Indian medicinal herbs as sources of antioxidants

Antioxidant activity of gilan Mentha pulegium during growth

Antioxidant activity and total phenolic contents of methanolic and hydroalcoholic-acetone extracts of Iranian Mentha pulegium in two stages of maturity were investigated. The aim was to investigate the most suitable solvent for extraction of antioxidants and to find the correlation existed between plant growth stage and its antioxidant capacity. In vitro antioxidant properties of the extracts were examined by 1, 1 diphenyl-2-picrylhydrazyl (DPPH) and Ferric Reducing/Antioxidant Power (FRAP) methods. Moreover, total phenolic contents were determined by the Folin-Ciocalteu method. On the other hand, the phenolic compounds were analyzed by chromatographic methods, TLC and SPE-reversed phase-HPLC. The results revealed that the antioxidant capacities and total phenol contents of the extracts in flowering season were higher than pre-flowering season. A positive relationship was found between the results obtained from three different assay methods used, i.e. FRAP, DPPH and phenol contents. The TLC chromatogram of the two extracts showed differences in the number of separated compounds of extracts. HPLC results indicated that the fraction collected with washing buffer (pH = 6) had highest antioxidant activity.

Antioxidant compounds, antioxidant activity and phenolic content in peel from three tropical fruits from Yucatan, Mexico

The aim of this study was to determine the antioxidant compounds, antioxidant activity and content of individual phenolic compounds of freeze-dried peel from three tropical fruits grown in Yucatan, México: purple star apple (Chrysophyllum cainito L.), yellow cashew and red cashew (Anacardium occidentale). The freeze-dried peels were good source of antioxidant compounds. ABTS and DPPH values in the peel from each fruit were 3050.95-3322.31 μM Trolox/100g dry weight (DW) or 890.19-970.01 mg of vitamin C/100 g DW, and 1579.04-1680.90 μM Trolox/100 g DW or 340.18-362.18 mg of vitamin C/100 g DW, respectively. Six phenolic compounds were identified in the peel from the tropical fruits studied: ferulic, caffeic, sinapic, gallic, ellagic and myricetin. This study demonstrated that freeze-dried peels from purple star apple, yellow cashew and red cashew, could serve as potential sources of antioxidants for use in food and pharmaceutical industries.

Antioxidant activity and total phenolic content of endophytic fungus Fennellia nivea NRRL 5504

Antioxidant is an interesting bioactivity since it has several correlations with disease such as Alzheimer, cancer, ageing and many others in which were promoted by free radicals. Investigation on our endophytic fungus collection namely Fennelia nivea NRRL 5504 revealed that the fermented mediumhas antioxidant property against DPPH through free radical scavenging effect. Fermentation in liquid medium i.e. Potatoes Dextrose Broth, resulted that the fermented medium reached about 86.51% (p < 0.05) of free radical inhibition on the eighth day. Results ofphytochemical screening from extracted fermentation medium showed the presence of terpenes, triterpenes, phenolic compound, tannin, flavonoid and also saponin. The highest antioxidant activity was showed by ethyl acetate extract. Calculation on total phenolic content of ethyl acetate crude extract was 0.544 mg g(-1) equivalent to pyrogallol. By exposure above, we have alternative source of antioxidant that came from our endophytic fungus collection which we isolated previously from Typhonium divaricatum Lodd.

Antioxidant Activity and Protection from DNA Damage by Water Extract from Pine (Pinus densiflora) Bark

Water extract from Pinus densiflora (WPD) was investigated for its antioxidant activity and its ability to provide protection from DNA damage. A series of antioxidant assays, including a 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging assay, a reducing power assay, a metal-chelating assay, a superoxide radical scavenging assay, and a nitrite scavenging ability, as well as a DNA damage protection assay were performed. Total phenolic content was found to be 211.32 mg Tan/g WPD. The extract scavenged 50% DPPH free radical at a concentration of 21.35 μg/mL. At that same concentration, the reducing power ability of WPD was higher than that of α-tocopherol. The extract chelated 68.9% ferrous ion at the concentration of 4 mg/mL. WPD showed better nitrite scavenging effect at the lower pH. Meanwhile, WPD exhibited a strong capability for DNA damage protection at 1 mg/mL concentration. Taken together, these data suggest water extract from Pinus densiflora could be used as a suitable natural antioxidant.

Analysis of phytochemical profile of Terminalia arjuna bark extract with antioxidative and antimicrobial properties

OBJECTIVE

To investigate phytochemical screening, antimicrobial activity and qualitative thin layer chromatographic separation of flavonoid components, antioxidant activity and total flavonoid compound of Terminalia arjuna.

