Role Of Phenolics Research Articles

The Role of Phenol and Flavonoid in the Synthesis and Application of Nano Graphene Oxide

The unique properties of graphene oxide have generated significant interest in recent years. Many potent aromatic drugs are water-insoluble, complicating their administration. Nano graphene oxide, a potential drug carrier, is typically synthesized through environmentally harmful chemical methods. This review emphasizes the need for more sustainable approaches to address these challenges while maintaining graphene oxide's effectiveness in drug delivery. Plant extracts are rich in bioactive compounds known as phytochemicals which have the ability to synthesize nano graphene oxide. A large and most intricate class of these phytochemicals are Phenolic compounds which have an aromatic ring and one or more hydroxyl groups in their structural conformations. Based on their structural composition, they are divided into subgroups that include phenolic acids, flavonoids, tannins, coumarins, lignans, quinones, stilbenes, and carotenoids. Plant polyphenols are gaining increasing attention because of their potent antioxidant properties and important roles in preventing oxidative stress-related diseases. The extraction, identification, and characterization of phenolic compounds from a range of plant sources has become a major area of study in the health and medical fields in recent years. The role of phenol and flavonoid in the synthesis and application of nano composites are also covered in this review.

Role of phenol and its derivative biometabolic compounds in bioregulation

Role of phenol and its derivative biometabolic compounds in bioregulation

An Insight into the Role of Phenolics in Abiotic Stress Tolerance in Plants: Current Perspective for Sustainable Environment

Phenolic compounds (PCs) are a prominent class of secondary metabolites produced by plants and are essential for the natural role of the entire plant life cycle. PCs are formed in plants under both favorable and unfavorable conditions and have essential functions in signaling pathways, such as cell division, nutrient mineralization, hormone control, and reproduction. Under abiotic stress conditions, plants produce more polyphenols, which aid them in adapting to their environment. The phenylpropanoid biosynthetic pathway is activated under various environmental stress conditions, such as drought, heavy metal toxicity, salinity, and high/low temperatures, resulting in the deposition of compounds. These compounds can neutralize reactive oxygen species (ROS) produced in excessive amounts in crops under stressful conditions and adversely affect plants. It is imperative to investigate the functions of PCs in response to several abiotic stresses, as the phenylpropanoid pathway plays a crucial role in the metabolic pathway in crop plants, leading to the biosynthesis of a wide range of PCs. These compounds play various roles in plant growth, development, and response to environmental stress. Therefore, this review provides a comprehensive understanding of PCs and their exchanges with other cellular components, which is crucial for harnessing their potential to improve crop resilience to environmental stresses.

Antioxidant, antibacterial, cytotoxic and thrombolytic activities of flowers of Mirabilis jalapa L: Possible role of phenolics and flavonoids

