Anti-obesity Effect of Bioengineered Silver Nanoparticles Synthesized from Persea americana on Obese Albino Rats.

BACKGROUND: Obesity is an immoderate or abnormal accretion of fat or adipose tissue in the body that is prone to damage the health of mankind. Persea americana (Avocados) is a nutritious fruit known for its several health benefits. The current research was planned to evaluate the anti-obesity activity of bioengineered Silver Nanoparticles (AgNPs) against a high-fat diet (HFD) treated obese albino rats. METHODS: AgNPs were synthesized and characterized for the Phytochemical constituents, UV-vis Spectroscopy, FTIR, SEM and XRD. Furthermore, the lipid profile in serum, biochemical parameters and histopathological changes in tissues of albino rats were determined. RESULTS: The present study revealed the presence of tannins, flavonoids, steroids and saponins, carbohydrates, alkaloids, phenols and glycosides. The peak was disclosed at 402 nm in UV-vis spectroscopy, confirming the synthesis of AgNPs. FTIR analysis showed two peaks at 3332.25 cm-1 which correspond to the O-H stretch of the carboxylic acid band, and 1636.40 cm-1 represents the N-H stretch of the amide of proteins, respectively. This result confirms their contribution to the capping and stabilization of AgNPs. The XRD results confirm the crystalline nature of AgNPs, and SEM results indicated that the synthesized AgNPs were spherical. Further, the results of the current study showed the improved lipid profile and biochemical parameters in rats supplemented with methanolic pulp extract of Persea americana AgNPs when compared with other experimental groups. The histopathological findings displayed improved results with reduced hepatocyte degradation under the influence of AgNPs treatment. CONCLUSION: All the experimental evidence indicated the possible anti-obesity effect of silver nanoparticles synthesized from the methanolic pulp extract of Persea americana.

Metabolomics-based profiling of 4 avocado varieties using HPLC-MS/MS and GC/MS and evaluation of their antidiabetic activity.

Seven avocado "Persea americana" seeds belonging to 4 varieties, collected from different localities across the world, were profiled using HPLC-MS/MS and GC/MS to explore the metabolic makeup variabilities and antidiabetic potential. For the first time, 51 metabolites were tentatively-identified via HPLC-MS/MS, belonging to different classes including flavonoids, biflavonoids, naphthodianthrones, dihydrochalcones, phloroglucinols and phenolic acids while 68 un-saponified and 26 saponified compounds were identified by GC/MS analysis. The primary metabolic variabilities existing among the different varieties were revealed via GC/MS-based metabolomics assisted by unsupervised pattern recognition methods. Fatty acid accumulations were proved as competent, and varietal-discriminatory metabolites. The antidiabetic potential of the different samples was explored using in-vitro amylase and glucosidase inhibition assays, which pointed out to Gwen (KG) as the most potent antidiabetic sample. This could be attributed to its enriched content of poly-unsaturated fatty acids and polyphenolics. Molecular docking was then performed to predict the most promising phytoligands in KG variety to be posed as antidiabetic drug leads. The highest in-silico α-amylase inhibition was observed with chrysoeriol-4'-O-pentoside-7-O-rutinoside, apigenin-7-glucuronide and neoeriocitrin which might serve as potential drug leads for the discovery of new antidiabetic remedies.

Nephroprotective and anti-inflammatory potential of aqueous extract from Persea americana seeds against cadmium-induced nephrotoxicity in Wistar rats.

Cadmium is a toxic metal and poses a high environmental risk to animals and humans, alike. It is thus pertinent to search for medicinal plants in protecting against cadmium toxicity. This study aims at investigating the ability of aqueous extract of Persea americana seeds (AEPA) in ameliorating the toxic effects of cadmium in the kidneys of cadmium-exposed Wistar rats. Male Wistar rats were grouped into five, of six animals each. Different groups of animals received normal saline (control group), 200 mg/kg body weight AEPA, 400 mg/kg AEPA, and standard drug, Livolin Forte, respectively. A last group of animals was left untreated. To induce toxicity, all animals, except the control group, were exposed to cadmium (200 mg/L, as CdCl2) in their main drinking water for 21 days. Biochemical analysis of serum kidney markers, oxidative stress and antioxidant status, as well as anti-inflammatory activities, was done using standard methods and kits. In silico analysis was performed on phytochemicals reported to be abundant in AEPA. Treatment with 400 mg/kg AEPA significantly reversed (P ≤ 0.05) the adverse effect of cadmium on serum creatinine, urea, uric acid and blood urea nitrogen, and restored (P ≤ 0.05) antioxidant status, evidenced by its significant effect on superoxide dismutase, catalase, glutathione-S-transferase, glutathione peroxidase, reduced glutathione, and lipid peroxidation activities. AEPA, at 400 mg/kg also exhibited significant anti-inflammatory effects, which was shown by reduced interleukin-2 and tumour necrosis factor α activities. Molecular docking of phytochemicals with the selected protein target also confirmed the therapeutic potential of AEPA. The study concluded that aqueous extract of AEPA protects against cadmium-induced kidney toxicity and inflammation.

