Rutin Research Articles

Stealth lipid polymer hybrid nanoparticles loaded with rutin for effective brain delivery – comparative study with the gold standard (Tween 80): optimization, characterization and biodistribution

The blood–brain barrier is considered the leading physiological obstacle hindering the transport of neurotherapeutics to brain cells. The application of nanotechnology coupled with surfactant coating is one of the efficacious tactics overcoming this barrier. The aim of this study was to develop lipid polymer hybrid nanoparticles (LPHNPs), composed of a polymeric core and a phospholipid shell entangled, for the first time, with PEG-based surfactants (SAA) viz. TPGS or Solutol HS 15 in comparison with the gold standard Tween 80, aiming to enhance brain delivery and escape opsonization. LPHNPs were successfully prepared using modified single-step nanoprecipitation technique, loaded with the flavonoid rutin (RU), extracted from the flowers of Calendula officinalis L., and recently proved as a promising anti-Alzheimer. The effect of the critical process parameters (CPP) viz. PLGA amount, Wlecithin/WPLGA ratio, and Tween 80 concentration on critical quality attributes (CQA); entrapment, size and size distribution, was statistically analyzed via design of experiments, and optimized using the desirability function. The optimized CPP were maintained while substituting Tween 80 with other PEG-SAA. All hybrid particles exhibited spherical shape with perceptible lipid shells. The biocompatibility of the prepared NPs was confirmed by hemolysis test. The pharmacokinetic assessments, post-intravenous administration to rats, revealed a significant higher RU bioavailability for NPs relative to drug solution. Biodistribution studies proved non-significant differences in RU accumulation within brain, but altered phagocytic uptake among various LPHNPs. The present study endorses the successful development of LPHNPs using PEG-SAA, and confirms the prospective applicability of TPGS and Solutol in enhancing brain delivery.

New combination between chitosan, single walled carbon nanotubes and neodymium(iii) oxide found to be useful in the electrochemical determination of rutin in the presence of morin and quercetin

A glassy carbon electrode surface was modified with a new combination of chitosan, single walled carbon nanotubes (SWCNT) and neodymium(iii) oxide (NdOX) and was found to be effective in the detection of rutin (RU).

The quantification of phytochemical constituents and in-vitro antioxidant activity of the crude extracts of Mesua ferrea L. (seeds)

Objective: To investigate the quantification of total phenolic, flavenoid content and in-vitro antioxidant activity of the hexane and ethanol extracts of Mesua ferrea (Seeds). Methods: The quantification of the total phenolic and flavonoid contents were estimated by taking gallic acid and rutin as a standard; In-vitro antioxidant activity was evaluated for extracts by using DPPH assay. Results: The hexane extract of M. ferrea (Seeds) have more phenolic and flavonoid content than other extracts. The selected plant extracts were produced concentration dependent percentage inhibition of different free radicals and produced maximum activity at a concentration of 700 g and there after the percentage inhibition were raised gradually to its maximum level with higher concentrations. Conclusion: In the present study we found that the extracts of M. Ferrea (Seeds) showed good antioxidant activity. Among the two extracts Hexane extract showed better activity than the other extract.

Identification and quantification of flavonoids in Carica papaya leaf and peroxynitrite-scavenging activity

ObjectiveTo characterize the types, contents, and peroxynitrite-scavenging activities of flavonoids in the leaf of Carica papaya (C. papaya). MethodsChromatographic and spectroscopic techniques along with high performance liquid chromatography quantitative analysis and peroxynitrite-scavenging assay were performed to isolate and quantify flavonoid compounds in the flavonoid-rich fraction (BuOH fraction) derived from MeOH extract of C. papaya leaves and evaluate their peroxynitrite-scavenging activities. ResultsSeven flavonoids were isolated from the leaves of C. papaya, including quercetin 3-(2G-rhamnosylrutinoside), kaempferol 3-(2G-rhamnosylrutinoside), quercetin 3-rutinoside, myricetin 3-rhamnoside, kaempferol 3-rutinoside, quercetin, and kaempferol. All of the substances exhibited potent activities on peroxynitrite scavenging (IC50 ≤ 4.15 μmol/L), which were stronger than the positive control, l-penicillamine (6.90 μmol/L). The content of kaempferol 3-(2G-rhamnosylrutinoside) was significantly higher than other identified compounds (123.18 mg/g BuOH fraction and 7.23 mg/g MeOH extract). ConclusionsThe results of the present study demonstrate the potent antioxidant flavonoids of C. papaya leaf, with kaempferol 3-(2G-rhamnosylrutinoside) as the major one.