METHODS

For phytochemical screening, some common and available standard tests were done. Antimicrobial bioassay was done through agar well diffusion method. Detection of antioxidant activity and flavonoid compounds were done through thin layer chromatography. Total antioxidant activity was measured by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) in colorimetric method. Aluminum chloride colorimetric method was used for total flavonoid determination.

RESULTS

Phytochemical screening showed the active compounds presence in high concentration, such as phytosterol, lactones, flavonoids, phenolic compounds and tannins and glycosides. The antimicrobial activity of extract showed that greater inhibition zone against Gram negative bacteria than Gram positive bacteria. This methanolic extract showed a promising antioxidant activity, as absorption of DPPH redicles decreased in DPPH free radical scavenging assay. Flavonoids components having antioxidant property present in the methanol extract at a level of 199.00 mg quercetin equivalent/g of dried methanol extract in colorimetric method.

CONCLUSIONS

The Terminalia arjuna bark extract revealed the presence of bio-active constituents which are known to exhibit medicinal as well as physiological activities.

Estimation of total phenolic content, in-vitro antioxidant and anti-inflammatory activity of flowers of Moringa oleifera

OBJECTIVE

To evaluate and compare the antioxidant potential and anti-inflammatory activity of ethanolic extract of flowers of Moringa oleifera (M. oleifera) grown in Oman.

METHODS

Flowers of M. oleifera were collected in the month of December 2012 and identified by a botanist. Alcoholic extract of the dry pulverized flowers of M. oleifera were obtained by cold maceration method. The ethanolic flower extract was subjected to preliminary phytochemical screening as the reported methods. Folin-Ciocalteu reagent was used to estimate total phenolic content. DPPH was used to determine in-vitro antioxidant activity and anti-inflammatory activity of flowers was investigated by protein denaturation method.

RESULTS

Phytochemical analysis of extract showed presence of major classes of phytochemicals such as tannins, alkaloids, flavonoids, cardiac glycosides etc. M. oleifera flowers were found to contain 19.31 mg/g of gallic acid equivalent of total phenolics in dry extract but exhibited moderate antioxidant activity. The anti-inflammatory activity of plant extract was significant and comparable with the standard drug diclofenac sodium.

CONCLUSIONS

The results of our study suggest that flowers of M. oleifera possess potent anti-inflammatory activity and are also a good source of natural antioxidants. Further study is needed to identify the chemical compounds responsible for their anti-inflammatory activity.

Nutritional composition and antioxidant properties of Cucumis dipsaceus Ehrenb. ex Spach leaf

The leaf of C. dipsaceus was evaluated for its nutritional and antioxidant properties. From the present investigation, significant amount of almost all essential amino acids and important minerals were quantified. Low levels of trypsin inhibitory units, phenolics, and tannins content were found as antinutritional content. Further, hot water extract of C. dipsaceus showed good activity especially in ABTS⁺, metal chelating, nitric oxide, and DPPH assays. Hence, the results conclude that C. dipsaceus could be a valuable nutraceutical supplement to the human diet.

Antioxidant activity and anti-adipogenic effects of wild herbs mainly cultivated in Korea

Wild herbs, which are edible plants that grow in mountainous areas, have diverse biological effects such as anti-obesity and anti-cancer activities. The aim of this study was to evaluate the total phenolic and flavonoid contents as well as the antioxidant activity of methanol extracts of Aster scaber, Ligularia fischeri, Kalopanax pictus, Codonopsis lanceolata, and Cirsium setidens and to assess their effects on lipid accumulation and reactive oxygen species (ROS) production during adipogenesis of 3T3-L1 cells. The results revealed that among the five studied wild herb extracts, Ligularia fischeri showed the highest total phenolic contents (215.8 ± 14.2 mg GAE/g) and Aster scaber showed the highest total flavonoid content (103.9 ± 3.4 mg RE/g). Furthermore, Aster scaber and Ligularia fischeri extracts showed higher antioxidant activity than the other wild herbs. Regarding anti-adipogenic activity, the Cirsium setidens extract significantly inhibited lipid accumulation (~80%) and ROS production (~50%) during adipogenesis of 3T3-L1 cells compared with control cells. These results suggest that wild herbs could be used for the development of functional foods as well as health promoting and pharmaceutical agents.

