The antioxidant and cytoprotective activity of Ocimum gratissimum extracts against hydrogen peroxide-induced toxicity in human HepG2 cells

Cleistocalyx nervosum var. paniala berry extract and cyanidin-3-glucoside inhibit hepatotoxicity and apoptosis

Excessive oxidative toxicity in liver cells is a significant risk factor that can cause cellular injury, leading to the development of chronic liver disease (CLD). Natural anthocyanins have been shown to prevent the harmful effects of oxidative toxicity in mammalian cells. Ripe Cleistocalyx nervosum var. paniala berry fruits are rich in anthocyanins, which have been reported to possess many health benefits. Therefore, this study examined the protective effect of ethanolic fruit extract of C. nervosum var. paniala (CNPE) against hydrogen peroxide (H2O2)-induced oxidative damage and cell death in human hepatoma HepG2 cells. Results showed that CNPE had strong antioxidant capabilities and high amounts of total phenolics and anthocyanins. HPLC analysis showed that CNPE consists of cyanidin-3-glucoside (C3G). Our investigations found that HepG2 cells pretreated with CNPE or anthocyanin C3G inhibited H2O2-induced cellular damage and apoptosis by increasing the viability of cells, the expression of antiapoptotic Bcl-2 protein, and the activities of cellular antioxidant enzymes, namely SOD, CAT, and GPx. Moreover, both CNPE and C3G significantly suppressed expression of apoptotic proteins (Bax and cytochrome c) and the activities of cleaved caspase-9 and caspase-3 caused by H2O2. Our results indicate that CNPE and C3G can suppress H2O2-induced hepatotoxicity and cell death through stimulation of endogenous antioxidant enzyme activities and inhibition of apoptosis pathway in HepG2 cells. These findings might support development of CNPE as an alternative natural product for preventing CLD.

Hepatoprotective potency of Litsea glutinosa (L.) C.B. Rob. leaf methanol extract on H2O2-induced toxicity in HepG2 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Leaves of Litsea glutinosa (L.) (Lauraceae) are traditionally used to treat hepatitis and liver injury by Bangladeshi folks. However, the hepatoprotective study of leaves of L. glutinosa has not been supported by any research.

AIM OF THE STUDY

To evaluate the antioxidant and hepatoprotective effects of leaves of methanol extract of L. glutinosa using the HepG2 cell line. Phytochemicals were identified with the help of a GC-MS study followed by In-silico docking of the promising compounds to justify our hepatoprotective effect.

MATERIALS & METHODS

The dried leaves of L. glutinosa (LGAO) were extracted by Soxhlet using methanol as solvent. Antioxidant effects were investigated using Superoxide dismutase (SOD), Reduced glutathione (GSH), Glutathione peroxidase (GPx), and Malondialdehyde (MDA) in HepG2 cells against H₂O₂ intoxicated group. The In-vitro hepatoprotective effect of LGAO (100 μg/ml) was determined in HepG2 cells as compared with the Silymarin-treated standard group (100 μg/ml) along with morphological changes of cells. Twelve numbers of phytochemicals were identified by GC-MS study. In-silico studies are performed for their inhibitory effects against Peroxisome proliferator-activated receptor alpha (PPAR-α) and Transforming growth factor-beta1 (TGF-β1) using AUTODOCK Tools-1.5.6 and Discovery studio 4.0.

RESULTS

Methanol extract of L. glutinosa possesses (LGAO) significant (p < 0.0001) increase in SOD, GSH, and GPx levels and a decrease in MDA as compared with the control one. MTT assay in HepG2 cells showed a significant (p < 0.0001) increase in the percentage of cell viability in LGAO and Silymarin-treated group i.e., 71.98%, 88.59% respectively as compared with the H₂O₂ intoxicated group alone i.e., 22.74%. Restoration of cell architecture in HepG2 cells was obtained by the LGAO and Silymarin-treated group treated with H₂O₂. Further, the In-silico study of Neophytadiene compound showed the highest docking score -10.2 and -8.6 towards receptors.