Effect of rutin against a mitochondrial toxin, 3-nitropropionicacid induced biochemical, behavioral and histological alterations-a pilot study on Huntington's disease model in rats.

Dietary compounds like flavonoids may offer protection against neurodegeneration. Huntington's disease (HD) is a neurodegenerative disorder characterized by symptoms like chorea and dementia. 3-Nitropropionic acid (3-NP), a Succinate dehydrogenase (SDH) inhibitor produces behavioral, biochemical and histological changes in the striatum, mimics HD in animals and humans. The present study was designed to examine the protective activity of Rutin (RT), a primary flavonoid from citrus fruits, green tea on 3-NP induced experimental model of HD in rats. Rats were pretreated with Rutin, a potent antioxidant (25 and 50mg/kg b.w.) orally prior to the intraperitoneally (i.p.) administration of 3-NP (10mg/kg b.w.) for 14days. Behavioral assessments were carried out on 5th, 10th and 15th day after 3-NP treatment. Body weight, biochemical and histological studies were analyzed on 15th day. Systemic administration of 3-NP significantly reduced the body weight, locomotor activities (Rota rod, Open field test), memory (Morris water maze) and antioxidants such as Glutathione (GSH) levels, activities of Superoxide dismutase (SOD), Catalase (CAT), Glutathione peroxidase (GPx), Glutathione-S-transferase (GST), Glutathione reductase (GR). 3-NP also produces striatal damage by increased the levels of lipid peroxides, nitrite, Glial Fibrillary Acidic Protein (GFAP) and activity of Acetylcholine esterase (AchE). Thus, Rutin treatment of 25 and 50mg/kg b.w. has significantly restored all the biochemical, behavioral and histological alterations caused by the 3-NP through its antioxidant activity. The findings of our study indicates that Rutin may have an important role in protecting the striatum from oxidative/nitrosative insults caused by 3-NP. These results suggest that RT might be a drug of choice to treat HD.

HPTLC and IR Spectral studies of the ethanolic extract of Phallusia nigra

Ascidians, commonly called as Sea Squirts are sedentary tunicates. Phallusia nigra is a simple ascidian belonging to the family Ascidiidae found in plenty throughout the year. The ethanolic extract of Phallusia nigra was subjected to HPTLC and IR spectral analysis to determine the possible bioactive components. In HPTLC studies, gallic acid, ferulic acid, caffeic acid and flavonoids such as rutin, isoquercitrin and quercetin were found to be present. The interpretation of the spectrum showed the presence of aliphatic bromo compounds, phenol or tertiary alcohols, carbonyl compound, carboxylic acids, lipids, proteins, alkanes and aromatic compound.

Designing an ultra-sensitive aptasensor based on an AgNPs/thiol-GQD nanocomposite for TNT detection at femtomolar levels using the electrochemical oxidation of Rutin as a redox probe

