Will the 'good fairies' please prove to us that vitamin E lessens human degenerative disease?

Myco-synthesized copper oxide nanoparticles using harnessing metabolites of endophytic fungal strain Aspergillus terreus: an insight into antibacterial, anti-Candida, biocompatibility, anticancer, and antioxidant activities

BACKGROUND

The overuse of antibiotics leads to the emergence of antibiotic-resistant microbes which causes high mortality worldwide. Therefore, the synthesis of new active compounds has multifunctional activities are the main challenge. Nanotechnology provides a solution for this issue.

METHOD

The endophytic fungal strain Aspergillus terreus BR.1 was isolated from the healthy root of Allium sativum and identified using internal transcribed spacer (ITS) sequence analysis. The copper oxide nanoparticles (CuO-NPs) were synthesized by harnessing the metabolites of the endophytic fungal strain. The UV-Visble spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), Transmission electron micrscopy (TEM), Energy dispersive X-ray (EDX), X-ray diffraction (XRD), Dynamic light scattering (DLS), and zeta potential (ζ) were used for the characterization of synthesized CuO-NPs. The activity against different pathogenic bacteria and Candida species were investigated by agar well-diffusion method. The biocombatibility and anticancer activity were assessed by MTT assay method. The scavenging of DPPH was used to investigate the antioxidant activity of synthesized CuO-NPs.

RESULTS

Data showed the successful formation of crystalline nature and spherical shape CuO-NPs with sizes in the ranges of 15-55 nm. The EDX reveals that the as-formed sample contains ions of C, O, Cl, and Cu with weight percentages of 18.7, 23.82, 11.31, and 46.17%, respectively. The DLS and ζ-potential showed high homogeneity and high stability of synthesized CuO-NPs with a polydispersity index (PDI) of 0.362 and ζ-value of - 26.6 mV. The synthesized CuO-NPs exhibited promising antibacterial and anti-Candida activity (concentration-dependent) with minimum inhibitory concentration (MIC) values in the ranges of 25-50 µg mL^-1. Moreover, the fungal mediated-CuO-NPs targeted cancer cells of MCF7 and PC3 at low IC₅₀ concentrations of 159.2 ± 4.5 and 116.2 ± 3.6 µg mL^-1, respectively as compared to normal cells (Vero and Wi38 with IC₅₀ value of 220.6 ± 3.7 and 229.5 ± 2.1 µg mL^-1, respectively). The biosynthesized CuO-NPs showed antioxidant activity as detected by the DPPH method with scavenging percentages of 80.5 ± 1.2% at a concentration of 1000 µg mL^-1 and decreased to 20.4 ± 4.2% at 1.9 µg mL^-1 as compared to ascorbic acid (control) with scavenging activity of 97.3 ± 0.2 and 37.5 ± 1.3% at the same concentrations, respectively.

CONCLUSION

The fungal mediated-CuO-NPs exhibited promising activity and can be integrated into various biomedical and theraputic applications.

Effects of different processing (Paozhi) on structural characterization and antioxidant activities of polysaccharides from Cistanche deserticola

In this study, five polysaccharides were extracted from processed Cistanche deserticola. The processing included crude product, enzymatic hydrolysis, hot air drying, stir-baking with wine and high-pressure steaming, and these polysaccharides were named as CP-CDPs, EH-CDPs, HAD-CDPs, SBW-CDPs and HPS-CDPs, respectively. The structural characteristics and biological activities were explored. The results showed that processing changed properties of C. deserticola polysaccharides. CP-CDPs had the highest brightness value L*(93.84) and carbohydrate content (61.27 %). EH-CDPs had minimum M_w (1531.50 kDa), while SBW-CDPs had maximum M_w (2526.0 kDa). Glucose was major predominant monosaccharide in CP-CDPs (89.82 %), HAD-CDPs (79.3 %), SBW-CDPs (59.41 %) and HPS-CDPs (63.86 %), while galactose was major monosaccharide in EH-CDPs (29.44 %). According to SEM, SBW-CDPs showed compact structures, while HPS-CDPs and HAD-CDPs had similar looser structure than SBW-CDPs; meanwhile, CP-CDPs showed irregular agglomeration shape and EH-CDPs was dense blocky shape. The AFM showed SBW-CDPs had the largest molecular chain than other polysaccharides. When scavenging activity reaching 50 %, the concentrations of CP-CDPs, EH-CDPs, HAD-CDPs, SBW-CDPs, HPS-CDPs are 2.25, 0.25, 0.75, 1.8 and 1.5 mg/mL, respectively. This study sheds light on the effects of traditional Chinese medicine processing on characteristics, bioactivities of C. deserticola polysaccharides, and provides the basis for applications in food and pharmaceutical industries.

Reflections of an Aging Free Radical Part 2: Meeting Inspirational People

Significance: During my long career in the field of redox biology, I met many inspiring people, especially Lester Packer. Recent Advances: This special issue of Antioxidants & Redox Signaling is dedicated to Lester Packer. Critical Issues: In this short review, I explore how Lester and other pioneers helped to develop the redox biology field and how I interacted with them. Future Directions: In our research to advance the field of redox biology, we stand on the shoulders of giants, including Lester Packer.

Mahmoud E, Elansary HO, Sannaningaiah D. Effect of Biofunctional Green Synthesized MgO-Nanoparticles on Oxidative-Stress-Induced Tissue Damage and Thrombosis

The present study describes the green biofunctional synthesis of magnesium oxide (MgO) nanoparticles using the aqueous Tarenna asiatica fruit extract. The characterization of Tarenna asiatica fruit extract MgO nanoparticles (TAFEMgO NPs) was achieved by X-ray powder diffraction, UV-Vis spectroscopy, FTIR, TEM, SEM, and energy-dispersive X-ray diffraction. TAFEMgO NPs scavenged the DPPH free radicals with an IC50 value of 55.95 μg/μL, and it was highly significant compared to the standard. To authenticate the observed antioxidant potential of TAFEMgO NPs, oxidative stress was induced in red blood cells (RBC) using sodium nitrite (NaNO₂). Interestingly, TAFEMgO NPs ameliorated the RBC damage from oxidative stress by significantly restoring the stress parameters, such as the protein carbonyl content (PCC), lipid peroxidation (LPO), total thiol (TT), super-oxide dismutase (SOD), and catalase (CAT). Furthermore, oxidative stress was induced in-vivo in Sprague Dawley female rats using diclofenac (DFC). TAFEMgO NPs normalized the stress parameters in-vivo and minimized the oxidative damage in tissues. Most importantly, TAFEMgO NPs restored the function and architecture of the damaged livers, kidneys, and small intestines by regulating biochemical parameters. TAFEMgO NPs exhibited an anticoagulant effect by increasing the clotting time from 193 s in the control to 885 s in the platelet rich plasma. TAFEMgO NPs prolonged the formation of the clot process in the activated partial thromboplastin time and the prothrombin time, suggest the effective involvement in both intrinsic and extrinsic clotting pathways of the blood coagulation cascade. TAFEMgO NPs inhibited adenosine di-phosphate (ADP)-induced platelet aggregation. TAFEMgO NPs did not show hemolytic, hemorrhagic, and edema-inducing properties at the tested concentration of 100 mg/kgbody weight, suggesting its non-toxic property. In conclusion, TAFEMgO NPs mitigates the sodium nitrite (NaNO₂)- and diclofenac (DFC)-induced stress due to oxidative damage in both in vitro and in vivo experimental models.

