Mechanism of the protective effects of sumac gall extract and gallic acid on the progression of CCl4-induced acute liver injury in rats

Hydrolysable tannins as a potential therapeutic drug for the human fibrosis-associated disease

Fibrosis is a pathological change with abnormal tissue regeneration due to a response to persistent injury, which is extensively related to organ damage and failure, leading to high morbidity and mortality worldwide. Although the pathogenesis of fibrosis has been comprehensively elucidated, there are few effective therapies for treating fibrotic diseases. Natural products are increasingly regarded as an effective strategy for fibrosis with numerous favorable functions. Hydrolysable tannins (HT) are a type of natural products that have the potential to treat the fibrotic disease. In this review, we describe some biological activities and the therapeutic prospects of HT in organ fibrosis. Furthermore, the underlying mechanisms of inhibition of HT on fibrotic organs in relation to inflammation, oxidative stress, epithelial-mesenchymal transition, fibroblast activation and proliferation, and extracellular matrix accumulation are discussed. Understanding the mechanism of HT against fibrotic diseases will provide a new strategy for the prevention and attenuation of fibrosis progression.

Gallic acid attenuates cerebral ischemia/re-perfusion-induced blood-brain barrier injury by modifying polarization of microglia

Microglia, the main immune effector cells in the central nervous system, play a dual role in the function/structure of the blood-brain barrier (BBB) and brain health. During and soon after a cerebral ischemic injury, microglia produce neurotrophic factors and neurotoxins that can impact on the injury itself and pathology progression. At the same time, microglia undergo polarization to M1 or M2 pro- vs. anti-inflammatory subtypes that also help drive the outcome of the injury process. Thus, agents that can mitigate cerebral ischemic injury progression, promote protective functions of microglia, and help maintain BBB and overall brain health/host neurologic function after a cerebral ischemic event would be of great use in clinical settings. Protective effects from gallic acid (GA) in cerebral ischemia/re-perfusion-induced injury to the BBB and other sites in the brain have not yet been assessed. To address this, a middle cerebral artery occlusion (MCAO) method was used to establish an experimental ischemic stroke model in mice. Mice were placed in sham operation (Sham), model (MCAO), MCAO + GA (50 mg/kg), MCAO + GA (100 mg/kg), or MCAO + GA (150 mg/kg) groups. At various times post-stroke, cerebral infarct volume and host neurological function were evaluated. In addition, qRT-PCR, Western blotting, and ELISA were used to evaluate the expression and tissue content of microglia-related factors. The results showed GA treatment protected the integrity of the BBB, significantly reduced brain edema, and helped lead to improved neurological function scores in the MCAO mice. Whether these changes were due to that GA attenuated cerebral ischemia/re-perfusion-induced activation of microglial cells overall, in part, by inhibiting their polarization to the M1 subtype, is uncertain. Taking these outcomes together, for now it is reasonable to suggest that use of GA either as a prophylactic or immediately in the event of a cerebral ischemic event/stroke could help to promote neuronal survival and allow for a more likely of host neurological function over time.

Potential benefits of gallic acid as skeletal muscle relaxant in animal experimental models

Background and Objective

Many natural bioactive chemicals have been shown to have functional activity, suggesting that they could be useful in the treatment and management of a wide range of chronic conditions. Flavonoids, which include gallic acid (GA), are the most abundant polyphenols found in nature. Skeletal muscle relaxants are drugs that reduce undesired spasms while maintaining awareness and reflexes unaffected. The purpose of this investigation was to determine if GA has any skeletal muscle relaxant properties in experimental animal models.

Materials and Methods

The muscle relaxant activity of three dosages of GA (5, 10, and 20 mg/kg) was compared to that of normal diazepam (5 mg/kg) utilizing climbing, chimney, and modified Kondziela's inverted tests. An analysis of variance (ANOVA) and a post-ANOVA Tukey multiple comparisons test were used to assess the data.