Mirabilis jalapa L. belongs to Nyctaginaceae family is an ornamental plant and domestically known as Sandhamaloti in Bangladesh. In this report we evaluated phenol and flavonoid content of cold methanol extractives of flower of M. jalapa and their role in antioxidant, antibacterial, cytotoxic and thrombolytic potentials. This study utilized HPLC to identify qualitative phenolic and flavonoid compounds. Gallic acid and Kaempferol were employed as standards for phenolic and flavonoid identification, respectively. Consequently, evaluating the overall phenolic and flavonoid content in the plant extract was considered a logical step. Flower of M. jalapa is an abundant source of phenols and flavonoids. The antioxidant activities in the phosphomolybdenum assay are differed in distinct extractives and have been found as 334.78 ± 0.62, 142.53 ± 0.51, 398.04 ± 0.81, 470.29 ± 0.55 and 480.90 ± 0.59 mg of ascorbic acid equivalent per gm of crude methanol extract (MSF), petroleum ether fraction (PSF), carbon tetrachloride fraction (CTF), chloroform fraction (CSF) and ethyl acetate fraction (ESF), respectively. The IC50 values for DPPH radical scavenging have been evaluated to be 13.70 ± 0.32, 49.05 ± 0.47, 6.76 ± 0.22, 9.30 ± 0.41 and 6.94 ± 0.31 μg/mL for MSF, PSF, CTF, CSF and ESF, respectively. The cytotoxicity was evaluated against brine shrimp lethality bioassay and LC50 values of MSF, PSF, CTF, CSF and ESF have been found 11.83 ± 0.32, 35.50 ± 0.54, 5.00 ± 0.18, 11.30 ± 0.30 and 4.61 ± 0.15 μg/mL, respectively in comparison to a standard vincristine sulphate 2.50 ± 0.11 μg/mL. Plant polyphenols and flavonoids having antioxidant properties exhibit potential antibacterial activity and our results revealed that the entire tested fractions of vegetation of M. jalapa exhibit potential antibacterial activity. On this observation, the thrombolytic activity, is the first strive in M. jalapa to investigate for more modern thrombolytic and its ethyl acetate fraction was shown to substantial (53.81 ± 0.52%) thrombolysis property. A high correlation was observed between antioxidant, cytotoxicity, thrombolytic and antibacterial activity with polyphenol and flavonoid contents (r2 = 0.903 to 0.996, p < 0.05). These data suggest the role of polyphenols and flavonoids in the bioactivities. Further study of this plant may lead to isolation of bioactive polyphenols and flavonoids which will be effective in the management of many chronic diseases.

Allelopathy of Faba Bean Cover Crop to Durum Wheat Under a Semi-Arid Environment

Problems facing farmers practicing conservation agriculture in the semi-arid zone of Tunisia include appropriate cover crop selection, management of allelopathic effects affecting subsequent crop performance, and influence of seasonal variation on allelopathy expression. Allelopathy expressed by faba bean (Vicia faba L.) toward durum wheat [Triticum turgidum ssp. durum (Desf.) Husn.] was studied using bioassays during three growing seasons. The role of phenols in the expression of such potential was also investigated. Analyses of plant samples at three phenological stages (flowering, fruiting, senescence) revealed that leaves were most inhibitory. Allelopathic potential differed among plant components and phenological stages, with the greatest inhibitory effects occurring at senescence (49%). Inhibition varied across growing seasons, suggesting an environmental impact linked to inter-monthly water-balance variability. Inter-monthly rainfall appeared to be negatively related to the intensity of the allelopathic potential. The total phenolic content varied among plant components, phenological stages, and growing seasons, and the results implied that climatic variation may impact phenol accumulation in plant tissues. Total phenolics content of roots and stems significantly (p = 0.003 and 0.03, respectively) contributed to faba bean allelopathy. Use of faba bean as a cover crop preceding durum wheat carries a risk of allelopathic effects, which could negatively impact grain yield. Understanding the allelopathy of faba bean as a cover crop is critical for efficient management of residues under conservation agriculture.

Allelopathy of Faba Bean Cover Crop to Durum Wheat Under a Semi-Arid Environment

Problems facing farmers practicing conservation agriculture in the semi-arid zone of Tunisia include appropriate cover crop selection, management of allelopathic effects affecting subsequent crop performance, and influence of seasonal variation on allelopathy expression. Allelopathy expressed by faba bean (Vicia faba L.) toward durum wheat [Triticum turgidum ssp. durum (Desf.) Husn.] was studied using bioassays during three growing seasons. The role of phenols in the expression of such potential was also investigated. Analyses of plant samples at three phenological stages (flowering, fruiting, senescence) revealed that leaves were most inhibitory. Allelopathic potential differed among plant components and phenological stages, with the greatest inhibitory effects occurring at senescence (49%). Inhibition varied across growing seasons, suggesting an environmental impact linked to inter-monthly water-balance variability. Inter-monthly rainfall appeared to be negatively related to the intensity of the allelopathic potential. The total phenolic content varied among plant components, phenological stages, and growing seasons, and the results implied that climatic variation may impact phenol accumulation in plant tissues. Total phenolics content of roots and stems significantly (p = 0.003 and 0.03, respectively) contributed to faba bean allelopathy. Use of faba bean as a cover crop preceding durum wheat carries a risk of allelopathic effects, which could negatively impact grain yield. Understanding the allelopathy of faba bean as a cover crop is critical for efficient management of residues under conservation agriculture.

