoic acid receptor agonist activity of naturally occurring diterpenes.

Recent accumulating evidence indicates that all-trans retinoic acid (ATRA) may be useful for preventing or treating inflammation, allergy, and autoimmune diseases, despite its severe side effects. In this study, screening of 99 crude drugs for retinoic acid receptor (RAR) ligands by luciferase reporter assay demonstrated that the methanol extract of Aralia cordata Rhizoma most effectively activates the transcriptional activity of RARα. Pimaradienoic acid (ent-pimara-8(14),15-dien-19-oic acid) was subsequently isolated as the constituent capable of activating RAR. Pimaric acid and abietic acid, which have similar structures to pimaradienoic acid, were also found to be novel RAR agonists, although abietic acid only slightly activated peroxisome proliferator-activated receptor gamma. These three natural RAR agonists with diterpene structures, while structurally different from ATRA, were able to increase the mRNA levels of the constitutive androstane receptor in HepG2 cells, induce F9 cell differentiation followed by Cyp26a1 mRNA expression, and differentiate HL-60 cells via RAR activation in a different manner from ATRA. These results demonstrate that some diterpenes exist as naturally occurring RAR agonists and that the differences in chemical structure between ATRA and these diterpenes may induce distinct gene activation and a specific cellular response.

Anti-tyrosinase and antimelanogenic effect of cinnamic acid derivatives from Prunus mahaleb L.: Phenolic composition, isolation, identification and inhibitory activity.

ETHNOPHARMACOLOGICAL RELEVANCE: The traditional use of Prunus species against skin diseases and especially for skin lightning cosmeceutical purposes is widespread in many cultures. Prunus mahaleb L. is a well known food plant and used in the baking industry for flavoring. The fruit kernels (endocarp) are used in India for hyperpigmentation. AIM OF THE STUDY: To investigate the chemical composition with the antimelanogenesis effect of P. mahaleb seed and kernel extracts and isolated compounds. MATERIALS AND METHODS: Isolation studies performed from the methanol extracts obtained from kernels and structures were determined using NMR and MS analysis. Antimelanogenesis effect was determined by mushroom tyrosinase assay, cellular tyrosinase assay and melanin content assay using B16F10 murine melanoma cells. RESULTS: Five cinnamic acid derivatives were isolated and their structures (2-O-ß-glucopyranosyloxy-4-methoxy-hydrocinnamic acid (1), cis-melilotoside (2), dihydromelilotoside (3), trans-melilotoside (4), 2-O-ß-glucosyloxy-4-methoxy trans-cinnamic acid (5)) were elucidated using advanced spectroscopic methods. Mushroom tyrosinase enzyme inhibition of extracts, fractions and pure compounds obtained from P. mahaleb kernels were investigated and structure-activity relationship revealed. According to a detailed, comprehensive and validated LC-MS/MS technique analysis, vanilic acid (41.407 mg/g), protocatechuic acid (8.992 mg/g) and ferulic acid (4.962 mg/g) in the kernel ethylacetate fraction; quinic acid (14.183 mg/g), fumaric acid (8.349 mg/g) and aconitic acid (5.574 mg/g) were found as major phenolic compounds in the water fraction. The correlation of trace element copper content in extracts and fractions with mushroom enzyme activity was determined. By examining the enzyme kinetics of the compounds with effective cinnamic acid derivatives, inhibition types and enzyme binding constants Ki were calculated. Compounds 1,3 and 5 exhibited high noncompetitive tyrosinase inhibitory activity against L-tyrosine substrates, with IC50 values of 0.22, 0.31 and 0.37 mM respectively. In addition compounds 1, 3 and 5 showed dose-dependent inhibitory effects on intracellular tyrosinase and melanin levels in α-melanocyte-stimulating hormone (α-MSH)-induced B16F10 melanoma cells. CONCLUSIONS: Potent tyrosinase inhibitory compounds and extracts of P. mahaleb kernels suggest that it could be a new, non-toxic and inexpensive resource for the cosmeceutical industry and in skin diseases associated with hyperpigmentation.

Iridoid-specific glucosyltransferase from Gardenia jasminoides.