Results

Animals given 10 and 20 mg/kg of GA had a great deal of trouble climbing up the chain, presumably because their muscles were relaxed. Similarly, rats given a high dose of GA (20 mg/kg) had a significantly (P < 0.05) longer response time in the chimney test, indicating a lack of attention and slowed muscle tone, resulting in problems with motor coordination. In inverted testing, animals given a high dose of GA had a significantly (P < 0.01) reduced holding capacity on the mesh for a longer period of time. A decrease in holding time is caused by a decrease in muscular contraction. The low dose of GA, on the other hand, failed to show muscle relaxant effect in any of the three models.

Conclusions

As a conclusion, our data show that GA has a dose-dependent skeletal muscle relaxant effect when administered orally to mice.

Hexavalent chromium reduction by gallic acid

Cr(VI) is widely used in industry and often large quantities have been accidently or due to lack of precautions released at the environment. The presence of high concentrations of Cr(VI) in waste streams causes concern due to its toxicity and solubility. However the Cr(III) is a useful micronutrient in human diet. The reduction of Cr(VI) to Cr(III) is a promising technology for a clean environment. Polyphenols are commonly found in plants and they are considered as strong natural antioxidants. In this study the reduction of hexavalent to trivalent chromium using gallic acid (GA), a polyhydroxyphenolic compound, was evaluated. The effect of pH, temperature, and Cr(VI) concentration on the kinetics of Cr(VI) reduction by GA were examined by conducting batch tests. It was found that reduction of Cr(VI) by GA is a rapid reaction under mild acidic conditions. Reduction was found to follow a 2nd order kinetics with respect to Cr(VI) concentration in the pH range 3-5. The results of the present study indicated that the treatment of contaminated waters with initial concentration of Cr(VI) 100 μΜ by gallic acid, below the environmental limit of 0.96 μM, required 20 min at pH 3 and 40 min at pH 4. At higher pH a different reduction mechanism seems to prevail and the required time for Cr(VI) reduction was approximately 10 h at pH 5 and 42 h at pH 6. The increase of temperature25 °C to 35 °C, at pH 6, was slightly accelerated the reaction.

Effects of Rhus coriaria L. hydroalcoholic extract on the lipid and antioxidant profile in high fat diet-induced hepatic steatosis in rats

Oxidative stress is related to increased fat deposition in the liver, known as hepatic steatosis. The present study is an evaluation of the anti-oxidative and antihyperlipidemic effects of the hydroalcoholic extract of Rhus coriaria L. (HARE) in rats on a high-fat diet (HFD). Twenty male Wistar rats were divided into four groups: control, HFD, HFD + HARE 50 mg/kg/day, and HFD + HARE 250 mg/kg/day for 12 weeks. Animals were weighed weekly and treated with the HARE extract for 12 weeks by gavage. Subsequently, the histopathological changes, oxidative markers, and lipid profile were evaluated. Statistical analysis was performed using the one-way analysis of variance (ANOVA) for multiple comparisons. First, the active ingredients of the extract were determined by HPLC. Then, the levels in the serum lipid profile (TG, cholesterol, HDL, and LDL) in rats fed with the HFD + HARE were analyzed where a significant reduction was observed. The HFD proved to increase the activity of the liver enzymes, the serum lipid levels, and the malondialdehyde (MDA) level. The ferric-reducing antioxidant activity power (FRAP), catalase (CAT), and superoxide dismutase (SOD) catalytic activity were reduced in the liver homogenate of HFD rats compared to the controls. Additionally, the aforementioned liver enzymes activities were reduced in response to HARE. Evaluation of oxidative stress determined a reduction in the MDA level while a raised FRAP was confirmed. In accordance with the present results, histopathological observations have also demonstrated that HARE ameliorated grade-1 hepatic steatosis induced by HFD. Taken together, the findings of this study introduce HARE as a future potential therapeutic agent in treating hepatic steatosis and reducing oxidative damages of an HFD in the liver.