In this paper, for the first time a highly sensitive and low-cost electrochemical aptasensor was fabricated based on a silver nanoparticles/thiol functionalized graphene quantum dot (AgNPs/thiol-GQD) nanocomposite for the measurement of 2,4,6-Trinitrotoluen (TNT) as a nitroaromatic explosive. For the first time Rutin (RU) as a biological molecule with inherent properties was used as the redox probe in the development of the TNT aptasensor was used. The system was based on a TNT-binding aptamer which is covalently attached onto the surface of a glassy carbon electrode (GCE) modified with the nanocomposite for the formation of a sensing layer and improving the performance of the aptasensor. Using the proposed nanocomposite provides a specific platform with increased surface area which is capable of loading more Aptamer (Ap) molecules as a receptor element of TNT on the electrode surface. So, TNT molecules is in an upward position to be measured and the obtained results indicate that the aptasensor exhibits two wide linear ranges and an unprecedented LOD compared with previously reported analytical methods for TNT detection. Applicability of the developed aptasensor to easily detect TNT in real samples was evaluated. It seems that the proposed strategy can be expanded to other nanoparticles and is expected to have promising implications in the design of electrochemical sensors or biosensors for the detection of various targets.

Facile preparation of molecularly imprinted polypyrrole-graphene-multiwalled carbon nanotubes composite film modified electrode for rutin sensing

In this paper, a novel molecularly imprinted composite film modified electrode was presented for rutin (RT) detection. The modified electrode was fabricated by electropolymerization of pyrrole on a graphene-multiwalled carbon nanotubes composite (G-MWCNTs) coated glassy carbon electrode in the presence of RT. The netlike G-MWCNTs composite, prepared by in situ hydrothermal process, had high conductivity and electrocatalytic activity. At the resulting MIP/G-MWCNTs/GCE electrode RT could produce a sensitive anodic peak in pH 1.87 Britton-Robinson buffer solution. The factors affecting the electrochemical behavior and response of RT on the modified electrode were carefully investigated and optimized. Under the selected conditions, the linear response range of RT was 0.01–1.0μmolL−1 and the detection limit (S/N=3) was 5.0nmolL−1. The electrode was successfully applied to the determination of RT in buckwheat tea and orange juice samples, and the recoveries for standards added were 93.4–105%.

Chemical constituents and anti-inflammatory activity of the aerial parts of Curcuma longa

Curcuma longa is a perennial foodstuff plant that is utilized widely in Asia. Here, we evaluated the effects of extracts of the aerial parts of C. longa on inflammatory processes in RAW264.7 macrophage cells. Dried aerial parts of C. longa were extracted with methanol and partitioned successively with CH2Cl2 and n-BuOH. This n-BuOH fraction (0–40 µg/ml) significantly suppressed the lipopolysaccharide-mediated induction of nitric oxide, prostaglandin E2, and pro-inflammatory cytokines. Western blotting found that the levels of nitric oxide synthase and cyclooxygenase-2 were also reduced in a concentration-dependent manner, in the absence of cytotoxicity. The major components present in this extract were isolated and chemically characterized using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry and nuclear magnetic resonance spectroscopy. Four flavonoids were identified: Quercetin 3-(2Gal-rhamnosyl-robinobioside) (1); Quercetin 3-rutinoside (2); Quercetin 3-rhamnosyl-(1→2)-rhamnoside (3); and Quercetin-3-O-rhamnoside (4).

Quantification of rutin in rat's brain by UHPLC/ESI-Q-TOF-MS/MS after intranasal administration of rutin loaded chitosan nanoparticles.

