Search Results (19)

Harnessing nature’s chemistry, this study explores the enhanced biomedical potential of Terminalia ferdinandiana Exell (Kakadu Plum) by transforming its aqueous leaf and fruit extracts into bio-inspired gold nanoparticles (AuNPs). The synthesis process was optimized by varying the Au³⁺/extract ratio and pH, with nanoparticle formation verified through UV–visible spectrophotometry, TEM, and DLS analyzes. Kakadu Leaf extract–conjugated AuNPs (AuKLs), synthesized at pH 8 with a 1:25 Au³⁺/extract ratio, produced the smallest and most uniform particles (21.1 nm; PDI 0.17). In contrast, fruit extract alone failed to generate stable nanoparticles, highlighting the pivotal role of leaf phytochemicals as natural reducing and stabilizing agents. Biological evaluations revealed that both the crude leaf extract and AuKLs possessed strong antioxidant capacity, while the AuKLs further exhibited selective anticancer activity effectively inhibiting breast cancer (MCF-7) and human cervical carcinoma (HeLa) cell proliferation without harming normal mammalian breast (MCF10A) cells. A combined 2:1 leaf-to-fruit extract formulation yielded well-stabilized AuNPs (AuKPLs) with biomedical properties comparable to AuKLs, though the fruit extract alone contributed minimally to both nanoparticle formation and biological performance. Overall, this study demonstrates that the phytochemical richness of T. ferdinandiana leaves enables the green synthesis of small, stable, and bioactive gold nanoparticles. The resulting nanoconjugates, AuKLs and AuKPLs, hold considerable promise for future pharmacological and therapeutic applications, bridging traditional plant-based medicine with modern nanotechnology. Full article

The emergence of HIV strains resistant to the current anti-retroviral drugs has necessitated the search for new anti-retroviral medications. Methanolic and aqueous T. ferdinandiana fruit extracts have potent inhibitory activity against several phases of the HIV-1 replicative cycle. Cell infectivity studies using a non-resistant HIV-1 pseudovirus demonstrated that the methanolic (IC₅₀ 16 µg/mL) and aqueous extracts (IC₅₀ 19 µg/mL) were potent inhibitors of viral infection in a non-replicating HIV-1 assay. Both extracts also inhibited HIV-1 reverse transcriptase (IC₅₀ values of 35 and 33 µg/mL for methanolic and aqueous extracts, respectively) and HIV-1 protease (IC₅₀ values of 19 and 27 µg/mL, respectively) in recombinant enzyme assays. Given their inhibitory activities against multiple phases of HIV-1 replication, T. ferdinandiana fruit extracts may be particularly useful as HIV-1 therapeutics. Furthermore, both extracts displayed good safety profiles and therapeutic indices, indicating their suitability for therapeutic usage. LC-MS metabolomic profiling analysis of the methanolic extract identified several interesting constituents, including a relative abundance of tannins, as well as several flavonoids and stilbenes. All of these compounds have previously been reported to have bioactivities consistent with the anti-HIV-1 activities reported herein. Based on these studies, methanolic and aqueous T. ferdinandiana fruit extracts are promising potential therapies for the prevention, treatment and management of HIV-1. Full article

This study uses a novel method in which extracts from different parts of a single plant are used to synthesize well-defined silver nanoparticles (AgNPs) to address the lack of capping agents in certain plant extracts. We focused on synthesizing AgNPs with enhanced biomedical activity using aqueous leaves and fruit extracts of Terminalia ferdinandiana Exell, a plant native to northern Australia that is known for its high phenolic content and associated health benefits. The impact of using parameters such as the Ag⁺ ion-to-extract ratio and pH on AgNP synthesis was examined. The formation of AgNPs was confirmed using UV–visible spectrophotometry, transmission electron microscopy, and dynamic light scattering. The AgNPs synthesized at a pH of 8 and 1:25 Ag⁺/extract ratio exhibited the lowest particle size and polydispersity index. The AgNPs synthesized with leaf extract (AgKL) were monodisperse and exhibited a smaller hydrodynamic diameter (37 nm) compared to the fruit extract nanoparticles (AgKP), which were polydisperse and larger (147 nm). Phytochemicals in T. ferdinandiana aqueous leaf extract act as effective capping and stabilizing agents, enabling the synthesis of small-sized and homogenous AgNPs, which the fruit extract alone could not achieve. The in vitro bioactivity was evaluated using antioxidant and antibacterial assays and compared with the crude extract. Both the AgNPs and T. ferdinandiana extracts demonstrated strong 2,2 diphenyl-1-picrylhydrazyl radical scavenging activity. However, only AgKL showed excellent antibacterial activity against Gram-negative and Gram-positive bacteria based on minimum inhibitory and bactericidal results. Mixing 50% leaf extract with fruit extract resulted in well-stabilized NPs (AgKPL) with a hydrodynamic diameter of 33.4 nm and superior antibacterial properties. These results indicate that AgKL and AgKPL have significant potential for pharmaceutical and biomedical applications. Full article