Antioxidant Capacity-Related Preventive Effects of Shoumei (Slightly Fermented Camellia sinensis) Polyphenols against Hepatic Injury

Shoumei is a kind of white tea (slightly fermented Camellia sinensis) that is rich in polyphenols. In this study, polyphenols were extracted from Shoumei. High-performance liquid chromatography (HPLC) showed that the polyphenols included mainly gallic acid, catechin, hyperoside, and sulfuretin. In an in vitro experiment, H₂O₂ was used to induce oxidative damage in human normal hepatic L-02 cells. In an animal experiment, CCl₄ was used to induce liver injury. The in vitro results showed that Shoumei polyphenols inhibited oxidative damage in normal hepatic L-02 cells, and the in vivo results showed that the polyphenols effectively reduced liver index values in mice with liver injury. The polyphenols also decreased aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), triglyceride (TG), total cholesterol (TC), blood urea nitrogen (BUN), nitric oxide (NO), malondialdehyde (MDA), interleukin 6 (IL-6), interleukin 12 (IL-12), tumour necrosis factor alpha (TNF-α), and interferon gamma (IFN-γ) levels and increased albumin (ALB), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) levels in the serum of mice with liver injury. Furthermore, pathological observation showed that the Shoumei polyphenols reduced CCl₄-induced hepatocyte damage. qRT-PCR and Western blotting showed that the polyphenols upregulated the mRNA and protein expression of neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS), manganese- (Mn-) SOD, copper/zinc- (Cu/Zn-) SOD, CAT, and inhibitor of nuclear factor kappa B (NF-κB) alpha (IκB-α) and downregulated the expression of inducible nitric oxide synthase (iNOS) and NF-κB p65. The Shoumei polyphenols had a preventive effect against CCl₄-induced mouse liver injury equivalent to that of silymarin. The four polyphenols identified as the key substances responsible for this effect mediated the effect through their antioxidant capacity. These results suggest that Shoumei polyphenols are high-quality natural products with liver-protective effects.

Could Sumac Be Effective on COVID-19 Treatment?

Sumac is an herbal product, commonly consumed as a spice and was used for medical treatment for centuries. The phytochemical structure of Sumac was studied extensively, and it was established that the herb contained tannins, polyphenols, flavonoids, organic acids, and essential oils. Various scientific studies demonstrated that Sumac had a free oxygen radical-scavenging effect, a protective effect against liver damage, antihemolytic, leukopenia, and antifibrogenic effects, along with its antiviral, antimicrobial, anti-inflammatory, and antioxidant properties. Recently, several scientific studies described the pathophysiology, clinical course, and the treatment of COVID-19 infection. The examination of the characteristics of COVID-19 infection revealed via the clinical studies suggests that Sumac extract could be useful in the treatment of COVID-19. Given the scientific studies focusing on the beneficial effects of Sumac, the present review aims to provide an encouraging viewpoint to investigate whether Sumac is effective in treating COVID-19 infection.

Preventive effect of lemon seed flavonoids on carbon tetrachloride-induced liver injury in mice

The aim of this study was to determine the preventive effect of lemon seed flavonoids (LSF) on carbon tetrachloride-induced liver injury in mice. Liver injury was induced by injection with 2 mL kg-1 of carbon tetrachloride after administration of LSF by gavage. Liver index, serological parameters, and expression intensities of related mRNA and protein in the liver tissue were observed. The results indicated that LSF reduced liver weight and liver index, downregulated serum levels of AST, ALT, ALP, TG, TC, BUN, NO, and MDA, and upregulated levels of ALB, SOD, CAT, and GSH-Px in the mice with liver injury. It also downregulated serum cytokines, such as IL-6, IL-12, TNF-α, and IFN-γ in these mice. qPCR and western blot confirmed that LSF upregulated mRNA and protein expression of Mn-SOD, Cu/Zn-SOD, CAT, GSH-Px, and IκB-α, and downregulated expression of NF-κB-p65, iNOS, COX-2, TNF-α, IL-1β, and IL-6 in the liver tissue of mice with liver injury. The preventive effect on carbon tetrachloride-induced liver injury was attributed to (-)-epigallocatechin, caffeic acid, (-)-epicatechin, vitexin, quercetin, and hesperidin, which were active substances that were detected in LSF by HPLC. Moreover, the effect of LSF is similar to that of silymarin, but the synergistic effect of the five active substances working in concert acted to produce a more robust liver-protecting effect.

