Salting-Out Assisted Liquid-Liquid Microextraction and Reverse-Phase Chromatographic Quantification of Two Neonicotinoid Insecticides from Fruits and Vegetables.

The present monograph describes the salting-out assisted liquid-liquid microextraction (SALLME) and reverse-phase high-performance liquid chromatography with diode array detector (RP-HPLC-DAD) based quantification of two frequently applied neonicotinoid insecticides, i.e., acetamiprid (ACE) and imidacloprid (IMD), from selected tropical fruits (citrus and guava) and vegetables (tomato, okra and cauliflower). The SALLME conditions like pH, liquid/solid ratio and salt ratio (NaCl/Na2SO4) were varied over a wide range of conditions for the enhanced recovery of IMD and ACE from spiked quality control (low, high and medium) of fruits and vegetables. Meanwhile, RP-HPLC-DAD quantification of IMD and ACE was found to be linear over 1-100 µg/L with the coefficient of determination (R2) value ≥0.997 and slope of the calibration curve (sensitivity) ≥2.3 × 104 peak area unit (µAu). The analysis of selected fruits and vegetables after 0 (1 h), 1, 3, 7, 10 and 14 days of foliar application revealed the presence of IMD and ACE residues in okra and guava higher than maximum residual limits set by the Codex Alimentarius Commission until the third day of spray. Overall, the SALLME-RP-HPLC-DAD was found to be a rapid, selective and expedient choice for the routine analysis of neonicotinoids in environmental and food commodities.

Isolation and characterization of novel antihypertensive bioactive peptides from brassica napus and angiotensin-converting enzyme (ace) inhibition potential.

Present study aimed to explore the antihypertensive potential of bioactive peptides isolated from Brassica napus protein as inhibitor of angiotensin converting enzyme. Protein was extracted and assessed for antihypertensive potential. The extracted protein showed 72% antihypertensive activity/potential with IC50 value of 24±5.60µg/mL. Thirty-one fractions of peptides were isolated by hydrolyzing protein at different time intervals, pH, temperature and enzyme/substrate ratio. The antihypertensive potential of all isolated fractions was measured. It was found that only one peptide fraction exhibited significantly high (75%) antihypertensive potential. This hydrolyzed fraction was characterized through Liquid-Chromatography-Electrospray-Ionization-Mass-Spectrometry (LC-ESI-MS/MS). Eleven bioactive peptides were identified in hydrolyzate of Brassica napus which include Serine-Threonine, Methionine-Valine, Methionine-Leucine, Glutamine-Phenylalanine, Alanine-Threonine-Phenylalanine, Alanine-Leucine-Proline-Glycine, Valine-Alanine-Phenylalanine-Glycine, Aspartic acid-Proline-Methionine-Glutamine, Valine-Glutamine-Cysteine-Tyrosine, Methionine-Cysteine-Tyrosine-Tyrosine-Phenylalanine and Alanine-Leucine-Leucine-Alanine-Cysteine-Proline-Alanine. The current study showed that Brassica napus is an important food, having high amount of bioactive peptides with high antihypertensive potential, can control blood pressure very efficiently.

Incidence and Prevalence of Drug-Resistant Epilepsy: A Systematic Review and Meta-analysis.

OBJECTIVE: To evaluate the incidence and prevalence of drug-resistant epilepsy (DRE) as well as its predictors and correlates, we conducted a systematic review and meta-analysis of observational studies. METHODS: Our protocol was registered with PROSPERO, and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Meta-analysis of Observational Studies in Epidemiology reporting standards were followed. We searched MEDLINE, Embase, and Web of Science. We used a double arcsine transformation and random-effects models to perform our meta-analyses. We performed random-effects meta-regressions using study-level data. RESULTS: Our search strategy identified 10,794 abstracts. Of these, 103 articles met our eligibility criteria. There was high interstudy heterogeneity and risk of bias. The cumulative incidence of DRE was 25.0% (95% confidence interval [CI]: 16.8-34.3) in child studies but 14.6% (95% CI: 8.8-21.6) in adult/mixed age studies. The prevalence of DRE was 13.7% (95% CI: 9.2-19.0) in population/community-based populations but 36.3% (95% CI: 30.4-42.4) in clinic-based cohorts. Meta-regression confirmed that the prevalence of DRE was higher in clinic-based populations and in focal epilepsy. Multiple predictors and correlates of DRE were identified. The most reported of these were having a neurologic deficit, an abnormal EEG, and symptomatic epilepsy. The most reported genetic predictors of DRE were polymorphisms of the ABCB1 gene. CONCLUSIONS: Our observations provide a basis for estimating the incidence and prevalence of DRE, which vary between populations. We identified numerous putative DRE predictors and correlates. These findings are important to plan epilepsy services, including epilepsy surgery, a crucial treatment option for people with disabling seizures and DRE.