Fisetin averts oxidative stress in pancreatic tissues of streptozotocin-induced diabetic rats

Persistent hyperglycemia is associated with chronic oxidative stress which contributes to the development and progression of diabetes-associated complications. The sensitivity of pancreatic β-cells to oxidative stress has been attributed to their low content of antioxidants compared with other tissues. Bioactive compounds with potent antidiabetic properties have been shown to ameliorate hyperglycemia mediated oxidative stress. Recently, we have reported that oral administration of fisetin (10 mg/Kg b.w.), a bioflavonoid found to be present in strawberries, persimmon, to STZ-induced experimental diabetic rats significantly improved normoglycemia. The present study was aimed to evaluate the antioxidant potential of fisetin in both in vitro and in vivo. Diabetes was induced by single intraperitoneal injection of streptozotocin (50 mg/kg body weight). Fisetin was administered orally for 30 days. At the end of the study, all animals were killed. Blood samples were collected for the biochemical estimations. The antioxidant status was evaluated. Histological examinations were performed on pancreatic tissues. Fisetin treatment showed a significant decline in the levels of blood glucose, glycosylated hemoglobin (HbA1c), NF-kB p65 unit (in pancreas) and IL-1β (plasma), serum nitric oxide (NO) with an elevation in plasma insulin. The treatment also improved the antioxidant status in pancreas as well as plasma of diabetic rats indicating the antioxidant potential of fisetin. In addition, the results of DPPH and ABTS assays substantiate the free radical scavenging activity of fisetin. Histological studies of the pancreas also evidenced the tissue protective nature of fisetin. It is concluded that, fisetin possesses antioxidant and anti-inflammatory property and may be considered as an adjunct for the treatment of diabetes.

In vitro antibacterial and free radical scavenging activity of green hull of Juglans regia

Antioxidant supplements from plants are vital to count the oxidative damage in cells. We assessed the antioxidants and antibacterial activity of green hull of Juglans regia in this study. According to our results the maximum antibacterial activity was observed in ethanolic extract when compared to other extract. So, the ethanolic extract was studied for antioxidant activity which exhibited high antiradical activity against DPPH, hydroxyl, and nitric oxide radicals. In conclusion, green hull of J. regia showed strong reducing power activity and total antioxidant capacity. The results justify the therapeutic application of plant in the indigenous system of medicine.

Medicinal Plant Active Compounds Produced by UV-B Exposure

Ultraviolet (UV) radiation is a part of the sunlight reaching Earth surface. The UV spectrum of solar radiation is by convention divided into three parts: UV-A: 310–400 nm, UV-B: 280–310 nm and UV-C: less than 280 nm. UV-B is the most energetic component reaching Earth surface because the stratospheric ozone layer effectively absorbs completely wavelengths below 290 nm. UV-B is an increasing threat due to increasing UV-B levels on Earth surface as a consequence of depletion of stratospheric O₃. In general, the effects of atmospheric UV-B radiation are negative for biological life. Enhanced levels of UV-B radiation can indeed negatively change plant physiological processes, growth and productivity. However, while studying UV-B effects on medicinal plants, some interesting phenomena have been discovered. For example, basil plants respond positively to UV-B radiation by increasing oil yield (Chang et al. J Horticult For 1:27–31, 2009). In other studies medicinal plants show beneficial aspects in term of increase in volatile oil yield and secondary metabolite production (Kumari et al. Ecotoxicol Environ Safety 72:2013–2019, 2009c, 2010). Medicinal herbs have great market value in India and worldwide. The medicinal value of plants depends upon phenolics, antioxidants and volatile yield. Therefore further UV-B experiments increasing the levels of these compounds are needed.

Here we review the effect of UV-B exposure on metabolites, volatiles, and antioxidants potential in medicinal plants. This chapter reports: (1) aspects of the global market for medicinal and aromatic plants in India in order to assist the medicinal plant industry to make informed decisions. (2) The biodiversity loss due to wild harvesting of plants, and as an alternative the cultivation strategy of medicinal plants. (3) Main medicinal plant species having rich antioxidant potential. (4) Main secondary metabolites of plant origin such as phenylpropanoids, terpenes, alkaloids, and volatile oil, and other important metabolites containing high antioxidant level used in human diet and health. (5) UV-B factors that enhance the quality of medicinal plant by increasing the content of secondary bioactive products. (6) Secondary metabolic pathways involving regulation of key enzymes, chalcone synthase, and phenylalanine ammonia lyase. Understanding of UV-B responses on secondary plant metabolites expand new opportunities for plant enriched in medicinal active compounds.