This study assessed the metabolite content and bioactivities of Kakadu plum (KP) from Western Australia (WA). LC-MS/MS and UHPLC-PDA analyzed sugar, vitamin C, and ellagic acid (EA). Functional properties were evaluated by spectroscopic technique, agar well diffusion, and microplate dilution methods. WA KP exhibited higher total sugar (16.3 ± 1.0 g/100 g DW) and free ellagic acid (EA) (23.2 ± 1.7 mg/g DW), along with abundant vitamin C (25.20 ± 0.16 to 131.50 ± 0.20 mg/g DW) compared to Northern Territory KP fruits. The fruit showed strong antioxidant activities, α-glucosidase inhibition, and effectiveness against bacteria, with positive correlations to total phenolic content (TPC), vitamin C, and EA. These findings highlight WA KP’s potential for functional foods and pharmaceuticals, emphasizing the importance of TPC, vitamin C, and EA in selecting high-quality fruit. Full article

Terminalia ferdinandiana Exell, Terminalia grandiflora Benth., Terminalia microcarpa Decne., and Terminalia muelleri Benth. (family: Combretaceae) belong to the genus Terminalia. Plants of this genus have been extensively used as traditional medicines to treat a variety of illnesses, including pathogen infections. However, we were unable to find any studies that have investigated the antibacterial activity of T. microcarpa. Similarly, whilst some preliminary studies have examined the antimicrobial properties of T. muelleri and T. grandiflora, they did not test the extracts against antibiotic-resistant pathogens. This study screens the antimicrobial activity of T. grandiflora, T. microcarpa, and T. muelleri and compares it to that of T. ferdinandiana extracts prepared from both the fruit and leaves against a range of pathogens, including multi-antibiotic-resistant strains. Solvents with varying polarities were used to extract different phytochemical constituents from the leaves of T. grandiflora, T. microcarpa, and T. muelleri and from the fruit and leaves of T. ferdinandiana. The aqueous and methanolic extracts each displayed significant antimicrobial activity when tested against the bacterial pathogens, including against the multidrug-resistant strains. When these extracts were tested in combination with selected antibiotics, some extracts potentiated the antimicrobial activity. This study identifies twelve synergistic, fifty-eight additive, and sixty non-interactive combinations, as well as thirty antagonistic effects. The extracts were evaluated for toxicity using the Artemia franciscana nauplii lethality assay (ALA) and were each classified as non-toxic, with the exception of the methanolic and aqueous T. ferdinandiana fruit extracts and the aqueous and ethyl acetate T. ferdinandiana leaf extracts. Metabolomic analysis using liquid chromatography–mass spectrometry (LC-MS) highlighted several flavonoids and tannins that may contribute to the antimicrobial activities reported herein. The potential antibacterial mechanism(s) of the T. ferdinandiana extracts are discussed in this study. Full article

Kakadu plum (Terminalia ferdinandiana), endemic to Australia, is growing in popularity due to its high levels of vitamin C and strong antioxidant properties. In this study, Kakadu plum fruit powder was used as a functional food ingredient with other plant materials to develop value-added products to enhance their nutritional and commercial value. The present study determined the bioactive properties of nine products, including three Kakadu plum fruit powder samples produced from different processing batches and five Kakadu plum-blended products. Vitamin C, the total phenolic content, and the ellagic acid content were determined. Bioactive properties such as antioxidant, antidiabetic, and antimicrobial assays were also performed. Cytotoxicity was tested to obtain more specific product information regarding food safety. Kakadu plum-blended products showed lower cytotoxicity and lower bioactive properties (antioxidant and antibacterial activities) in comparison to Kakadu plum powder. However, overall, most of the bioactive properties were shown to be higher in the blends when compared with the commercial blueberry powder as a benchmark antioxidant product. Therefore, there is great potential for Kakadu plum to contribute to the growing functional food and ingredient markets. Full article