Isolation and characterization of antihypertensive peptides from soy bean protein

Proteins and peptides are the most diverse biomolecules found in nature and make our interest due to their wide applications in food and pharmaceutical industry. Angiotensin Converting Enzyme (ACE) plays a major role in controlling blood pressure. The inhibition of ACE with peptides is a main target in the regulation of hypertension. The objective of the present study was to investigate the therapeutic potential of soy bean. This was accomplished by isolation of ACE inhibitory peptides using response surface methodology (RSM) and characterization of these bioactive peptides by mass spectrometry. 31 hydrolyzed fractions were isolated and evaluated for their ACE inhibition potential. Hydrolyzed fraction having highest ACE inhibitory activity was characterized by liquid chromatography-mass spectrometry (LC-MS) technique. RSM results showed maximum ACE inhibition potential (64%) by hydrolyzate was obtained at 45 ºC temperature, pH 8.0, E/S 0.2 in 2 hours hydrolysis time. Results of LC-MS analysis revealed Ser-Gly, Ser-Pro, Met-Ala, His-Ala, Lys-Pro, Phe-Thr, Met-Leu, Pro-Arg, Ala-Pro-Val, Pro-Ala-Leu, Val-Met-Gly, Pro-Leu-Val, Pro-Pro-Gln, His-Arg-Gly, Ser-Phe-Val-Leu, Ala-Val-His-Try, Arg-Thr-Val-Arg, His-His-Tyr-Leu-Val, Asp-Gly-Ala-Cys-Ser-Ala-Asn and MetVal-Thr-Gly-Pro-Gly-Cys-His bioactive peptides in hydrolyzed fraction of soy bean. Our data provide evidence that response surface methodology is a good approach for isolation of antihypertensive bioactive peptides with more potent activity as nutraceuticals or pharmaceuticals. Therefore soy bean can be use for industrial production of pharmaceutical grade natural medicines for handling high blood pressure.

Identification of Hypotensive Biofunctional Compounds of Coriandrum sativum and Evaluation of Their Angiotensin-Converting Enzyme (ACE) Inhibition Potential.

The aim of this study was to identify and characterize the bioactive compounds of Coriandrum sativum responsible for the treatment of hypertension and to explore their mechanism of action as angiotensin-converting enzyme (ACE) inhibitors. Bioactive fractions like alkaloids, flavonoids, steroids, and tannins were extracted and evaluated for their ACE inhibition potential. Among them, only flavonoid-rich fraction showed high ACE inhibition potential with IC50 value of 28.91 ± 13.42 µg/mL. The flavonoids were characterized through LC-ESI-MS/MS. Seventeen flavonoids were identified in this fraction of Coriandrum sativum in negative ionization mode which includes pinocembrin, apigenin, pseudobaptigenin, galangin-5-methyl ether, quercetin, baicalein trimethyl ether, kaempferol dimethyl ether, pinobanksin-5-methylether-3-O-acetate, pinobanksin-3-O-pentenoate, pinobanksin-3-O-phenylpropionate, pinobanksin-3-O-pentanoate, apigenin-7-O-glucuronoide, quercetin-3-O-glucoside, apigenin-3-O-rutinoside, rutin, isorhamnetin-3-O-rutinoside, and quercetin dimethyl ether-3-O-rutinoside, while six flavonoids including daidzein, luteolin, pectolinarigenin, apigenin-C-glucoside, kaempferol-3-7-dimethyl ether-3-O-glucoside, and apigenin-7-O-(6-methyl-beta-D-glucoside) were identified in positive ionization mode. The results of this study revealed that Coriandrum sativum is a valuable functional food that possesses a number of therapeutic flavonoids with ACE inhibition potential that can manage blood pressure very efficiently.