Improvement Effect of Lotus Leaf Flavonoids on Carbon Tetrachloride-Induced Liver Injury in Mice

In this study, the effect of lotus leaf flavonoids (LLF) on carbon tetrachloride (CCl4)-induced liver injury in mice was studied. CCl4 was injected intraperitoneally to induce liver injury in Kunming mice. Mice were treated with LLF by gavage, and the mRNA expression levels in serum and liver were detected. Compared with the model group, LLF significantly reduced the liver index and serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglyceride (TG), and total cholesterol (TC) levels in mice with CCl4-induced liver injury. Pathological observation showed that LLF effectively reduced morphological incompleteness and hepatocyte necrosis in CCl4-treated liver tissue. The result of quantitative polymerase chain reaction (qPCR) indicated that LLF significantly up-regulated the mRNA expression levels of copper/zinc superoxide dismutase (Cu/Zn-SOD), manganese superoxide dismutase (Mn-SOD), and catalase (CAT) and down- regulated the expression levels of tumor necrosis factor-alpha (TNF-α), nuclear factor kappa B (NF-κB), and interleukin-1β (IL-1β) (p < 0.05). Thus, LLF is an active ingredient that ameliorates liver injury, and it has good application prospect.

Isolation and Identification of Lactobacillus plantarum HFY05 from Natural Fermented Yak Yogurt and Its Effect on Alcoholic Liver Injury in Mice

Yak yogurt is a type of naturally fermented dairy product prepared by herdsmen in the Qinghai-Tibet Plateau, which is rich in microorganisms. In this study, a strain of Lactobacillus plantarum was isolated and identified from yak yogurt in Hongyuan, Sichuan Province and named Lactobacillus plantarum HFY05 (LP-HFY05). LP-HFY05 was compared with a common commercial strain of Lactobacillus delbrueckii subsp. bulgaricus (LDSB). LP-HFY05 showed better anti-artificial gastric acid and bile salt effects than LDSB in in vitro experiments, indicating its potential as a probiotic. In animal experiments, long-term alcohol gavage induced alcoholic liver injury. LP-HFY05 effectively reduced the liver index of mice with liver injury, downregulated the levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, triglyceride, total cholesterol, blood urea nitrogen, nitric oxide, and MDA and upregulated the levels of albumin, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase in the serum of liver-injured mice. LP-HFY05 also reduced the levels of interleukin (IL)-6, IL-12, tumor necrosis factor-alpha, and interferon-gamma in the serum of liver-injured mice. The pathological observations showed that LP-HFY05 reduced the damage to liver cells caused by alcohol. Quantitative polymerase chain reaction and Western blot assays further showed that LP-HFY05 upregulated neuronal nitric oxide synthase, endothelial nitric oxide synthase, manganese-SOD, cuprozinc-SOD, CAT, and inhibitor of κB-α mRNA and protein expression and downregulated the expression of nuclear factor-κB-p65 and inducible nitric oxide synthase in the livers of liver-injured mice. A fecal analysis revealed that LP-HFY05 regulated the microbial content in the intestinal tract of mice with liver injury, increased the content of beneficial bacteria, including Bacteroides, Bifidobacterium, and Lactobacillus and reduced the content of harmful bacteria, including Firmicutes, Actinobacteria, Proteobacteria, and Enterobacteriaceae, thus, regulating intestinal microorganisms to protect against liver injury. The effect of LP-HFY05 on liver-injured mice was better than that of LDSB, and the effect was similar to that of silymarin. LP-HFY05 is a high-quality microbial strain with a liver protective effect on experimental mice with alcoholic liver injury.

