The protective effect of gentisic acid on rheumatoid arthritis via the RAF/ERK signaling pathway.

BACKGROUND: RAF and ERK pathways are known to be activated in human rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS), which play an important role in the pathogenesis and destruction of RA. Gentisic acid (GA) was a natural product derived from plants, which has been reported can attenuate pressure overload-induced cardiac hypertrophy and fibrosis in mice through inhibition of the ERK1/2 pathway. Whether GA can inhibit the occurrence and development of RA through RAF/ERK signaling pathway has not been reported. The purpose of this study is to determine whether GA may have a certain therapeutic effect on RA-FLS. METHOD: Bovine type II collagen was used to establish a rat model of rheumatism. Enzyme-linked immunosorbent assay was used to detect inflammatory factors, anti-inflammatory mediators, and rheumatoid factor. Hematoxylin and eosin and TUNEL staining were used to detect the effect of GA on histochemical with rheumatoid arthritis. RAF, ERK, and p-ERK expressions in synovial tissue were measured by western blot and immunohistochemical. Besides, human rheumatoid arthritis fibroblast-like synoviocytes cell line MH7A was used to investigate the biological behavior influenced by GA. Apoptosis assay was performed to detect apoptosis of GA on MH7A cells. Transwell invasion assay was performed to detect the ability of cell migration. RESULT: The result showed that GA could reduce joint swelling and inflammation. At the same time, it can also promote the apoptosis of synovial cells and down-regulate the RAF/ERK pathway. CONCLUSION: GA may ameliorate inflammatory factors' abnormality, synovial hyperplasia, and apoptosis of synovium via inhibiting the RAF/ERK signaling pathway.

Modulation of Inflammatory Pathways and Adipogenesis by the Action of Gentisic Acid in RAW 264.7 and 3T3-L1 Cell Lines.

Gentisic acid (GA), a benzoic acid derivative present in various food ingredients, has been shown to have diverse pharmaceutical activities such as anti-carcinogenic, antioxidant, and hepatoprotective effects. In this study, we used a co-culture system to investigate the mechanisms of the anti-inflammatory and anti-adipogenic effects of GA on macrophages and adipocytes, respectively, as well as its effect on obesity-related chronic inflammation. We found that GA effectively suppressed lipopolysaccharide-stimulated inflammatory responses by controlling the production of nitric oxide and pro-inflammatory cytokines and modulating inflammation-related protein pathways. GA treatment also inhibited lipid accumulation in adipocytes by modulating the expression of major adipogenic transcription factors and their upstream protein pathways. Furthermore, in the macrophage-adipocyte co-culture system, GA decreased the production of obesity-related cytokines. These results indicate that GA possesses effective anti-inflammatory and anti-adipogenic activities and may be used in developing treatments for the management of obesity-related chronic inflammatory diseases.

Homogentisic Acid and Gentisic Acid Biosynthesized Pyomelanin Mimics: Structural Characterization and Antioxidant Activity.

Pyomelanin mimics from homogentisic acid (HGA) and gentisic acid (GA) were biosynthesized by the oxidative enzyme T. versicolor laccase at physiological pH to obtain water soluble melanins. The pigments show brown-black color, broad band visible light absorption, a persistent paramagnetism and high antioxidant activity. The EPR approach shows that at least two different radical species are present in both cases, contributing to the paramagnetism of the samples. This achievement can also shed light on the composition of the ochronotic pigment in the Alkaptonuria disease. On the other hand, these soluble pyomelanin mimics, sharing physico-chemical properties with eumelanin, can represent a suitable alternative to replace the insoluble melanin pigment in biotechnological applications.

Screening of antimicrobial synergism between phenolic acids derivatives and UV-A light radiation.