CONCLUSION

Methanol extract of leaves of L. glutinosa showed potential hepatoprotective effect In-vitro which justified our traditional claim. The presence of phytochemical Neophytadiene may be responsible for the said effect. Furthermore, molecular docking scores were consistent with the In-vitro results. They targeted the substantial inhibitory effects of Litsea glutinosa against receptors to establish the correlation between experimental and theoretical results.

Hepatoprotective Effects of Sweet Cherry Extracts (cv. Saco)

Cancer is the second cause of death worldwide. Among cancers, hepatocellular carcinoma is one of the most prevalent. Evidence indicates that the daily consumption of fruits and vegetables can prevent the onset of various cancers due to the presence of bioactive compounds. Sweet cherries are known for their richness in phenolics, including anthocyanins, which are the major constituents, and presumably, the key contributors to their biological activity. Therefore, the present study aimed to evaluate the effects of three different cherry fractions on human hepatocellular carcinoma (HepG2) cells viability and effectiveness to improve the redox status of these cells under oxidative damage induced by nitric oxide radicals and hydrogen peroxide. Phenolic characterization of fractions was performed by Fourier transform infrared spectroscopy. The obtained results indicated that enriched phenolic fractions of sweet cherries (cv. Saco, can impair cell viability and suppress cells growth after 72 h of exposure, promoting necrosis at the highest tested concentrations (>50 µg/mL). Additionally, fractions also showed the capacity to protect these cells against oxidative injury by capturing radicals before they can attack cells’ membrane and by modulating reactive oxygen and nitrogen species generation, as demonstrated by bioinformatic tools.

In Vitro Tests for a Rapid Evaluation of Antidiabetic Potential of Plant Species Containing Caffeic Acid Derivatives: A Validation by Two Well-Known Antidiabetic Plants, Ocimum gratissimum L. Leaf and Musanga cecropioides R. Br. ex Tedlie (Mu) Stem Bark

Plant bioactive extracts represent a major resource for identifying drugs and adjuvant therapy for type 2 diabetes. To promote early screening of plants' antidiabetic potential, we designed a four in vitro tests strategy to anticipate in vivo bioactivity. Two antidiabetic plants were studied: Ocimum gratissimum L. (Oc) leaf extract and Musanga cecropoides R. Br. ex Tedlie (Mu) stem bark extract. Chemical compositions were analyzed by LCMS and HPLC. Antidiabetic properties were measured based on (1) INS-1 cells for insulin secretion, (2) L6 myoblast cells for insulin sensitization (Glut-4 translocation), (3) L6 myoblast cells for protection against hydrogen peroxide (H2O2) oxidative stress (cell mortality), and (4) liver microsomial fraction for glucose-6-phosphastase activity (G6P). Oc extract increased insulin secretion and insulin sensitivity, whereas it decreased oxidative stress-induced cell mortality and G6P activity. Mu extract decreased insulin secretion and had no effect on insulin sensitivity or G6P activity, but it increased oxidative stress-induced cell mortality. Results were compared with NCRAE, an antidiabetic plant extract used as reference, previously characterized and reported with increased insulin secretion and insulin sensitivity, protection against oxidative stress, and decreased G6P activity. The proposed set of four in vitro tests combined with chemical analysis provided insight into the interest in rapid early screening of plant extract antidiabetic potential to anticipate pharmaco-toxicological in vivo effects.

Neoxanthin prevents H2O2-induced cytotoxicity in HepG2 cells by activating endogenous antioxidant signals and suppressing apoptosis signals

BACKGROUND

The liver has a solid inbuilt antioxidant defense system to regulate oxidative stress. However, exposure to an excessive level of ROS causes liver injury. This study examined the cytoprotective effect of neoxanthin, a xanthophyll antioxidant molecule isolated from Solanum trilobatum in stress-induced HepG2 cells.