LC-ESI-MS/MS based characterization of phenolic components in fruits of two species of Solanaceae.

The present work appraises the phenolic profile of fruit extracts from two species (Solanum indicum and Solanum surattense) of Solanaceae. The bioactive components from both the species were extracted with different concentrations of acidified (hydrolysis) and aqueous methanol (non-hydrolyzed) and analyzed for the total phenolics calorimetrically. The hydrolyzed extracts of both the species were characterized for phenolic compounds profiling using LC-ESI-MS/MS. The hydrolysis of fruit samples produced greater extract yield (31.9-50.7%) and total phenolics (250.4-289.5 mg GAE/g of extract) than non-hydrolyzed (11.1-19.2 and 161.5-171.2, respectively). The hydrolyzed extracts from both the species, with higher contents of total phenols were analyzed for phenolic profiling using LC-ESI-MS/MS technique and the data authenticated the presence of caftaric acid, ellagic acid, myricetin, apigenin-7-glucoside and methoxy chrysin in S. indicum while isoquercitrin, gallocatechin, quercetin and catechin in S. surattense. The current study explores the profile of valuable phenolic bioactives of the selected species of Solanaceae, thereby supporting their potential applications as ingredients of functional foods and neutraceuticals.

Escalation of liver malfunctioning: A step toward Herbal Awareness.

ETHNOPHARMACOLOGICAL RELEVANCE: About 2-5% of the world's population is suffering from liver toxicity including Pakistan with the second highest rate of hepatitis prevalence. Liver is a vital body organ which not only performs metabolic activities but also aids in detoxification, storage and digestion of food. Now a day's malnutrition, alcohol consumption and drug addiction are major causes of liver diseases throughout the world. In fact, there is no possible outcome to compensate liver malfunction for long term, and transplantation of liver is the only option left after the irretrievable injury of hepatic function. Subsequently, natural based therapeutic approaches are in the process of scrupulous testing as strong hepatoprotective mediator. In this regard plants are well thought hepatoprotective agents having multiple active components. In this review, based on species' pharmacology and safety we have compiled some plants which show strong hepatoprotective activity, main phytoconstituents with biological activities and few commercially used herbal formulations. MATERIALS AND METHODS: Ethnopharmacological information was gathered by an extensive literature survey like WHO monographs on selected herbal medicinal plants (Vol 1-Vol 4); Principles and Practice of Phytotherapy, Mills S and Bone K, Churchill Livingstone, London, UK; Herbal Drugs and Phytopharmaceuticals, Wichtl M Medpharm Press, Stuttgart 3rd edn; Pharmacology and Applications of Chinese Materia Medica Vols 1 and 2, Chang H-M and But P P-H World Scientific, Singapore; British Herbal Compendium Vol. 2, Bradley P British Herbal Medicine Association, Bournemouth, UK; ESCOP Monographs 2nd edn. Thieme, Stuttgart, Germany; as well as by using electronic databases such as Pubchem, Chemspider, http://www.herbal-ahp.org; http://www.ahpa.org; http://whqlibdoc.who.int/publications/2003/9241546271.pdf; http://www.escop.com, Pubmed, HubMed and Scopus. RESULTS: Data for more about 29 plants have been accomplished for their bioactive constituent(s), biological activities and medicinal uses. Some of the plants have been identified as strong hepato-modulator. Such knowledge about traditional medicinal plants can be globally applied for safe and evidence based use in pharmacological applications. CONCLUSION: With the rise in liver risks a meek struggle has been made to draw attention toward herbal therapy. Hepatoprotective constituents of said plants are expressed with chemical structures. However, for certain plants active constituents are not still isolated/purified but overall plant extract was found effective in providing protection against hepatic injury. As a future perspective, there is need to purify plant active constituents for ethnomedical rationale.

Enzyme-assisted supercritical fluid extraction: an alternative and green technology for non-extractable polyphenols.