The objective of this study was to investigate synergistic antibacterial activity based on a combination of UV-A light and three classes of food grade compounds: benzoic acid derivatives, cinnamic acid derivatives, and gallates. By using Escherichia coli O157:H7 as the model strain, it was observed that three cinnamic acid derivatives (ferulic acid, coumaric acid, and caffeic acid) and one benzoic acid derivative (2,5-dihydroxybenzoic acid) presented strong synergistic antibacterial activity with UV-A light radiation, where 1 mM levels of these compounds plus with 15 min of UV-A light (total light dose of 6.1 cm-2) led to more than 7-log CFU mL-1 of bacterial inactivation. In contrast, synergistic antibacterial activity between UV-A light and most benzoic acid derivatives (benzoic acid, gallic acid, vanillic acid, and 2,5-dimethoxybenzoic acid) were only observed after higher concentrations of these compounds were applied (10 mM). Lastly, from the three gallates tested (methyl gallate, ethyl gallate, and propyl gallate), only propyl gallate showed strong antibacterial synergism with UV-A light, where 10 mM of propyl gallate plus 15 min of UV-A light led to approximately 6.5-log of bacterial reduction. Presence of antioxidant compounds mitigated the light-mediated antibacterial activity of gallic acid, 2,5-dihydroxybenzoic acid, and propyl gallate. Similarly, the light-mediated antibacterial activity of these compounds was significantly (P < 0.05) reduced against metabolic-inhibited bacterial cells (sodium azide pretreatment). On the other hand, the antibacterial synergism between ferulic acid and UV-A light was not affected by the presence of antioxidants or the metabolic state of the bacterial cells. Due to the increasing concerns of antimicrobial resistant (AMR) pathogens, the study also investigated the proposed synergistic treatment on AMR Salmonella. Combinations of 1 mM of ferulic acid or 1 mM of 2,5-dihydroxybenzoic acid with UV-A light radiation was able to inactivate more than 6-log of a multi-drug resistant Salmonella Typhimurium strain.

Marine Fungus Aspergillus chevalieri TM2-S6 Extract Protects Skin Fibroblasts from Oxidative Stress.

The strain Aspergillus chevalieri TM2-S6 was isolated from the sponge Axinella and identified according to internal transcribed spacer (ITS) molecular sequence homology with Aspergillus species from the section Restricti. The strain was cultivated 9 days on potato dextrose broth (PDB), and the medium evaluated as antioxidant on primary normal human dermal fibroblasts (NHDF). The cultivation broth was submitted to sterile filtration, lyophilized and used without any further processing to give the Aspergillus chevalieri TM2-S6 cultivation broth ingredient named ACBB. ACCB contains two main compounds: tetrahydroauroglaucin and flavoglaucin. Under oxidative stress, ACCB showed a significant promotion of cell viability. To elucidate the mechanism of action, the impact on a panel of hundreds of genes involved in fibroblast physiology was evaluated. Thus, ACCB stimulates cell proliferation (VEGFA, TGFB3), antioxidant response (GPX1, SOD1, NRF2), and extracellular matrix organization (COL1A1, COL3A1, CD44, MMP14). ACCD also reduced aging (SIRT1, SIRT2, FOXO3). These findings indicate that Aspergillus chevalieri TM2-S6 cultivation broth exhibits significant in vitro skin protection of human fibroblasts under oxidative stress, making it a potential cosmetic ingredient.

Complex Mitochondrial Dysfunction Induced by TPP+-Gentisic Acid and Mitochondrial Translation Inhibition by Doxycycline Evokes Synergistic Lethality in Breast Cancer Cells.

The mitochondrion has emerged as a promising therapeutic target for novel cancer treatments because of its essential role in tumorigenesis and resistance to chemotherapy. Previously, we described a natural compound, 10-((2,5-dihydroxybenzoyl)oxy)decyl) triphenylphosphonium bromide (GA-TPP+C10), with a hydroquinone scaffold that selectively targets the mitochondria of breast cancer (BC) cells by binding to the triphenylphosphonium group as a chemical chaperone; however, the mechanism of action remains unclear. In this work, we showed that GA-TPP+C10 causes time-dependent complex inhibition of the mitochondrial bioenergetics of BC cells, characterized by (1) an initial phase of mitochondrial uptake with an uncoupling effect of oxidative phosphorylation, as previously reported, (2) inhibition of Complex I-dependent respiration, and (3) a late phase of mitochondrial accumulation with inhibition of α-ketoglutarate dehydrogenase complex (αKGDHC) activity. These events led to cell cycle arrest in the G1 phase and cell death at 24 and 48 h of exposure, and the cells were rescued by the addition of the cell-penetrating metabolic intermediates l-aspartic acid ß-methyl ester (mAsp) and dimethyl α-ketoglutarate (dm-KG). In addition, this unexpected blocking of mitochondrial function triggered metabolic remodeling toward glycolysis, AMPK activation, increased expression of proliferator-activated receptor gamma coactivator 1-alpha (pgc1α) and electron transport chain (ETC) component-related genes encoded by mitochondrial DNA and downregulation of the uncoupling proteins ucp3 and ucp4, suggesting an AMPK-dependent prosurvival adaptive response in cancer cells. Consistent with this finding, we showed that inhibition of mitochondrial translation with doxycycline, a broad-spectrum antibiotic that inhibits the 28 S subunit of the mitochondrial ribosome, in the presence of GA-TPP+C10 significantly reduces the mt-CO1 and VDAC protein levels and the FCCP-stimulated maximal electron flux and promotes selective and synergistic cytotoxic effects on BC cells at 24 h of treatment. Based on our results, we propose that this combined strategy based on blockage of the adaptive response induced by mitochondrial bioenergetic inhibition may have therapeutic relevance in BC.