Copper oxide nanoparticles synthesized from an endophytic fungus Aspergillus terreus: Bioactivity and anti-cancer evaluations

The mycofabricated metal nanoparticles (NPs) plays a significant role in cancer therapeutics and imparts a strategy in medicine. The current investigation focused to synthesize the Copper Oxide Nanoparticles (CuONPs) using an endophytic fungus isolated from Aegle marmelosa medicinal tree located in Western Ghats, India. The endophytic fungus FCBY1 explored the highest antagonistic and antioxidant activities among the 16 pigmented endophytic fungal strains which were isolated from the collected samples. The fungus FCBY1 was identified for its morphological and molecular characteristics where the (Internal Transcribed Spacer) ITS 1, 5.8 ribosomal gene and ITS 2 were sequenced; and the organism FCBY1 is Aspergillus terreus. The endophyte was put through for the synthesis of CuONPs and the size and structure of the synthesized particles were characterized by Scanning Electron Microscope (SEM). The confirmation of the CuONPs was characterized by FT-IR, EDAX and XRD analyses. The CuONPs exhibited the maximized antibacterial and antifungal activities against the human clinical pathogens; moreover the particles also explicated the free radicals/ROS scavenging at minimum concentration, which was assessed through DPPH, nitric oxide radical scavenging assays, and reductive power ability. The anti-cancer activity of CuONPs on colon cancer cell lines (HT-29) was evaluated by MTT (IC₅₀: 22 μg/mL) and FACS analyses (32.11% cells gated in S phase of cell cycle). Angiogenesis inhibition in tumor cells was estimated through in vivo HET- CAM assessment and the highest concentration 60 μL tested inhibited the blood vessels at the percentage of 31.36% and 81.81%. The CuONPs explicated the anti-cancer activities in a concentration - dependent manner and the results of this investigation manifest the significant role of the CuONPs in cancer therapeutics.

The modulatory potential of herbal antioxidants against oxidative stress and heavy metal pollution: plants against environmental oxidative stress

Free radicals, principally reactive oxygen species (ROS), contribute to oxidative stress in human beings. Free radicals have different mechanisms of action and affect lipids, proteins, and DNA. Heavy metals including cadmium (Cd), lead (Pb), and arsenic are environmental pollutants that may induce oxidative stress and produce ROS, leading to harmful effects on different body systems such as the liver and brain. On the other side, antioxidants can have protective effects against oxidative stress and decrease their toxicity. Herbal antioxidants have potential antioxidative effects. These antioxidants positively affect neurodegenerative diseases, atherosclerotic diseases, lung fibrosis, kidney injuries, and liver toxicities induced by oxidative agents, including heavy metals. In this manuscript, we explained the mechanisms of oxidative stress, and also discussed heavy metals which contribute to human oxidative stress. We further discussed different herbal antioxidants, their mechanisms of action, and their clinical use for various diseases.

Micronutrient Food Supplements in Patients with Gastro-Intestinal and Hepatic Cancers

Colorectal carcinogenesis is the second most common cause of mortality across all types of malignancies, followed by hepatic and stomach cancers. Chemotherapy and radiotherapy are key approaches to treating cancer patients, but these carry major concerns, such as a high risk of side effects, poor accessibility, and the non-selective nature of chemotherapeutics. A number of natural products have been identified as countering various forms of cancer with fewer side effects. The potential impact of vitamins and minerals on long-term health, cognition, healthy development, bone formation, and aging has been supported by experimental and epidemiological studies. Successful treatment may thus be highly influenced by the nutritional status of patients. An insufficient diet could lead to detrimental effects on immune status and tolerance to treatment, affecting the ability of chemotherapy to destroy cancerous cells. In recent decades, most cancer patients have been taking vitamins and minerals to improve standard therapy and/or to decrease the undesirable side effects of the treatment together with the underlying disease. On the other hand, taking dietary supplements during cancer therapy may affect the effectiveness of chemotherapy. Thus, micronutrients in complementary oncology must be selected appropriately and should be taken at the right time. Here, the potential impact of micronutrients on gastro-intestinal and hepatic cancers is explored and their molecular targets are laid down.

The Effect of the Hydroalcoholic Extract of Watercress on the Levels of Protein Carbonyl, Inflammatory Markers, and Vitamin E in Chronic Hemodialysis Patients

Introduction

Chronic kidney disorder is a main public health concern. Inflammatory processes and oxidative stress are common in end-stage renal disease patients. We aimed to evaluate the effect of the hydroalcoholic extract of watercress (WC) on the inflammatory cytokines and protein carbonyl (PCO) contents in chronic hemodialysis patients.

Methods

This was a double-blind randomized clinical trial performed on 46 hemodialysis patients. The participants were randomly divided into two groups: intervention group (500 mg hydroalcoholic extract of WC every day for 4 weeks) and control group (500 mg of white flour every night for 4 weeks). The blood samples were taken to determine the levels of vitamin E, PCO, and inflammatory cytokines at baseline and the end of treatment.

Results

Forty-five patients completed the study (22 patients in the intervention group and 23 patients in the control group). There was a significant reduction in the PCO level (20.33 ± 4.40 vs. 15.06 ± 6.41, P=0.001) in the intervention group; also, this change was statistically significant relative to the control group. Furthermore, there were significant reductions in hs-CRP (8953.30 ± 5588.06 vs. 7249.86 ± 5091.62, P=0.007) and IL-6 (60.10 (55.99, 73.10) vs. 55.21 (53.39, 60.48), P=0.050) in the intervention group, but these changes were not significant in comparison with the control group.

Conclusion

We conclude that the hydroalcoholic extract of WC reduced the PCO content in hemodialysis patients via inhibition of protein oxidation. Although WC administration had caused a significant reduction in IL-6 and CRP levels, these differences were not statistically significant relative to the control group. Further research is needed to identify the antioxidant and anti-inflammatory effects of WC in hemodialysis patients.