This contribution proposes an enzyme-assisted eco-friendly process for the extraction of non-extractable polyphenols (NEPPs) from black tea leftover (BTLO), an underutilized tea waste. BTLO hydrolyzed with various enzyme formulations was extracted using supercritical carbon dioxide and ethanol as co-solvent (SC-CO2 + EtOH). A conventional solvent extraction (CSE) was performed using EtOH + H2O (80:20, v/v) for comparison purposes. The results revealed that hydrolysis of BTLO with 2.9% (w/w) kemzyme at 45 °C and pH 5.4 for 98 min improved the liberation of NEPPs offering 5-fold higher extract yield (g/100 g) as compared with non-treated BTLO. In vitro antioxidant evaluation and LC-MS characterization of extracts revealed the presence of phenolic acids (mainly caffeic and para-coumaric acid) of high antioxidant value. Scanning electron micrograph of the hydrolyzed BTLO samples indicated noteworthy changes in the ultrastructure of BTLO. Moreover, polyphenol extracts obtained by SC-CO2 + EtOH extraction were found to be cleaner and richer in polyphenols as compared to CSE. The devised enzyme-assisted SC-CO2 + EtOH extraction process in the present work can be explored as an effective biotechnological mean for the optimal recovery of antioxidant polyphenols. Graphical abstract Enzymatic pretreatment can effectively liberate non-extractable polyphenols (NEPPs) while hydrolyzing the cellulosic and hemicellulosic framework of black tea left overs (BTLO).

Antioxidant and genoprotective activity of selected cucurbitaceae seed extracts and LC-ESIMS/MS identification of phenolic components.

Cucurbitaceae are one of most widely used plant species for human food but lesser known members have not been examined for bioactive components. The purpose of this study was to evaluate the antioxidant and genoprotective activities from three cucurbitaceae seeds extracts and to identify phenolic components by LC-ESIMS/MS analysis. From the results, the yield of seeds extract was 20-41% (w/w) and samples had 16-40% total phenols as gallic acid equivalents (GAE). Compared with methanol solvent, using acidified methanol led to increased extraction yield by 1.4 to 10-fold, higher phenolic content (149.5 ± 1.2 to 396.4 ± 1.9 mg GAE/g), higher DPPH radical quenching and enhanced genoprotective activity using the pBR322 plasmid assay. LC-ESI-MS/MS analysis led to identification of 14-17 components, based on authentic standards and comparison with literature reports, as mainly phenolic acids and esters, flavonol glycosides. This may be the first mass spectrometric profiling of polyphenol components from cucurbitaceae seeds.

Variation in biochemical and antioxidant attributes of Raphanus sativus in response to foliar application of plant leaf extracts as plant growth regulator.

The present study was aimed to appraise the variations in biochemical, antioxidant and nutritional attributes of radish (Raphanus sativus L.) under foliar application of plant leaf aqueous extracts i.e., mulberry leaf extract (MLE), brassica leaf extract (BLE), sorghum leaf extract (SLE) and moringa leaf extract (MoLE) as natural growth regulators. Samples were collected after three sprays of extracts and analyzed. Total phenolic constituents were determined using Folin-Ciocalteu reagent method, whereas antioxidant potential was evaluated by 1,1 diphenyl-2-picrylhydrazyl radical radical scavenging and reducing power assays. Results revealed that application of MLE, BLE, SLE, and MoLE not only improved growth, but also enhanced biochemical and antioxidant activities. Foliar spray of MoLE furnished relatively three folds higher amounts of extractable bioactive compounds (37.65 ± 0.94%), phenolic constituents (54.51-182.71 mg GAE/g f.w). The radical scavenging capacity (RSC) and reducing potential were also enhanced considerably. Furthermore, the moisture, dietary fiber, crude protein, and carotenoids were also enhanced in response of foliar spray of plant extracts. From results, it is concluded that plant extracts are effective sources of natural growth regulars and might be useful for the production of vegetables with improved nutritional value and antioxidant activity.

RSM based optimized enzyme-assisted extraction of antioxidant phenolics from underutilized watermelon (Citrullus lanatus Thunb.) rind.