Oxidant and Antioxidant Effects of Gentisic Acid in a 177Lu-Labelled Methionine-Containing Minigastrin Analogue.

BACKGROUND: The radiolabelling of receptor-binding peptides for therapy is a challenge since the peptide itself is exposed (during labelling, storage and transport) to radiation-induced damage, directly or indirectly, in aqueous solution. Hence, the use of radiostabilizers seems to be mandatory, especially in peptide molecules that contain radiation-sensitive amino acids. OBJECTIVE: The aim of this study was to investigate the effect of two stabilizers, gentisic acid and methionine, to delve into how each of them affects the radiolabelling and stability of the minigastrin analogue [177Lu]Lu-DOTA-His-His-Glu-Ala-Tyr-Gly-Trp-Met-Asp-Phe-NH2 through the analysis of the 22 species distinguished over time by an optimized HPLC system. METHODS: The stabilizers, in different combinations, were present from the beginning of the labelling process carried out at 96 °C for 15 min. The stability was studied for up to 7 days. RESULTS: The unexpected selective oxidation of the methionine residue of the radiolabelled peptide, promoted by gentisic acid, led to studying the effect of pH, from 3.5 to 6.0, in the presence of only this stabilizer. A pH-dependent antioxidant behaviour was revealed, showing a decrease in peptide impurities but an increase in the selective oxidation as the pH was increased. CONCLUSION: The selective oxidation of the methionine residue could be induced by oxidizing species probably produced in the reaction between gentisic acid and free radicals of water, during the protection of the radiolabelled peptide from the attack of these harmful species. Therefore, the addition of methionine becomes necessary to effectively decrease this selective oxidation in the methioninecontaining peptide.

Assessing Anticancer Potential of Blueberry Flavonoids, Quercetin, Kaempferol, and Gentisic Acid, Through Oxidative Stress and Apoptosis Parameters on HCT-116 Cells.

In recent years, natural products gained popularity with their anti-inflammatory and antioxidant effects mediated by chemical compounds within their composition. Study results offering them as palliative therapy options in cancer or as anticancer agents with high levels of cytotoxicity brought a new approach to combine cancer treatment protocols with these products. From a different perspective, edible types of these products are suggested in daily diets due to their potential cancer preventive effects. Our preliminary work was on blueberry extracts (Vaccinium myrtillus) as a main representative of these natural products, and the contents of the extracts were analyzed with liquid chromatography tandem mass spectrometry (LC MS/MS) to reveal the composition and distribution of polyphenolic compounds within. The most abundant polyphenols detected in V. myrtillus extracts were quercetin, kaempferol, and a phenolic acid, gentisic acid (GA). The compounds were further evaluated on treated HCT-116 cells for their potential anticancer effects by measuring total antioxidant status, total oxidant status, and 8-hydroxydeoxyguanosine levels for evaluation of oxidative stress and through protein array analysis and flow cytometric analysis for evaluation of apoptosis. In analysis of oxidative stress parameters, reduced total oxidant levels and reduced oxidative stress index levels were found in cells treated with the compounds in comparison with untreated cells. In apoptosis-related protein profiles, at least twofold reduction in various apoptotic proteins was observed after quercetin and kaempferol treatment, whereas a different profile was observed for GA. Overall, results of this study showed that quercetin and kaempferol have strong cytotoxic, antioxidant, and apoptotic effects, although GA is mostly effective as an antioxidant polyphenol on HCT-116 cells.

Holo-lipocalin-2-derived siderophores increase mitochondrial ROS and impair oxidative phosphorylation in rat cardiomyocytes.