Influence of growth stage and season on the antioxidant constituents of Cosmos caudatus

The impact of tropical seasons (dry and wet) and growth stages (8, 10 and 12 weeks) of Cosmos caudatus on the antioxidant activity (AA), total phenolic content (TPC) as well as the level of bioactive compounds were evaluated using high performance liquid chromatography (HPLC). The plant morphology (plant height) also showed variation between the two seasons. Samples planted from June to August (during the dry season) exhibited a remarkably higher bioactivity and height than those planted from October to December (during the wet season). The samples that were harvested at eight weeks of age during the dry season showed the highest bioactivity with values of 26.04 g GAE/100 g and 22.1 μg/ml for TPC and IC₅₀, respectively. Identification of phytochemical constituents in the C. caudatus extract was carried out by liquid chromatography coupled with diode array detection and electrospray tandem mass (LC-DAD-ESIMS/MS) technique and the confirmation of constituents was achieved by comparison with literature data and/or co-chromatography with authentic standards. Six compounds were indentified including quercetin 3-O-rhamnoside, quercetin 3-O-glucoside, rutin, quercetin 3-O-arabinofuranoside, quercetin 3-O-galactoside and chlorogenic acid. Their concentrations showed significant variance among the 8, 10 and 12-week-old herbs during both seasons.

Protective effect of Enicostema axillare on mutagenicity of Salmonella typhimurium by increasing free radical scavenging abilities

CONTEXT

Enicostema axillare A. Raynal (Gentianaceae) has been used in the traditional Indian system of medicine as a depurative and for the treatment of skin diseases, tumors, intermittent fever, and helminthiasis.

OBJECTIVE

E. axillare was investigated for antimutagenic and antioxidant effects.

MATERIALS AND METHODS

The antioxidant and antimutagenic activities of E. axillare fractions were determined by 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging assay and Ames test using Salmonella typhimurium tester strains TA98 and TA100 against direct-acting mutagens, such as sodium azide (NaN₃), 4-nitro-O-phenylene diamine (NPD), and mutagen needing activation, such as 2-aminofluorene (2AF). Toxicity study of these fractions was also performed.

RESULTS AND DISCUSSION

The ethyl acetate fraction showed maximum antimutagenic effect by 88.25 and 84.46% (preincubation) and 85.13 and 84.47% (coincubation) of inhibition against NaN₃ and NPD-induced mutagenicity, respectively. Inhibition of S9-dependent mutagens such as 2AF was higher than direct-acting mutagens by the ethyl acetate fraction of E. axillare. It showed 90.25 and 92.00% of inhibition in the preincubation and coincubation experiments. The ethyl acetate fraction showed higher total antioxidant capacity (24.79 ± 0.29 µg) and low IC₅₀ value for DPPH radical scavenging assay (192.27 ± 3.67 µg). The overall effect of E. axillare fractions was found to be in the order: ethyl acetate > methanol > hexane in these assays. In subacute toxicity study, with oral administration of these fractions, no marked biochemical and histopathologic changes were observed.

CONCLUSION

The significant antimutagenic and antioxidant activities of E. axillare might provide a scientific validation for the traditional use of this plant.

Optimization of Antioxidant Potential of Penicillium granulatum Bainier by Statistical Approaches

A three-step optimization strategy which includes one-factor-at-a-time classical method and different statistical approaches (Plackett-Burman design and response surface methodology) that were applied to optimize the antioxidant potential of Penicillium granulatum. Antioxidant activity was assayed by different procedures and compared with total phenolic content. Primarily, different carbon and nitrogen sources were screened by classical methods, which revealed sucrose and NaNO3 to be the most suitable. In second step, Plackett-Burman design also supported sucrose and NaNO3 to be the most significant. In third step, response surface analysis showed 4.5% sucrose, 0.1% NaNO3, and incubation temperature of 25°C to be the optimal conditions. Under these conditions, the antioxidant potential assayed through different procedures was 78.2%, 70.1%, and 78.9% scavenging effect for DPPH radical, ferrous ion, and nitric oxide ion, respectively. The reducing power showed an absorbance of 1.6 with 68.5% activity for FRAP assay.