Growing location is known to affect the metabolite content and functionality of wild harvested fruits. Terminalia ferdinandiana, commonly known as Kakadu plum (KP), is among the most commercially important native Australian bush foods. Therefore, we evaluated the composition and in vitro bioactivity of aqueous acidified ethanol (AAE) and water extracts prepared from KP fruit wild harvested in the Northern Territory (NT) and Western Australia (WA). Compositional analysis included vitamin C, total ellagic acid (TEA), and total phenolic content (TPC), while in vitro bioactivity was assessed through anti-inflammatory (RAW 264.7 macrophages) activity and cell viability (Hep G2) assay. The IC₅₀ of the extracts ranged from 33.3 to 166.3 µg/mL for NO inhibition and CC₅₀ from 1676 to 7337 µg/mL for Hep G2 cell viability inhibition. The AAE KP fruit extracts from the NT exhibited potent anti-inflammatory activity and impacted Hep G2 cell viability more than other extracts, most likely due to TEA (3189 mg/100 g dry weight (DW)), vitamin C (180.5 mg/g DW) and TPC (196 mg GAE/g DW) being higher than in any other extract. Overall, the findings of the present study are promising for using KP fruit and derived products in functional foods, nutraceuticals, or dietary supplements. Full article

Phytochemicals play a pivotal role in human health and drug discovery. The safety evaluation of plant extracts is a prerequisite to ensure that all phytochemicals are safe before translational development and human exposure. As phytochemicals are natural, they are generally considered safe, although this is not always true. The objective of this study was to investigate and compare the phytochemical composition, antioxidant potential, and safety evaluation of native Australian Muntries (Kunzea pomifera), Kakadu plum (Terminalia ferdinandiana), Davidson plum (Davidsonia) and Quandong peach (Santalum acuminatum) through the in vivo vertebrate zebrafish embryonic model. The highest total phenolic content (TPC; 793.89 ± 22.27 μg GAE/mg) was quantified in Kakadu plum, while the lowest TPC (614.44 ± 31.80 μg GAE/mg) was quantified in Muntries. Developmental alterations, mortality, and morbidity were assessed for toxicological screening of these selected native Australian fruit extracts. In this study, muntries were quantified as having the least LC₅₀ value (169 mg/L) compared to Davidson plum (376 mg/L), Kakadu plum (>480 mg/L), and Quandong peach (>480 mg/L), which indicates that muntries extract was more toxic than other fruit extracts. Importantly, we found that adverse effects were not correlated to the total phenolic content and antioxidant potential of these native Australian fruits and cannot simply be predicted from the in vitro analysis. Conclusively, these selected native Australian fruit extracts are categorized as safe. This study could explore the use of these native Australian fruits in cosmetics, pharmaceuticals, and drug discovery. Full article

A large variety of unique and distinct flora of Australia have developed exceptional survival methods and phytochemicals and hence may provide a significant avenue for new drug discovery. This study proposes a bioassay guided fractionation protocol that maybe robust and efficient in screening plants with potential bioactive properties and isolating lead novel compounds. Hence, five native Australian plants were selected for this screening process, namely Pittosporum angustifolium (Gumbi gumbi), Terminalia ferdinandiana (Kakadu plum, seeds (KPS), and flesh (KPF)), Cupaniopsis anacardioides (Tuckeroo, seeds (TKS) and flesh (TKF)), Podocarpus elatus (Illawarra plum, seeds (IPS) and flesh (IPF)) and Pleiogynium timoriense (Burdekin plum, seeds (BPS) and flesh (BPF)). The methanolic extracts of the plants samples were analysed for Total phenolic content (TPC) and antioxidant capacity measure by FRAP. The highest values were found in the KPF which were 12,442 ± 1355 mg GAE/ 100 g TPC and 16,670 ± 2275 mg TXE/100 g antioxidant capacity. Extracts of GGL was deemed to be most potent with complete cell inhibition in HeLa and HT29, and about 95% inhibition in HuH7 cells. Comparative activity was also seen for KPS extract, where more than 80% cell inhibition occurred in all tested cell lines. Dose-dependent studies showed higher SI values (0.72–1.02) in KPS extracts than GGL (0.5–0.73). Microbial assays of the crude extracts were also performed against five bacterial strains commonly associated with causing food poisoning diseases were selected (Gram positive—Staphylococcus aureus and Gram negative—Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa bacteria). KPF extracts were effective in suppressing microbial growth of all tested bacterial strains except for P. aeruginosa, while TKS and TKF were only slightly effective against S. aureus. Due to the potential of the GGL crude extract to completely inhibit the cells compared to KPS, it was further fractionated and tested against the cell lines. HPLC phenolic profiling of the crude extracts were performed, and numerous peak overlaps were evident in the fruit extracts. The KPF extracts demonstrated the strongest peaks which was coherent with the fact that it had the highest TPC and antioxidant capacity values. A high occurrence of t-ferulic acid in the GGL extracts was found which may explain the cytotoxic activity of GGL extracts. Peaks in KPS and KPF extracts were tentatively identified as gallic acid, protocatechuic acid, 4-hydroxybenzoic acid and syringic acid and possibly ellagic acid. HPLC time-based fractionation of the GGL extract (F1–F5) was performed and Dose dependent cytotoxic effects were determined. It was construed that F1, having the highest SI value for HeLa, HT29 and HuH7 (1.60, 1.41 and 1.67, respectively) would be promising for further fractionation and isolation process. Full article