White Peony (Fermented Camellia sinensis) Polyphenols Help Prevent Alcoholic Liver Injury via Antioxidation

White peony is a type of white tea (Camellia sinensis) rich in polyphenols. In this study, polyphenols were extracted from white peony. In vitro experiments showed that white peony polyphenols (WPPs) possess strong free radical scavenging capabilities toward 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). Long-term alcohol gavage was used to induce alcoholic liver injury in mice, and relevant indices of liver injury were examined. WPPs effectively reduced the liver indices of mice with liver injury. The serum levels of aspartate aminotransferase (ATS), alanine aminotransferase (ALT), alkaline phosphatase (ALP), triglycerides (TG), total cholesterol (TC), blood urea nitrogen (BUN), nitric oxide (NO), and malondialdehyde (MDA) were downregulated, while those of albumin (ALB), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were upregulated. WPPs also reduced the serum levels of interluekin-6 (IL-6), interluekin-12 (IL-12), tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ) in mice with liver injury. Pathology results showed that WPPs reduced alcohol-induced liver cell damage. Quantitative polymerase chain reaction (qPCR) and western blot results revealed that WPPs upregulated the mRNA and protein expressions of neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS), manganese superoxide dismutase (Mn-SOD), cupro–zinc superoxide dismutase (Cu/Zn-SOD), and CAT and downregulated iNOS expression in the liver of mice with liver injury. WPPs protected against alcoholic liver injury, and this effect was equivalent to that of silymarin. High-performance liquid chromatography revealed that WPPs mainly contained the polyphenols gallic acid, catechinic acid, and hyperoside, which are critical for exerting preventive effects against alcoholic liver injury. Thus, WPPs are high-quality natural products with liver protective effects.

Gallic acid as main product in the water extractives of Quercus frainetto ten

The autoclave extraction of Hungarian oak (Quercus frainetto Ten.) wood gave 5.3% extractives. The chloroform soluble fraction obtained from the extracts of Q. frainetto allows to identify sesamin. The insoluble fraction contains mainly ribose and mannose. Water extraction in autoclave of thermo-treated Q. frainetto wood gave a lower amount of extractives (3.31%). The main product of the insoluble fraction was, on the basis of its mass spectrum, the monoacetyl derivative of gallic acid.

Effects of dietary gallic acid supplementation on performance, antioxidant status, and jejunum intestinal morphology in broiler chicks

Gallic acid (GA), widely distributed in plants and feeds, is known to have a diverse range of activities such as anti-oxidant, anti-inflammatory, antibacterial, anti-allergic, anti-mutagenic, and anti-carcinogenic. The purpose of this study was to investigate the efficacy of inclusion of dietary GA at levels 0, 25, 50, 75, 100, or 150 mg/kg on growth performance, antioxidant status, and jejunum intestinal morphology of broiler chicks. In total, 630 one-day-old Arbor Acres (AA) male broiler chicks were randomly allotted to 6 treatment groups for a period of 6 weeks. The results indicate that dietary addition of GA at 75 to 100 mg/kg improved feed conversion efficiency in both the grower (d 21 to 42, P = 0.045) and overall (d 1 to 42, P = 0.026) periods. Dietary addition of GA at a concentration ≥100 mg/kg was able to exhibit higher breast muscle ratio at 42 d (P = 0.043). Interestingly, dietary GA inclusion level from 50 to 100 mg/kg reduced the crypt depth (P = 0.009) and increased the villus height:crypt depth ratio (VCR) of the birds (P = 0.006). Dietary supplementation of GA at 100 mg/kg decreased plasma malondialdehyde (MDA) content at 42 d of age (P = 0.030). Moreover, dietary addition of GA linearly increased plasma total antioxidant capacity (P = 0.039) and plasma total superoxide dismutase activities (P = 0.049) at 21 d of age. However, analysis of plasma biochemical markers revealed that dietary supplementation of GA did not exhibit beneficial health effects. Overall, we conclude that 75 to 100 mg/kg of GA are suitable for enhanced growth performance and health benefits in a broiler diet.