A Narrative Review on Therapeutic Potentials of Watercress in Human Disorders

Watercress (WC) is an aquatic vegetable that belongs to the Brassicaceae family, and it often grows near water. In traditional medicine, WC is a known remedy for hypercholesterolemia, hyperglycemia, hypertension, arthritis, bronchitis, diuresis, odontalgia, and scurvy. It also acts as an antiestrogenic and can be used as a nutritional supplement. It has been reported that these therapeutic effects are due to primary metabolites such as isothiocyanates, glucosinolates, polyphenols (flavonoids, phenolic acids, and proanthocyanidins), vitamins (B₁, B₂, B₃, B₆, E, and C), terpenes (including carotenoids), and bioelements which exist in this plant. Many pharmacological studies confirm the antioxidant, antibacterial, anticancer, antipsoriatic, anti-inflammatory, cardioprotective, renoprotective, hepatoprotective, and antigenotoxicity effects of WC. The consumption of WC extract can be useful in reducing the complications of hypercholesterolemia and hyperglycemia. Furthermore, the extract of WC could markedly augment the antioxidant enzymes such as superoxide dismutase and catalase activity. Interestingly, consumption of food rich in polyphenols such as WC extract can help reduce oxidative stress, DNA damage, and cancer susceptibility. Several studies also showed that WC extract significantly reduced liver injury as a result of cholestatic hepatic injury, gamma radiation, arsenic, and acetaminophen-induced hepatotoxicity. In this review, the researchers focus on the phytochemical and biochemical characterizations of WC and its therapeutic effects in the treatment of human diseases.

Phytochemical and antioxidant activity evaluation of the bark of Tampoi ( Baccaurea macrocarpa)

Background: Tampoi ( Baccaurea macrocarpa) is a tropical rainforest plant that produces edible fruit and is native to Southeast Asia, especially East Kalimantan, Indonesia. Previous research showed that Tampoi potentially can be developed as a drug. It was reported that the extract of Tampoi fruit displayed antioxidant activity, which was correlated with its phenolic and flavonoid substances. There is no information about the antioxidant activity of other parts of this plant, such as the bark, which might also have this kind of activity. Therefore, the aim of this study was to evaluate the phytochemical using GC-MS analysis, toxicity againt Artemia salina, and antioxidant activity with DPPH radical scavenging method of the bark of Tampoi.

Methods: The bark of Tampoi was extracted with methanol and concentrated using rotary evaporator to obtain the methanol extract of the bark. Secondary metabolites of this extract was determined using phytochemical analysis. Afterward, the methanol extract was tested for its toxicity using brine shrimp lethality test and antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl method.

Results: Phytochemical evaluation results showed that the methanol extract of bark of this plant contains several secondary metabolites including alkaloids, flavonoids, phenolics, steroids, and triterpenoids. The toxicity test displayed no toxic property due to a LC ₅₀ value above 1000 ppm. For antioxidant activity, the result exhibited that the methanol extract of bark of this plant could be categorized as an active extract with IC ₅₀ value of 11.15 ppm. Moreover, based on gas chromatography-mass spectrometer analysis, there are 37 isolated compounds from the bark, one of which is methylparaben, a phenolic predicted to act as an antioxidant.

Conclusion: The results obtained in this research demonstrated that the bark of Tampoi ( B. macrocarpa) has potential as an antioxidant.

Diversity of Streptomyces spp. from mangrove forest of Sarawak (Malaysia) and screening of their antioxidant and cytotoxic activities

Streptomycetes have been the center of attraction within scientific community owing to their capability to produce various bioactive compounds, for instance, with different antimicrobial, anticancer, and antioxidant properties. The search for novel Streptomyces spp. from underexplored area such as mangrove environment has been gaining attention since these microorganisms could produce pharmaceutically important metabolites. The aim of this study is to discover the diversity of Streptomyces spp. from mangrove in Sarawak and their bioactive potentials — in relation to antioxidant and cytotoxic activities. A total of 88 Streptomyces isolates were successfully recovered from the mangrove soil in Kuching, state of Sarawak, Malaysia. Phylogenetic analysis of all the isolates and their closely related type strains using 16S rRNA gene sequences resulted in 7 major clades in the phylogenetic tree reconstructed based on neighbour-joining algorithm. Of the 88 isolates, 18 isolates could be considered as potentially novel species according to the 16S rRNA gene sequence and phylogenetic analyses. Preliminary bioactivity screening conducted on the potential novel Streptomyces isolates revealed significant antioxidant activity and notable cytotoxic effect against tested colon cancer cell lines (HCT-116, HT-29, Caco-2, and SW480), with greater cytotoxicity towards SW480 and HT-29 cells. This study highlighted that the Sarawak mangrove environment is a rich reservoir containing streptomycetes that could produce novel secondary metabolites with antioxidant and cytotoxic activities.

The Antioxidant Activity of Polysaccharides Derived from Marine Organisms: An Overview

Marine-derived antioxidant polysaccharides have aroused extensive attention because of their potential nutritional and therapeutic benefits. However, the comprehensive comparison of identified marine-derived antioxidant polysaccharides is still inaccessible, which would facilitate the discovery of more efficient antioxidants from marine organisms. Thus, this review summarizes the sources, chemical composition, structural characteristics, and antioxidant capacity of marine antioxidant polysaccharides, as well as their protective in vivo effects mediated by antioxidative stress reported in the last few years (2013-2019), and especially highlights the dominant role of marine algae as antioxidant polysaccharide source. In addition, the relationships between the chemical composition and structural characteristics of marine antioxidant polysaccharides with their antioxidant capacity were also discussed. The antioxidant activity was found to be determined by multiple factors, including molecular weight, monosaccharide composition, sulfate position and its degree.