Lipocalin-2 (Lcn2), a critical component of the innate immune response which binds siderophores and limits bacterial iron acquisition, can elicit spillover adverse proinflammatory effects. Here we show that holo-Lcn2 (Lcn2-siderophore-iron, 1:3:1) increases mitochondrial reactive oxygen species (ROS) generation and attenuates mitochondrial oxidative phosphorylation in adult rat primary cardiomyocytes in a manner blocked by N-acetyl-cysteine or the mitochondria-specific antioxidant SkQ1. We further demonstrate using siderophores 2,3-DHBA (2,3-dihydroxybenzoic acid) and 2,5-DHBA that increased ROS and reduction in oxidative phosphorylation are direct effects of the siderophore component of holo-Lcn2 and not due to apo-Lcn2 alone. Extracellular apo-Lcn2 enhanced the potency of 2,3-DHBA and 2,5-DHBA to increase ROS production and decrease mitochondrial respiratory capacity, whereas intracellular apo-Lcn2 attenuated these effects. These actions of holo-Lcn2 required an intact plasma membrane and were decreased by inhibition of endocytosis. The hearts, but not serum, of Lcn2 knockout (LKO) mice contained lower levels of 2,5-DHBA compared with wild-type hearts. Furthermore, LKO mice were protected from ischemia/reperfusion-induced cardiac mitochondrial dysfunction. Our study identifies the siderophore moiety of holo-Lcn2 as a regulator of cardiomyocyte mitochondrial bioenergetics.

Inhibitory effects of edible seaweeds, polyphenolics and alginates on the activities of porcine pancreatic α-amylase.

Edible seaweeds are valuable because of their organoleptic properties and complex polysaccharide content. A study was conducted to investigate the potential of dried edible seaweed extracts, its potential phenolic compounds and alginates for α-amylase inhibitory effects. The kinetics of inhibition was assessed in comparison with acarbose. The methanol extract of Laminaria digitata and the acetone extract of Undaria pinnatifida showed inhibitory activity against α-amylase, IC50 0.74 ±â€¯0.02 mg/ml and 0.81 ±â€¯0.03 mg/ml, respectively; both showed mixed-type inhibition. Phenolic compound, 2,5-dihydroxybenzoic acid was found to be a potent inhibitor of α-amylase with an IC50 value of 0.046 ±â€¯0.004 mg/ml. Alginates found in brown seaweeds appeared to be potent inhibitors of α-amylase activity with an IC50 of (0.075 ±â€¯0.010-0.103 ±â€¯0.017) mg/ml, also a mixed-type inhibition. Overall, the findings provide information that crude extracts of brown edible seaweeds, phenolic compounds and alginates are potent α-amylase inhibitors, thereby potentially retarding glucose liberation from starches and alleviation of postprandial hyperglycaemia.

Cytotoxicity, mutagenicity, and antimutagenicity of the gentisic acid on HTC cells.

Gentisic acid (GA) exhibits antioxidant, anti-inflammatory, and antibiotic activities. This substance can be found in citrus fruits, grapes, olive oil, and peas. Considering that there are few studies in the literature on the toxicity of GA, the present work aimed to investigate its cytotoxic, mutagenic, and antimutagenic activities on HTC cells. GA was diluted in culture medium at the final concentration of 0.08, 0.16, 0.8, 1.6, and 8 µg/mL. The cytotoxicity was determined by the MTT assay and Trypan Blue exclusion method, with methyl methanesulfonate and doxorubicin as positive controls, respectively. The cytokinesis-block micronucleus assay determined the mutagenic/antimutagenic activity with benzo[a]pyrene as positive control. Negative control received culture medium only. GA (0.08-8 µg/mL) was not cytotoxic to HTC cells by the MTT assay nor the Trypan Blue exclusion method as no statistical difference was observed when compared to the control. Concentration of 0.08 and 0.8 µg/mL showed no mutagenic or clastogenic effects, as no significant micronuclei inductions were observed, different from 8 µg/mL, that was mutagenic. Furthermore, none of the concentrations presented an antiproliferative activity. The antimutagenic activity of GA (0.08 µg/mL) was observed at the simultaneous treatment, as it reduced the frequency of micronuclei by 76% (24 h) and 79% (48 h). Although pre- and post-treatments were not statistically different from the mutagen, they reduced the induced-damage by 11% and 21%, respectively. The present study indicated the absence of cytotoxicity and antiproliferative activities of GA, in addition to their antimutagenic/protective effects that may contribute to human health.

Different inhibition mechanisms of gentisic acid and cyaniding-3-O-glucoside on polyphenoloxidase.