Recent trends on gellan gum blends with natural and synthetic polymers: A review

Gellan gum (GG), a linear negatively charged exopolysaccharide,is biodegradable and non-toxic in nature. It produces hard and translucent gel in the presence of metallic ions which is stable at low pH. However, GG has poor mechanical strength, poor stability in physiological conditions, high gelling temperature and small temperature window.Therefore,it is blended with different polymers such as agar, chitosan, cellulose, sodium alginate, starch, pectin, polyanaline, pullulan, polyvinyl chloride, and xanthan gum. In this article, a comprehensive overview of combination of GG with natural and synthetic polymers/compounds and their applications in biomedical field involving drug delivery system, insulin delivery, wound healing and gene therapy, is presented. It also describes the utilization of GG based materials in food and petroleum industry. All the technical scientific issues have been addressed; highlighting the recent advancement.

Synthesis and cytotoxic activity of 4-O-β-D-galactopyranosyl derivatives of phenolic acids esters

The glycosylation of naturally occurring phenolic acids has a significant impact on their solubility, stability and physiochemical properties. D-Galactose residue was found to form a part of glycoconjugates in several tissues and involved in a variety of physiological process. To the best of our knowledge, we have noticed a little information about the glycosylation of the phenolic acids with galactose residue. In this work, we describe the glycosylation of methyl vanillate and methyl ferulate with peracetylated-β-D-galactopyranose in the presence of BF₃·OEt₂. The coupling reaction yielded efficiently and selectively only the acetylated β-D-galactopyranosides 3 and 6. Removal of the acetyl groups using sodium methoxide afforded the corresponding β-D-galactopyranosides 4 and 7 in good yields. Anticancer activity in vitro was evaluated against two human cancer cell lines (MCF-7 breast cancer cell lines and PC-3 prostate cancer cell lines). β-D-galactopyranosides 4 and 7 demonstrated improved cytotoxic activity compared to the parental esters.

The gallic acid-phospholipid complex improved the antioxidant potential of gallic acid by enhancing its bioavailability

Gallic acid (GA) is well known for its antioxidant and hepatoprotective activity, though its effectiveness is restricted due to rapid metabolism and elimination. To overcome these problems, gallic acid-phospholipid complex was prepared and the effect of phospholipid complexation was investigated on carbon tetrachloride (CCl4)-induced oxidative damage in rat liver. The complex significantly reduced the hepatic marker enzymes in rat serum and restored the antioxidant enzyme levels with respect to CCl4-induced group (P < 0.05 and P < 0.01). Also, the complex improved the pharmacokinetics of GA by increasing the relative bioavailability and elimination half-life. The study therefore suggests that phospholipid complexation has enhanced the therapeutic efficacy of GA which may be due to its improved absorption and increased bioavailability in rat serum.

The gallic acid-phospholipid complex improved the antioxidant potential of gallic acid by enhancing its bioavailability

Gallic acid (GA) is well known for its antioxidant and hepatoprotective activity, though its effectiveness is restricted due to rapid metabolism and elimination. To overcome these problems, gallic acid-phospholipid complex was prepared and the effect of phospholipid complexation was investigated on carbon tetrachloride (CCl4)-induced oxidative damage in rat liver. The complex significantly reduced the hepatic marker enzymes in rat serum and restored the antioxidant enzyme levels with respect to CCl4-induced group (P < 0.05 and P < 0.01). Also, the complex improved the pharmacokinetics of GA by increasing the relative bioavailability and elimination half-life. The study therefore suggests that phospholipid complexation has enhanced the therapeutic efficacy of GA which may be due to its improved absorption and increased bioavailability in rat serum.