METHODS AND RESULTS

The cytotoxic effect of H₂O₂ and cytoprotective potential of β-carotene, lutein, and neoxanthin was analyzed by WST-1 assay. The intracellular ROS level and mitochondrial membrane potential (MMP) were measured using DCFH-DA (2', 7'-dichlorofluorescin diacetate) and JC-10 MMP assay. The expression of anti-oxidant and apoptotic markers was measured by western blot analysis. Neoxanthin pretreatment exhibited better protection than β-carotene and lutein against cell death caused by H₂O₂. It significantly arrested H₂O₂-mediated elevation of intracellular ROS levels and protected MMP. The intracellular antioxidant enzymes HO-1 and SOD-2 were upregulated by neoxanthin pretreatment. Neoxanthin also activated the protein expression of redox-sensitive transactivation factors, Nrf2 and NF-kB. The cytoprotective effect of neoxanthin was associated with increased expression of the anti-apoptotic protein, Bcl-2 and decreased pro-apoptotic protein Bax.

CONCLUSIONS

For the first time, our results demonstrate that neoxanthin offers adequate protection against stress-mediated cytotoxicity in hepatocytes by activating the intracellular antioxidant defense system and blocking apoptosis.

Toxic effects of fluoride in intestinal epithelial cells and the mitigating effect of methanol extract of coconut haustorium by enhancing de novo glutathione biosynthesis

Fluoride ions are an important environmental contaminant and pollutant found in a wide variety of environmental conditions. The fluoride in drinking water is evident to induce toxic effects including neurodegeneration, skeletal and dental fluorosis as well as organ damage. Nutraceuticals and functional foods are emerging as possible preventive agents against fluoride toxicity. Hence, the possible use of an emerging functional food-the coconut haustorium is being evaluated against sodium fluoride-induced toxicity in intestinal cells (IEC-6). The cells exposed to fluoride showed significant cell death mediated through the increased lipid peroxidation and glutathione depletion. The glutathione biosynthetic enzymes were inhibited by the exposure to fluoride and the apoptotic genes (caspases 3/7 and apaf-1) were upregulated. The CHE pre-treatment improved the activity of enzymes involved in the de novo biosynthesis of glutathione and subsequently improved the intracellular GSH pool. The improved antioxidant defense was also evident from the reduced expression of apoptotic genes (p < 0.05). Overall, the study concludes that fluoride ions induce oxidative stress-mediated apoptosis in intestinal epithelial cells, via inhibiting glutathione biosynthesis. Methanol extract of coconut haustorium increased glutathione biosynthesis and subsequently prevented fluoride toxicity in IEC-6 cells by virtue of its antioxidant potentials.

Borassus flabellifer Linn haustorium methanol extract mitigates fluoride-induced apoptosis by enhancing Nrf2/Haeme oxygenase 1 -dependent glutathione metabolism in intestinal epithelial cells

Fluoride is the most common cause of drinking water-associated toxicity and is known to induce various metabolic imbalances and dental/skeletal fluorosis. The present study analyzed the protective effect of Borassus flabellifer Linn. haustorium extract (BHE) against fluoride-induced intestinal redox metabolism and apoptosis. The total polyphenols and total flavonoids present in BHE were estimated to be 39.67 ± 5.14 mg gallic acid equivalent/g extract and 8.59 ± 0.74 mg quercetin equivalent. In cultured intestinal epithelial cells (IEC-6), sodium fluoride exposure-induced apoptosis mediated through antioxidant enzyme inhibition and subsequent oxidative damages. Further, there observed an increased expression of caspase-3, caspase-7, and apoptotic protease activating factor-1 (apaf-1) genes, increased cytochrome C release, and caspase 3/7 activity indicating the apoptosis- mediated cell death (p < 0.05). Upon pretreatment with BHE, the cytotoxic effect of fluoride was reduced by decreasing the expression of apoptotic genes and increased the cytochrome release as well as caspase 3/7 activity (p < 0.01). Providing the mechanistic basis, the expression of nuclear factor erythroid 2-related factor-2 (Nrf2)/haeme oxygenase-1 (HO1) gene was increased in the BHE pretreated cells; corroborating to these, there observed increased activity of glutathione biosynthetic enzymes (p < 0.05) and glutathione reductase. Hence, the protective effect of BHE may be mediated through Nrf2-mediated glutathione biosynthesis, the subsequent establishment of redox balance, and inhibition of apoptosis in intestinal epithelial cells.