Molecular evidence for the involvement of alternative splicing in jejunum epithelial cells in broiler chickens fed dietary supplementation with olive mill wastewater.

There is no doubt that alternative splicing is conserved in chickens and mammals, but evaluating the effects of nutrition on alternative splicing in chickens is crucial in a wide range of fields. Although the olive diet has been extensively studied in human, mouse, and chicken systems, little is known about its impact on chicken alternative splicing systems. Hence, the current study aimed to assess the effect of feeding polyphenol-enriched olive mill wastewater to female broiler chickens via alternative splicing by analyzing high-throughput sequencing raw reads of RNA utilizing genomics and bioinformatics methodologies. It also aimed to look for differences in isoform expression and discover molecular functions and biological processes linked to differentially transcribed genes. The findings of our study revealed that 51 genes involved in isoform switching and alternative splicing events were not used evenly. This is due to the reduced use of ATSS in olive mill wastewater groups compared to control groups. Furthermore, the gene ontology analysis revealed that 25 GO terms were enriched in biological processes, 16 GO terms were enriched in molecular function, and 25 GO terms were enriched in cellular components. Kinase and adenylyltransferase activities were significantly enriched in terms. The molecular analysis presented herein provides valuable insight into the role of phenolics in alternative gene-splicing mechanisms in chickens, demonstrating how an industrial waste product can be repurposed as a feed supplement with a satisfactory outcome.

Salt-Tolerant Plants, Halophytes, as Renewable Natural Resources for Cancer Prevention and Treatment: Roles of Phenolics and Flavonoids in Immunomodulation and Suppression of Oxidative Stress towards Cancer Management.

Halophytes and xerophytes, plants with adequate tolerance to high salinity with strong ability to survive in drought ecosystem, have been recognized for their nutritional and medicinal values owing to their comparatively higher productions of secondary metabolites, primarily the phenolics, and the flavonoids, as compared to the normal vegetation in other climatic regions. Given the consistent increases in desertification around the world, which are associated with increasing salinity, high temperature, and water scarcity, the survival of halophytes due to their secondary metabolic contents has prioritized these plant species, which have now become increasingly important for environmental protection, land reclamation, and food and animal-feed security, with their primary utility in traditional societies as sources of drugs. On the medicinal herbs front, because the fight against cancer is still ongoing, there is an urgent need for development of more efficient, safe, and novel chemotherapeutic agents, than those currently available. The current review describes these plants and their secondary-metabolite-based chemical products as promising candidates for developing newer cancer therapeutics. It further discusses the prophylactic roles of these plants, and their constituents in prevention and management of cancers, through an exploration of their phytochemical and pharmacological properties, with a view on immunomodulation. The important roles of various phenolics and structurally diverse flavonoids as major constituents of the halophytes in suppressing oxidative stress, immunomodulation, and anti-cancer effects are the subject matter of this review and these aspects are outlined in details.

Antioxidant, cytotoxic, antibacterial and thrombolytic activities of Centella asiatica L.: possible role of phenolics and flavonoids

