The phytochemical composition and unexplored potential of Australian native plants for application in physical activity-related muscle recovery and inflammation: a literature review

Native plants are adaptable in various environmental conditions in part through the production of unique phytochemicals which may have beneficial effects on human health. Native Australian fruits contain higher phytochemical and antioxidant levels than most Western fruits, suggesting potential for greater health benefits arising from their consumption. These beneficial effects, in turn, may be mediated by the inhibition of inflammatory pathways as well as oxidative stress via the regulation of reactive oxygen (ROS) and/or nitrogen (RNS) species levels. Unaccustomed or strenuous exercise causes muscle damage and soreness, that may be driven by increased ROS and inflammation. There is growing interest in the application of polyphenol-rich food supplementation for the alleviation of exercise-induced oxidative stress, for the reduction of exercise-induced inflammation and improvement of muscle recovery. Therefore, the aim of this review was to provide an overview of the phytochemical and bioactive composition of some Australian native plant foods and their potential use for functional food development in the management of muscle recovery and inflammation. Native plant foods and food products could be beneficial for reducing inflammation, though it is important to note that most of the research in this field has been conducted in animal models or in vitro, in addition to there being little data on skeletal muscle inflammation. Further studies, particularly in humans, would be needed to confirm these effects and to determine the appropriate dosages and forms of native foods and food products for consumption to reduce inflammation and enhance muscle recovery.

Anti-oxidant potential of plants and probiotic spp. in alleviating oxidative stress induced by H2O2

Cells produce reactive oxygen species (ROS) as a metabolic by-product. ROS molecules trigger oxidative stress as a feedback response that significantly initiates biological processes such as autophagy, apoptosis, and necrosis. Furthermore, extensive research has revealed that hydrogen peroxide (H2O2) is an important ROS entity and plays a crucial role in several physiological processes, including cell differentiation, cell signalling, and apoptosis. However, excessive production of H2O2 has been shown to disrupt biomolecules and cell organelles, leading to an inflammatory response and contributing to the development of health complications such as collagen deposition, aging, liver fibrosis, sepsis, ulcerative colitis, etc. Extracts of different plant species, phytochemicals, and Lactobacillus sp (probiotic) have been reported for their anti-oxidant potential. In this view, the researchers have gained significant interest in exploring the potential plants spp., their phytochemicals, and the potential of Lactobacillus sp. strains that exhibit anti-oxidant properties and health benefits. Thus, the current review focuses on comprehending the information related to the formation of H2O2, the factors influencing it, and their pathophysiology imposed on human health. Moreover, this review also discussed the anti-oxidant potential and role of different extract of plants, Lactobacillus sp. and their fermented products in curbing H2O2‑induced oxidative stress in both in-vitro and in-vivo models via boosting the anti-oxidative activity, inhibiting of important enzyme release and downregulation of cytochrome c, cleaved caspases-3, - 8, and - 9 expression. In particular, this knowledge will assist R&D sections in biopharmaceutical and food industries in developing herbal medicine and probiotics-based or derived food products that can effectively alleviate oxidative stress issues induced by H2O2 generation.

Promising remedies for cardiovascular disease: Natural polyphenol ellagic acid and its metabolite urolithins

BACKGROUND

Cardiovascular disease (CVD) is a significant worldwide factor contributing to human fatality and morbidity. With the increase of incidence rates, it is of concern that there is a lack of current therapeutic alternatives because of multiple side effects. Ellagic acid (EA), the natural polyphenol (C₁₄H₆O₈), is abundant in pomegranates, berries, and nuts. EA and its intestinal microflora metabolite, urolithins, have recently attracted much attention as a potential novel "medicine" because of their wide pharmacological properties.

PURPOSE

This study aimed to critically analyze available literature to summarize the beneficial effects of EA and urolithins, and highlights their druggability and therapeutic potential in various CVDs.

METHODS

We systematically studied research and review articles between 1984 and 2022 available on various databases to obtain the data on EA and urolithins with no language restriction. Their cardiovascular protective activities, underlying mechanism, and druggability were highlighted and discussed comprehensively.

RESULTS

We found that EA and urolithins may exert preventive and curative effects on CVD with negligible side effects and possibly regulate lipid metabolism imbalance, pro-inflammatory factor production, vascular smooth muscle cell proliferation, cardiomyocyte apoptosis, endothelial cell dysfunction, and Ca²⁺ intake and release. Potentially, this may lead to the prevention and amelioration of atherosclerosis, hypertension, myocardial infarction, cardiac fibrosis, cardiomyopathy, cardiac arrhythmias, and cardiotoxicities in vivo. Several molecules and signaling pathways are associated with their therapeutic actions, including phosphatidylinositol 3-kinase/protein kinase B, mitogen-activated protein kinase, NF-κB, nuclear factor erythroid-2 related factor 2, sirtuin1, miRNA, and extracellular signal-regulated kinase 1/2.

CONCLUSION

In vitro and in vivo studies shows that EA and urolithins could be used as valid candidates for early prevention and effective therapeutic strategies for various CVDs.