Mulberry water extracts (MWEs) ameliorated carbon tetrachloride-induced liver damages in rat

Mulberry extracts are antidiabetic and antihyperlipidemic, as well as preventive of cardiovascular disease. The current study investigates the protective mechanisms of mulberry water extracts (MWEs) in carbon tetrachloride (CCl(4))-induced hepatic injury. Oral administration of MWEs significantly reduced the lipid peroxidation triggered by CCl(4), as shown by the reduced production of thiobarituric acid-reactive substance (TBARS). The levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) were also reduced via cotreatment with MWEs compared with CCl(4) treatment alone. Cotreatment with MWE evidently reduced CCl(4)-induced liver weight and inhibited lipid deposition and fibrogenesis. In a similar manner, cotreatment with silymarin, a well-known liver protective agent, also reversed the CCl(4)-induced effects, such as reduced TBARS formation, decreased serum AST, ALT, and ALP levels, blocked lipid accumulation, and liver fibrosis. Furthermore, MWEs attenuated the proinflammatory genes such as cyclooxygenase 2, nuclear factor kappa B, and inducible nitric oxide synthase expression. The current findings suggest that MWEs such as silymarin exhibit protective and curative effects against CCl(4)-induced liver damage and fibrosis via decreased lipid peroxidation and inhibited proinflammatory gene expression.

Gallic acid induces apoptosis via caspase-3 and mitochondrion-dependent pathways in vitro and suppresses lung xenograft tumor growth in vivo

Several studies have shown that gallic acid (GA) induces apoptosis in different cancer cell lines, whereas the mechanism of action of GA-induced apoptosis at the molecular level in human non-small-cell lung cancer NCI-H460 cells is not well-known. Here, GA decreasing the percentage of viable NCI-H460 cells was investigated; GA-induced apoptosis involved G2/M phase arrest and intracellular Ca(2+) production, the loss of mitochondrial membrane potential (DeltaPsi(m)), and caspase-3 activation. The efficacious induction of apoptosis and DNA damage was observed at 50-500 microM for 24 and/or 48 h as examined by flow cytometry, DAPI staining, and Comet assay methods. Western blotting and flow cytometric analysis also demonstrated that GA increased protein levels of GADD153 and GRP78, activation of caspase-8, -9, and -3, loss of DeltaPsi(m) and cytochrome c, and AIF release from mitochondria. Moreover, apoptosome formation and activation of caspase cascade were associated with apoptotic cell death. GA increased Bax and Bad protein levels and decreased Bcl-2 and Bcl-xL levels. GA may also induce apoptosis through a caspase-independent AIF pathway. In nude mice bearing NCI-H460 xenograft tumors, GA inhibited tumor growth in vivo. The data suggest that GA induced apoptosis in NCI-H460 lung cancer cells via a caspase-3 and mitochondrion-dependent pathway and inhibited the in vivo tumor growth of NCI-H460 cells in xenograft models.

DNA-protective effects of sumach (Rhus coriaria L.), a common spice: results of human and animal studies

Sumach (Rhus coriaria L.) is widely used as a spice. The aim of this study was the investigation of its DNA-protective effects in humans and animals. Prevention of the formation of strand breaks and oxidized DNA bases as well as the protection against H(2)O(2)- and (+/-)-anti-benzo[a]pyrene-7,8-dihydro-diol-9,10-epoxide (BPDE)-induced DNA-damage were monitored in human lymphocytes in a placebo controlled trial (N=8/group) with ethanolic extract of sumach (3.0g/day, 3 days) in single cell gel electrophoresis assays. Furthermore, DNA-protective effects of sumach were monitored in different inner organs of rats under identical conditions. No alteration of DNA-migration was detectable in human lymphocytes under standard conditions, but a decrease of the tail-lengths due to formation of oxidized purines and pyrimidines (52% and 36%) was found with lesion-specific enzymes. Also damage caused by H(2)O(2) and BPDE was significantly reduced by 30% and 69%, respectively. The later effect may be due to induction of glutathione S-transferase (GST). After the intervention, the overall GST (CDNB) activity in plasma was increased by 40%, GST-alpha by 52% and GST-pi by 26% (ELISA). The antioxidant effects of extract are probably due to scavenging which was observed in in vitro experiments, which also indicated that gallic acid is the active principle of sumach. The animal experiments showed that sumach also causes protection in inner organs. Supplementation of the drinking water (0.02g/kg per animal) decreased the formation of oxidized DNA bases in colon, liver, lung and lymphocytes; also after gamma-irradiation pronounced effects were seen.

