Comprehensive Assessment of the Safety of Eucommia ulmoides Leaf Extract for Consumption as a Traditional Chinese Health Food

To ensure the export quality of Eucommia ulmoides leaf extract(ELE)and facilitate E.ulmoides leaf inclusion in the directory of traditional Chinese health foods,an overall safety assessment of ELE was performed,including genotoxicity and long-term toxicity,according to the national food safety standards of China.No variations in the reverse mutation number of the nominal bacterial strains were observed under ELE treatment in comparison with the solvent control.Additionally,the micronucleus rates of in vivo mammalian erythrocytes and in vitro mammalian cells under ELE treatment were equivalent to or significantly lower than those of the solvent control.The fold change in the trifluorothymidine resistance mutation frequency of the thymidine kinase gene under ELE treatment was less than three times in comparison with the solvent control,suggesting that ELE did not cause genotoxicity.Moreover,animal experiments showed that the growth performance of rats under ELE treatment was enhanced because the body weights of rats increased.No oxidative injury or inflammatory responses were induced and no histopathological lesions of tissues were detected under ELE treatment.In addition,plasma triglycerides and low-density lipoprotein cholesterol levels significantly decreased,and plasma high-density lipoprotein cholesterol levels significantly increased with ELE treatment,suggesting that ELE was health-promoting.Furthermore,moderate to excellent antimicrobial activities,a favorable anticancer capacity,and superior antioxidant abilities of ELE were found,implying ELE possesses good bioactivities.Therefore,we affirmed ELE is safe to consume as a traditional Chinese health food.

Antioxidant Activity and Soothing Efficacy of Tambourissa Trichophylla Leaf Extract in Vitro Study

Present study is aimed to investigate in vitro biological efficacy of Tambourissa trichophylla leaf extract(TTLE),a plant-derived ingredient in cosmetic,on antioxidant activity and soothing efficacy.The total phenols content of TTLE was determined by the Folin-Ciocalteu method,antioxidant activity was tested by DPPH free radical scavenging assay,hyaluronidase inhibition activity was performed by using in vitro enzyme inhibitory assays based on spectrophotometric evaluation,and the soothing efficacy of TTLE was performed by the expression of nitric oxide(NO)and interleukin-6(IL-6)produced by LPS-induced RAW264.7 cells.The results shown that the total phenolic content of TTLE was as high as 54%,the DPPH scavenging activity was 81.18%at the concentration of 25μg/mL,the hyaluronidase inhibition activity was 69.04%at the concentration of 5 mg/mL,and the inhibition of NO and IL-6 were 15.70%and 76.57%at 0.05 mg/mL,respectively.TTLE has a high content of total phenols,high antioxidant activity and soothing effects,which indicated that TTLE was a promising ingredient in the development and application of cosmetics.

Olive leaf extract inhibits lead poisoning-induced brain injury

Olive leaves have an antioxidant capacity, and olive leaf extract can protect the blood, spleen and hippocampus in lead-poisoned mice. However, little is known about the effects of olive leaf extract on lead-induced brain injury. This study was designed to determine whether olive leaf extract can inhibit lead-induced brain injury, and whether this effect is associated with antioxidant capacity. First, we established a mouse model of lead poisoning by continuous intragastric administration of lead acetate for 30 days. Two hours after successful model establishment, lead-poisoned mice were given olive leaf extract at doses of 250, 500 or 1 000 mg/kg daily by intragastric administration for 50 days. Under the transmission electron microscope, olive leaf extract attenuated neuronal and capillary injury and reduced damage to organelles and the matrix around the capillaries in the frontal lobe of the cerebral cortex in the lead-poisoned mice. Olive leaf extract at a dose of 1 000 mg/kg had the greatest protective effect. Spectrophotometry showed that olive leaf extract significantly in- creased the activities of superoxide dismutase, catalase, alkaline phosphatase and acid phes- phatase, while it reduced malondialdehyde content, in a dose-dependent manner. Furthermore, immunohistochemical staining revealed that olive leaf extract dose-dependently decreased Bax protein expression in the cerebral cortex of lead-poisoned mice. Our findings indicate that olive leaf extract can inhibit lead-induced brain injury by increasing antioxidant capacity and reducing apop- tosis.