BackgroundCentella asiatica L. (Apiaceae), a green leafy vegetable, has been used as a popular folk medicine in Bangladesh in the treatment of various ailments. The plant is reported to contain phenolics and flavonoids, but their bioactive potentials are not yet completely known. The present study was designed to investigate the role of the phenolic and flavonoids in the antioxidant, cytotoxicity, antibacterial and thrombolytic activities.MethodsFour solvent fractions viz. methanol (MSF), ethyl acetate (ESF), chloroform (CSF) and petroleum ether (PSF) were prepared from the dried powder of the whole plant by the modified Kupchan method. Total phenolic content and flavonoid content were determined by Folin Ciocalteu method and aluminum chloride colorimetric method, respectively. The antioxidant activity was assessed by the DPPH radical scavenging and total antioxidant capacity assays. The antibacterial activity was determined by the disc diffusion method and cytotoxicity was evaluated by the brine shrimp lethality bioassay. Thrombolytic activity was assayed using streptokinase as standard.ResultsQualitative analysis of phytochemical revealed the presence of phenolics and flavonoids along with other bioactive constituents. Among the extractives, CSF contained the highest content of phenolics (155.46 ± 0.52 mg GAE/g) and flavonoids (345.17 ± 1.12 mg QE/g) and exhibited the most potent antioxidant activity in terms of total antioxidant capacity (179.01 ± 0.89 mg AAE/g) and DPPH scavenging ability (IC50; 15.31 ± 0.32 µg/mL). Similarly, CSF showed the highest cytotoxicity with LC50 values of 13.80 ± 0.23 µg/mL, and thrombolytic activity with 43.94 ± 0.62% clot lysis. The fraction also exhibited broad spectrum antibacterial activity. A significant correlation was observed between the flavonoid content and total antioxidant activity (r2 = 0.894, p < 0.05), while high correlation was seen between phenolic and flavonoid content and DPPH radical scavenging, total antioxidant capacity and cytotoxicity (r2 = 0.612–0.928). Similarly, a positive correlation was found between phenolic and flavonoid content with thrombolytic and antibacterial activities.ConclusionThese results revealed that C. asiatica is a rich source of phenolics and flavonoids and correlated with antioxidant, cytotoxicity, antibacterial and thrombolytic activities. Hence isolation of phenolics and flavonoids from this plant may offer potential candidates which may be effective in the prevention of many chronic diseases.

Possible Role of Phenolics and Flavonoids in Antioxidant, Cytotoxic and Thrombolytic Activities of Eclipta prostata L.

Eclipta prostata (E. prostata) L, is a herbal medicinal plant, which is reported to contain phenolics and flavonoids, but very little is known about its bioactive potentials. In this report, we reexamined the phenols and flavonoid content and evaluated different bioactivities of organic soluble fractions from the shoots of E. prostata for the first time. Among the extractives, chloroform soluble fraction (CSF) possessed the highest content of phenols (156.03 ± 0.52 mg gallic acid equivalent /g of dry extract) and flavonoids (67.47 ± 0.56 mg quercetin equivalent /g of dry extract) and exhibited the most potent antioxidant properties in terms of total antioxidant capacity (198.71 ± 0.89 mg ascorbic acid equivalent/g of dry extract) and DPPH free radical scavenging ability (IC50; 17.68 ± 0.32 μg/ml). Similarly, CSF showed the highest cytotoxicity with LC50 values of 16.03±0.23 μg/ml, and thrombolytic activity with 36.06 ± 0.39% clot lysis. A significant correlation was observed between flavonoid content and total antioxidant capacity (r2 = 0.894, p &lt; 0.05), while high correlation was seen between polyphenols and flavonoid content with free radical scavenging, total antioxidant capacity and cytotoxicity (r2 = 0.612 - 0.928). These findings suggest that E. prostata is a precious source of polyphenols having potential bioactivities, which could be utilized for the management of lifestyle diseases. Bangladesh Pharmaceutical Journal 25(2): 164-174, 2022 (July)

Polyphenol-enriched extract from pearl millet (Pennisetum glaucum) inhibits key enzymes involved in post prandial hyper glycemia (α-amylase, α-glucosidase) and regulates hepatic glucose uptake