Avocado Peels and Seeds: Processing Strategies for the Development of Highly Antioxidant Bioplastic Films.

The industrial processing of avocados annually generates more than 1.2 million tons of avocado peels (APs) and avocado seeds (ASs) that have great potential in the production of active bioplastics, although they have never been considered for this aim until now. Separately, the APs and ASs, as well as a combination of avocado peels and seeds (APSs), were evaluated here for the first time for the preparation of antioxidant films, with application in food packaging. Films were prepared by casting, after their processing by three different methods: (1) hydrolysis in acid media, (2) hydrolysis followed by plasticization, and (3) hydrolysis and plasticization followed by blending with pectin polymers in different proportions (25 and 50 wt %). The results indicate that the combination of hydrolysis, plasticization, and pectin blending is essential to obtain materials with competitive mechanical properties, optical clarity, excellent oxygen barrier properties, high antioxidant activity, biodegradability, and migration of components in TENAX suitable for food contact applications. In addition, the materials prepared with APSs are advantageous from the point of view of the industrial waste valorization, since the entire avocado wastes are used for the production of bioplastics, avoiding further separation processes for their valorization.

Cytotoxicity of a Lipid-Rich Extract from Native Mexican Avocado Seed (Persea americana var. drymifolia) on Canine Osteosarcoma D-17 Cells and Synergistic Activity with Cytostatic Drugs.

Osteosarcoma is the most common malignant bone tumor in both children and dogs. It is an aggressive and metastatic cancer with a poor prognosis for long-term survival. The search for new anti-cancer drugs with fewer side effects has become an essential goal for cancer chemotherapy; in this sense, the bioactive compounds from avocado have proved their efficacy as cytotoxic molecules. The objective of this study was to determine the cytotoxic and antiproliferative effect of a lipid-rich extract (LEAS) from Mexican native avocado seed (Persea americana var. drymifolia) on canine osteosarcoma D-17 cell line. Also, the combined activity with cytostatic drugs was evaluated. LEAS was cytotoxic to D-17 cells in a concentration-dependent manner with an IC50 = 15.5 µg/mL. Besides, LEAS induced caspase-dependent cell apoptosis by the extrinsic and intrinsic pathways. Moreover, LEAS induced a significant loss of mitochondrial membrane potential and increased superoxide anion production and mitochondrial ROS. Also, LEAS induced the arrest of the cell cycle in the G0/G1 phase. Finally, LEAS improved the cytotoxic activity of cisplatin, carboplatin, and in less extension, doxorubicin against the canine osteosarcoma cell line through a synergistic effect. In conclusion, avocado could be a potential source of bioactive molecules in the searching treatments for osteosarcoma.

Avocado (Persea americana) pulp improves cardiovascular and autonomic recovery following submaximal running: a crossover, randomized, double-blind and placebo-controlled trial.

Previous studies have demonstrated that regular avocado consumption presents advantageous effects on cardiovascular system. However, little attention has been paid to the use of avocado as a dietary supplement, in particular, for individuals involved in physical exercise training. Therefore, this study aims to evaluate the effect of acute avocado pulp intake on cardiovascular and autonomic recovery subsequent to moderate exercise. Using a crossover, randomized, double-blind and placebo-controlled trial design, 16 healthy female adults underwent two protocols: Avocado pulp (600 mg in capsule) and placebo (600 mg starch in capsule). After the ingestion of Avocado pulp or placebo, the subjects were seated for 60 min at rest, followed by running on a treadmill at a submaximal level and then remained seated for 60 min during recovery from the exercise. Heart rate (HR), heart rate variability (HRV) [rMSSD, SD1, HF (ms2)] and skin conductance were evaluated before and during exercise, as well as during recovery. HR, systolic blood pressure, HRV and skin conductance recovered faster when subjects were given avocado pulp prior to exercise. In conclusion, avocado pulp improved cardiovascular and autonomic recovery after exercise, suggesting a reduced risk of cardiovascular events after exertion. The current results support the beneficial effects of ingestion of avocado prior to submaximal treadmill running.

Novel effect of Arthrocen (avocado/soy unsaponifiables) on pentylenetetrazole-induced seizure threshold in mice: Role of GABAergic pathway.