Effect of Camellia sinensis teas on left ventricular hypertrophy and insulin resistance in dyslipidemic mice

The control of dyslipidemia using plants is an important subject of studies since it has numerous benefits in cardiovascular protection. The objective of this study was to evaluate the effect of three Camellia sinensis L. teas (green, red, and white) on left ventricular hypertrophy and insulin resistance in low-density lipoprotein receptor knockout (LDLr-/-) mice fed a high-fat diet. The LDLr-/- mice were divided into four experimental groups: Group C: standard feed; Group CT: standard feed and three teas, Group HL: high-fat feed; HLT Group: high-fat feed and three teas. The three types of tea (green, red, and white) originated from different processing of the Camellia sinensis L. plant, and were administered associated once a day at a dose of 25 mg/kg by gavage for 60 days. The teas partially prevented hyperlipidemia, the decrease of the serum levels of high-density lipoproteins (HDL), insulin resistance, and increased C-reactive protein (CRP) levels, and completely prevented left ventricular hypertrophy in LDLr -/- mice of the HLT group. In conclusion, the three Camellia sinensis L. teas used to control genetic dyslipidemia associated with a high-fat diet can be used as an auxiliary treatment associated with the control of lipid intake, thus promoting cardiac protection against hyperlipidemia.

Hepatoprotective Effects of Xylose-Taurine Reduced Against Hydrogen Peroxide-Induced Oxidative Stress in Cultured Hepatocytes

In this study, Xylose-Taurine reduced (X-T-R) was synthesized to enhance biological activities. Hence, we investigated the hepatoprotective effects of X-T-R against H2O2-induced hepatocyte damage and apoptosis. The results showed that X-T-R led to the cytoprotective effect against H2O2-induced oxidative stress in cultured hepatocytes such as the improvement of cell viability and the reduction of reactive oxygen species (ROS) production. Additionally, pre-treatment with X-T-R increased the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H dehydrogenase:quinone 1 (NQO1) and heme oxygenase 1 (HO-1) in cultured hepatocytes. Furthermore, X-T-R protected the cells against apoptosis via regulating the expression level of Bcl-2/Bax as well as the activation of caspase-3. According to the results obtained, X-T-R may be a bio-material for the therapy of hepatic diseases.

UPLC-ESI-MS/MS and HPTLC Method for Quantitative Estimation of Cytotoxic Glycosides and Aglycone in Bioactivity Guided Fractions of Solanum nigrum L

Solanum nigrum L., is traditionally used for the management of the various liver disorders. Investigating the effect of polarity based fractionation of S. nigrum for its hepatoprotective effect on Hep G2 cells in vitro to provide base of its activity by quantifying in steroidal glycosides responsible for hepatoprotective potential. A new UPLC-ESI-MS/MS method following a high performance thin layer chromatography (HPTLC) has been developed and validated for quantification of steroidal glycosides and aglycone (solasonine, solamargine, and solasodine, respectively). The in vitro antioxidant potential, total phenolics, and flavonoid content were also determined in different fractions. The newly developed UPLC-ESI-MS/MS and HPTLC methods were linear (r² ≥ 0.99), precise, accurate, and showing recovery more than 97%. The n-butanol enriched fraction of S. nigrum berries was found to be the most potent hepatoprotective fraction against all other fractions as it showed significantly (p < 0.01) better in vitro anti-oxidant potential than other fractions. Quantification by both methods revealed that, content of steroidal glycosides and aglycones are more than 20% in n-butanol fraction as compared to other fractions. The screened steroidal glycoside n-butanol enriched fraction underwent bioefficacy studies against D-galactosamine and H₂O₂ induced toxicity in HepG2 cell line showing significant (p < 0.05) liver protection. However, developed method can be used for the quality control analysis with respect to targeted metabolites and it can be explored for the pharmacokinetic and pharmacodynamic analysis in future.