Rutin (RT), an antioxidant drug, has been utilized to treat cerebral ischemia hence a sensitive quantification method for estimation of RT in brain homogenate is necessary to develop. This study aims to prepare RT loaded Chitosan Nanoparticles (RT-CS-NPs) develop and validate ultra-high performance liquid chromatography-electrospray ionization-synapt mass spectrometric method Synapt Mass Spectrometry (Synapt MS) (UHPLC/ESI-QTOF-MS/MS) for quantification of RT in brain homogenate from Wistar rat. The process of chromatographic separation was carried out on Waters ACQUITY UPLC™ with the components of separation in detail as; column: BEH C-18 with dimension as 2.1 mm×100 mm and particle size 1.7 µm, mobile phase: acetonitrile (85 % v/v/v): 2 mM ammonium formate (15 % v/v/v): formic acid (0.1 % v/v/v) and flow rate: 0.25 mL/min. Liquid-liquid extraction method (LLE), in mixture, i.e. ethyl acetate:acetonitrile, was considered to optimize the recovery of analyte from the brain homogenate of Wistar rat. Over a total run time of 5 minutes, the elution time for RT and internal standard (IS), i.e. Tolbutamide, observed was 2.67 and 2.82 min respectively whereas the transition observed for RT and IS was at m/z 611.1023/303.1071 and 271.1263/155.1073, respectively. Results, regarding various processes and parameters studied for RT as summarized, established a linear dynamic range over a concentration range of 1.00 ng/mL - 1000.0 ng/mL with r2; 0.9991±0.0010. Accuracy for intra and inter-assay in terms of % CV revealed a range of 0.45- 2.11 whereas lower limit of detection (LOD) and quantitation (LOQ) observed was 0.09 ng/mL and 0.142 ng/mL, respectively. The analyte stability as well as method specificity and accuracy, i.e. recovery > 86 %, supports the idea for application of current developed method in order to quantify and evaluate the RT-loaded-CS-NPs for RT determination in brain homogenate after intranasal drug delivery.

Etch characteristics of Ru thin films using O2/Ar, CH4/Ar, and O2/CH4/Ar plasmas

The etch characteristics of Ru thin films patterned with TiN hard masks in O2/Ar, CH4/Ar and O2/CH4/Ar gas mixtures were studied using inductively coupled plasma reactive ion etching. When the Ru films were etched in O2/Ar gas, the etch rates of the Ru films and TiN hard masks decreased but the etch selectivity of the Ru films to the hard mask increased with increasing O2 concentration. The etch profiles of Ru films at various O2 concentrations were very similar, showing high etch slopes of >80° with uneven sidewalls. In the case of CH4/Ar gas, as the CH4 concentration increased, the etch rates of the Ru films and TiN hard masks and the etch selectivity of Ru films decreased. The etch profile of Ru films etched in 20% CH4/Ar showed the etch slope of approximately 60° and the etch slopes became worse with increasing CH4 concentration. The addition of O2 to the CH4/Ar gas resulted in a significant improvement in the etch profile, but both etch rates decreased slightly. Optical emission spectroscopy of O2/CH4/Ar plasma showed that O species could oxidize the Ru films to RuOx, and that inhibition layers containing C or CHx were formed, which protected the pattern sidewalls. X-ray photoelectron spectroscopy also identified the formation of RuOx and C or CHx compounds on the film surface. These findings indicated that Ru etching in O2/CH4/Ar gas chemistry could provide a good etch profile without redeposition or etch residues.

Inhibitory Effect on Lipid Absorption and Variability of Chemical Constituents from Capparis sicula subsp. sicula and Capparis orientalis.

In continuation of our research program on Mediterranean dietary plants, a bioassay-guided fractionation of extracts from several accessions of Capparis sicula subsp. sicula and Capparis orientalis aerial parts was carried out. Antilipidemic activity of samples was assayed using inhibition of pancreatic lipase. To study the metabolic variability in Capparis species, HPTLC analyses were performed in order to characterize the species through the detection, isolation, and quantitative evaluation of rutin taken as significant chemical marker. The best activity was exerted by C. orientalis accession no. C10 and C. sicula subsp. sicula accession no. C6. The bioactivity evaluation of specific chemical markers, rutin and glucocapparin, led to the identification of a potent antilipidemic compound rutin. The HPTLC analysis showed large variation among the different analyzed samples with respect to rutin concentration. The chemical investigation showed a different composition between the species and between the collection zones. The variations showed by the studied accessions of caper could be attributed to exogenous factors. Capparis species contained predominantly quercetin rutinoside (rutin), accompanied by other constituents such as the glucosinolate glucocapparin. These rutin-rich extracts exhibited pronounced dose-dependent enzyme inhibitory activities toward pancreatic lipase.