Hydroxytyrosol and olive leaf extract exert cardioprotective effects by inhibiting GRP78 and CHOP expression

Myocardial infarction triggers massive biochemical changes, even cardiac cell death. Endoplasmic reticulum stress is involved in the pathology of myocardial infarction-mediated apoptosis. In the present study, myocardial cell line H9c2 cells were treated with cobalt chloride（CoCl_2） to induce hypoxia. Isoproterenol was used for two successive days to induce myocardial infarction in SD rats. The cardioprotective effect of olive leaf extract（OLE） and its main constituent hydroxytyrosol and the underlying mechanisms were evaluated. The results showed that hydroxytyrosol markedly protected H9c2 cells against CoCl2-induced apoptosis. Hydroxytyrosol could reduce the mRNA and protein expression of GRP78 and CHOP induced by CoCl2 in vitro. In vivo, the decreased ejection fraction and fractional shortening, increased heart weight/body ratio, the formation of infarction, disordered cardiac muscle fibers and infiltration of inflammatory cells induced by isoproterenol could be significantly ameliorated by pretreatment with OLE for a month. Similarly, OLE could also reverse the increase of GRP78 and CHOP expression induced by isoproterenol. Therefore, OLE and hydroxytyrosol exert a cardioprotective effect through endoplasmic reticulum stress, which could be a new target for the prevention and treatment of cardiovascular diseases.

Protective Effect of Ginkgo Biloba Leaf Extract on Learning and Memory Deficit Induced by Aluminum in Model Rats

Objective： To examine the protective effect of Ginkgo biloba leaf extract （GbE） on learning and memory deficit induced by aluminum chloride （AlCl3）, and explore its mechanisms. Methods： The rat models with learning and memory deficit were induced by administering via gastrogavage and drinking of AlCl3 solution. And the model rats were treated with GbE at the dose of 50, 100, 200 mg/kg every day for 2 months accompanied with drinking of AlCl3 solution, respectively. Their abilities of spatial learning and memory were tested by Morris water maze, and the acetylcholinesterase （ACHE） activity in serum was assayed with chemical method, the AChE expression in hippocampus was observed by immunohistochemistry assay, and then quantitative analysis was done by BI 2000 image analysis system. Results： Learning and memory deficit of rats could be induced by AlCl3 solution （P〈0.01）, and AChE expressions in rats hippocampus were increased （P〈0.01）; GbE ameliorated learning and memory deficit and reduced AChE expression in rats hippocampus in a dose-dependent manner, while GbE significantly increased serum AChE activity at the dose of 200 mg/kg each day （P〈0.05）. Conclusion： GbE can ameliorate learning and memory deficit induced by AlCl3, which may be due to its inhibition of the AChE expression in hippocampus.

Anti-angiogenesis and anti-inflammatory effects of Moringa oleifera leaf extract in the early stages of streptozotocin-induced diabetic nephropathy in rats

Objective:To investigate the effect of Moringa oleifera leaf extract on angiogenesis and inflammatory process in a rat model of streptozotocin-induced diabetic nephropathy.Methods:Four weeks after a single injection of 50 mg/kg streptozotocin,rats were treated with 100 or 200 mg/kg/day Moringa oleifera leaf extract,1 mg/kg/day dapagliflozin,or a combination of Moringa oleifera leaf extract and dapagliflozin for further eight weeks.Renal function,kidney histology,and gene expression were evaluated at the end of the experiment.Results:Renal function of diabetic rats was significantly impaired as evidenced by increased blood urea nitrogen,albuminuria,24-h proteinuria,and high creatinine clearance which indicated glomerular hyperfiltration.In addition,diabetic rats showed an increase in gene expressions of vascular endothelial growth factor-A(VEGF-A),angiopoietin-2(Ang2),the Ang2/Ang1 ratio,tumor necrosis factor-α,interleukin-1βand monocyte chemoattractant protein-1.Immunohistochemical staining demonstrated a significant increase in the density of glycoprotein CD34.Moringa oleifera leaf extract markedly improved all renal dysfunction markers and modulated the upregulated expression of angiogenic factors and inflammatory genes.Conclusions:Moringa oleifera leaf extract could suppress abnormal angiogenesis and inflammatory processes possibly by downregulating gene expression of angiogenesis factors and proinflammatory cytokines.