Phenolics of Arbutus unedo L. (Ericaceae) fruits: identification of anthocyanins and gallic acid derivatives

Arbutus unedo L., the strawberry tree (Ericaceae family), is an evergreen shrub or small tree, typical of the Mediterranean fringe and climate. The aim of the present study was to evaluate the profile of the phenolic constituents of A. unedo fruits. Seven compounds were purified by Sephadex LH-20 column chromatography of the MeOH extract followed by HPLC and were characterized as arbutin, beta-D-glucogalline, gallic acid 4-O-beta-D-glucopyranoside, 3-O-galloylquinic acid, 5-O-galloylquinic acid, 3-O-galloylshikimic acid, and 5-O-galloylshikimic acid, by means of NMR and ESI-MS analyses. Moreover, LC-PDA-MS analysis of the red pigment of A. unedo fruits revealed the presence of three anthocyanins recognized as cyanidin 3-O-beta-D-galactopyranoside, delphinidin 3-O-beta-D-glucopyranoside, and cyanidin 3-O-beta-D-arabinopyranoside. These pigments were also quantified.

Structure-activity relationship analysis of antioxidant ability and neuroprotective effect of gallic acid derivatives

Gallic acid and its derivatives are a group of naturally occurring polyphenol antioxidants which have recently been shown to have potential healthy effects. In order to understand the relationship between the structures of gallic acid derivatives, their antioxidant activities, and neuroprotective effects, we examined their free radical scavenging effects in liposome and anti-apoptotic activities in human SH-SY5Y cell induced by 6-hydrodopamine autooxidation. It was found that these polyphenol antioxidants exhibited different hydrophobicity and could cross through the liposome membrane to react with 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical in a time and dose-dependent manner. At the same time, the structure-antioxidant activity relationship of gallic acid derivatives on scavenging DPPH free radical in the liposome was also analyzed based on theoretical investigations. Analysis of cell apoptosis, intracellular GSH levels, production of ROS and the influx of Ca(2+) indicated that the protective effects of gallic acid derivatives in cell systems under oxidative stress depend on both their antioxidant capacities and hydrophobicity. However, the neuroprotective effects of gallic acid derivatives seem to depend more on their molecular polarities rather than antioxidant activities in the human SH-SY5Y cell line. In conclusion, these results reveal that compounds with high antioxidant activity and appropriate hydrophobicity are generally more effective in preventing the injury of oxidative stress in neurodegenerative diseases.

Free radical scavenging action of the medicinal herb Limonium wrightii from the Okinawa islands

Free radical scavenging action of Limonium wrightii O. kunthe was examined in vitro and in vivo by using electron spin resonance spectrometer and chemiluminescence analyzer. A water extract of L. wrightii showed a strong scavenging action for the 1,1-diphenyl-2-picrylhydrazyl, or superoxide anion and moderate for hydroxyl radical. The extract also depressed production of reactive oxygen species from polymorphonuclear leukocytes stimulated by phorbor-12-mysistate acetate and inhibited lipid peroxidation in rat liver microsomes. When the extract was given intraperitoneally to mice prior to carbon tetrachloride (CCl4) treatment, CCl4-induced liver toxicity, as seen by an elevation of serum aspartate aminotransferase and alanine aminotransferase activities, was significantly reduced. Gallic acid was identified as the active component of L. wrightii with a strong free radical scavenging action. Our results demonstrate the free radical scavenging action of L. wrightii and that gallic acid contributes to these actions.