Gentisic acid and cyanidin-3-O-glucoside are important bioactive polyphenols which are widely distributed in many fruits and cereals. In this work, kinetic study, spectral analysis and computational simulation were used to compare the inhibitory effects and inhibition mechanisms of gentisic acid and cyanidin-3-O-glucoside on mushroom polyphenoloxidase (PPO). The inhibitory effect of cyanidin-3-O-glucoside on PPO was much stronger than that of gentisic acid. Gentisic acid inhibited PPO in a reversible mixed-type manner while cyanidin-3-O-glucoside was an irreversible inhibitor. Gentisic acid and cyanidin-3-O-glucoside made the thermal inactivation of PPO easier, and induced apparent conformational changes of PPO. Compared with gentisic acid, cyanidin-3-O-glucoside had stronger effects on the thermal inactivation and conformation of PPO. Molecular docking results revealed gentisic acid bound to the active site of PPO by hydrogen bonding, π-π stacking and van der Waals forces. However, cyanidin-3-O-glucoside might irreversibly interact with the Met or Cys in PPO by covalent bonds.

Free radical scavengers improve liver function but not morphological changes induced by reperfusion injury.

OBJECTIVE: Reperfusion injury (RI) is associated with high generation of reactive oxygen species (ROS), but the extent of involvement of these agents in the injury remains controversial. The present study aimed to examine the effectiveness of ROS scavengers against hepatic reperfusion injury in the rat. METHODS: The RI was induced in the liver using an isolated slow-flow, reflow perfused rat liver in both anterograde and retrograde perfusion. The effects of gentisic acid, N-acetyl cysteine, and trolox C on the superoxide production, liver function, and morphological changes were examined using different biochemical and histological assays. RESULTS: The hepatic RI caused a significant (p < 0.05) increase in superoxide production and enzyme releases and a decrease in bile flow in both directions. Histological changes induced by RI include apoptosis, necrosis, pale cytoplasm, cell vacuolation, and attenuation of cell cords. Although the production of superoxide in retrograde direction was significantly less than the anterograde, the extent of the injury in the retrograde was greater than the anterograde direction. Pretreatment of the livers with each of the test compounds significantly reduced the release of lactate dehydrogenase and aspartate aminotransferase and improved bile flow in the liver exposed to hypoxia/reperfusion. However, they failed to protect the liver against the structural alterations induced by RI. CONCLUSION: ROS scavengers can reduce superoxide-induced damage and improve the liver function, but they are not able to prevent the structural changes. It shows that ROS are not the sole causative mechanism of hepatic RI and other mechanisms and mediators may be involved.

Inhibitory effects of benzaldehyde derivatives from the marine fungus Eurotium sp. SF-5989 on inflammatory mediators via the induction of heme oxygenase-1 in lipopolysaccharide-stimulated RAW264.7 macrophages.

Two benzaldehyde derivatives, flavoglaucin (1) and isotetrahydro-auroglaucin (2), were isolated from the marine fungus Eurotium sp. SF-5989 through bioassay- and 1H NMR-guided investigation. In this study, we evaluated the anti-inflammatory effects of these compounds in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. We demonstrated that compounds 1 and 2 markedly inhibited LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production by suppressing inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression without affecting cell viability. We also demonstrated that the compounds reduced the secretion of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß) and interleukin-6 (IL-6). Furthermore, compounds 1 and 2 inhibited LPS-induced nuclear factor-κB (NF-κB) activation by suppressing phosphorylation of IkappaB (IκB). These results indicated that the anti-inflammatory effects of these benzaldehyde derivatives in LPS-stimulated RAW264.7 macrophages were due to the inactivation of the NF-κB pathway. In addition, compounds 1 and 2 induced heme oxygenase-1 (HO-1) expression through the nuclear transcription factor-E2-related factor 2 (Nrf2) translocation. The inhibitory effects of compounds 1 and 2 on the production of pro-inflammatory mediators and on NF-κB binding activity were reversed by HO-1 inhibitor tin protoporphyrin (SnPP). Thus, the anti-inflammatory effects of compounds 1 and 2 also correlated with their ability of inducing HO-1 expression.

Neuritogenic surfaces using natural product analogs.

Neuritogenic surfaces are generated by a simple dip-coating procedure, as glass slides are coated with a neurotrophin-like small organic molecule in the presence of a collagen matrix. The surfaces retain their biological activity for multiple cycles and the protocol is suitable for various substrates and coating conditions.

Antioxidant and anti-inflammatory activities of methanol extracts of Tremella fuciformis and its major phenolic acids.