Iridoids are one of the most widely distributed secondary metabolites in higher plants. They are pharmacologically active principles in various medicinal plants and key intermediates in the biosynthesis of monoterpenoid indole alkaloids as well as quinoline alkaloids. Although most iridoids are present as 1-O-glucosides, the glucosylation step in the biosynthetic pathway has remained obscure. We isolated a cDNA coding for UDP-glucose:iridoid glucosyltransferase (UGT85A24) from Gardenia jasminoides. UGT85A24 preferentially glucosylated the 1-O-hydroxyl group of 7-deoxyloganetin and genipin but exhibited only weak activity toward loganetin and no activity toward 7-deoxyloganetic acid. This suggests that, in the biosynthetic pathway of geniposide, a major iridoid compound in G. jasminoides, glucosylation occurs after methylation of 7-deoxyloganetic acid. UGT85A24 showed negligible activity toward any acceptor substrates other than iridoid aglycones. Thus, UGT85A24 has a remarkable specificity for iridoid aglycones. The mRNA level of UGT85A24 overlaps with the marked increase in genipin glucosylation activity in the methyl jasmonate-treated cell cultures of G. jasminoides and is related to iridoid accumulation in G. jasminoides fruits.

Iridoid content and biological activities of Veronica cuneifolia subsp. cuneifolia and V. cymbalaria.

CONTEXT: The genus Veronica L. (Plantaginaceae) is represented by 79 species, 26 of which are endemic in Turkey. Some Veronica species are used for the treatment of different inflammatory diseases and cancer in traditional medicine. In addition, chemotaxonomy of the genus is important for the reclassification of the family Plantaginaceae after different phylogenetic studies. OBJECTIVE: Veronica cuneifolia subsp. cuneifolia D. Don and V. cymbalaria Bodard were studied from the view point of iridoid glucosides which are known as chemotaxonomical markers for this genus. Radical scavenging and cytotoxic activities of the extracts were also determined in this study. MATERIAL AND METHODS: Major compounds, isolated from iridoid fractions of V. cuneifolia subsp. cuneifolia were used as the standard compounds for HPLC after determination of their structures, and investigated for their presence in iridoid fractions of V. cymbalaria. Additionally, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and SO radical scavenging and cytotoxic activities against three cancer and a noncancerous cell lines of both extract were also tested using the MTT method. RESULTS: While aucubin, catalpol, verproside, amphicoside, verminoside, and veronicoside were obtained from V. cuneifolia subsp. cuneifolia, two more iridoid glucosides, 6-O-veratroylcatalposide and 6-O-isovanilloylcatalpol, were isolated from V. cymbalaria. Comparing both species, V. cuneifolia subsp. cuneifolia showed stronger radical scavenging and cytotoxic activities than V. cymbalaria. DISCUSSION: Our results demonstrated that the iridoid contents of both species were very close to each other confirming to the chemotaxonomic studies on Veronica species and their different bioactivity range make the plants interesting from the view point of natural drug discovery research.

Identification of Maple Anthocyanin and its Antiproliferative Activity against LLC, T47D and C3H10T1/2 Cells.

BACKGROUND: The genus Acer contains around 200 species, with more than 400 garden varieties. There is considerable diversity in these species and garden varieties, and each can be characterized by morphology and chemical composition. The red appearance of Acer leaves is due to anthocyanin compounds, including cyanidin glycosides, delphinidin glycosides, and galloylated anthocyanins. Few studies have investigated the diversity of anthocyanin compounds in garden varieties, and no studies have examined the pharmacological effects of these compounds. OBJECTIVE: The purpose of this study was to identify the anthocyanins of Acer palmatum cv. 'Chishio', a garden variety of A. palmatum and evaluate their antiproliferative and antioxidant activities. METHODS: A methanol extract of fresh leaves was partitioned with ethyl acetate. The extract was purified by column chromatography and compounds were subsequently identified by 1H and 13C NMR and ESI-HRMS. Antiproliferative activity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4- sulfophenyl)-2H-tetrazolium, inner salt (MTS) colorimetric assay. The antioxidant assay was evaluated by scavenging activity using the stable radical DPPH. RESULTS: The anthocyanins cyanidin-3-O-(6''-O-α-rhamnopyranosyl- ß-glucopyranoside), cyanidin-3-O- ß- glucopyranoside, cyanidin-3-O-[2''-O-(galloyl)-6''-O-(rhamnosyl)-ß-glucoside], and cyanidin-3-O-[2''-O-(galloyl)- ß-glucopyranoside] were isolated from A. palmatum cv. 'Chishio'. All four anthocyanin compounds showed antiproliferative activity against LLC and T47D cells, and galloylated anthocyanin showed antiproliferative activity against C3H10T1/2 cells. All four anthocyanins inhibited the activity of DPPH radicals in a dosedependent manner. CONCLUSION: Maple anthocyanins could be a new cancer therapeutic agent or prophylactic medicine.