Rutin ameliorates high cholesterol diet induced alteration in lipid profile Interleukin‐3 (IL3) and Interleukin6 (IL6) and liver inflammation

Non alcoholic fatty liver disease (NAFLD) has become a very common metabolic disorder. It refers to a group of conditions where excess fats are deposited in hepatic cells. High cholesterol diet (HCD) causes dyslipidemic syndrome and hyperlipidemia. Furthermore, hypercholesterolemia induceshepatic oxidative stress and inflammation and activation of inflammatory mediators and suppression of the anti‐inflammatory genes. The natural flavonoid (Rutin) possesses an antioxidant activity with protective potential. Therefore, we designed this study with the aim to investigate the potential ameliorative potential of rutin against HCD‐induced alteration of lipid profile and hepatic interleukins; Interleukin‐3 (IL3) and Interleukin6 (IL6). Male Wistar rats were allocated into four groups as follow (1) control (Rat chow), (2) Rutin (0.2% in rat chow), (3) HCD (1% cholesterol and 0.5% cholic acid in rat chow) and (4) rutin (0.2%) + HCD. Animals received freshly prepared experimental diets for 6 consecutive weeks. In plasma, levels triglyceride (TG), total cholesterol (TC), low‐density lipoprotein (LDL) and high‐density lipoprotein (HDL)were estimated. In hepatic tissue, gene expressions of Interleukin‐3 (IL3) and Interleukin6 (IL6) were determined using real time PCR. HCD significantly increased plasma levels of TG, TC and LDL by 48%, 89% and 67% respectively and significantly decreased the HDL levels by 17% compared to control group. Rutin supplementation in combination with HCD, significantly decreased TG and LDL levels and insignificant decrease plasma levels of TC and HDL compared to control group. Results also showed a significant increase by 5.8 fold in the expression of IL‐6 and significant decrease by 3 folds in IL‐3 expression in rats fed with HCD compared to control group. Interestingly, administration of rutin in combination with HCD corrected the alteration in the expression of these genes to their values in the control group. In conclusion: Combination of the natural occurring antioxidant, Rutin, with HCD protects against HCD associated hepatic inflammation and the altered lipid profile.Support or Funding Informationking saud university

Potentiating the Heat Inactivation of Escherichia coli O157:H7 in Ground Beef Patties by Natural Antimicrobials.

Escherichia coli O157: H7 (EHEC) is a major foodborne pathogen largely transmitted to humans through the consumption of undercooked ground beef. This study investigated the efficacy of two food-grade, plant-derived antimicrobials, namely rutin (RT), and resveratrol (RV) with or without chitosan (CH) in enhancing EHEC inactivation in undercooked hamburger patties. Further, the effect of aforementioned treatments on beef color and lipid oxidation was analyzed. Additionally, the deleterious effects of these antimicrobial treatments on EHEC was determined using scanning electron microscopy (SEM). Ground beef was inoculated with a five-strain mixture of EHEC (7.0 log CFU/g), followed by the addition of RT (0.05%, 0.1% w/w) or RV (0.1, 0.2% w/w) with or without CH (0.01% w/w). The meat was formed into patties (25 g) and stored at 4°C for 5 days. On days 1, 3, and 5, the patties were cooked (65°C, medium rare) and surviving EHEC was enumerated. The effect of these treatments on meat color and lipid oxidation during storage was also determined as per American Meat Science Association guidelines. The study was repeated three times with duplicate samples of each treatment. Both RT and RV enhanced the thermal destruction of EHEC, and reduced the pathogen load by at least 3 log CFU/g compared to control (P < 0.05). The combination of RT or RV with CH was found to be more effective, and reduced EHEC by 5 log CFU/g (P < 0.05). EHEC counts in uncooked patties did not decline during storage for 5 days (P > 0.05). Moreover, patties treated with RV plus CH were more color stable with higher a∗ values (P < 0.05). SEM results revealed that heat treatment with antimicrobials (CH + RV 0.2%) resulted in complete destruction of EHEC cells and extrusion of intracellular contents. Results suggest that the aforementioned antimicrobials could be used for enhancing the thermal inactivation of EHEC in undercooked patties; however, detailed sensory studies are warranted.