Enzyme assisted solvent extraction (EASE) of phenolic compounds from watermelon (C. lanatus) rind (WMR) was optimized using Response Surface Methodology (RSM) with Rotatable Central Composite Design (RCCD). Four variables each at five levels i.e. enzyme concentration (EC) 0.5-6.5 %, pH 6-9, temperature (T) 25-75 °C and treatment time (t) 30-90 min, were augmented to get optimal yield of polyphenols with maximum retained antioxidant potential. The polyphenol extracts obtained under optimum conditions were evaluated for their in-vitro antioxidant activities and characterized for individual phenolic profile by RP-HPLC-DAD. The results obtained indicated that optimized EASE enhanced the liberation of antioxidant phenolics up to 3 folds on fresh weight basis (FW) as compared to conventional solvent extraction (CSE), with substantial level of total phenolics (173.70 mg GAE/g FW), TEAC 279.96 mg TE/g FW and DPPH radical scavenging ability (IC50) 112.27 mg/mL. Chlorogenic acid (115.60-1611.04), Vanillic acid (26.13-2317.01) and Sinapic acid (113.01-241.12 µg/g) were major phenolic acid found in EASEx of WMR. Overall, it was concluded that EASE might be efficient and green technique to revalorize under-utilized WMR into potent antioxidant phenolic for their further application in food and nutraceutical industries.

Utilization of waste fruit-peels to inhibit aflatoxins synthesis by Aspergillus flavus: a biotreatment of rice for safer storage.

Antifungal activity in lemon and pomegranate peels was considerable against Aspergillus flavus, higher in pomegranate (DIZ 37mm; MIC 135µg/mL). Powdered peels (5, 10, 20% w/w) were mixed in inoculated rice. The inhibitory effect on fungal-growth and production of aflatoxins by A. flavus was investigated at storage conditions - temperature (25, 30°C) and moisture (18%, 21%) for 9months. The maximum total aflatoxins accumulated at 30°C, 21% moisture and at 25°C, 18% moisture were 265.09 and 163.45ng/g, respectively in control. Addition of pomegranate-peels inhibited aflatoxins production to 100% during four month-storage of rice at 25°C and 18% moisture, while lemon-peels showed similar inhibitory effect for 3months at same conditions. However a linear correlation was observed in aflatoxins level with temperature and moisture. Studies showed that both fruit-wastes are potent preventer of aflatoxin production in rice, useful for a safer and longer storage of rice.

In vitro antimutagenic, antioxidant activities and total phenolics of clove (Syzygium aromaticum L.) seed extracts.

The present work explores antimutagenic and antioxidant potential as well as total phenolics of aqueous and acidified methanol extractable components from clove (Syzygium aromaticum L.) seed. The magnitude of antimutagenic activity of clove seed extracts (CSE) against two mutant bacterial strains: S. typhimurium TA98 and S. typhimurium TA100 (Ames bacterial test) ranged from 34.11-79.74%. Antioxidant activity in terms of measurement of DPPH radical scavenging capacity and inhibition of linoleic acid peroxidation was noted to be 71.16-94.58% and 54.96-86.89%, respectively. CSE also exhibited an appreciable amount of total phenolics with contribution between 22.80 and 115.33 GAE mg/100g. A strong correlation between total phenolics and tested biological activities were recorded. The results of this study advocate that clove seed can be explored as a viable source of bioactives for the development of chemotherapeutic drugs against cancer in addition to acting as nutraceutical and functional food ingredient.

In vitro Antioxidant Activities of Trianthema portulacastrum L. Hydrolysates.

Hydrolysates of Trianthema portulacastrum in acidified methanol were evaluated for their total phenolic (TP) constituents and respective antioxidant activities using in vitro assays (i.e., 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, percent inhibition of linoleic acid peroxidation, and ferric reducing power). The observed results indicate that root, shoot, and leaf fractions of T. portulacastrum contain 50.75~98.09 mg gallic acid equivalents/g dry weight of TP. In addition, these fractions have substantial reducing potentials (0.10~0.59), abilities to inhibit peroxidation (43.26~89.98%), and DPPH radical scavenging capabilities (6.98~311.61 µg/mL IC50). The experimental data not only reveal T. portulacastrum as potential source of valuable antioxidants, but also indicate that acidified methanol may be an ideal choice for the enhanced recovery of phenolic compounds with retained biological potential for the food and pharmaceutical industry.

Variation in antioxidant and antimicrobial activities in Lantana camara L. flowers in relation to extraction methods.