Methanol extract subfractions of the edible white jelly mushroom (Tremella fuciformis), were assessed for the following antioxidant properties: ABTS(+) radical scavenging activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and inhibitory activity of human low-density lipoprotein (LDL) oxidation. Among the subfractions tested, the chloroform subfraction exhibited the strongest antioxidant activity, with the highest total phenolic content (66.31 µg CAE/mg extract) and flavonoids content (5.12 µg QE/mg extract). The ABTS(+) radical scavenging activity of the chloroform subfraction was 7.89 µmol trolox/mg extract, which was the highest among all subfractions. This subfraction also showed the highest DPPH radical scavenging activity and inhibitory activity of LDL oxidation. In addition, the chloroform subfraction demonstrated anti-inflammatory activity through inhibition of nitric oxide production and inducible nitric oxide synthase expression in RAW 264.7 cells. Major phenolic acids from the mushroom extract were identified as 4-hydroxybenzoic acid (323 mg/kg dry weight of mushroom), gentisic acid (174 mg/kg dry weight of mushroom), and 4-coumaric acid (30 mg/kg dry weight of mushroom).

Aspirin metabolites are GPR35 agonists.

Aspirin is widely used as an anti-inflammatory, anti-platelet, anti-pyretic, and cancer-preventive agent; however, the molecular mode of action is unlikely due entirely to the inhibition of cyclooxygenases. Here, we report the agonist activity of several aspirin metabolites at GPR35, a poorly characterized orphan G protein-coupled receptor. 2,3,5-Trihydroxybenzoic acid, an aspirin catabolite, was found to be the most potent GPR35 agonist among aspirin metabolites. Salicyluric acid, the main metabolite of aspirin, was also active. These results suggest that the GPR35 agonist activity of certain aspirin metabolites may contribute to the clinical features of aspirin.

Modulatory effects of gentisic acid against genotoxicity and hepatotoxicity induced by cyclophosphamide in Swiss albino mice.

OBJECTIVES: This study evaluated the protective effects of gentisic acid (GA) against genotoxicity and hepatotoxicity induced by cyclophosphamide (CP) in Swiss albino mice. METHODS: Mice were pretreated with GA orally at doses of 50 and 100 mg/kg for 14 consecutive days before the administration of a single intraperitoneal dose of 50 mg/kg CP. The ameliorative effect of GA on genotoxicity was studied using the in-vivo bone marrow micronuclei induction test, DNA integrity and alkaline unwinding assay. The activity of various oxidative stress enzymes were estimated in hepatic tissue. KEY FINDINGS: A single intraperitoneal administration of CP in mice increased the malondialdehyde level, depleted the glutathione content and antioxidant enzyme activity (glutathione peroxidase, glutathione reductase, catalase and quinone reductase), and induced DNA strand breaks and micronuclei induction. Oral pretreatment with GA at both doses caused a significant reduction in malondialdehyde and glutathione levels, restoration of antioxidant enzyme activity, reduction in micronuclei formation and DNA fragmentation. Serum toxicity marker enzymes such as aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase were increased after CP treatment but restored in GA pretreated groups. CONCLUSION: The results support the protective effect of GA against CP induced genotoxicity and hepatotoxicity.

Gentisides C-K: nine new neuritogenic compounds from the traditional Chinese medicine Gentiana rigescens Franch.

Nine new alkyl 2,3-dihydroxybenzoates, gentisides C-K, were isolated from the traditional Chinese medicine Gentiana rigescens Franch. Their structures and stereochemistry were elucidated by spectroscopic methods, and comparison of the specific rotation with that of the gentiside B. These metabolites are additional members of the gentisides which belong to a novel class of neuritogenic compounds. They are structurally different from one another because they possess varying alkyl chain lengths, with or without an isobutyl or isopropyl group at the end of the alkyl chain. These compounds are potent inducers of neurite outgrowth on PC12 cells. The gentiside C possessing the shortest alkyl chain length exhibited the highest neuritogenic activity among all of the gentisides. Gentiside C showed a significant neuritogenic activity at 1 µM against PC12 cells comparable to that seen for the best nerve growth factor (NGF) concentration of 40 ng/mL. In addition, evident neuritogenic activity was observed in the cells when treated with gentiside C at a concentration as low as 0.03 µM. The structure-activity relationships within the gentisides A-K revealed that alkyl chain length is important for the activity, but structure diversity at the end of the alkyl chain is not.