The herbal medicine compound falcarindiol from Notopterygii Rhizoma suppresses dendritic cell maturation.

Dendritic cells (DCs) are important for regulating the immune response. We report an herbal medicine compound called falcarindiol that affects DC function. Ethanol extracts of 99 crude drugs that are the main components of 210 traditional Japanese medicines (Kampo medicine) approved by the Ministry of Health, Labor and Welfare in Japan were prepared and screened using the murine epidermal-derived Langerhans cell line XS106. Notopterygii Rhizoma strongly suppressed major histocompatibility complex (MHC) class II expression in XS106 cells. Activity-guided fractionation led to the isolation and identification of falcarindiol as a principal active compound in Notopterygii Rhizoma. Falcarindiol (1-5 microM) dose-dependently suppressed MHC II expression in XS106 cells. Fresh-isolated bone marrow-derived DCs were examined for the production of MHC II, CD80, CD86, interleukin (IL)-12p70, and IL-10. Treatment of bone marrow-derived DCs with 5 muM falcarindiol significantly inhibited lipopolysaccharide-induced phenotype activation and cytokine secretion and inhibited MHC II expression by CD40 ligation, but not phorbol 12-myristate 13-acetate + ionomycin or IL-12. Falcarindiol inhibited DC maturation by blocking the canonical pathway of nuclear factor-kappaB and phosphorylated p38. Topical application of 0.002 and 0.01% falcarindiol before sensitization dose-dependently suppressed delayed-type hypersensitivity to ovalbumin (p < 0.01). Falcarindiol induces immunosuppressive effects in vitro and in vivo and might be a novel therapy for autoimmune or allergic diseases.

Hydroxy monounsaturated fatty acids as agonists for peroxisome proliferator-activated receptors.

The physiological and pathological role of oxidized polyunsaturated fatty acids (PUFAs) has been extensively studied, whereas those of hydroxy monounsaturated fatty acids (MUFAs) are not well understood. This study demonstrated that 11-hydroxy-(9Z)-octadecenoic acid ((9Z)-11-HOE), which was isolated from adlay seeds (Coix lacryma-jobi L. var. ma-yuen STAF.), can activate peroxisome proliferator-activated receptor (PPAR)alpha, delta and gamma in luciferase reporter assays more efficiently than (9Z)-octadecenoic acid (oleic acid), and to the same degree as linoleic acid. (9Z)-11-HOE increased the mRNA levels of UCP2 and CD36 in C2C12 myotubes and THP- 1 cells, respectively, and these effects were blocked by the PPARdelta- and gamma-specific antagonists GSK0660 and T0070907, respectively. Evaluation of the structure.activity relationship between hydroxy MUFAs and PPAR activation revealed that (9E)-11-HOE, the geometrical isomer of (9Z)-11-HOE, activated PPARs more potently than (9Z)-11-HOE, and that PPAR activation by hydroxyl MUFAs was not markedly influenced by the position of the hydroxy group or the double bond, although PPARdelta seemed to possess ligand specificity different to that of PPARalpha or gamma . Additionally, the finding that 11-hydroxy octadecanoic acid, the hydrogenated product of (9E)-11- HOE, was also capable of activating PPARs to a similar extent as (9E)-11-HOE indicates that the double bond in hydroxy MUFAs is not essential for PPAR activation. In conclusion, (9Z)-11-HOE derived from alday seeds and hydroxy MUFAs with a chain length of 16 or 18 acted as PPAR agonists. Hydroxylation of MUFAs may change these compounds from silent PPAR ligands to active PPAR agonists.

Tradescantia pallida extract inhibits biofilm formation in Pseudomonas aeruginosa.