Aegle marmelos fruit extract attenuates isoproterenol-induced oxidative stress in rats

Myocardial infarction is a major public health concern and the leading cause of death throughout the world. The present study investigates the ability of Aegle marmelos fruit extract to prevent pathological changes and oxidative stress after isoproterenol induced myocardial infarction in rats. In vitro studies showed that Aegle marmelos fruit extract possesses antioxidant activity. Administration of isoproterenol (85 mg/kg body weight) to rats resulted in significantly elevated plasma transaminases, lactate dehydrogenase and creatine kinase, however, cardiac tissue analyses showed decreased activity of the above enzymes compared to experimental control rats. Further, isoproterenol administration significantly increased plasma and cardiac tissue thiobarbituric acid reactive substances and lowered the activities of cardiac tissue superoxide dismutase, catalase, reduced glutathione, glutathione peroxidase and glutathione-S-transferase when compared to control groups. Pretreatment with Aegle marmelos fruit extract at a dose of 150 mg/kg body weight for a period of 45 days significantly prevented the observed alterations. Our data suggest that Aegle marmelos fruit extract exerts its protective effect by decreasing thiobarbituric acid reactive substances and elevating antioxidants status in isoproterenol treated rats. Both biochemical and histopathological results in the isoproterenol-induced myocardial infarction model emphasize the beneficial action of Aegle marmelos fruit extract as a cardioprotective agent.

Hepatoprotective effects of pecan nut shells on ethanol-induced liver damage

The hepatoprotective activity of the aqueous extract of the shells of pecan nut was investigated against ethanol-induced liver damage. This by-product of the food industry is popularly used to treat toxicological diseases. We evaluated the phytochemical properties of pecan shell aqueous extract (AE) and its in vitro and ex vivo antioxidant activity. The AE was found to have a high content of total polyphenols (192.4±1.9 mg GAE/g), condensed tannins (58.4±2.2 mg CE/g), and antioxidant capacity, and it inhibited Fe(2+)-induced lipid peroxidation (LP) in vitro. Rats chronically treated with ethanol (Et) had increased plasmatic transaminases (ALT, AST) and gamma glutamyl transpeptidase (GGT) levels (96%, 59.13% and 465.9%, respectively), which were effectively prevented (87; 41 and 383%) by the extract (1:40, w/v). In liver, ethanol consumption increased the LP (121%) and decreased such antioxidant defenses as glutathione (GSH) (33%) and superoxide dismutase (SOD) (47%) levels, causing genotoxicity in erythrocytes. Treatment with pecan shell AE prevented the development of LP (43%), GSH and SOD depletion (33% and 109%, respectively) and ethanol-induced erythrocyte genotoxicity. Catalase activity in the liver was unchanged by ethanol but was increased by the extract (47% and 73% in AE and AE+Et, respectively). Therefore, pecan shells may be an economic agent to treat liver diseases related to ethanol consumption.

Stabilization of sunflower oil with Carum copticum Benth & Hook essential oil

In this study, application of various concentrations (0.025%, 0.05% and 0.075%) of Carum copticum essential oil (EO) were examined on oxidative stability of sunflower oil and there were compared to Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) during storage at 37 and 47 °C. The main compounds of EO were identified as thymol (50.07%), γ- terpinene (23.92%) and p-cymene (22.9%). Peroxide value (PV), anisidine value (AnV) and thiobarbituric acid (TBA) value measurement in sunflower oil showed that all concentrations of EO had antioxidant effect in comparison to BHA and BHT. Samples added with EO at 0.075% were the most stable during storage at both temperatures (P < 0.05). Furthermore, Totox value, antioxidant activity (AA), stabilization factor (F) and antioxidant power (AOP) determination confirmed efficacy of this EO as antioxidant in sunflower oil. EO also was able to reduce the stable free radical 2, 2-diphenyl-1-picrylhydrazyl (DPPH) with a 50% inhibition concentration (IC50) of 20.3 ± 0.9 μg/mL. Therefore, the results indicate that EO could be used as a natural antioxidant in food lipids.

Protective effects of aucubin on H₂O₂-induced apoptosis in PC12 cells

The present study investigated the neuroprotective effects of aucubin on hydrogen peroxide (H₂O₂)-induced apoptosis in PC12 cells. Exposure of PC12 cells to 0.25 mm H₂O₂ induced a leakage of lactate dehydrogenase and decreased cell viability, as shown by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. In a dose over 0.1 mm, aucubin increased PC12 cellular viability and markedly attenuated H₂O₂-induced apoptotic cell death. Quantitation of apoptosis by flow cytometry indicated that aucubin inhibited H₂O₂-induced apoptosis in PC12 cells. Nuclear damage was alleviated by aucubin, as shown by Hoechst staining. In addition, the levels of malondialdehyde were reduced and the activity of superoxide dismutase, catalase and glutathione peroxidase was augmented in these cells. These results indicated that aucubin inhibited H₂O₂-induced apoptosis in PC12 cells through regulation of the endogenous oxidant-antioxidant balance. Our results suggest that aucubin is a potential protective agent for the treatment of oxidative-stress-induced neurodegenerative disease.