Antioxidant potentiality of three herbal teas consumed in Bandundu rural areas of Congo

The aim of this study was to evaluate and compare the cellular antioxidant activities of Lantana montevidensis, Lippia multiflora, and Ocimum gratissimum leaves often consumed as herbal teas in a rural area of Bandundu severely affected by konzo, which is related to oxidative damage. Consequently, dietary supplements with proven antioxidant potentialities could be of real interest to promote in this area. Phytochemical screening by TLC and HPLC-DAD of extracts revealed the presence of verbascoside as a major phenolic compound. Verbascoside in L. montevidensis and O. gratissimum is reported here for the first time. All extracts displayed high ABTS and DPPH radical-scavenging activities at the concentration range of 1-40 μg mL^-1 according to order: L. multiflora > O. gratissimum > L. montevidensis. L. multiflora showed the best cellular antioxidant activity using DCFH-DA on HL-60 monocytes assay at 1-20 μg mL^-1. These herbal teas may be used as nutraceuticals for their potent antioxidant activity.

Thymol reduces oxidative stress, aortic intimal thickening, and inflammation-related gene expression in hyperlipidemic rabbits

Atherosclerosis plays a key role in the development of cardiovascular diseases, and is often associated with oxidative stress and local inflammation. Thymol, a major polyphenolic compound in thyme, exhibits antioxidant and anti-inflammatory properties. In this study, we measured the in vitro antioxidant activity of thymol, and investigated the effect of thymol on high-fat-diet-induced hyperlipidemia and atherosclerosis. New Zealand white rabbits were fed with regular chow, high-fat and high-cholesterol diet (HC), T3, or T6 (HC with thymol supplementation at 3 mg/kg/d or 6 mg/kg/d, respectively) for 8 weeks. Aortic intimal thickening, serum lipid parameters, multiple inflammatory markers, proinflammatory cytokines, and atherosclerosis-associated indicators were significantly increased in the HC group but decreased upon thymol supplementation. In summary, thymol exhibits antioxidant activity, and may suppress the progression of high-fat-diet-induced hyperlipidemia and atherosclerosis by reducing aortic intimal lipid lesion, lowering serum lipids and oxidative stress, and alleviating inflammation-related responses.

Influence of gallic acid on α-amylase and α-glucosidase inhibitory properties of acarbose

Acarbose is an antidiabetic drug which acts by inhibiting α-amylase and α-glucosidase activities but with deleterious side effects. Gallic acid (GA) is a phenolic acid that is widespread in plant foods. We therefore investigated the influence of GA on α-amylase and α-glucosidase inhibitory properties of acarbose (in vitro). Aqueous solutions of acarbose and GA were prepared to a final concentration of 25μM each. Thereafter, mixtures of the samples (50% acarbose + 50% GA; 75% acarbose+25% GA; and 25% acarbose+75% GA) were prepared. The results revealed that the combination of 50% acarbose and 50% GA showed the highest α-glucosidase inhibitory effect, while 75% acarbose+25% GA showed the highest α-amylase inhibitory effect. Furthermore, all the samples caused the inhibition of Fe²⁺-induced lipid peroxidation (in vitro) in rat pancreatic tissue homogenate, with the combination of 50% acarbose and 50% GA causing the highest inhibition. All the samples also showed antioxidant properties (reducing property, 2,2'-azino-bis (-3-ethylbenzthiazoline-6-sulphonate [ABTS*] and 1,1-diphenyl-2-picrylhydrazyl [DPPH] free radicals scavenging abilities, and Fe²⁺ chelating ability). Therefore, combinations of GA with acarbose could be employed as antidiabetic therapy, with a possible reduction of side effects of acarbose; nevertheless, the combination of 50% acarbose and 50% GA seems the best.