Inhibitory effects of Albizia lebbeck leaf extracts on germination and growth behavior of some popular agricultural crops

An experiment was conducted to observe the inhibitory effects of the leaf extracts derived from Albizia lebbeck （L.） Benth. On germination and growth behavior of some popular agricultural crops （receptor） of Bangladesh. Experiments were set on sterilized petridishes with a photoperiod of 24 h at room temperature of 27-30℃. The effects of the different concentrations of aqueous extracts were compared to distil water （control.）. The aqueous extracts of leaf caused significant inhibitory effect on germination, root and shoot elongation and development of lateral roots of receptor plants. Bioassays indicated that the inhibitory effect was proportional to the concentrations of the extracts and higher concentration （50%-100%） had the stronger inhibitory effect whereas the lower concentration （10%-25%） showed stimulatory effect in some cases. The study also revealed that, inhibitory effect was much pronounced in root and lateral root development rather than germination and shoot growth.

The leaf extract of crofton weed(Eupatorium adenophorum)inhibits primary root growth by inducing cell death in maize root border cells

The extract of crofton weed(Eupatorium adenophorum) inhibits seed germination and weed growth;however,the physiological mechanisms underlying the effect of crofton weed extract on the modulation of seedling growth and root system development remain largely unclear.In this study,we investigated the effects of the leaf extract of crofton weed(LECW) on primary root(PR) growth in maize seedlings.Treatment with LECW markedly inhibited seed germination and seedling growth in a dose-dependent manner.Physiological analysis indicated that the LECW induced reactive oxygen species(ROS) accumulation in root tips,thereby leading to cell swelling and deformation both in the root cap and elongation zone of root tips,finally leading to cell death in root border cells(RBCs) and PR growth inhibition.The LECW also inhibited pectin methyl esterase(PME) activity,thereby decreasing the RBC number.Taken together,our results indicated that the LECW inhibited PR growth by inducing ROS accumulation and subsequent cell death in RBCs.The present study provides a better understanding of how the LECW modifies root system development and provides insight for evaluating the toxicity of crofton weed extracts in plants.

Ginkgo biloba leaf extract effects on inducible nitric oxide synthase, Bcl-2, and Bax expression in rat models of spinal cord injury