Nutritional value, micronutrient and antioxidant capacity of some green leafy vegetables commonly used by southern coastal people of Bangladesh

Southern coastal people of Bangladesh are highly vulnerable to food insecurity and malnutrition due to coastal flooding, deforestation and increased soil salinity. A number of green leafy vegetables are found in the southern coastal belt being traditionally eaten as daily basis by local people. But they are unaware of nutritional and medicinal use of these vegetables. To contribute to their wider utilization, five common vegetables namely Hibiscus sabdariffa, Trianthema portulacastrum, Diplazium esculentum, Heliotropium indicum L. and Hygrophila auriculata were selected for analysis of nutritional proximate, micronutrients and antioxidant potential. Nutritional properties were analyzed in terms of moisture, pH, protein, lipid, ash, fibre, minerals and carbohydrate. Total flavonoid, tannin and antioxidant capacity were evaluated using established protocols. The results demonstrated that collected plants are rich in carbohydrate, fibre, proteins, moisture and ash content but low in lipid content. The mineral elements were high with remarkable amount of Na (19.9–21.5 mg/gm), K (7.9–13.5 mg/gm) and P (1.0–1.8 mg/gm). All the samples were found to have considerable amount of flavonoid (90.6–144.5 mg QE/gm) and tannin content (26.8–57.2 mg GAE/gm). The IC₅₀ value of DPPH and superoxide radical scavenging was the lowest for H. indicum (37.1 and 83.4 μg/ml, respectively) whereas T. portulacastrum possessed high reducing power (IC₅₀ 53.7 μg/ml). Among the five investigated species, T. portulacastrum and H. indicum were found to have good nutritional and antioxidant properties, thus can be promoted as a significant source of nutritional and antioxidant food supplements.

DNA Damage Protecting Activity and Antioxidant Potential of Launaea taraxacifolia Leaves Extract

BACKGROUND

The leaf extract of Launaea taraxacifolia commonly known as African Lettuce is used locally to treat dyslipidemia and liver diseases, which are associated with oxidative stress. Methanol extract from L. taraxacifolia leaves was tested for its antioxidant activity and its ability to protect DNA from oxidative damage.

MATERIALS AND METHODS

In vitro antioxidant potential of the leaf extract was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide (NO), and hydroxyl (OH) radical scavenging assays. Ferric reducing power, total antioxidant capacity (TAC), metal chelating, and anti-lipid peroxidation ability of the extract were also examined using gallic acid, ascorbic acid, citric acid, and ethylenediaminetetraacetic acid as standards.

RESULTS

L. taraxacifolia leaves extract showed antioxidant activity with IC50 values of 16.18 μg/ml (DPPH), 123.3 μg/ml (NO), 128.2 μg/ml (OH radical), 97.94 μg/ml (metal chelating), 80.28 μg/ml (TAC), and 23 μg/ml (anti-lipid peroxidation activity). L. taraxacifolia leaves extract exhibited a strong capability for DNA damage protection at 20 mg/ml concentration.

CONCLUSION

These findings suggest that the methanolic leaf extract of L. taraxacifolia could be used as a natural antioxidant and also as a preventive therapy against diseases such as arteriosclerosis associated with DNA damage.

Antigenotoxic and Antioxidant Activity of Methanol Stem Bark Extract of Napoleona Vogelii Hook & Planch (Lecythidaceae) In Cyclophosphamide-Induced Genotoxicity

BACKGROUND:

Napoleona vogelii is used in traditional medicine for cancer management.

AIM:

The study was conducted to evaluate the antigenotoxic and antioxidant activities of methanol stem bark extract of N. vogelii in male Sprague Dawley rats.

MATERIALS AND METHOD:

Thirty male Sprague Dawley rats were randomly divided into group 1 (control) administered 10 mL/kg distilled water, groups 2 and 3 were co-administered 100 mg/kg, 200 mg/kg of N. vogelli and 5 mg/kg cyclophosphamide (CPA) respectively for 7 days p.o. Groups 4 and 5 were administered only 5 mg/kg CPA and 200 mg/kg NV respectively.

RESULTS:

The LD50 oral was greater than 4 g/kg. There were significant (p < 0.0001) increases in plasma enzymatic and non-enzymatic antioxidant enzymes and significant (p < 0.0001) decrease in percentage micronuclei in bone marrow of extract treated rats compared to rats administered 5 mg/kg CPA alone. There was steatosis pointing to cytotoxic injury in the liver of rats co-administered 200 mg/kg NV and 5 mg/kg CPA. Gas chromatography-mass spectrometry analysis of the extract showed the presence of phytol and unsaturated fatty acids.

CONCLUSION:

N. vogelii possesses antigenotoxic and antioxidant activities associated with the presence of phytochemicals, phytol and unsaturated fatty acids.

Antioxidant and Antiradical Properties of Selected Flavonoids and Phenolic Compounds

Phenolic compounds and flavonoids are known by their antioxidant properties and one of the most important sources for humans is the diet. Due to the harmful effects of synthetic antioxidants such as BHA and BHT, natural novel antioxidants have become the focus of attention for protecting foods and beverages and reducing oxidative stress in vivo. In the current study, we investigated the total antioxidant, metal chelating, Fe³⁺ and Cu²⁺ reduction, and free radical scavenging activities of some phenolic and flavonoid compounds including malvin, oenin, ID-8, silychristin, callistephin, pelargonin, 3,4-dihydroxy-5-methoxybenzoic acid, 2,4,6-trihydroxybenzaldehyde, and arachidonoyl dopamine. The antioxidant properties of these compounds at different concentrations (10–30 μg/mL) were compared with those of reference antioxidants such as BHA, BHT, α-tocopherol, and trolox. Each substance showed dose-dependent antioxidant activity. Furthermore, oenin, malvin, arachidonoyl dopamine, callistephin, silychristin, and 3,4-dihydroxy-5-methoxybenzoic acid exhibited more effective antioxidant activity than that observed for the reference antioxidants. These results suggest that these novel compounds may function to protect foods and medicines and to reduce oxidative stress in vivo.

Assessment of free radical scavenging and anti-proliferative activities of Tinospora cordifolia Miers (Willd)

Background

Tinospora cordifolia (Guduchi or Amrita) is an important drug of Ayurvedic System of Medicine and found mention in various classical texts for the treatment of diseases such as jaundice, fever, diabetes, cancer and skin disease etc. In view of its traditional claims, antioxidant and anti-proliferative activities were evaluated in the present study.

Methods

Ethanol extract (TCE) and subsequent petroleum ether (TCP), dichloromethane (TCD), n-Butanol (TCB) and aqueous (TCA) fractions of were prepared from stems of T cordifolia. Total phenolic, flavonoid content and anti-oxidant activity was assessed by different methods. Anti-proliferative activity was assessed in cervical carcinoma (HeLa) cell lines by MTT and SRB assay.

Results

Ethanol extract and n-butanol fractions shown to be superior in their scavenging activity in all the tested methods. n-butanol fractions shown antioxidant activity with an IC₅₀ of 14.81 ± 0.53, 29.48 ± 2.23, 58.20 ± 0.70 and 21.17 ± 1.19 μg/mL by DPPH, ABTS, Nitric oxide and iron chelating activities respectively. Anti-proliferative activity results demonstrates that the TCD and ethanol extract of T cordifolia exhibits potent cytotoxic effect against HeLa with an IC₅₀ of 54.23 ± 0.94 μg/mL and 101.26 ± 1.42 μg/mL respectively by MTT assay; and with an IC₅₀ of 48.91 ± 0.33 μg/mL and 87.93 ± 0.85 μg/mL respectively by SRB assay.