Comparative Study of Novel Ratio Spectra and Isoabsorptive Point Based Spectrophotometric Methods: Application on a Binary Mixture of Ascorbic Acid and Rutin.

This paper presents novel methods for spectrophotometric determination of ascorbic acid (AA) in presence of rutin (RU) (coformulated drug) in their combined pharmaceutical formulation. The seven methods are ratio difference (RD), isoabsorptive_RD (Iso_RD), amplitude summation (A_Sum), isoabsorptive point, first derivative of the ratio spectra (1DD), mean centering (MCN), and ratio subtraction (RS). On the other hand, RU was determined directly by measuring the absorbance at 358 nm in addition to the two novel Iso_RD and A_Sum methods. The work introduced in this paper aims to compare these different methods, showing the advantages for each and making a comparison of analysis results. The calibration curve is linear over the concentration range of 4–50 μg/mL for AA and RU. The results show the high performance of proposed methods for the analysis of the binary mixture. The optimum assay conditions were established and the proposed methods were successfully applied for the assay of the two drugs in laboratory prepared mixtures and combined pharmaceutical tablets with excellent recoveries. No interference was observed from common pharmaceutical additives.

Antioxidative Activities in Rutin Rich Noodles and Cookies Made with a Trace Rutinosidase Variety of Tartary Buckwheat (&lt;i&gt;Fagopyrum tataricum&lt;/i&gt; Gaertn.), ‘Manten-Kirari’

Antioxidative Activities in Rutin Rich Noodles and Cookies Made with a Trace Rutinosidase Variety of Tartary Buckwheat (&lt;i&gt;Fagopyrum tataricum&lt;/i&gt; Gaertn.), ‘Manten-Kirari’

Synergistic Effects of Organic Additives Based on the Intermolecular Interactions on Electrodeposition of Tin

The synergistic effects of surfactant-surfactant and additive-surfactant based on intermolecular interaction are demonstrated by means of electrochemical measurement and electrodeposition of tin. Three synergistic systems were studied: anionic-cationic surfactant mixture, phthalic acid (PA)-surfactant and rutin (RT)-surfactant. The low critical micelle concentration (CMC) values and improved deposition inhibition obtained from the anionic-cationic mixed surfactant systems indicate that intermolecular electrostatic interactions are an important driving force for the synergistic effect. A comparative study of phthalic acid (PA)-surfactants and rutin (RT)-surfactants indicates that the adsorption behavior of the additives can be varied through the conscious design of the intermolecular interactions between the additive and the anionic-cationic mixed surfactant. The measurements of the carbon contents indicate that the incorporation of organic additives into tin deposits can be improved by the synergistic effects based on the intermolecular interaction of surfactant-surfactant and additive-surfactant. In addition, the synergistic effects based on the intermolecular interaction can affect the morphology of tin deposits. Therefore, it may be a practical way to control the quality of a deposit and the electrodeposition process through a proper design of the intermolecular interaction between the organic additives.

Characterization of the quality of novel rye-buckwheat ginger cakes by chemical markers and antioxidant capacity

