Analytical assessment of modulated electric flux triggered degradation of chlorfenapyr and deltamethrin pesticides in guava fruits.

The purpose of this study was to explore the new effective method and investigate the dissipation of chlorfenapyr and deltamethrin (DM) pesticides used in the treatment of guava fruit from tropical and sub-tropical areas of Pakistan. Five different solutions of varying concentrations of pesticides were prepared. This study involved the in-vitro and in-vivo analysis of modulated electric flux-triggered degradation as an efficient method for the safer degradation of selected pesticides. The Taser gun was used as a tool for providing different numbers of electrical shocks of million voltages to the pesticides present in guava fruit at different temperatures. The degraded pesticides were extracted and analyzed by High-performance liquid chromatography (HPLC). The HPLC chromatograms verified that significant dissipation of pesticides took place when these were exposed to 9 shocks at 37 °C, which proved the efficiency of this degradation method. More than 50% of the total spray of both pesticides was dissipated. Thus, modulated electrical flux-triggered degradation is one of the effective methods for pesticide degradation.

Guava (Psidium guajava L.) seed: A low-volume, high-value byproduct for human health and the food industry.

Guava processing industries generate peel and seeds as primary waste fractions. Guava seeds obtained after fruit processing possess untapped potential in the field of food science due to the presence of a diversity of nutritional and bioactive compounds. Along with offering a detailed understanding of the nutritional attributes of guava seeds, the present review comprehensively elaborates on the therapeutic activities of their bioactive compounds, their techno-functional properties, and their other edible and nonedible applications. The limited molecular and biochemical mechanistic studies outlining the antioxidant, immunomodulatory, anticancer, antimicrobial, neuroprotective and antidiabetic activities of guava seeds available in the literature are also extensively discussed in this review. The use of guava seed constituents as food additives and food functional and structural modulators, primarily as fat reducers, emulsifiers, water and oil holding agents, is also conceptually explained. Additional human intervention and molecular mechanistic studies deciphering the effects of guava seeds on various diseases and human health are warranted.

Assessment of renal and hepato-protective potential of guava leaves in male Sprague dawley rats.

Present research project was an attempt to explore the functional/nutraceutical worth of guava leaves from two locally grown varieties (Ruby & Safeda). For the purpose, guava leaves extract was fed to experimental male Sprague Dawley rats to explore the nutraceutical potential of guava leaves against hepatotoxicity. Two studies were performed on two types of rats i.e. study I (normal rats), study II (hepatotoxic rats). In both studies, 250 mg/kg each of pink guava leaves extracts (T1) and white guava leaves extracts (T2) was added in the feed. Feed intake and body weights of the rats were recorded. At the end of the first and eighth week of study, the blood samples of the rats were analyzed to check the effect of guava leaves extracts on renal functioning (Alkaline Phosphatase, Alanine Transaminase and Aspartate Transaminase) as well as liver functioning parameters including urea and creatinine. In both studies, comparatively higher feed consumption was observed in the control group than the rest of the treatments. At the end of study I, the highest weight (207±9.21 g) was observed in T0 whereas, during study II, the maximum value (202±5.58 g) was found in T2 (rats consuming white guava leaves extract) that indicates its effectiveness against hepatotoxicity. Regarding renal functioning tests, pink guava leaves were more effective in decreasing urea and creatinine levels in rats as compared to the white guava leaves in both study plans. Likewise, in each of study trial, pink guava leaves were more effective in reducing AST, ALT and ALP than white guava leaves and control. From the present investigation, it is deduced that guava leaves were effective against hepatotoxicity.

Optimization of ultrasound-assisted water extraction of flavonoids from Psidium guajava leaves by response surface analysis.

Psidium guajava leaves are rich in health-promoting flavonoids compounds. For better utilization of the resource, the ultrasound-assisted aqueous extraction was investigated using Box-Behnken design under response surface methodology. A high coefficient of determination (R2 = 97.8%) indicated good agreement between the experimental and predicted values of flavonoids yield. The optimal extraction parameters to obtain the highest total flavonoids yield were ultrasonic power of 407.41 W, extraction time of 35.15 min, and extraction temperature of 72.69 °C. The average extraction rate of flavonoids could reach 5.12% under the optimum conditions. Besides, HPLC analysis and field emission scanning electron microscopy indicated that the ultrasonic treatment did not change the main component of flavonoids during extraction process and the higher flavonoids content was attributed by the disruption of the cell walls of guava particles. Thus, the extraction method could be applied successfully for large-scale extraction of total flavonoids from guava leaves.

