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.

Measurement of total soluble solids and moisture in puree and dry powder of Kakadu plum (Terminalia ferdinanadiana) samples using hand-held near infrared spectroscopy

Recent research has shown the potential of portable and handheld NIR instruments to monitor and measure the composition of fruits and vegetables. Current research has also shown the possibility of using portable instruments as tools to monitor composition along the entire food value chain. The objective of this study was to evaluate two sample presentation methods (dry powder and fruit puree) to measure total soluble solids (TSS) and moisture (M) in wild harvested Kakadu plum (KP) ( Terminalia ferdinandiana, Combretaceae). Kakadu plum is an endemic plant of Australia that contains high concentrations of vitamin C, ellagic acid as well as other bioactive compounds. These properties make this plant of high economic and social importance for the Aboriginal communities of Australia. Fruit samples were wild harvested in January 2020 from locations in the Kimberley region (Western Australia, Australia) and analysed using both reference and NIR spectroscopic methods. The SECV and RPD values in cross validation were 0.65% (RPD: 2.2) and 0.22% (RPD: 4.2) to predict M and TSS in the KP dry powder samples. The SECV and RPD values obtained in cross validation for the KP fruit puree samples were 0.56% (RPD: 2.8) and 0.24% (RPD: 3.8) for M and TSS, respectively. The results of this study demonstrated the ability of NIR spectroscopy to measure M and TSS in wild harvest fruit. These findings can be also utilised by the Aboriginal communities to develop a grading/sorting system to rapidly screen and evaluate relevant chemical parameters associated with fruit quality and safety.

Terminalia ferdinandiana inhibited the increased of matrix metalloproteinase-1 and prevent collagen decreased in mice skin exposed to UV-B

Kakadu cream contained 0,1% Kakadu plum (Terminalia ferdinandiana) extract with a high content of phenolic compound, flavonol, tocopherol, luthein, chlorophyll, and ellagic acid has potential to prevent the Ultraviolet-B (UV-B) effect on skin aging acceleration. To date, there’s no in vivo experiment on the effect of kakadu plum extract on collagen nor matrix metalloproteinase-1(MMP-1). This research aims to evaluate the effectiveness of Kakadu cream administration in inhibiting the increase of MMP-1 expressions and prevent the decrease of collagen amount in mice (Mus musculus) skin exposed to UV-B. An experimental study with a post-test only control group design was employed in 36 male mice, 6-8 weeks old, weighing 20-25 grams. The samples were divided randomly into two groups, a control group given base cream and the study group, given Kakadu cream 0,1% on their shaved backs, 1 cm2 in size as the UV-B exposure's location. The UV-B irradiation was done three times a week for 4 weeks. The base and Kakadu cream were given twice a day. Comparative analysis was carried out to compare MMP-1 expression and collagen amount in both groups. The results show that the mean of MMP-1 expression on the study group was significantly lower compared to control group (p<0.001). The mean collagen amount was significantly higher in the study group than in the control group (p< 0,001). From the results, can be concluded that Kakadu cream inhibited the increase MMP-1 expression and prevent the decrease of collagen amount in mice skin exposed to UV-B.

Effects of Fruit Maturity on Physicochemical Properties, Sugar Accumulation and Antioxidant Capacity of Wild Harvested Kakadu Plum (Terminalia ferdinandiana)

: 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).

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.

The Use of a Micro Near Infrared Portable Instrument to Predict Bioactive Compounds in a Wild Harvested Fruit—Kakadu Plum (Terminalia ferdinandiana)

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.