BACKGROUND：Ginkgo biloba leaf extract exhibits neuroprotective effects in spinal cord injury. However, the mechanisms of action remain unclear. OBJECTIVE： To investigate inducible nitric oxide synthase （iNOS） and Bcl-2/Bax expression in the injured spinal cord, and to explore the neuroprotective mechanisms of ginkgo biloba leaf extract in rats with spinal cord injury. DESIGN, TIME AND SETTING： The randomized, controlled, cell molecular biology experiment was performed at Soochow University, China from March 2007 to March 2008. MATERIALS： A total of 120 healthy, adult Sprague Dawley rats were selected for this study. Rat models of moderate acute thoracic （T9） spinal cord injury were established using the modified Allen method. Shuxuening injection was obtained from Zhenbaodao Pharmaceutical Co., Ltd., China. Methylprednisolone was purchased from North China Pharmaceutical Co., Ltd. METHODS： All rats were equally and randomly divided into four groups. Only the spinal cord was exposed in the sham operation group rats. In the trauma group, rats were not treated with drugs following spinal cord injury. Rats in the hormone group were intraperitoneally injected with 30 mg/kg methylprednisolone following spinal cord injury. Rats in the ginkgo biloba leaf extract group were intraperitoneally infused with a 1.0 mL/kg Shuxuening injection per day. MAIN OUTCOME MEASURES： At 1 hour, as well as 1, 3, 5, 7, and 14 days after spinal cord injury, iNOS- and Bcl-2/Bax-positive cells were quantified with immunohistochemistry. Pathological changes were detected using hematoxylineosin staining under an optical microscope. RESULTS： Spinal cord injury in the ginkgo biloba leaf extract and hormone groups was milder compared with the trauma group. Demyelination was significantly ameliorated and the necrotic cavity was obviously reduced in the injured spinal cord of rats in the ginkgo biloba leaf extract and hormone groups at each time point. iNOS expression was increased in the injured spinal cord, and reached a peak at 5 days. The number of iNOS-positive cells was lower in the ginkgo biloba leaf extract and hormone groups compared with the trauma group （P 〈 0.05-0.01）. The number of iNOS-positive cells was lower in the ginkgo biloba leaf extract group compared with the hormone group at 7 and 14 days after spinal cord injury （P 〈 0.05）. Bcl-2 expression reached a peak at 3 days, and Bax expression reached a peak at 5 days following rat spinal cord injury. Bcl-2 expression was increased, but Bax expression was decreased in the ginkgo biloba leaf extract and hormone groups compared with the trauma group （P 〈 0.05-0.01）. Bcl-2 expression was greater, but Bax expression was reduced in the ginkgo biloba leaf extract group compared with the hormone group at 7 and 14 days after spinal cord injury （P 〈 0.05）. CONCLUSION： Ginkgo biloba leaf extract exhibits neuroprotective effects by upregulating Bcl-2 expression, downregulating Bax expression, and significantly inhibiting high expressions of iNOS in the injured spinal cord. The neuroprotective effects of ginkgo biloba leaf extract are greater compared with methylprednisolone at 1 week after spinal cord injury.

Modulatory Effect of Distillate of Ocimum sanctum Leaf Extract (Tulsi) on Human Lymphocytes Against Genotoxicants

Objective To study the modulatory effect of distillate of Ocimum sanctum （traditionally known as Tulsi） leaf extract （DTLE） on genotoxicants. Methods In the present investigation, we studied the antigenotoxic and anticlastogenic effect of distillate of Tulsi leaf extract on （i） human polymorphonuclear leukocytes by evaluating the DNA strand break without metabolic activation against mitomycin C （MMC） and hexavalent chromium （Cr^＋6） and （ii） human peripheral lymphocytes （in vitro） with or without metabolic activation against mitomycin C （MMC）, hexavalent chromium （Cr^＋6） and B[a]P by evaluating chromosomal aberration （CA） and micronucleus assay （MN）. Three different doses of DTLE, 50 μL/mL, 100 μL/mL, and 200 μL/mL were selected on the basis of cytotoxicity assay and used for studying DNA strand break, chromosomal aberration and micronucleus emergence. The following positive controls were used for inducing genotoxicity and clastogenicity MMC （0.29 μmol/L） for DNA strand break, chromosomal aberration and 0.51 μmol/L for micronucleus assay; Potassium dichromate （Cr^＋6） 600 μmol/L for DNA strand break and 5 μmol/L for chromosomal aberration and micronucleus assay; Benzo[a]pyrene （30 μmol/L） for chromosomal aberration and 40 μmol/L for micronucleus assay. The active ingredients present in the distillate of Tulsi leaf extract were identified by HPLC and LC-MS. Results Mitomycin C （MMC） and hexavalent chromium （Cr^＋6） induced statistically significant DNA strand break of respectively 69% and 71% （P〈0.001） as revealed by fluorometric analysis of DNA unwinding. Furthermore, the damage could be protected with DTLE （50 μL/mL, 100 μL/mL, and 200 μL/mL） on simultaneous treatment. Chromosomal aberration and micronucleus formation induced by MMC, Cr^＋6 and B[a]P were significantly protected （P〈0.001） by DTLE with and without metabolic activation. Conclusion Distillate of Tulsi leaf extract possesses antioxidants contributed mainly by eugenol, luteolin and apigenin as identified by LC-MS. These active ingredients may have the protective effect against genotoxicants.