Pesticide residues in cashew apple, guava, kaki and peach: GC-µECD, GC-FPD and LC-MS/MS multiresidue method validation, analysis and cumulative acute risk assessment.

A multiresidue method for the determination of 46 pesticides in fruits was validated. Samples were extracted with acidified ethyl acetate, MgSO4 and CH3COONa and cleaned up by dispersive SPE with PSA. The compounds were analysed by GC-FPD, GC-µECD or LC-MS/MS, with LOQs from 1 to 8 µg/kg. The method was used to analyse 238 kaki, cashew apple, guava, and peach fruit and pulp samples, which were also analysed for dithiocarbamates (DTCs) using a spectrophotometric method. Over 70% of the samples were positive, with DTC present in 46.5%, λ-cyhalothrin in 37.1%, and omethoate in 21.8% of the positive samples. GC-MS/MS confirmed the identities of the compounds detected by GC. None of the pesticides found in kaki, cashew apple and guava was authorised for these crops in Brazil. The risk assessment has shown that the cumulative acute intake of organophosphorus or pyrethroid compounds from the consumption of these fruits is unlikely to pose a health risk to consumers.

Assessment of antioxidant activity of spray dried extracts of Psidium guajava leaves by DPPH and chemiluminescence inhibition in human neutrophils.

This work evaluated the physicochemical properties and antioxidant activity of spray dried extracts (SDE) from Psidium guajava L. leaves. Different drying carriers, namely, maltodextrin, colloidal silicon dioxide, Arabic gum, and ß -cyclodextrin at concentrations of 40 and 80% relative to solids content, were added to drying composition. SDE were characterized through determination of the total phenolic, tannins, and flavonoid content. Antioxidant potential of the SDE was assessed by two assays: cellular test that measures the luminol-enhanced chemiluminescence (LumCL) produced by neutrophils stimulated with phorbol myristate acetate (PMA) and the DPPH radical scavenging (DPPH∗ method). In both assays the antioxidant activity of the SDE occurred in a concentration-dependent manner and showed no toxicity to the cells. Using the CLlum method, the IC50 ranged from 5.42 to 6.50 µg/mL. The IC50 of the SDE ranged from 7.96 to 8.11 µg/mL using the DPPH(•) method. Psidium guajava SDE presented significant antioxidant activity; thus they show high potential as an active phytopharmaceutical ingredient. Our findings in human neutrophils are pharmacologically relevant since they indicate that P. guajava SDE is a potential antioxidant and anti-inflammatory agent in human cells.

Assessment of antioxidant capacity and cytotoxicity of selected Malaysian plants.

Thirteen Malaysian plants; Artocarpus champeden, Azadirachta indica, Fragaria x ananassa, Garcinia mangostana, Lawsonia inermis, Mangifera indica, Nephelium lappaceum, Nephelium mutobile, Peltophorum pterocarpum, Psidium guajava and Syzygium aqueum, selected for their use in traditional medicine, were subjected to a variety of assays. Antioxidant capability, total phenolic content, elemental composition, as well as it cytotoxity to several cell lines of the aqueous and ethanolic extracts from different parts of these selected Malaysian plants were determined. In general, the ethanolic extracts were better free radical scavengers than the aqueous extracts and some of the tested extracts were even more potent than a commercial grape seed preparation. Similar results were seen in the lipid peroxidation inhibition studies. Our findings also showed a strong correlation of antioxidant activity with the total phenolic content. These extracts when tested for its heavy metals content, were found to be below permissible value for nutraceutical application. In addition, most of the extracts were found not cytotoxic to 3T3 and 4T1 cells at concentrations as high as 100 microg/mL. We conclude that although traditionally these plants are used in the aqueous form, its commercial preparation could be achieved using ethanol since a high total phenolic content and antioxidant activity is associated with this method of preparation.