Pseudomonas aeruginosa is capable of biofilm formation. In this study, we investigated the effects of aqueous Tradescantia pallida extract on Pseudomonas aeruginosa growth and biofilm formation. Aqueous Tradescantia pallida extracts significantly inhibited both bacterial growth and biofilm formation. However, methanolic Tradescantia pallida extracts inhibited neither. Aqueous Tradescantia pallida extracts were deactivated by heating but were not deactivated by light exposure. The ingredients retained the inhibitory effect on the bacterial growth and biofilm formation after ultrafiltration of aqueous Tradescantia pallida extract. Furthermore, polyphenol-rich Tradescantia pallida extracts inhibited bacterial growth, thus, polyphenols are possible to be an active ingredient. We observed the biofilm by scanning electron microscopy, and quantitative and qualitative differences in the biofilm and cells morphology. Interestingly, the biofilm treated aqueous Tradescantia pallida extracts remained premature. We postulated that premature biofilm formation was due to the inhibition of swarming motility. Indeed, aqueous Tradescantia pallida extracts inhibited swarming motility. These results demonstrate that Peudomonas aeruginosa growth and biofilm formation are inhibited by aqueous Tradescantia pallida extracts.

Application of a quantitative 1H-NMR (1H-qNMR) method for the determination of geniposidic acid and acteoside in Plantaginis semen.

A quantitative 1H-NMR method (1H-qNMR) was developed to determine the concentration of acteoside and geniposidic acid in Plantaginis semen, which is an important crude drug for diuretic purposes. The purity of geniposidic acid and acteoside was determined by the ratio of the intensity of the H-3 signal at δ 7.51 ppm or the H-7″ signal at δ 7.58 ppm in methanol-d 4 to that of a hexamethyldisilane (HMD) signal at 0.04 ppm, respectively. The concentration of HMD was corrected with the International System of Units traceability using potassium hydrogen phthalate of certified reference material grade. The geniposidic acid content in two batches of Plantaginis semen as determined by 1H-qNMR was found to be 0.84 and 1.00 %, and the acteoside content was determined to be 0.80 and 0.93 %. We demonstrated that this method is useful for the quantitative analysis of geniposidic acid and acteoside in Plantainis semen.

Bromobenzene-induced lethal toxicity in mouse is prevented by pretreatment with zinc sulfate.

In the current study, we evaluated the protective effect of zinc (Zn) against bromobenzene (BB) -induced lethal toxicity. We used Zn because this element is known to be an inducer of metallothionein (MT), which is in turn known to serve as an endogenous scavenger of free radicals. We administered Zn (as ZnSO4) at 50 mg/kg subcutaneously once-daily for 3 successive days prior to a single intraperitoneal administration of 1.2 g/kg BB in male ddY mice. Our results showed that pretreatment with Zn completely abolished the BB-induced mortality of mice until 48 h. We also found that pretreatment of mice with Zn significantly decreased the functional marker levels and reduced the histological damage both in liver and kidney as assessed at 18 h post-BB. We also showed that pretreatment with Zn enhanced antioxidative activity, resulting in decreased lipid peroxidation in both liver and kidney. Moreover, BB-induced calcium levels were downregulated by pretreatment with Zn. In addition, Zn-induced MT was decreased in Zn + BB-treated animals, implying that MT was consumed by BB-induced radicals. These findings suggest that prophylaxis with Zn protects mice from BB-induced lethal toxicity by decreasing oxidative stress in liver and kidney, presumably by induction of MT, which scavenges radicals induced by BB exposure.

Application of a quantitative (1)H-NMR method for the determination of paeonol in Moutan cortex, Hachimijiogan and Keishibukuryogan.

Quantitative (1)H-NMR ((1)H-qNMR) was applied to the determination of paeonol concentration in Moutan cortex, Hachimijiogan, and Keishibukuryogan. Paeonol is a major component of Moutan cortex, and its purity was calculated from the ratio of the intensity of the paeonol H-3' signal at δ 6.41 ppm in methanol-d 4 or 6.40 ppm in methanol-d 4 + TFA-d to that of a hexamethyldisilane (HMD) signal at 0 ppm. The concentration of HMD was corrected with SI traceability by using potassium hydrogen phthalate of certified reference material grade. As a result, the paeonol content in two lots of Moutan cortex as determined by (1)H-qNMR was found to be 1.59 % and 1.62 %, respectively, while the paeonol content in Hachimijiogan and Keishibukuryogan was 0.15 % and 0.22 %, respectively. The present study demonstrated that the (1)H-NMR method is useful for the quantitative analysis of crude drugs and Kampo formulas.