Effects of Ginkgo Leaf Extract on Function of Dendritic Cells and Th1/Th2 Cytokines in Patients with Unstable Angina Pectoris

Objective： To investigate the effects of Ginkgo leaf extract （GLE） on function of dendritic cells （DO） and Th1/Th2 cytokines in patients with unstable angina pectoris（UAP）. Methods： Fifty-four patients with UAP were equally assigned into two groups, the treated group and the control group, both treated with conventional Western medicine, but with GLE given additionally to the treated group. Blood of all patients was taken before and 4 weeks after treatment to prepare the peripheral mononuclear cells, then which were incubated in the completed medium containing granulocyte-macrophage colony stimulatory factor （GMCSF） and interleukin-4 （IL-4） to induce mature DO. The expression of co-stimulating factor CD86 （B7-2） on the surface of DC was detected by flow cytometry, and the stimulating capacity of DC was determined by mixed lymphocyte reaction （MLR）. The blood levels of cytokines, interferon-γ （IFN-γ）, and IL-4, were analyzed by ELISA, and blood C-reactive protein （CRP） level by turbidimetry. Moreover, the direct effect of Ginkgolide B on CD86 expression on DO were also tested in vitro. Results： After treatment, CD86 expression on DO, the stimulating capacity of DO as well as levels of IFN-γ and ORP were lowered in both groups （P〈0.05 or P〈0.01）, but the changes were much more significant in the treated group than those in the control group. Ginkgolide B showed a direct inhibitory effect on the CD86 expression on DO. Conclusion： The inhibition of GLE on DO and thereby the suppression on inflammatory reaction may be one of the mechanisms of GLE in treating patients with UAP.

Enhanced cytotoxic effect on human lung carcinoma cell line(A549) by gold nanoparticles synthesized from Justicia adhatoda leaf extract

Objective: To synthesize bio-inspired gold nanoparticles(AuNPs) using the leaf extract of Justicia adhatoda and evaluate the anti-cancer activity on human lung cancer cell line(A549).Methods: Synthesis of AuNPs was done using an aqueous leaf extract of Justicia adhatoda as a green route. The bio-synthesized AuNPs were confirmed and characterized by using various spectral studies such as UV-Vis spectrum, Scanning Electron Microscope with EDAX, Transmission Electron Microscope, Fourier Transmission Infrared Spectroscope analysis and Surface Enhanced Raman Spectroscopy. The cell viability was determined by MTT reduction assay. In addition, cytomorphology and the nuclear morphological study of A549 cell line was observed under fluorescence microscope. Results: UV-Vis spectrum showed surface plasmon resonance peak at 547 nm, scanning electron microscope and transmission electron microscope studies showed the monodispersed spherical shape and its average size in the range of 40.1 nm was noticed. Fourier Transmission Infrared Spectroscope analysis confirmed that the C=O group of amino acids of proteins had strong ability to bind with the surface of nanoparticle. Interestingly, our results also demonstrated inhibited proliferation of A549 cell line by MTT(IC50 value: 80 μg/mL). Cell morphology was observed and cell death was caused by apoptosis as revealed by propidium iodide staining. Conclusions: The current study proves the anticancer potential of bio-synthesized AuNPs. Thus, synthesized AuNPs can be used for the treatment of human lung cancer cell(A549) and it can be exploited for drug delivery in future.

Ginkgo Leaf Extract and Armillariella Mellea Powders Oral(银杏蜜环口服溶液) attenuates inflammation of microglia in habenular nucleus through CX3CL1-CX3CR1 axis in post stroke depression