Conclusion

The outcomes of the present study support the fact that T Cordifolia is a promising source of antioxidant agent and propose its further investigation. Moreover, dichloromethane fraction of T cordifolia shown to be the most potent anti-proliferative fraction and further mechanistic and phytochemical investigations are under way to identify the active principles.

Antioxidant Activities and Phenolic Compounds of Several Tissues of Pawpaw (Asimina triloba [L.] Dunal) Grown in Korea

Pawpaw (Asimina triloba [L.] Dunal) possesses antioxidant compounds and strong inhibitors of cancer cells, and is widely cultivated in North America, Canada, and Korea. We analyzed the total phenolic and total flavonoid contents (TPC and TFC, respectively) of pawpaw plants grown in Korea and the antioxidant activities of their roots, twigs, leaves, and fruit with respect to 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity, 2,2'-azino-bis diammonium salt (ABTS) radical scavenging activity, ferrous (Fe²⁺ ) chelating ability, and nitrite scavenging activity. Pearson's correlation analyses revealed a linear correlation between TPC and antioxidant activities (r² >0.69). Root methanol extracts had higher TPC and antioxidant activities than other extracts, which was also consistent with those from the phenolic compounds found in those extracts. Therefore, antioxidant activities seem to depend on the TPC of each pawpaw tissue and pawpaw roots might be useful as a natural source of natural antioxidants.

Evaluation of antioxidant and anticancer activity of copper oxide nanoparticles synthesized using medicinally important plant extracts

Copper oxide (CuO) nanoparticles were synthesized by green chemistry approach using different plant extracts obtained from the leaves of Azadirachta indica, Hibiscus rosa-sinensis, Murraya koenigii, Moringa oleifera and Tamarindus indica. In order to compare their efficiency, the same copper oxide nanoparticles was also synthesized by chemical method. Phytochemical screening of the leaf extracts showed the presence of carbohydrates, flavonoids, glycosides, phenolic compounds, saponins, tannins, proteins and amino acids. FT IR spectra confirmed the possible biomolecules responsible for the formation of copper oxide nanoparticles. The surface plasmon resonance absorption band at 220-235nm in the UV-vis spectra also supports the formation of copper oxide nanoparticles. XRD patterns revealed the monoclinic phase of the synthesized copper oxide nanoparticles. The average size, shape and the crystalline nature of the nanoparticles were determined by SEM, TEM and SAED analysis. EDX analysis confirmed the presence of elements in the synthesized nanoparticles. The antioxidant activity was evaluated by three different free radical scavenging assays. The cytotoxicity of copper oxide nanoparticles was evaluated against four cancer cell lines such as human breast (MCF-7), cervical (HeLa), epithelioma (Hep-2) and lung (A549), and one normal human dermal fibroblast (NHDF) cell line. The morphological changes were evaluated using Hoechst 33258 staining assay. Copper oxide nanoparticles synthesized by green method exhibited high antioxidant and cytotoxicity than that synthesized by chemical method.

Distribution of free, esterified, and insoluble bound forms of phenolics in tea seeds and their antioxidant activity

In this study, phenolic compounds in their phenolic extract (PE), free phenolic (FP), esterified phenolic (EFP), and insoluble bound phenolic (ISBP) forms were extracted from tea seeds and quantified using HPLC to obtain information on the phenolics that are present in tea seeds along with their antioxidant activities. The total phenolic content of the ISBP fraction was higher than that of the FP and EFP fractions. The phenolic acids in tea seeds exist either in esterified or glycosided forms. Moreover, hydroxycinnamic acid derivatives have been identified as important phenolic acid components in tea seeds. The ISBP fraction was an effective antioxidant based on the results obtained from the in vitro assays performed, which include the DPPH and 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)-derived nitrogen-centered radical scavenging activities, Fe³⁺-2,4,6-tripyridyl-s-triazine reducing ability, as well as Cu²⁺ and Fe²⁺ ion chelating effects.

In vitro antioxidant and anticancer activity of Leea indica leaf extracts on human prostate cancer cell lines

Background

To determine the phytochemical constituents, antioxidant, and anticancer activities of Leea indica leaf extracts on DU-145 and PC-3 human prostate cancer cell lines.

Methods

Leaf sample was subjected to Soxhlet extraction method with increasing polarity of solvents, namely, chloroform, ethyl acetate, methanol, ethanol, and aqueous. Phytochemical screening was done using different biochemical tests. Quantitative analysis for phenol was determined by Folin–Ciocalteu reagent method. The antioxidant activity was tested using 2,2-diphenyl-1-picrylhydrazyl, ferric ion reducing power assay, and phosphomolybdenum assay. In vitro anticancer activity on DU-145 and PC-3 human prostate cancer cell lines was evaluated by (3-(4, 5-dimethyl thiazole-2yl)-2, 5-diphenyl tetrazolium bromide) MTT assay.

Results

Phytochemical screening confirmed the presence of phyto-constituents like alkaloids, flavonoids, glycosides, phenols, lignins, saponins, sterols, tannins, anthraquinone, and reducing sugar. Methanol and ethanol extracts exhibited higher phenolic content as compare to aqueous extract. Antioxidant capacities were shown highest in methanol and ethanol extracts based on the test performed. The methanol and ethanol leaf extracts were found to be selectively cytotoxic in vitro to (DU-145 and PC-3) prostate cancer cell lines with IC₅₀ values 529.44 ± 42.07 μg/mL and 677.11 ± 37.01 μg/mL for DU-145 and 547.55 ± 33.52 μg/mL and 631.99 ± 50.24 μg/mL for PC-3 respectively, while it had no cytotoxic effect on normal mice embryo fibroblast cells.

Conclusion

The results indicate that Leea indica was a promising antioxidant and anticancer agent for DU-145 and PC-3 human prostate cancer cell lines. However, further studies are needed to conclude its therapeutic use.