Inhibitory effects of polyphenol-enriched extract from Ziyang tea against human breast cancer MCF-7 cells through reactive oxygen species-dependent mitochondria molecular mechanism

A polyphenol-enriched extract from selenium-enriched Ziyang green tea (ZTP) was selected to evaluate its antitumor effects against human breast cancer MCF-7 cells. In ZTP, (−)-epigallocatechin gallate (28.2%) was identified as the major catechin, followed by (−)-epigallocatechin (5.7%) and (−)-epicatechin gallate (12.6%). ZTP was shown to inhibit MCF-7 cell proliferation (half maximal inhibitory concentration, IC₅₀ = 172.2 μg/mL) by blocking cell-cycle progression at the G0/G1 phase and inducing apoptotic death. Western blotting assay indicated that ZTP induced cell-cycle arrest by upregulation of p53 and reduced the expression of CDK2 in MCF-7 cells. ZTP-caused cell apoptosis was associated with an increase in Bax/Bcl-2 ratio, and activation of caspase-3 and -9. MCF-7 cells treated with ZTP also showed an overproduction of reactive oxygen species, suggesting that reactive oxygen species played an important role in the induction of apoptosis in MCF-7 cells. This is the first report showing that ZTP is a potential novel dietary agent for cancer chemoprevention or chemotherapy.

Analysis of aroma compounds and nutrient contents of mabolo (Diospyros blancoi A. DC.), an ethnobotanical fruit of Austronesian Taiwan

Diospyros blancoi A. DC. is an evergreen tree species of high-quality wood. Mabolo, the fruit of this plant, is popular among the natives in Taiwan, but its potential in economic use has not been fully explored. Mabolo has a rich aroma. Of the 39 different volatile compounds isolated, its intact fruit and peel were found to both contain 24 compounds, whereas the pulp contained 28 compounds. The most important aroma compounds were esters and α-farnesene. Our data show that mabolo is rich in dietary fiber (3.2%), and the contents of other nutrients such as malic acid, vitamin B2, vitamin B3, folic acid, pantothenic acid, and choline chloride were 227.1 mg/100 g, 0.075 mg/100 g, 0.157 mg/100 g, 0.623 mg/100 g, 0.19 mg/100 g, and 62.52 mg/100 g, respectively. Moreover, it is rich in calcium and zinc; the contents of which were found to be 42.8 mg/100 g and 3.6 mg/100 g, respectively. Our results show that D. blancoi has the potential to be bred for a novel fruit.

Nutritional and nutraceutical characteristics of Sageretia theezans fruit

The fruit of Sageretia theezans is one of many underutilized edible fruits that grow along the southern seashores of East Asia. In this study, to evaluate the nutritional and nutraceutical values of S. theezans fruit, the composition of minerals, organic acids, and proximate and fatty acids, the total phenolic, total flavonoid, and total anthocyanin content, and the antioxidant and antidiabetic activities of S. theezans fruit were analyzed. The results indicate that S. theezans fruit could be classified as a potential potassium-, malic acid-, and linoleic/oleic acid-rich fruit. In addition, The ethyl acetate (EtOAc) fraction of the 70% ethanol (EtOH) crude extract exhibited strong antioxidant activities including free radical scavenging and reducing power activities compared with the same concentration of butylated hydroxytoluene. Furthermore, the EtOAc fraction showed significant inhibition of α-glucosidase activity. The analysis of the total phenolic and flavonoid content suggested that the remarkable antioxidant and antidiabetic activities of the EtOAc fraction are due to the presence of high levels of polyphenolic compounds.