BACKGROUND: The present work was designed to appraise how different extraction solvents and techniques affect the extractability of antioxidant and antimicrobial components from Lantana camara (L. camard) flowers. MATERIAL AND METHODS: Four extraction solvents including 100% methanol, 80% methanol, 100% ethanol and 80% ethanol coupled with three extraction techniques namely stirring, microwave-assisted stirring and ultrasonic-assisted stirring employed to isolate extractable components from the flowers of L. camara. The extracts produced were evaluated for their antioxidant and antimicrobial attributes. RESULTS AND DISCUSSION: The yield of extractable components varied over a wide range 4.87-30.00% in relation to extraction solvent and techniques. The extracts produced contained considerable amounts of total phenolics (8.28-52.34 mg GAE/100 g DW) and total flavonoids (1.24-7.88 mg CE/100 g DW). Furthermore, a promising antioxidant activity in terms of DPPH° scavenging, inhibition of linoleic acid peroxidation and reducing power, as well as antimicrobial potential of the extracts were recorded against the selected bacterial and fungal strains. CONCLUSIONS: It was concluded that both extraction solvent and techniques employed affected the antioxidant and antimicrobial attributes of the extracts from L. camara flowers. With few exceptions, overall methanolic extracts produced by ultrasonic-assisted stirring offered superior activities followed by the microwave-assisted stirring and then stirring. The results advocate the use of appropriate extraction strategies to recover potent antioxidant and antimicrobial agents from the flowers of L. camara for nutraceutical and therapeutic.

Occurrence of aflatoxins in selected processed foods from Pakistan.

A total of 125 (ready to eat) processed food samples (70 intended for infant and 55 for adult intake) belonging to 20 different food categories were analyzed for aflatoxins contamination using Reverse Phase High Performance Liquid Chromatography (RP-HPLC) with fluorescent detection. A solvent mixture of acetonitrile-water was used for the extraction followed by immunoaffinity clean-up to enhance sensitivity of the method. The limit of detection (LOD) (0.01-0.02 ng·g(-1)) and limit of quantification (LOQ) (0.02 ng·g(-1)) was established for aflatoxins based on signal to noise ratio of 3:1 and 10:1, respectively. Of the processed food samples tested, 38% were contaminated with four types of aflatoxins, i.e., AFB1 (0.02-1.24 µg·kg(-1)), AFB2 (0.02-0.37 µg·kg(-1)), AFG1 (0.25-2.7 µg·kg(-1)) and AFG2 (0.21-1.3 µg·kg(-1)). In addition, the results showed that 21% of the processed foods intended for infants contained AFB1 levels higher than the European Union permissible limits (0.1 µg·kg(-1)), while all of those intended for adult consumption had aflatoxin contamination levels within the permitted limits.

Investigation on the antioxidant activity of leaves, peels, stems bark, and kernel of mango (Mangifera indica L.).

Bioactive polyphenols, cartenoids, and anthocyanins present in fruits and vegetables are receiving much attention because of their potential antioxidant activity. This study was conducted to determine antioxidant activity of leaves, peels, stem bark, and kernel of mango varieties langra and chonsa. Total phenolic (TPC) and total flavonoid contents (TFCs) in segments of langra ranged from 63.89 to 116.80 mg GAE/g DW and 45.56 to 90.89 mg CE/g DW, respectively, and that of chonsa were 69.24 to 122.60 mg GAE/g DW and 48.43 to 92.55 mg CE/g DW, respectively. The 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and linoleic inhibition capacity in segments of langra ranged from 53.30% to 61.10% and 40.0% to 47.20%, respectively, whereas for chonsa; 56.40% to 66.0% and 48.1% to 49.0%, respectively. The reducing potentials of different segments of langra and chonsa at concentration of 10 mg/mL were 0.512 to 0.850 and 0.595 to 0.665 mV, respectively. Comparison between both varieties showed chonsa exhibited better antioxidant activity. Data were analyzed by analysis of variance (ANOVA) using completely randomised design (CRD) under factorial.

Variation in antioxidant attributes at three ripening stages of guava (Psidium guajava L.) fruit from different geographical regions of Pakistan.