Arthrocen, an avocado/soy unsaponifiable (ASU)-containing agent, is now used in the clinic and has potentially to decrease joint inflammation and pain associated with mild to severe osteoarthritis. Phytosterols are the major component of Arthrocen with documented anti-inflammatory properties, antioxidant, and analgesic effects. Here, we evaluated ASU anticonvulsant effect by its oral administration in pentylenetetrazole (PTZ)-induced seizure threshold and Maximal Electroshock Seizure (MES) Models. Also, the involvement of N-methyl-d-aspartate (NMDA) receptor, benzodiazepine receptor, and nitric oxide (NO) pathway were studied in anticonvulsant effect of ASU in male NMRI mice. Acute administration of Arthrocen (150, 75, 30, 10 mg/kg) by oral gavage significantly (p < 0.001) increased the clonic seizure threshold induced by intravenous administration of PTZ. Nonspecific inducible NO synthase (NOS) inhibitor L-NAME (10 mg/kg) and a specific NMDA receptor antagonist MK-801 (0.05 mg/kg) did not affect the anticonvulsant effect of Arthrocen, while pretreatment with flumazenil (0.25 mg/kg), a selective benzodiazepine receptor antagonist, reversed this effect (p < 0.01). Also, Arthrocen treated mice did not affect tonic hindlimb extension in the MES model. The data showed that Arthrocen might produce its anticonvulsant effect by enhancing GABAergic neurotransmission and/or action in the brain.

Perseorangin: A natural pigment from avocado (Persea americana) seed.

High consumer demand has led global food color manufacturers and food companies to dramatically increase the development and use of natural colors. We have previously reported that avocado (Persea americana) seeds, when crushed in the presence of air, develop a red-orange color in a polyphenol oxidase-dependent reaction. The objective of this study was to identify the major colored compound in colored avocado seed extract (CASE). Column chromatography and high performance liquid chromatography were used to isolate the most abundant colored compound in CASE. This compound, henceforth referred to as perseorangin, was a yellow-orange solid. Structural analysis was performed using high-resolution mass spectrometry, and infrared and nuclear magnetic resonance spectroscopy. We determined that perseorangin is a glycosylated benzotropone-containing compound with a molecular formula of C29H30O14. Liquid chromatography with electrospray ionization mass spectrometry-based metabolomic analysis of CASE and uncolored avocado seed extract showed that perseorangin was unique to CASE.

Hass avocado (Persea americana Mill.) oil enriched in phenolic compounds and tocopherols by expeller-pressing the unpeeled microwave dried fruit.

This study investigated how the quality of avocado oil is affected by the fruit ripening stage and peeling, and the drying process used. Expeller pressed avocado oils were obtained from unripe or ripe pitted avocados after drying peeled or unpeeled pulps by convection oven, microwave or freeze-drying. Oils from the unpeeled microwave dried pulp (from unripe or ripe avocados) showed the highest induction period (54.2-83.6 h) and antioxidant capacity (4.07-5.26 mmol TE/kg), and high amounts (mg/100 g) of α-tocopherol (11.6-21.0), ß-carotene (0.49-0.65) and chlorophyll (44.3-54.0), and unsaponifiable matter (2.48-2.99 g/100 g). Pulp drying process and avocado (un)peeling were the major contributors to the induction period (R2 = 0.61; p = 0.0139) and antioxidant capacity (R2 = 0.62; p = 0.011), and the oils from microwave dried unpeeled pulp were those that presented the best performance. The phenolic composition of these oils improved with ripening and keeping the peel during the pressing process.

Changes in cell wall pectins and their relation to postharvest mesocarp softening of "Hass" avocados (Persea americana Mill.).

The avocado is a climacteric fruit and begins a softening process after harvest. During ripening, the mesocarp changes in texture, and this affects fruit quality and cold storage capacity. Softening is commonly associated with cell wall disassembly in climacteric fruits. However, changes in the cell wall structure and composition during avocado softening are poorly understood. To understand this process, cell wall pectins in "Hass" avocado fruit were studied during ripening at 20 °C after harvest and after cold storage. Additionally, avocados were treated with 1-MCP to evaluate the delay in softening. Biochemical analysis showed a decrease in galacturonic acid (GalA) in alcohol-insoluble residues (AIR) and water-soluble pectin concomitant to softening, paralleled by an increase in polygalacturonase (PG) activity. In the same way, the ß-galactosidase activity increased in soft avocado fruit, along with a reduction in galactose in cell wall material and the Na2CO3-soluble fraction. The arabinose content in the cell wall material did not change during softening. However, there was a change in arabinose ratios between the different fractions of pectin, mainly in the fractions soluble in water and in Na2CO3. The cold storage of avocado fruit did not induce softening of the fruit, but the content of GalA showed a substantial decrease, accompanied by an increase in PG activity. Thus, our work supports the hypothesis that the solubilization of neutral sugars such as arabinose and rhamnose, as well as the loss of galactose content mediated by the enzyme ß-galactosidase, were the main factors that began the coordinated action of cell wall remodeling enzymes that resulted in the loss of firmness of avocado fruit.