OBJECTIVE The Ginkgo Leaf Extract and Armillariella Mellea Powders Oral(Yinxingmihuan Koufu Rongye,YXMH),a representative drug for"Treating both Brain and Heart",showed considerable clinical effects in isch⁃emic cardiovascular and cerebral vascular diseases.Recently,it is reported that YXMH has the potential for treating myocardial and cerebral ischemia related mental disorders,such as post stroke depression(PSD)and chronic heart disease(CHD)associated anxiety disorder.However,its mechanism has not been clearly elucidated.Meanwhile,increasing evidence revealed that there are close functional links between depression and habenular nucleus.The present study investigates the underlying mechanism of YXMH on attenuating the inflammation of microglia in habenular nucleus through CX3CL1-CX3CR1 axis in in a rat model of PSD.METHODS Rats were randomly devided into sham group,model group,Ginaton group(18 mg·kg^-1),Armillariella Mellea group(600 mg·kg-1),Fluoxetine group(10 mg·kg^-1),YXMH high-dose group(618 mg·kg^-1)and YXMH low-dose group(309 mg·kg^-1).The PSD model was induced by transarterial microembolization combined with sleep deprivation(2-Chloro-D-phenylalanine,PCPA,IH,200 mg·kg^-1,for 3 times,before the behavior test)in SD male rats.Then rats were treated with corresponding medicaments through gavage once a day until 3 weeks later,followed by body mass measurement,neurological deficit score evaluation,gripping strength and thermal withdrawl latency measurement,as well as depression related behavioral indicators,the open field test(OFT)and sucrose preference test.The pathological morphological changes of habenular nucleus was observed by HE staining,the expression of IBA-1 was measured and analyzed by immunohistochemistry staining,and alterations of proteins and genes related to the CX3CL1-CX3CR1 axis were analyzed using Western blotting(CX3CL1,CX3CR1)and real-time polymerase chain reaction(PCR)(CX3CL1,CX3CR1).RESULTS Compared with the sham group,rats in the model group manifested as decreased body mass,deficient neurological behavior and gripping strength,reduced loco⁃motor activity and sugar water consumption,as well as elevated thermal withdrawl latency(P<0.05,P<0.01).Mean⁃while,the pathological morphology of the habenular nucleus on the ischemic hemisphere showed significant neuronal degeneration,microglial proliferation,inflammatory cells and glia cells infiltration,together with up-regualted expression of IBA-1,CX3CL1,CX3CR1 protein and CX3CL1,CX3CR1 mRNA.YXMH attenuated inflammation of microglia in habenular nucleus through improving pathological morphology,inhibiting IBA-1 activation,down-regulating the expres⁃sion of CX3CL1 and CX3CR1 proteins and genes,and thus improved the behavior performance of ischemic injury and depression.CONCLUSION YXMH ameliorates neurological deficit and depressive behavior in rat model of PSD induced by transarterial microembolization combined with sleep deprivation,and the mechanism is probably related to attenu⁃ating inflammation of microglia in habenular nucleus through CX3CL1-CX3CR1 axis.

Nanoencapsulation of Antioxidant-Rich Fraction of Roasted <i>Moringa oleifera</i>L. Leaf Extract: Physico-Chemical Properties and <i>in Vitro</i>Release Mechanisms

Nanocapsules (NC) of antioxidant rich fraction of roasted Moringa leaves were prepared using emulsion coacervation technique with alginate (ALG) and/or chitosan (CTS) as biopolymers. NC were characterized based on particle size, polydispersity index (PDI), zeta potential, encapsulation efficiency (EE) and loading capacity (LC). Substituting CTS with ALG in NC caused a reduction in particle size and PDI, and enhanced EE. Mean particle size dropped from 1209 nm in 1:3 to 413 nm in 3:1 ALG/CTS-NC;PDI decreased from 0.9% to 0.2% and zeta potential from -5.4 to -28.1 mV. The highest EE (87.6%) and LC (13%) were obtained with ALG-CTS-NC (3:1). ALG-NC were spherical while both CTS and ALG-CTS-NC were ovoid. ALG and ALG-CTS-NC were oil/water emulsions while CTS-NC formed water/oil emulsions. 60% and 70% of bioactives in ALG-CTS-NC (3:1) were released in simulated gastric and intestinal fluids respectively after 400 min. Release of antioxidants from NC is concentration-dependent (First order model) and involves simultaneously diffusion (Higuchi model), swelling (korsmeyer-Peppas model) and erosion (Hixson-Crowell model) mechanisms.