AbstractThe total phenolics and flavonoids, rutin, early, advanced and finalMaillard reaction products, and antioxidative capacity determined against 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) radical cation and superoxide anion radicals were used for the characterization of the quality of novel rye-buckwheat ginger cakes enriched with rutin (quercetin rutinoside). The cakes were prepared substituting 30 % of rye flour by light buckwheat flour or flour from roasted buckwheat dehulled grains and employing a dough fermentation-like incubation step. Enrichment of ginger cakes with rutin showed protective effect on lysine blockage, improved antioxidant properties, inhibited the formation of furosine and free fluorescent compounds thus stimulating the Maillard reaction progress towards melanoidin formation. The loss of the nutritional quality of cakes enriched with rutin was related to the formation of fluorescent compounds linked to protein and carboxymethyllysine at an advanced stage of the Maillard reaction. It can be concluded that free fluorescence intermediatory compounds, carboxymethyllysine and browning are the best chemical markers for the characterization of the quality of this novel type of ginger cakes. This study also indicates that rye-buckwheat ginger cakes enriched with rutin can be recommended for wider consumption since daily consumption of 250 g of these cakes may have a prophylactic or therapeutic effect corresponding to typical pharmacological drugs with rutin as the active component.

Photoprotection by dietary phenolics against melanogenesis induced by UVA through Nrf2-dependent antioxidant responses

Dietary phenolics may play a protective role in UV-mediated skin pigmentation through their antioxidant and UV-absorbing actions. In this study, we investigated whether genetic silencing of Nrf2, regulating the transcription of antioxidant genes, affected melanogenesis in primary human epidermal melanocytes (HEMn) and B16F10 melanoma cells subjected to UVA (8J/cm2) exposure. Then, we explored the antimelanogenic actions of phenolics; caffeic acid (CA) and ferulic acid (FA) providing partial UVA protection; quercetin (QU) and rutin (RU) providing strong UVA protection and; avobenzone (AV), an efficient UVA filter, in association with modulation of Nrf2-mediated antioxidant defenses in response to UVA insults in B16F10 cells. Upon oxidative insults, Nrf2 silencing promoted melanogenesis in both HEMn and B16F10 cells irradiated with UVA. Stimulation of melanogenesis by UVA correlated with increased ROS and oxidative DNA damage (8-OHdG), GSH depletion as well as a transient downregulation of Nrf2 nuclear translocation and of Nrf2-ARE signaling in B16F10 cells. All test compounds exerted antimelanogenic effects with respect to their abilities to reverse UVA-mediated oxidative damage as well as downregulation of Nrf2 activity and its target antioxidants (GCLC, GST and NQO1) in B16F10 cells. In conclusion, defective Nrf2 may promote melanogenesis under UVA irradiation through oxidative stress mechanisms. Compounds with antioxidant and/or UVA absorption properties could protect against UVA-induced melanogenesis through indirect regulatory effect on Nrf2-ARE pathway.

Effect of Syzygium cumini and Bauhinia forficata aqueous-leaf extracts on oxidative and mitochondrial parameters in vitro.

Aqueous-leaf extract of Syzygium cumini and Bauhinia forficata are traditionally used in the treatment of diabetes and cancer, especially in South America, Africa, and Asia. In this study, we analyzed the effects of these extracts on oxidative and mitochondrial parameters in vitro, as well as their protective activities against toxic agents. Phytochemical screenings of the extracts were carried out by HPLC analysis. The in vitro antioxidant capacities were compared by DPPH radical scavenging and Fe2+ chelating activities. Mitochondrial parameters observed were swelling, lipid peroxidation and dehydrogenase activity. The major chemical constituent of S. cumini was rutin. In B. forficata were predominant quercetin and gallic acid. S. cumini reduced DPPH radical more than B. forficata, and showed iron chelating activity at all tested concentrations, while B. forficata had not similar property. In mitochondria, high concentrations of B. forficata alone induced a decrease in mitochondrial dehydrogenase activity, but low concentrations of this extract prevented the effect induced by Fe2++H2O2. This was also observed with high concentrations of S. cumini. Both extracts partially prevented the lipid peroxidation induced by Fe2+/citrate. S. cumini was effective against mitochondrial swelling induced by Ca2+, while B. forficata alone induced swelling more than Ca2+. This study suggests that leaf extract of S. cumini might represent a useful therapeutic for the treatment of diseases related with mitochondrial dysfunctions. On the other hand, the consumption of B. forficata should be avoided because mitochondrial damages were observed, and this possibly may pose risk to human health.