Antioxidant and antidiabetic activities of 11 herbal plants from Hyrcania region, Iran

In the present study, 2,2-diphenyl-1-picrylhydrazyl radical scavenging, α-amylase and α-glucosidase inhibition activities, and total phenolic contents of n-hexane, ethyl acetate, and methanol extracts of various parts of Allium paradoxum, Buxus hyrcana, Convolvulus persicus, Eryngium caucasicum, Heracleum persicum, Pimpinella affinis, Parrotia persica, Primula heterochroma, Pyrus boissieriana, Ruscus hyrcanus, and Smilax excelsa were investigated. These plants, which mostly serve as food flavoring, were collected from Hyrcania region, Sari, Iran. Some extracts of H. persicum, S. excels, P. boissieriana, P. persica, and P. heterochroma exhibited significant antidiabetic activities in α-amylase and α-glucosidase assays, more effective than acarbose (concentrations that cause 50% inhibition = 75.7 μg/mL and 6.1 μg/mL against α-amylase and α-glucosidase, respectively). Also, C. persicus, P. boissieriana, and P. heterochroma showed strong antioxidant activities, compared with butylated hydroxytoluene (concentration that causes 50% inhibition = 16.7 μg/mL). In conclusion, this study can recommend these plants as good candidates for further investigations to find potent antidiabetic natural products or probable lead compounds. Statistical analysis showed significant correlation between the 2,2-diphenyl-1-picrylhydrazyl scavenging activity and total phenolic contents (r = 0.711, p < 0.001).

Effect of acetone extract from stem bark of Acacia species (A. dealbata, A. ferruginea and A. leucophloea) on antioxidant enzymes status in hydrogen peroxide-induced HepG2 cells

Acacia species are multipurpose trees, widely used in the traditional systems of medicine to treat various ailments. The major objective of the present study was to determine the gene expression of enzymatic antioxidants by acetone extract from the stem bark of three Acacia species (Acacia dealbata, Acacia ferruginea and Acacia leucophloea) in hydrogen peroxide (H2O2)-induced human hepatoma (HepG2) cells. The expression of antioxidant enzymes such as superoxide dismutase containing copper-zinc (CuZnSOD)/manganese (MnSOD), catalase (CAT) and glutathione peroxidase (GPx) in HepG2 cells was evaluated by real-time PCR. The results of antioxidant enzyme expression in real-time PCR study revealed that the H2O2 (200 μM) challenged HepG2 cells reduced the expression of enzymes such as SOD, GPx and CAT. However, the cells pre-treated with acetone extracts of all the three Acacia species significantly (P > 0.05) up-regulated the expression of antioxidant enzymes in a concentration dependent manner (25, 50 and 75 μg/mL). In conclusion, the findings of our study demonstrated that the acetone extract of Acacia species effectively inhibited H2O2 mediated oxidative stress and may be useful as a therapeutic agent in preventing oxidative stress mediated diseases.

Chemical compositions of the volatile extracts from seeds of Dendranthema nankingense and Borago officinalis

Volatile extracts from the seeds of Dendranthema nankingense Hand.-Mazz. and Borago officinalis L. were prepared using simultaneous distillation and extraction, and analyzed with gas chromatography–mass spectrometry on two capillary gas chromatography columns of different polarity. Ninety-five volatile compounds were identified in D. nankingense seeds, with hexanal, benzeneacetaldehyde, borneol, (−)-camphor, and 3-methyl-1-butanol being the predominant species. Sixty-five volatile compounds were identified in B. officinalis seeds, with 2-pentanone, 2,3-dihydro-benzofuran, 3-methyl butanal, and hexanal being the most abundant species. Thirty-three compounds, including short-chain aliphatic aldehydes, alcohols, and ketones, were common to both seeds. The volatile composition of both seeds varied significantly depending on their respective origins. The volatile terpenoids borneol and (−)-camphor could be key bioactive contributors to the characteristic flavor and cooling effects of D. nankingense. For the first time, coumaran was identified as an abundant species in plant seeds.