Chemopreventive action of xanthone derivatives on photosensitized DNA damage.

Photosensitized DNA damage participates in solar-UV carcinogenesis, photogenotoxicity and phototoxicity. A chemoprevention of photosensitized DNA damage is one of the most important methods for the above phototoxic effects. In this study, the chemopreventive action of xanthone (XAN) derivatives (bellidifolin [BEL], gentiacaulein [GEN], norswertianin [NOR] and swerchirin [SWE]) on DNA damage photosensitized by riboflavin was demonstrated using [32P]-5'-end-labeled DNA fragments obtained from genes relevant to human cancer. GEN and NOR effectively inhibited the formation of piperidine-labile products at consecutive G residues by photoexcited riboflavin, whereas BEL and SWE did not show significant inhibition of DNA damage. The four XAN derivatives decrease the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo), an oxidative product of G, by photoexcited riboflavin. The preventive action for the 8-oxodGuo formation of these XAN derivatives increased in the following order: GEN>NOR>>BEL>SWE. A fluorescence spectroscopic study and ab initio molecular orbital calculations suggested that the prevention of DNA photodamage is because of the quenching of the triplet excited state of riboflavin by XAN derivatives through electron transfer. This chemoprevention is based on neither antioxidation nor a physical sunscreen effect; rather, it is based on the quenching of a photosensitizer. In conclusion, XAN derivatives, especially GEN, may act as novel chemopreventive agents by the quenching mechanism of an excited photosensitizer.

Chemical constituents and antioxidant activity of Mallotus roxburghianus leaves.

Mallotus roxburghianus is used in the traditional medicine in North-Eastern India, but previously no work has been done on the identification of bioactive compounds. Two new compounds, 3-(1-C-beta-D-glucopyranosyl)-2,6-dihydroxy-5-methoxybenzoic acid (6) and 2,4,8,9,10-pentahydroxy-3,7-dimethoxyanthracene-6-O-beta-D-rhamnopyranoside (7) together with beta-sitosterol (1), stigmasterol (2), betulinic acid (3), 4-hydroxybenzoic acid (4), beta-sitosterol-beta-D-glucoside (5), and bergenin (8) were isolated and identified from the leaves of M. roxburghianus. The chloroform soluble portion of the alcoholic extract of leaf, and compounds 3, 6, 7, and 8 exhibited encouraging antioxidant activities.

CYP98A6 from Lithospermum erythrorhizon encodes 4-coumaroyl-4'-hydroxyphenyllactic acid 3-hydroxylase involved in rosmarinic acid biosynthesis.

Rosmarinic acid is the dominant hydroxycinnamic acid ester accumulated in Boraginaceae and Lamiaceae plants. A cytochrome P450 cDNA was isolated by differential display from cultured cells of Lithospermum erythrorhizon, and the gene product was designated CYP98A6 based on the deduced amino acid sequence. After expression in yeast, the P450 was shown to catalyze the 3-hydroxylation of 4-coumaroyl-4'-hydroxyphenyllactic acid, one of the final two steps leading to rosmarinic acid. The expression level of CYP98A6 is dramatically increased by addition of yeast extract or methyl jasmonate to L. erythrorhizon cells, and its expression pattern reflected the elicitor-induced change in rosmarinic acid production, indicating that CYP98A6 plays an important role in regulation of rosmarinic acid biosynthesis.

Production of unnatural glucosides of curcumin with drastically enhanced water solubility by cell suspension cultures of Catharanthus roseus.

Catharanthus roseus cell suspension cultures converted exogenously supplied curcumin to a series of glucosides, none of which has been found in nature so far. The efficiency of glucosylation was dependent on culture stage of the cells and medium sucrose concentration. Methyl jasmonate and salicylic acid enhanced the glucoside formation only when they were added to the cultures prior to the addition of curcumin. The glucoside yield was 2.5 micromol/g fresh weight of the cells at an optimal culture condition. The water solubility of curcumin-4',4"-O-beta-D-digentiobioside was 0.65 mmol/ml, which was 20 million-fold higher than that of curcumin.