Evaluation of in vitro antioxidant and anticancer activity of Allophylus cobbe leaf extracts on DU-145 and PC-3 human prostate cancer cell lines

Allophylus cobbe (L.) Raeusch. belonging to the family Sapindaceae, is a commonly distributed small shrub in Western Ghats of India previously reported for its traditional medicinal properties. It is used for the treatment of various ailments. The present study is aimed at investigating preliminary phytochemicals, inducing the determination of the total phenolic contents, antioxidant assays and anticancer activity of A. cobbe leaf extracts on (DU-145) and (PC-3) cell lines. Preliminary phytochemical screening showed a broad spectrum of secondary metabolites. Highest amount of phenolic content was present in aqueous extract (91.96 ± 0.61 mg/g GAE) and it also proved to have the most potent antioxidant activity at a concentration of 100 mg/ml (64.71 ± 0.15%). IC₅₀ value was (431.10 ± 15.05 µg/mL) for DU-145 and (362.08 ± 24.17 µg/mL) for PC-3 cell lines while the standard drug paclitaxel showed an IC₅₀ value of 0.3 µM/mL. Morphological changes was observed in cancerous cells undergoing apoptosis in human prostate cancer cell lines (DU-145 and PC-3) while the extract showed no cytotoxicity towards normal cells (MEF-L929). It can be concluded that the tested extracts holds significant antioxidant and anticancer activities. However further investigation on lead compounds of A. cobbe will enable its therapeutic use.

Evaluation of Ajuga bracteosa for antioxidant, anti-inflammatory, analgesic, antidepressant and anticoagulant activities

Background

Ajuga bracteosa has been extensively used traditionally for the treatment of a variety of diseases. The aim of the study was to scientifically validate the wide-scale exploitation of A. bracteosa in folk medicine various in vitro and in vivo assays. Moreover, these activities were related to the intrinsic biologically active phytoecdysteroids of A. bracteosa.

Methods

Aerial and root parts of A. bracteosa were first extracted separately with chloroform (AbCA and AbCR) and the residue was again extracted with methanol (AbMA and AbMR). Total flavonoid and phenolic contents were assayed as quercetin (QE) and gallic acid equivalents (GAE), respectively. These extracts were analyzed for in vitro antioxidant assessment including DPPH and H₂O₂ (% inhibition of free radicals), and reducing power and phosphomolybdenum methods (ascorbic acid equivalents AAE mg/g DW). Further, these extracts were assayed in vivo in separate groups of Sprague–Dawley rats for carrageenan induced rat paw edema inhibition, hotplate antinociception, forced swim antidepression and anticoagulation. Dose of each crude extract and standard drug given to rats was 200 mg/Kg- and 10 mg/10 mL/Kg body weight respectively. Plant extracts and standard drugs were administered orally, 60 min prior to the conduction of assays. Moreover, biologically active phytoecdysteroids were screened in A. bracteosa with the help of RP-HPLC.

Results

AbMA represented highest values of flavonoids (QE 1.98 % DW) and phenolic contents (GAE 5.94 % DW), significantly scavenged DPPH radicles (IC₅₀ 36.9) and reduced ferric ions with 718.4 mg ascorbic acid equivalent/g (AAE). Highest total antioxidant capacity was expressed by AbMR (927 mg AAE) with an IC₅₀ value 19.1 μg/mL. The extracts which were found potent anti-oxidants, were also good at in vivo activities. AbMA significantly reduced edema in all the three hours of treatment (67.9, 70.3 and 74.3 %). AbMA also showed maximum nociceptor suppression in analgesic assay by delaying the time to start licking of paws in rats (57.7 ± 4.9 s). In addition, maximum anti-coagulation was also exhibited by AbMA (89.3 s), while all extracts were found strong antidepressants (≤15.66 s immobility time). Screening of biologically active phytoecdysteroids revealed the presence of 20-hydroxyecdysone (20-HE), makisterone (MKA), cyasterone (CYP) and ajujalactone (AJL). Total phytoecdysteroid content found in A. bracteosa was 1232.5 μg/g DW and 20-HE was most abundant (1232.5 μg/g DW) as compared to other phytoecdysteroids.

Conclusion

Based on the tested in vitro and in vivo activities, AbMA was found to be a promising bioactive extract. These activities can be attributed to the intrinsic polyphenols and phytoecdysteroids contents of A. bracteosa.

Effect of incorporation of Cyperus rotundus L. rhizome powder on quality attributes of minced beef meat

The primary objective of this study was to investigate the biological effectiveness of C. rotundus rhizome powder (CRRP) in improving the quality, storability, and safety of minced beef meat. CRRP was analyzed for its flavonoid and polyphenol content, antioxidants and antimicrobial activity, and its effect on the chemical properties, microbiological and sensory quality of minced beef meat. The results revealed that CRRP had a flavonoid and polyphenol contents of 24.30 mg CE/g and 353.10 mg GAE/g, respectively. The aqueous extract of CRRP showed inhibition zones of 16.3 and 11.7 mm against E. coli and S. aureus, respectively. The CRRP exhibited greater increase in TRPA, chelation of Fe²⁺ ions, and scavenging of H₂O₂ with the increase in CRRP extract concentration. Incorporation of various concentration of CRRP in minced beef meat significantly affected the physicochemical properties, microbial load, and sensory quality of the product. The effect was concentration dependent, and the highest level of CRRP (5 %) was more effective in retarding microbial growth and reducing peroxidation, but it negatively affected the sensory quality of the product. Therefore, CRRP at 2.5 % concentration was recommended as a functional additive to preserve minced meat.

Nicotine alkaloids as antioxidant and potential protective agents against in vitro oxidative haemolysis

The capacity of eleven nicotine alkaloids to reduce oxidative stress was investigated. In order to provide a structure-activity relationships analysis, new nicotine derivatives with a substituent introduced into the pyrrolidine ring were synthesized and investigated together with nicotine and its known analogs. All newly synthesized compounds were characterized by (1)H, (13)C NMR and EI-MS technique. The antioxidant properties of nicotine, its known analogs and newly produced derivatives, were evaluated by various antioxidant assays such 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH(•)) scavenging, ferrous ions (Fe(2+)) chelating activity and total reducing ability determination by Fe(3+) → Fe(2+) transformation assay. The protective effects of all compounds tested against 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH) and tert-butyl hydroperoxide (t-BuOOH)-induced oxidative haemolysis and morphological injury of human erythrocytes, were estimated in vitro. The results showed that nicotine alkaloids exhibited various antiradical efficacy and antioxidant activity in a structure- and a dose-dependent manner. In addition, the capacity of nicotine alkaloids to protect erythrocytes from AAPH- and t-BuOOH-induced oxidative haemolysis, was dependent on its incubation time with cells. Our findings showed that chemical and biological investigations conducted simultaneously can provide comprehensive knowledge concerning the antioxidant potential of nicotine alkaloids. This knowledge can be helpful in better understanding the properties of nicotine alkaloids under oxidative stress conditions.