Inhibition of carbohydrate digestion and modulation of glucose uptake are the major mechanisms of anti-hyperglycemic potential known to be played by phenolics; but the role of archaeologically relevant staple pearl millet (Pennisetum glaucum; PM), is still much unknown. A combined approach using in vitro inhibitory data and in silico docking of PM phenolics against key players of glucose homeostasis (salivary α-amylase: SA; pancreatic α-amylase: PA; α-glucosidase, maltase-glucoamylase: MGAM and GLUT2) were carried out. Observed notable inhibition with HHB299 having the most relevant effect (IC50: 73.06 ± 0.37 μg/mL for α-amylase; IC50: 73.80 ± 0.12 μg/mL for α-glucosidase). The role of phenolics on basal glucose uptake into hepatocytes, revealed a maximum of 241.25% in PC612 and the least of 198.1% in HHB67imp. Virtual screening via docking found that 3, 4-Di-OMe luteolin, acacetin as the major flavonoids while salicylic acid, melilotic acid as the key phenolic acids contributing towards the observed anti-diabetic effect. Further, structure-activity relationship (SAR) identified the critical functional groups required for the protein-phenolic molecular interactions. This report validates the role of PM phenolics in inhibiting carbolytic enzymes and regulating GLUT and thus probes the link towards the anti-diabetic potential.

Antioxidant and acetylcholinesterase inhibition capacity of hyrosols from lamiaceae plants for biopesticide use: role of phenolics

ABSTRACT The aim of this study was to investigate the main volatiles and polyphenolic compounds in hydrosols extracted from three Romanian Lamiaceae plants, sage (Salvia officinalis), rosemary (Rosmarinus officinalis) and lavender (Lavandula angustifolia) by steam distillation. The antioxidant and acetylcholinesterase inhibition capacity of hydrosols were assessed for their further use as biopesticides. The results have shown that sage and rosemary hydrosols presented better antioxidant activity than lavender hydrosol in all free radical scavenging and metal chelating assays. A strong relationship between the antioxidant activity of hydrosols’ and their total phenolic and flavonoid content was found based on Pearson correlation coefficients. Sage and rosemary hydrosols exerted higher acetylcholinesterase inhibition than lavender hydrosol, but this activity was moderate correlated to phenolic content and low correlated to flavonoid content. These results suggested that volatiles and other compounds present in hydrosols were also involved in this process. In conclusion, Lamiaceae plant hydrosols could be further tested, as such or mixed, as natural products for the control of pests in eco-agrosystems.

Effect of phenolic compound in resistance to mungbean yellow mosaic virus in mungbean

The project was undertaken to study the roleof phenol against MYMV resistance in mungbean plants in natural condition.The present investigation was undertaken during the spring season at Research Farm of Tirhut College of Agriculture, Dholi, Muzaffarpur, Bihar. Four genotypes of mungbean namely HUM-16,TMV-37, Samrat and LGG 450 has been taken. The estimation of total phenol content protocol was carried out with Folin-Ciocalteu Reagent (FCR) by Bray and Thorpe 1954. The absorbance at 650 nm at 1mg/g concentration of phenol was found to be 0.727 a.u. This value was taken as standard as it is very close to the mean value. Highest value of absorbance at 650 nm was found in TMV 37, followed by HUM 16 and Samrat respectively. LGG 450 showed the least value of absorbance which was in direct correlation with MYMV resistance.

Metabolome-Wide, Phylogenetically Controlled Comparison Indicates Higher Phenolic Diversity in Tropical Tree Species.

Tropical plants are expected to have a higher variety of defensive traits, such as a more diverse array of secondary metabolic compounds in response to greater pressures of antagonistic interactions, than their temperate counterparts. We test this hypothesis using advanced metabolomics linked to a novel stoichiometric compound classification to analyze the complete foliar metabolomes of four tropical and four temperate tree species, which were selected so that each subset contained the same amount of phylogenetic diversity and evenness. We then built Bayesian phylogenetic multilevel models to test for tropical–temperate differences in metabolite diversity for the entire metabolome and for four major families of secondary compounds. We found strong evidence supporting that the leaves of tropical tree species have a higher phenolic diversity. The functionally closer group of polyphenolics also showed moderate evidence of higher diversity in tropical species, but there were no differences either for the entire metabolome or for the other major families of compounds analyzed. This supports the interpretation that this tropical–temperate contrast must be related to the functional role of phenolics and polyphenolics.