The present investigation was carried out to appraise the levels of total phenols and vitamin C as well as antioxidant potential at three different ripening stages (un-ripe, semi-ripe and fully-ripe) of guava (Psidium guajava L.) fruit collected from three different geographical regions of Pakistan (Islamabad, Faisalabad and Bhakkar). The antioxidant potential of guava fruit extracts was assessed by means of different in-vitro antioxidant assays, namely inhibition of peroxidation in linoleic acid system, reducing power and radical scavenging capability. Overall, fruit at the un-ripe stage (G1) exhibited the highest levels of TPC, TFC, reducing power and DPPH radical scavenging activity, followed by the semi-ripe (G2) and fully-ripe (G3) stages. On the other hand, vitamin C content increased as the fruit maturity progressed, with highest value seen at the fully-ripe stage (G3) followed by the semi-ripe (G2) and un-ripe stage (G1). The concentration of vitamin C in fruits varied as: Faisalabad (136.4-247.9 mg 100 g⁻¹), Islamabad (89.7-149.7 mg 100 g⁻¹) and Bhakkar (73.1-129.5 mg 100 g⁻¹). The results showed that different stages of maturation and geographical locations had profound effects on the antioxidant activity and vitamin C contents of guava fruit.

Antioxidant and antimicrobial attributes and phenolics of different solvent extracts from leaves, flowers and bark of Gold Mohar [Delonix regia (Bojer ex Hook.) Raf].

This paper describes the antioxidant and antimicrobial activities and phenolic components of different solvent (absolute methanol, absolute ethanol, absolute acetone, 80% methanol, 80% ethanol, 80% acetone and deionized water) extracts of leaves, flowers and bark of Gold Mohar [Delonix regia (Bojer ex Hook.) Raf.]. The extract yields from leaves, flowers and bark ranged from 10.19 to 36.24, 12.97 to 48.47 and 4.22 to 8.48 g/100 g dry weight (DW), respectively. Overall, 80% methanol extract produced from the leaves exhibited significantly (P < 0.05) higher antioxidant activity, with high phenolic contents (3.63 g GAE/100 g DW), total flavonoid contents (1.19 g CE/100 g DW), inhibition of peroxidation (85.54%), DPPH scavenging capacity (IC(50) value 8.89 µg/mL) and reducing power (1.87). Similarly, this 80% methanol leaves extract also showed superior antimicrobial activity. HPLC analysis of the 80% methanol extracts for individual phenolics revealed the presence of gallic, protocatechuic and salicylic acid in leaves; gallic, protocatechuic, salicylic, trans-cinnamic and chlorogenic acid in flowers, and gallic acid in bark as the main (amount > 1.50 mg/100 g DW) phenolic acids. Besides, small amounts ( < 1.50 mg/100 g DW) of some other phenolic acids such as sorbic, sinapic, p-coumaric, m-coumaric, ferulic, caffeic, 3-hydroxybenzoic, 4-hydroxycinnamic and 4-hydroxybenzoic acids were also detected. The extracts of the tested parts of Gold Mohar, especially, the leaves, might be valuable for functional food and therapeutic applications.

Effect of extraction solvent/technique on the antioxidant activity of selected medicinal plant extracts.

Theeffects of four extracting solvents [absolute ethanol, absolute methanol, aqueous ethanol (ethanol: water, 80:20 v/v) and aqueous methanol (methanol: water, 80:20 v/v)] and two extraction techniques (shaking and reflux) on the antioxidant activity of extracts of barks of Azadirachta indica, Acacia nilotica, Eugenia jambolana, Terminalia arjuna, leaves and roots of Moringa oleifera, fruit of Ficus religiosa,and leaves of Aloe barbadensis were investigated. The tested plant materials contained appreciable amounts of total phenolic contents (0.31-16.5 g GAE /100g DW), total flavonoid (2.63-8.66 g CE/100g DW); reducing power at 10 mg/mL extract concentration (1.36-2.91), DPPH(.) scavenging capacity (37.2-86.6%), and percent inhibition of linoleic acid (66.0-90.6%). Generally higher extract yields, phenolic contents and plant material antioxidant activity were obtained using aqueous organic solvents, as compared to the respective absolute organic solvents. Although higher extract yields were obtained by the refluxing extraction technique, in general higher amounts of total phenolic contents and better antioxidant activity were found in the extracts prepared using a shaker.