The etiology of oxidative stress in the various species of animals, a review

Oxidative stress is the consequence of an imbalance of pro-oxidants and antioxidants leading to cell damage and tissue injury. The exhaustion of antioxidant systems is one of the reasons for the occurrence of oxidative stress, which results in avalanche production of reactive oxygen species (ROS) or free radicals. High oxidative stress is common in organs and tissues with high metabolic and energy demands, including skeletal and heart muscle, liver and blood cells. Stress arises in animals in response to unavoidable or adverse environmental conditions. In the external environment, which affects the body of the cow, there are four main groups of stressors: physical, chemical, biological and psychological. Physical stressors include fluctuations in ambient temperature as well as mechanical injuries. High ambient temperature is one of the factors affecting the productivity of cows. Biological stressors are conditioned by errors and irregularities in habits. Both of these phenomena have an adverse impact on both the resistance of animals and fertility and are the etiological agent of oxidative stress. Various mechanisms may be responsible for metal-induced oxidative stress: direct or indirect generation of ROS, depletion of glutathione and inhibition of antioxidant enzymes are well known for all redox-active and redox-inactive metals.

Epiphytic marine pigmented bacteria: A prospective source of natural antioxidants

Awareness on antioxidants and its significance in human healthcare has increased many folds in recent time. Increased demand requisite on welcoming newer and alternative resources for natural antioxidants. Seaweed associated pigmented bacteria screened for its antioxidant potentials reveals 55.5% of the organisms were able to synthesize antioxidant compounds. DPPH assay showed 20% of the organisms to reach a antioxidant zone of 1 cm and 8.3% of the strains more than 3 cm. Pseudomonas koreensis (JX915782) a Sargassum associated yellowish brown pigmented bacteria have better activity than known commercial antioxidant butylated hydroxytoluene (BHT) against DPPH scavenging. Serratia rubidaea (JX915783), an associate of Ulva sp. and Pseudomonas argentinensis (JX915781) an epiphyte of Chaetomorpha media , were also contributed significantly towards ABTS (7.2% ± 0.03 to 15.2 ± 0.09%; 1.8% ± 0.01 to 15.7 ± 0.22%) and FRAP (1.81 ± 0.01 to 9.35 ± 0.98; 7.97 ± 0.12 to 18.70 ± 1.84 μg/mL of AsA Eq.) respectively. 16S rRNA gene sequence analysis revealed bacteria that have higher antioxidant activity belongs to a bacterial class Gammaproteobacteria. Statistical analysis of phenolic contents in relation with other parameters like DPPH, ABTS, reducing power and FRAP are well correlated (p < 0.05). Results obtained from the current study inferred that the seaweed associated pigmented bacteria have enormous potential on antioxidant compounds and need to be extracted in a larger way for clinical applications.

Antioxidant, oxidative DNA damage protective and antimicrobial activities of the plant Trigonella foenum-graecum

BACKGROUND

The plant Trigonella foenum-gracecum (TFG) is used as antidiabetic and diuretic. In order to ascertain antioxidant potential of leaf (early and mature) and seed of TFG, total phenolics, free radical scavenging assay, superoxide anion radical scavenging activity, reducing power, lipid peroxidation, ferric thiocyanate assay, hydroxyl radical scavenging activity and DNA damage protective activities were determined. The study was further carried out to assay the antimicrobial activity and HPLC analysis of plant parts.

RESULTS

Ethanol extracts of leaf (early and mature) exhibited a high content of phenolics (54.79 and 41.28 g kg(-1) GAE) when it was compared with seed extract (23.85 g kg(-1) GAE). Results showed that mature TFG leaf extract had the lowest IC50 for the free radical scavenging assay (IC50 = 2.23 mg mL(-1)), superoxide anion radical scavenging activity (IC50 = 2.71 mg mL(-1)), hydroxyl radical scavenging activity (IC50 = 17.30 mg mL(-1)) and highest reducing power (10.14 ascorbic acid equivalents mL(-1)). However, the ethanol seed extract showed the maximum inhibition of lipid peroxidation and the ferric thiocyanate assay. Mature leaf also showed the maximum DNA damage protection activity and higher concentration of phytochemicals.

CONCLUSION

The results showed that the mature TFG leaf had a higher antioxidant activity, which may be due to the presence of total phenolics. It may be used in herbal drugs or as a nutritional supplement.

Role of Secondary Metabolites and Radical Scavenging Aptitude for Better Adaptability of Mangroves in Varying Salinity of Sundarbans, India

Comparative adaptability in five halophytes (Bruguiera gymnorrhiza, Excoecaria agallocha, Heritiera fomes, Phoenix paludosa and Xylocarpus granatum, of which, H. fomes and X. granatum presently are stressed in Sundarbans area) were evaluated with respect to occurrence of total phenol, flavonoids, and radical scavenging ability following ABTS [2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid)], DPPH (1, 1-diphenyl-2-picrylhydrazyl) assay and Fe2+ chelating ability. Amount of total phenol (TP) and flavonoids (TF) were much higher in all taxa grown in Sundarbans than those of mesophytic one. TP and TF were significantly augmented as the substrate salinity increased in B. gymnorrhiza, E. agallocha and P. paludosa but disordered in H. fomes and X. granatum, where increment occurred only up to a certain salinity level. Percent of free radical scavenging of extractants by DPPH and ABTS radical perceived significant correlation with salinity in former three but differ in H. fomes and X. granatum. Ferrous ion chelating ability also showed the similar trend. Owing to polyphenols occurrence and ROS scavengers, the present work clearly indicates the better adaptability of B. gymnorrhiza, E. agallocha and P. paludosa in elevated substrate salinity than those of the other two. Lower ROS scavenging ability of H. fomes and X. granatum also points to their perilous occurrence in elevated saline zones.

Phytochemical investigation and radical scavenging activities of Melia azedarach and its DNA protective effect in cultured lymphocytes

CONTEXT

Melia azedarach Linn (Meliaceae) is an Ayurvedic medicinal plant which is native to India. It is traditionally used for the treatment of leprosy, inflammation, scrofula, anthelmintic, antilithic, diuretic, deobstruent and cardiac disorders.

OBJECTIVE

To evaluate the phytochemical constituents and antioxidant activities of the ethanol leaf extract of Melia azedarach (MA) and its protective effect against H2O2-induced cellular damage in cultured lymphocytes.

MATERIALS AND METHODS

The dose-dependent study of MA (20, 40, 60, 80, 100 µg/ml) was used to study in vitro radical scavenging assays. The effective dose of MA (60 µg/ml) was further used to study the H2O2-induced DNA damage (comet assay and DNA fragmentation assay) in cultured lymphocytes.