Major Indian spices- An introspection on variability in quality

Indian spices like black pepper, cardamom, ginger, turmeric and cinnamon are valued for their culinary and nutraceutical properties. The quality attributes that impart these properties are essential oil, oleoresin and the aroma/pungent principles. Variability in essential oil constituents of black pepper, relevance of bulk density, codex standards and role of phenolics in deciding quality traits possess great relevance in academic and industrial applications. Curing of turmeric and maturity at harvest play a crucial role in drying and curcumin content. Geographical location has great relevance in deciding the curcumin content of turmeric. Coumarin content of cinnamon and cassia has implications in industrial application. This article provides an introspection in to the research programmes on quality attributes of spices carried out at ICAR-Indian Institute of Spices Research for the last three decades in comparison with international scenario.

Biological Activity of Phenolic Compounds in Extra Virgin Olive Oils through Their Phenolic Profile and Their Combination with Anticancer Drugs Observed in Human Cervical Carcinoma and Colon Adenocarcinoma Cells.

The roles of phenolics from olive oils as effective anticancer agents have been documented in various in vitro studies of different cancer cells lines, but the relationship between the phenolic profile of olive oil and its biological activity needs more elucidation. In this study, we analysed phenolic profiles of extra virgin olive oils (EVOOs) from different autochthonous cultivars from Croatia (Oblica, Bjelica, Buža, Žižolera) and investigated the biological effect of EVOO phenolic extracts (EVOO-PEs) on human cervical (HeLa) and human colon (SW48) cancer cell lines alone and in combination with cisplatin (cDDP), carboplatin (CBP), 5-fluorouracil (5-FU) and irinotecan. The quantitative evaluation of olive oil polyphenols was performed by HPLC-DAD and spectrophotometric analysis. The biological effect of EVOO-PEs alone and in combination with anticancer drugs was measured by MTT assay. Analysed EVOO-PEs differ in phenolic profile and inhibited HeLa and SW48 cells in a dose-dependent manner. Further, it is shown that EVOO-PEs (Oblica-Sea, Buža and Žižolera), in combination with anticancer drugs, increase the metabolic activity of HeLa and SW48 cells and have a protective role. These data imply careful consummation of olive oil during chemotherapy of cancer patients.

GASMoC method: a phenol-free technique to detect acid-fast bacilli.

The genre Mycobacterium includes a series of pathological species, such as M. tuberculosis, which is important for pathology laboratories to detect for a correct diagnosis. The Ziehl-Neelsen technique (ZNT) is the most commonly histochemical method used to detect these bacilli and uses a heated mixture of carbol-fuchsine, which contains basic fuchsine and phenol. Whereas the former component is responsible for the pinkish staining of acid-fast mycobacteria, the role of phenol is not completely understood and it has been suggested that its exclusion does not impact the detection ability of the ZNT. Since phenol is highly toxic and induces several injuries, the goal of this study is to determine the detection capacity of mycobacteria through a method that excludes the use of phenol. Accordingly, the GASMoC method, a modified ZNT that employs a solution of aqueous basic fuchsine heated at 37°C, was tested on histological samples positive for mycobacteria and the results were compared to that of the ZNT. Data demonstrated that the GASMoC method was able to detect acid-fast bacilli (AFB) in all analyzed cases. Remarkably, microscopic inspection of mycobacteria was easier when the GASMoC method was applied. In conclusion, our study demonstrates that AFB detection does not require phenol and that the GASMoC method, a phenol-free technique, may substitute the ZNT in pathology laboratories.