Terminalia ferdinandiana (Kakadu plum) is an Australian native plant that has recently gained the attention of researchers due to its highly antioxidant compounds that have substantial health benefits. To raise the value, in this study, it is used for the first time to synthesize ZnO nanoparticles for anti-lung cancer and anti-inflammatory activities. The formation of KKD-ZnO-NPs (ZnO particles obtained from Kakadu plum) were confirmed using a UV-Visible spectrophotometer. Fourier transform infrared (FTIR) spectroscopy analysis confirmed the functional groups that are responsible for the stabilization and capping of KKD-ZnO-NPs. The flower shape of the synthesized KKD-ZnO-NPs was confirmed by field emission-scanning electron microscopy (FE-SEM) and field emission-transmission electron microscopy (FE-TEM) analyses. The crystallites were highly pure and had an average size of 21.89 nm as measured by X-ray diffraction (XRD). The dynamic light scattering (DLS) revealed size range of polydisperse KKD-ZnO-NPs was 676.65 ± 47.23 nm with a PDI of 0.41 ± 0.0634. Furthermore, the potential cytotoxicity was investigated in vitro against human lung cancer cell lines (A549) and Raw 264.7 Murine macrophages cells as normal cells to ensure safety purposes using MTT assay. Thus, KKD-ZnO-NPs showed prominent cytotoxicity against human lung adenocarcinoma (A549) at 10 μg/mL and increased reactive oxygen species (ROS) production as well, which could promote toxicity to cancer cells. Moreover, upregulation of p53 and downregulation of bcl2 gene expression as apoptosis regulators were confirmed via RT-PCR. In addition, KKD-ZnO-NPs possess a similar capacity of reduction in proinflammatory-nitric oxide (NO) production when compared to the L-NMMA as inflammation’s inhibitor, indicating anti-inflammatory potential. Incorporation of Kakadu plum extract as reducing and stabilizing agents enabled the green synthesis of flower-shaped KKD-ZnO-NPs that could be an initiative development of effective cancer therapy drug. Full article

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. Full article

Kakadu plum (KP; Terminalia ferdinandiana Exell, Combretaceae) is an emergent indigenous fruit originating from Northern Australia, with valuable health and nutritional characteristics and properties (e.g., high levels of vitamin C and ellagic acid). In recent years, the utilization of handheld NIR instruments has allowed for the in situ quantification of a wide range of bioactive compounds in fruit and vegetables. The objective of this study was to evaluate the ability of a handheld NIR spectrophotometer to measure vitamin C and ellagic acid in wild harvested KP fruit samples. Whole and pureed fruit samples were collected from two locations in the Kimberley region (Western Australia, Australia) and were analysed using both reference and NIR methods. The standard error in cross validation (SECV) and the residual predictive deviation (RPD) values were 1.81% dry matter (DM) with an RPD of 2.1, and 3.8 mg g⁻¹ DM with an RPD of 1.9 for the prediction of vitamin C and ellagic acid, respectively, in whole KP fruit. The SECV and RPD values were 1.73% DM with an RPD of 2.2, and 5.6 mg g⁻¹ DM with an RPD of 1.3 for the prediction of vitamin C and ellagic acid, respectively, in powdered KP samples. The results of this study demonstrated the ability of a handheld NIR instrument to predict vitamin C and ellagic acid in whole and pureed KP fruit samples. Although the RPD values obtained were not considered adequate to quantify these bioactive compounds (e.g., analytical quantification), this technique can be used as a rapid tool to screen vitamin C in KP fruit samples for high and low quality vitamin C. Full article