Australian native fruits and vegetables: Chemical composition, nutritional profile, bioactivity and potential valorization by industries

Australian native plants have adapted themselves to harsh climatic conditions enabling them to produce unique and high levels of secondary metabolites. Native fruits and vegetables have been an integral part of the Indigenous Australian diet and Bush medicine for centuries. They have recently gained popularity owing to their rich dietary fiber, minerals, polyphenolic and antioxidant contents. This review presents a comprehensive summary and critical assessment of the studies performed in the last few decades to understand the phytochemical and nutritional profiles and therapeutic properties of Australian native fruits and vegetables. Furthermore, the potential of these fruits and vegetables as functional food ingredients and in the prevention and treatment of different diseases is discussed. Research on the nutritional and phytochemical profiles and therapeutic activity of Australian vegetables is limited with most studies focused on native fruits. These fruits have demonstrated promising antioxidant, anticancer, anti-inflammatory and antimicrobial activities mostly in in vitro models. More research to a) identify novel bioactive compounds, b) define optimal post-harvest and extraction methods, and c) understand molecular mechanisms of pharmacological activity through preclinical and clinical studies is prudent for the prospective and wider use of Australian native fruits and vegetables by the food, pharmaceutical, and nutraceutical industries.

Protective Effect and Potential Antioxidant Role of Kakadu Plum Extracts on Alcohol-Induced Oxidative Damage in HepG2 Cells

Serial alcohol consumption causes alcoholic liver disease (ALD), which can lead to fatty liver, hepatitis, and cirrhosis. Terminalia ferdinandiana (Kakadu plum) is an indigenous fruit of Australia, which is utilized as a functional food. It is a commercially important antioxidant as it contains a more eloquent level of ascorbic acid than other oranges. In this study, we analyzed the chemical constituents of vitamin C, gallic acid, ellagic acid, and daidzin via High-performance liquid chromatography (HPLC) in the Kakadu plum from two different regions including the Northern Territory (NT) and Western Australia (WA), and compared their biochemical properties. The vitamin C content was much higher (almost 70%) in Kakadu plum (KKD) from the NT than WA. Moreover, ROS generation was inhibited significantly in HepG2 (human hepatoma) cells with the KKD-NT extract treatment when compared to the KKD-WA extract treatment. The cytotoxicity produced by ethanol was significantly suppressed in response to the treatment with both of the samples. In addition, our samples (KKD-NT and KKD-WA) increased the activity of two key enzymes involving alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) that metabolize ethanol. These results show the biochemical confirmation of the mechanism by which KKD exhibits its biological functions including relief from alcohol hangovers as well as protection of the liver cells by the suppression of ROS production and toxic insults.

Unlocking the Secrets of Terminalia Kernels Using Near-Infrared Spectroscopy

In recent years, the native food industry in Australia has increased in both value and volume due to the discovery of a wide range of phytochemicals (e.g., vitamin C, polyphenols) that have potential health benefits. Thus, plant organs and tissues of these native plants are used in a wide range of applications. In particular, the kernel of a native plum, the Kakadu plum (Terminalia ferdinandiana, Combretaceae) is considered to be rich in lipids and other phytochemical compounds. The aim of this study was to evaluate the use of NIR spectroscopy to analyze and characterize kernel samples and tissues of wild harvest fruit samples. The Fourier transform near-infrared reflectance spectra of cracked kernels, seeds cover tissues, and dry powder Kakadu plum kernels were acquired. Both principal component analysis and partial least squares discriminant analysis were used to analyze and interpret the spectral data. A correct classification rate of 93%, 86%, and 80% was achieved for the identification of kernel provenance using all tissues, seed coats, and the whole nuts, respectively. The results of this study reported for the first time the analysis of Kakadu plum kernels and their tissues using NIR spectroscopy.

Hydrolysable tannins in Terminalia ferdinandiana Exell fruit powder and comparison of their functional properties from different solvent extracts

This study identified and quantified hydrolysable tannins (HTs) in Terminalia ferdinandiana Exell (Kakadu plum) fruit, freeze dried powder extracted with 80% aqueous acetone (AA) and 80% aqueous acidified ethanol (AAE), using UHPLC-Q/Orbitrap/MS/MS. The vitamin C and ellagic acid were quantified by UHPLC-PDA. A total of seven HTs were identified: corilagin, 3,4,6-tri-O-galloyl-β-d-glucose, elaeocarpusin, chebulinic acid, chebulagic acid, helioscopin B, and punicalagin, with five classified as ellagitannins. The two extracts AA and AAE, comprised of gallic acid (2.5 and 2.2 mg/g DW), punicalagins α and β (2.8 and 1.3 mg/g DW), respectively, and both contained ellagic acid (~4 g/100 g DW). These extracts showed high antioxidant properties and strong antimicrobial effects against methicillin-resistant Staphylococcus aureus clinical isolate, Staphylococcus aureus, and Shewanella putrefaciens. These results suggest that Kakadu plum fruit is a rich, edible source of ellagitannins, ellagic acid and vitamin C with potential applications in food, cosmetic and nutraceutical industries.

Antimicrobial Activity, Total Phenolic and Ascorbic Acid Content of Terminalia Ferdinandiana Leaves at Various Stages of Maturity

This work investigated the effect of leaf development (maturity) on morphology, antimicrobial activity, total phenolic (TPC) and ascorbic acid content in leaves of Terminalia ferdinandiana, an endemic plant of Australia. The results of this study indicated that total ascorbic acid was in the range of 23.0 to 35.5 mg/100 g dry weight (DW), showing an increase with advance of maturity. TPC in water and methanolic extracts were in the range of 237.3 - 598.6 and 210.3 - 319.6 mg Gallic acid equivalent (GAE)/ g DW, respectively. Leaf extracts exhibited pronounced inhibitory activity towards Staphylococcus aureus where total ascorbic acid and TPC were positively correlated with the observed antimicrobial activity. These results indicated that leaves extracts might be used as an alternative to synthetic antimicrobial agents, with a great potential for application as an environmentally friendly sanitizer in the hospitality and healthcare industries.