Bioactive compounds and quality parameters of avocado oil obtained by different processes.

The objective of this study was to evaluate the quality of avocado oil whose pulp was processed through different drying and oil extraction methods. The physicochemical characteristics of avocados cv. Breda were determined after drying the pulp in an oven under ventilation (40 °C and 60 °C) and vacuum oven (60 °C), followed by the oil extracted by mechanical pressing or the Soxhlet method. From the approximately 72% pulp found in the avocado fruit, the 16% fraction is lipids. The quality indices evaluated in avocado oil showed better results when the pulp was dried at 60 °C under vacuum and oil extraction was done by the Soxhlet method with petroleum ether, whereas the bioactive compounds were better preserved when the avocado pulp was dried at 60 °C under ventilation and mechanical pressing was used for the oil extraction. Among the fatty acids found, oleic acid was the main.

α-Lipoic Acid Potentiates the Anti-Inflammatory Activity of Avocado/Soybean Unsaponifiables in Chondrocyte Cultures.

Objective Pro-inflammatory mediators such as prostaglandin E-2 (PGE2) play major roles in the pathogenesis of osteoarthritis (OA). Although current pharmacologic treatments reduce inflammation, their prolonged use is associated with deleterious side effects prompting the search for safer and effective alternative strategies. The present study evaluated whether chondrocyte production of PGE2 can be suppressed by the combination of avocado/soybean unsaponifiables (ASU) and α-lipoic acid (LA). Design Chondrocytes from articular cartilage of equine joints were incubated for 24 hours with: (1) control media, (2) ASU, (3) LA, or (4) ASU + LA combination. Cells were activated with lipopolysaccharide (LPS), interleukin 1ß (IL-1ß) or hydrogen peroxide (H2O2) for 24 hours and supernatants were immunoassayed for PGE2. Nuclear factor-kappa B (NF-κB) analyses were performed by immunocytochemistry and Western blot following 1 hour of activation with IL-1ß. Results LPS, IL-1ß, or H2O2 significantly increased PGE2 production. ASU or LA alone suppressed PGE2 production in LPS and IL-1ß activated cells. Only LA alone at 2.5 µg/mL was inhibitory in H2O2-activated chondrocytes. ASU + LA inhibited more than either agent alone in all activated cells. ASU + LA also inhibited the IL-1ß induced nuclear translocation of NF-κB. Conclusions The present study provides evidence that chondrocyte PGE2 production can be inhibited by the combination of ASU + LA more effectively than either ASU or LA alone. Inhibition of PGE2 production is associated with the suppression of NF-κB translocation. The potent inhibitory effect of ASU + LA on PGE2 production could offer a potential advantage for a combination anti-inflammatory/antioxidant approach in the management of OA.

Secondary metabolites from the unripe pulp of Persea americana and their antimycobacterial activities.

The fruits of Persea americana (Avocado) are nowadays used as healthy fruits in the world. Bioassay-guided fractionation of the active ethyl acetate soluble fraction has led to the isolation of five new fatty alcohol derivatives, avocadenols A-D (1-4) and avocadoin (5) from the unripe pulp of P. americana, along with 12 known compounds (6-17). These structures were elucidated by spectroscopic analysis. Among the isolates, avocadenol A (1), avocadenol B (2), (2R,4R)-1,2,4-trihydroxynonadecane (6), and (2R,4R)-1,2,4-trihydroxyheptadec-16-ene (7) showed antimycobacterial activity against Mycobacterium tuberculosis H(37)R(V)in vitro, with MIC values of 24.0, 33.8, 24.9, and 35.7 µg/ml, respectively.

Profiling LC-DAD-ESI-TOF MS method for the determination of phenolic metabolites from avocado (Persea americana).

A powerful HPLC-DAD-ESI-TOF MS method was established for the efficient identification of the chemical constituents in the methanolic extracts of avocado (Persea americana). Separation and detection conditions were optimized by using a standard mix containing 39 compounds belonging to phenolic acids and different categories of flavonoids, analytes that could be potentially present in the avocado extracts. Optimum LC separation was achieved on a Zorbax Eclipse Plus C18 analytical column (4.6×150 mm, 1.8 µm particle size) by gradient elution with water+acetic acid (0.5%) and acetonitrile as mobile phases, at a flow rate of 1.6 mL/min. The detection was carried out by ultraviolet-visible absorption and ESI-TOF MS. The developed method was applied to the study of 3 different varieties of avocado, and 17 compounds were unequivocally identified with standards. Moreover, around 25 analytes were tentatively identified by taking into account the accuracy and isotopic information provided by TOF MS.