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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.

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.

Context: Parasites are the leading killers in subtropical areas of which malaria took the lion share from protozoan diseases. Measuring the impact of antimalarial drug resistance is difficult, and the impact may not be recognized until it is severe, especially in high transmission areas. Aims: To evaluate the in vivo antimalarial activities of hydroalcoholic extracts of the roots of Piper capense and Adhatoda schimperiana, against Plasmodium berghei in mice. Methods: Four-day suppressive and curative test animal models were used to explore the antimalarial activities of the plants. 200, 400, and 600 mg/kg of each plant extract was administered to check the activities versus vehicle administered mice. Mean survival time and level of parasitemia were the major variables employed to compare the efficacy vs. negative control. Results: In both models the 400 and 600 mg/kg doses of Adhatoda schimperiana and the 600 mg/kg dose Piper capense. showed significant parasitemia suppression and increased in mean survival time at p≤0.05. The middle dose of Piper capense had a border line inhibition where the extracts were considered active when parasitemia was reduced by ≥ 30%. Conclusions: The hydroalcoholic extracts of the roots of Adhatoda schimperiana and Piper capense possess moderate antimalarial activities, which prove its traditional claims. Thus, further studies should be done to isolate the active constituents for future use in the modern drug discovery.

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.