RESULTS

The ethanol extract of MA (20, 40, 60, 80, 100 µg/ml) exhibited a significant dose-dependent inhibition of in vitro radical scavenging assays and their corresponding IC50 values as follows: hydroxyl radical (26.50 ± 0.26 µg/ml), superoxide anion (30.00 ± 0.32 µg/ml), nitric oxide radical (48.00 ± 0.48 µg/ml), DPPH radical (30.55 ± 0.32 µg/ml) and reducing power (22.00 ± 0.22 µg/ml). The increase in the severity of DNA damage and TBARS was increased significantly (p<0.05) at 500 µM H2O2-treated cultured lymphocytes and RBC cellular membranes. The phytochemical screening studies identified 13 chemical constituents present in the leaf extract of MA.

DISCUSSION AND CONCLUSION

The results of this study demonstrate that MA offers protection against H2O2-induced cellular damage and it can be developed as an effective antioxidant during oxidative stress.

Assessment of antioxidant potential, total phenolics and flavonoids of different solvent fractions of monotheca buxifolia fruit

OBJECTIVES

This study was conducted to investigate the antioxidant potential of methanol extract and its derived fractions (hexane, ethyl acetate, butanol, and aqueous) of fruits of Monotheca buxifolia (Falc.) Dc., a locally used fruit in Pakistan.

METHODS

Dried powder of the fruit of M. buxifolia was extracted with methanol and the resultant was fractionated with solvents having escalating polarity; n-hexane, chloroform, ethyl acetate, n-butanol and the residual soluble aqueous fraction. Total phenolic and total flavonoid contents were estimated for the methanol and various fractions. These fractions were also subjected to various in vitro assays to estimate the scavenging activity for 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), superoxide, hydroxyl, hydrogen peroxide and reductive ability for ferric ions and phosphomolybdate assay.

RESULTS

The n-butanol, aqueous and methanol fractions possessed high amount of phenolics and flavonoids compared with other fractions, and subsequently showed a pronounced scavenging activity on DPPH, ABTS, superoxide, hydroxyl and hydrogen peroxide radicals and had a potent reductive ability on ferric ion and phosphomolybdate assay. There was a found significant correlation between total phenolic and flavonoid contents and EC50 of DPPH, superoxide, hydrogen peroxide radical and phosphomolybdate assays, whereas a nonsignificant correlation was found with the hydroxyl radical and ABTS radical assay.

CONCLUSION

M. buxifolia fruit can be used as natural antioxidant source to prevent damage associated with free radicals.

Comparative antioxidant study of stem and stem induced callus of Phyllanthus fraternus webster-an important antiviral and hepatoprotective plant

Phyllanthus fraternus is widely used in the cure of various liver diseases and possess antiviral properties especially against hepatitis virus. In the present study, evaluation of the antioxidant activity of stem and calli induced from stem has been done by different assays. Extraction was done by standard method in water and ethanol. Total antioxidant capacity was measured by 1, 1-diphenyl-2-picrylhydrazyl free radical scavenging method. Lipid peroxidation was measured in terms of thiobarbituric acid-reactive substances (TBARS) by using egg yolk homogenates as lipid-rich media, and superoxide radical scavenging activity was measured using riboflavin-light-nitro blue tetrazolium assay. Reducing power was determined on the basis of Fe(3+)-Fe(2+) transformation in the presence of the extract. In addition to the antioxidant activity, polyphenolic compounds like total phenolics and flavonoids were also measured by spectroscopic method. Results showed that the ethanolic extract of stem is more potent in antioxidant activity than its aqueous extract and ethanolic extract of calli. A significant correlation between antioxidant capacity and polyphenolic content and reducing potential was observed, indicating that phenolic compounds and reducers present in extract are major contributors to the antioxidant potential. Thus, this plant extract could be used as a potent natural antioxidant.

Antioxidants and ROS scavenging ability in ten Darjeeling tea clones may serve as markers for selection of potentially adapted clones against abiotic stress

Ten Darjeeling tea clones (BT15/263, RR17/144, B777, T253, B157, Sundaram, HV39, AV2, K1/1 and TTV1) were collected from the experimental garden of Darjeeling Tea Research and Development Centre, Kurseong. Total phenol, flavonoids and two antioxidating enzymes (peroxidase and superoxide dismutase) were estimated. The total phenol ranged between 241 and 28 GAE mg g(-1) of leaf dry weight. The highest amount obtained in four clones, B15/263 (241.47), RR17/144 (221.2), B777 (154.54) and B157 (140.23 mg g(-1)). Flavonoids were estimated as Catechin equivalent (CE) and ranged between 56.88 and 20.81 CE mg g(-1) leaf dry weight. Higher amounts occurred in BT15/263 (56.88 mg g(-1)), B777 (56.69) and RR17/144 (48.63). Antioxidant activities were measured following DPPH and ABTS free radicle scavenging procedures and the results were well according to total polyphenol content among the clones (in total phenols, ranges of correlation in DPPH assay were r (2)  = 0.990-0.989, p ≤ 0.05; in flavonoids r (2)  = 0.954, p ≤ 0.01-0.987, p ≤ 0.05). Similarly, ABTS percent scavenging results were quiet significant. The IC50 values were determined for both DPPH and ABTS assay. PAGE expressions of isoforms in two antioxidative enzymes and quantification of them also varied much among the investigated clones. The incidence of total phenols, flavonoids, PRX and SOD and ROS scavenging assay in in-situ condition, might be used as biochemical markers towards the superior adaptability against abiotic stress. In the present work, four clones (B15/263, B777, RR17/144 and B157) would be designated as comparatively better suited to the predicted abiotic stress.

Isolation and characterization of biologically active melanin from Actinoalloteichus sp. MA-32

Melanins are enigmatic pigments and biological macromolecules that are produced by a wide variety of microorganisms including several species of bacteria and fungi. The present study was carried out on isolation and characterization of melanin from marine actinobacteria, Actinoalloteichus sp. MA-32. Medium composition and culture conditions for the melanin production by Actinoalloteichus sp. MA-32 were optimized using two statistical methods: Plackett-Burman design applied to find the key ingredients and conditions for the best yield of melanin production and central composite design used to optimize the concentration of the four significant variables: glycerol, L-tyrosine, NaCl and trace salt solution. The melanin was optimally active at pH 7-9 and temperature 45-60°C and it was most stable up to pH 11 and 4% of NaCl concentration. Melanin was examined by UV-vis absorption spectroscopy and infrared spectrometry. Melanin has potential antibacterial activity as it showed greater antagonistic and it has a strong antioxidant potential observed in the in vitro evaluation of its DPPH radical-scavenging activity, superoxide radical-scavenging activity, nitric oxide-scavenging activity, reducing power and metal chelating activity. The observed activities indicate that melanin might be a novel potential antioxidant. This study suggested that the melanin could potentially be used as a natural antioxidant in the food, cosmetic and pharmaceutical industries.