Hepatic Impact of Mandragora officinarum Leaf Extract on Wistar Albino Rats

This study evaluates the hepatic effects of Mandragora officinarum leaf extract on wistar albino rats. A total of twenty-four (24) rats were randomly divided into 4 groups labeled A, B, C and D and kept in a well-ventilated room. Group A served as control and these rats were fed distilled water. Rats in groups B, C, and D were given three (3) different doses of the leaf extract (1.5, 3.5 and 5.0 mL/KgBW) respectively. They were administered once daily for 14 and 28 days consecutively. Animals were sacrificed 24 hours after the last treatment. Blood samples were collected into heparinized sample bottles for analysis. Aspartate aminotransferase, Alanine aminotransferase and histology results were normal when the leaf extract was given for 14 days. Alkaline phosphatase significantly decreased within the same time interval. Alkaline phosphatase increased in a dose-dependent manner for 28 days. All other liver enzymes were within normal limits. Histopathological changes were seen in all doses when Mandragora officinarum leaf extract was used for 28 days. These changes also worsened with increasing doses. This suggests that the use of mandragora officinarum leaf extract for long periods at a time can cause hepatic damage.

Oleuropein from Olive Leaf Extract as Natural Antioxidant of Frozen Hamburger

Oxidation is one of the major causes of hamburger deterioration. Antioxidants are used to minimize oxidation process. There is a growing interest in the substitution of synthetic food antioxidants by natural ones from vegetable sources. In meat industry, sodium erythorbate is antioxidant that is usually used and is an example of chemical antioxidant. Effect of olive leaf extract rich in olenropein on the quality of frozen hamburger was investigated. The objective of this study was to evaluate the usage of oleuropein from olive leaf extract as natural antioxidant in frozen hamburger stored at -12 ℃ compared with sodium erythorbate. Results suggested that olive leaf extracts might be useful to the meat industry as an efficient alternative to synthetic antioxidants by retarding oxidation of hamburger compared with sodium erythorbate 0.5% of olenropein and 0.5% of sodium erythorbate are the best concentrations to be used in frozen hamburger.

Assessments of Antibacterial and Antioxidant Properties in the Methanolic and Aqueous Leaf Extracts of Pistacia lentiscus against Different Antibiotic Resistance Pathogenic Bacteria

The current study was carried out to determine the bioactivity of P. lentiscus leaf extracts as potential antibacterial and antioxidant properties. The plant extracts were examined for antibacterial activity against antibiotic-resistant Staphylococcus aureus, Staphylococcus haemolyticus, Pseudomonas aeruginosa, and Proteus mirabilis using the agar well method (according to the guidelines of Clinical and Laboratory Standard Institute). The antioxidant potential of 3 plant leaf extracts was determined by their ability to convert Fe3+ to Fe2+ and scavenge the DPPH free radical. At all concentrations studied, the methanolic leaf extract had higher total phenolic and flavonoid content, as well as stronger antioxidant and antibacterial inhibitory activity compared to aqueous extract. Our findings with P. aeruginosa were especially interesting, because this bacterium was inhibited by methanol extract than that of the reference antibiotics. The results also demonstrated a link between DPPH radical scavenging ability, reducing power, and total phenolic and flavonoid content of plant extracts (r > 0.97, R2 > 0.95, P = 0.01). As a result, the methanolic leaf extract of the chosen plant might be employed as an effective antioxidant and antibacterial agent for the treatment of a variety of morbidities.

Inactivation of Protein Tyrosine Phosphatase 1B （PTP1B） Activity by the Aqueous Partition of Guava Leaf Extract