Terminalia ferdinandiana (Kakadu plum), belonging to the family Combretaceae, is endemic to Australia and has a long history of traditional medicinal applications and food cuisine by the Australian Indigenous people. This study investigated the effects of maturity stages on the morphology, physicochemical parameters (total soluble solids (TSS), total acid content (TAC), and pH), soluble sugar profile and antioxidant capacity of Kakadu plum (KP) fruits that were wild harvested from different trees and classified into four different maturity stages (immature to mature). TSS and TAC were determined by standard assays/procedures, main sugars by UHPLC–MS/MS and antioxidant capacity (total phenolic content (TPC) and DPPH free radical scavenging capacity) by spectrophotometry. The results showed that soluble sugars (glucose, sucrose and fructose) ranging from 1.3 to 17.7% dry weight (DW), TSS (17.0–52.7% DW) and TAC (1.3–6.7% DW) increased with maturity. However, antioxidant capacity (TPC in the range of 7.4–21.9% DW and DPPH free radical scavenging capacity from 22 to 76% inhibition at the extract concentration of 20 g·L⁻¹) did not follow the same trend as the one observed for soluble sugars, TSS and TAC. These differences were associated with the tree-to-tree variability as a consequence of the wild harvest condition. This study provides important information to both the KP industry and Indigenous enterprises regarding the selection of the appropriate maturity stage to harvest KP fruit to target for different markets (e.g., low-sugar vs. high-sugar fruit). Full article

Globally, the agricultural sector is facing many challenges in response to climate change, unsustainable farming practices and human population growth. Despite advances in technology and innovation in agriculture, governments around the world are recognizing a need for transformative agricultural systems that offer solutions to the interrelated issues of food security, climate change, and conservation of environmental and cultural values. Approaches to production are needed that are holistic and multisectoral. In planning for future agricultural models, it is worth exploring indigenous agricultural heritage systems that have demonstrated success in community food security without major environmental impacts. We demonstrate how indigenous practices of customary harvest, operating in multifunctional landscapes, can be scaled up to service new markets while still maintaining natural and cultural values. We do this through a case analysis of the wild harvest of Kakadu plum fruit by Aboriginal people across the tropical savannas of northern Australia. We conclude that this system would ideally operate at a landscape scale to ensure sustainability of harvest, maintenance of important patterns and processes for landscape health, and incorporate cultural and livelihood objectives. Applied to a variety of similar native products, such a production system has potential to make a substantial contribution to niche areas of global food and livelihood security. Full article

Abstract: Kakadu plum (KP), a native Australian fruit, is a rich source of vitamin C, minerals and phenolic compounds. A better understanding of the (phyto)chemical composition and biological properties of KP will facilitate the development of functional KP products for the food, pharmaceutical, nutraceutical and cosmetic industry. KP is usually harvested wild and hence, its composition and functional properties may vary considerably depending on the cultivar, maturity, environmental conditions as well as post-harvest treatment. The present study aimed to assess the levels of ascorbic acid (AA) and ellagic acid (EA), the main bioactive compounds in KP, in a commercially available freeze-dried KP powder. The functional properties of a polyphenol-enriched extract obtained from this product were also evaluated. AA and EA were quantified by UHPLC_PDA. The polyphenol-enriched extract was tested for in vitro antioxidant and antimicrobial properties, using the DPPH radical scavenging assay and agar well diffusion, respectively. Total AA content in the freeze-dried powder was 200 mg/g dry weight (DW) and total EA was 46.6 mg/g DW. The polyphenol-enriched extract had a high DPPH radical scavenging capacity and strong antimicrobial activity against methicillin resistant Staphylococcus aureus. Our findings demonstrate that AA and EA, the main bioactive compounds in KP, are retained at high levels in the freeze-dried KP fruit powder. Furthermore, the polyphenol-enriched KP extract has the potential to be used as a natural preservative in the food industry due to its strong antioxidant and antimicrobial activity. Full article