Extraction of water-soluble polysaccharide and the antioxidant activity from Semen cassiae

Water-soluble polysaccharide was isolated from Semen cassiae using water for extraction and ethanol for deposition. The optimized conditions for polysaccharide isolation by orthogonal experiments were a sample to liquid ratio of 1:30 at 80°C for 3.5 hours; the yield of polysaccharide from Semen cassiae under these conditions was 5.46%. Different polysaccharides (SCPW-1, SCPW-2, SCPW-3, SCPW-4, SCPW-5, SCPS-1, SCPS-2) were obtained from the extract (i.e., crude polysaccharide) by DEAE-cellulose column chromatography. The polysaccharides obtained showed different structures by Fourier transform infrared therein the five elected from the seven kinds separated. The antioxidant activities of the extract were evaluated. The scavenging rates of the present extract on hydroxyl and superoxide were 43.32% and 64.97%, respectively, at a concentration of polysaccharide of 94.03 μg/mL, which was better than vitamin C at the same concentration. The scavenging rate of the present extract on 1,1-diphenyl-2-picrylhydrazyl was 13.33% at a polysaccharide concentration of 94.03 μg/mL, which was less than vitamin C at the same concentration.

Ocimum gratissimum is Effective in Prevention against Liver Fibrosis in Vivo and in Vitro

Ocimum gratissimum is a traditional herb commonly found in tropical regions, which prevents free radical damage and protects the liver from oxidative stress. In this study, we tested in vivo and in vitro the effectiveness of O. gratissimum extracts (OGEs) in anti-hepatic fibrosis in rats. Male Wistar rats were administered with carbon tetrachloride (CCl4) by intraperitoneal injection and varying amounts of oral injection of OGE doses (0–40 mg/kg body weight) for 8 weeks. Our experiments showed that OGE significantly reduced liver damage, including steatosis and fibrosis, in a dose-dependent manner, as well as significantly decreased the elevation in plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT). It also inhibited the formation of lipid peroxidative products during CCl4 treatment. Moreover, OGE-inhibited CCl4-induced liver collagen accumulation and promoted the expression of catalase, an anti-oxidative enzyme. The inhibition of fibrosis factors α-SMA expression was also observed. In primary cultures, OGE significantly inhibited the serum-induced activation of hepatic stellate cells (HSCs), and the expression of α-SMA and collagen α (I). These data suggest that O. gratissimum possesses anti-hepatic fibrosis properties via its anti-oxidative components.

Antioxidant effects of Camellia sinensis L. extract in patients with type 2 diabetes

The prevalence of diabetes mellitus (DM) has dramatically increased in the past decade. Furthermore, increasing evidence from research shows that oxidative stress (OS) plays a crucial role in the pathogenesis of diabetes and in its complications. A search for ways to reduce oxidative damage has become the focus of interest for the majority of scientists. In this study, we determined the radical scavenging activity of single green tea constituents by using an on-line high performance liquid chromatography (HPLC)-2,2-diphenyl-1-picrylhydrazyl (DPPH) method and evaluated the antioxidant effects on type 2 diabetic patients by performing a double-blind, placebo-controlled study. Epigallocatechin gallate was identified as the most potent antioxidant, contributing approximately 50% of the total antioxidant capacity of green tea extract. We also found a statistically significant decrement of lipid peroxidation markers in patients treated with green tea extract after 9 months or after 18 months of follow-up. Overall, these findings are attractive for diabetic patients, helping them to keep a high level of performance and well-being, which ultimately may delay the time of disability and reduce mortality.