Guava leaf tea has been used as a folk medicine for treating hyperglycemic conditions in Asia and Africa. The hypoglycemic efficacy of guava leaf has been documented by many scientists in these regions, but the hypoglycemic mechanism is poorly understood. Guava leaves were extracted with methanol and the crude extract was partitioned against hexane, ethyl acetate, and butanol in sequence. The leftover in water is defined as the aqueous partition. A second smaller batch was extracted with hot water directly. Oral glucose tolerance test was carried out on healthy mice instead of diabetic mice that lack endogenous insulin. Glucose uptake was examined with 3T3-L1 adipocytes. Oxidative effect on PTP1B （protein tyrosine phosphatase 1b） was carried out with real-time PTP1B enzymatic assay. The aqueous partition of guava leaf extract possesses a potent inhibitory effect on PTP1B enzymatic activity and this PTP1B inhibition is through a slow oxidative but reversible inactivation on the enzyme. The reversible inactivation would suggest guava leaf extract may augment PTP1B inhibition alongside the endogenous H2O2 which itself is induced by insulin. In addition, our study confirmed the hypoglycemic efficacy being associated with guava leaf and found the most effective molecules reside in the aqueous partition which is also less cytotoxic to Chinese hamster ovary cells when compared to other less polar partitions. The guava leaf extract can modulate insulin activity through a redox regulation on PP1B enzymatic activity. It is speculated that a compound similar to gallocatechin in the aqueous partition can reduce an oxygen molecule to hydrogen peroxide which in turn oxidizes the catalytic residue Cys in PTP1B. Therefore, the guava leaf tea can serve as a functional hypoglycemic drink that is suitable for either healthy or diabetic subjects.

An Optimum Dose of Olive Leaf Extract Improves Insulin Receptor Substrate-1,Tyrosine Kinase,and Glucose Transporters,While High Doses Have Genotoxic and Apoptotic Effects

Type 2 diabetes is the most common type of diabetes. Conventionally many drugs are used for the treatment of diabetes such as biguanides, sulfonylureas, meglitinides, etc. But the desired effective treatment is still not to be achieved. So researches are going on for the development of effective alternative therapy against diabetes. Olive leaves are traditionally used in the treatment of the disease. However, studies on its mechanism of action are not yet enough. The aim of this study was to investigate whether olive leaf extract (OLE) improves insulin receptor substrate-1 (IRS-1), tyrosine kinase (TK), GLUT-2, and GLUT-4. Oleuropein levels were analyzed from OLE obtained by using four different solvents, and the highest content of methanol extract was selected for the study. Different concentrations of OLE (2.5 to 320 μg/mL) were incubated with hepatocellular carcinoma (HepG2) cells for 24 hours. After incubation, cell viability was assessed based on luminometric ATP cell viability assay kit. Intracellular reactive oxygen species (ROS) generating level was detected using 2,7dichlorodihydrofluorescein-diacetate (H2DCF-DA) fluorescent probes. Apoptosis was evaluated by acridine orange/ethidium bromide double staining method. Genotoxicity was evaluated by alkaline single cell gel electrophoresis assay (Comet Assay). Protein expression levels of IRS-1, TK, GLUT-2, and GLUT-4 were analyzed by western blotting technique from the obtained cell lysates. Although an optimum doses of OLE (10 μg/mL) maximally increased cell proliferation, decreased ROS generation improved IRS-1, TK, GLUT-2, and GLUT-4 protein expression levels (about fivefold), higher doses (10 to 320 μg/mL) markedly decreased the cell viability, increased DNA damage, apoptosis and ROS generation in a concentration-dependent manner. OLE can be used in the treatment of type 2 diabetes. However, in order to find the most effective and non-toxic concentration, dose optimization is required.

Study on the Anti-inflammatory and Repairing Effects of Cannabis Sativa Leaf Extract by Epikutis Model Substitution

To explore the anti-inflammatory effect of Cannabis sativa leaf extracts and their repair to damaged skin,a 3D epidermal model(Epikutis®)was used.During the experiment,after epithelial cell surface was pretreated with SLS for 24 h,the anti-inflammatory effect and repair effect of Cannabis sativa leaf extract were observed by testing tissue viability and the representative pro-inflammatory factors such as IL-1α,TNF-αand IL-8.The tissue viability was detected by the MTT test.The results showed that the Cannabis sativa leaf extract effectively inhibited the secretion of inflammatory factors IL-1α,TNF-αand IL-8,and the tissue viability of the skin model was significantly improved after using the sample.The Cannabis sativa leaf extract has a repairing effect on skin barrier damage by inhibiting skin inflammatory reaction.