Iron plaque formation in the roots of Pistia stratiotes L.: importance in phytoremediation of cadmium

Aquatic macrophytes play an important role in the removal of toxic metals from wastewater. Therefore, the induction of Fe plaque on the roots, and its consequences on Cd tolerance investigated in an aquatic macrophyte Pistia stratiotes L. The presence of Fe2+ ion but not Fe3+ resulted in Fe plaque formation. Induction of Fe plaque decreased Ca and increased K and Fe accumulations in the root. Plaque formed plants had accumulated less Cd until 50.0 µM CdCl2 treatments because plaque acted as a barrier to Cd exposure. However, at higher concentrations (500.0 µM CdCl2), plaque formed plants contained more Cd in the roots. Cadmium inducible ion leakage in the root and lowering of the photosynthetic pigment content were less in plants with a plaque. Stretching of aromatic carbonyl groups and alkyl groups among plaque formed plants upon Cd treatments indicated the putative role of phenolics in Cd detoxification.

In Vitro Studies on the Use of Some Plant Extracts as Bio control Agents against Fusarium Oxysporum Causing Rhizome Rot of Turmeric (Curcuma longa L.) and Role of Phenolics

Different plant extracts were studied in vitro for their efficiency of suppressing F.oxysporum causing rhizome rot of turmeric and role of Total Phenolic Content (TPC) of plant extracts in the antifungal activity, is also studied. The selected plant leaf extracts have shown significant antifungal activity (in vitro) against the mycelial growth of F.oxysporum causing rhizome rot of turmeric. Among them, Ocimum sanctum exhibited maximum antifungal activity of 99.45% inhibition over the pathogen and it has high total phenolic content of 280mg/100g. C.procera exhibited minimum inhibition percentage of 79.68. It has also least TPC of 75mg/100g.

Role of phenol and phosphite antioxidant combinations in the thermal stabilisation of metallocene LLDPE (mLLDPE): Optimisation and performance and influence of metal stearates on multiple extrusions

This study progresses our earlier studies and takes the performance characteristics of a 1:1 Irganox 1010: Irgafos 168 combination at 1000 ppm each through multiple extrusion processes in a metallocene LLDPE (mLLDPE) investigating for the first time the role of a broad range of calcium and zinc stearates based on animal vs vegetable origins of the stearine function. In this case performance was assessed using Melt Flow Rate (MFR) coupled with HPLC to determine not only the additive depletions after processing but also the rate of production of the phosphite to phosphonate. Comparative control studies were also undertaken on the single use of the separate antioxidants. Both stearates influenced the activity of the antioxidants in particular their consumption. A greater consumption after the third and fifth extrusion was observed with metal stearates produced from the vegetable stearine. Moreover, zinc stearates seemed to provide a greater detrimental effect than calcium stearates. Hydroperoxide analysis on the stearates confirmed the animal stearine to contain higher levels of peroxides which may contribute toward the higher activity. The optimisation of the thermal stabilisation of the metallocene polyethylene (mLLDPE) has also been investigated in this study. Several conditions of stability were determined for the determination of the optimal antioxidant (phenol:phosphite) ratio. The main parameter was high melt stability for a maximum processing stability of the final package via DSC analysis (OIT) coupled with assessments of embrittlement time (oven ageing) and yellowness index. Long-term stability against thermo-oxidation was considered coupled with a consideration of their hydrolytic stability as a complicating factor. In this work the (phenol/phosphite) antioxidant formulations with two different phenolic antioxidants (Irganox 1010, Irganox 1076) and six different phosphite antioxidants (Irgafos 168, Irgafos P-EPQ, Adekastab PEP-8, Adekastab PEP-36, Adekastab PEP-24G, Adekastab HP-10) were assessed at different levels taking into account the various criteria for optimal performance providing hitherto useful information than many prior studies on 1:1% ratios i.e. how much phosphite is required for optimal activity. A question often posed in the field with the results concluding an interesting unified optimum ratio of 4:1 (for most antioxidants studied) taking into account all the critical parameters.