Berry fruits are an important dietary source of health-promoting antioxidant polyphenols. Interestingly, berry leaves of diverse species, including strawberries, have shown higher bioactive phytochemical content in the leaves than in the fruit. Moreover, the vegetative part of the plants is usually discarded, representing a presumably large source of underutilized bioactive biomass. In this investigation, the polyphenol profiles of tropical highland strawberry (Fragaria x ananassa cv. Festival) leaves and fruits were compared by high-performance liquid chromatography coupled with a diode array detector (UHPLC-DAD) and mass spectrometry (HPLC-MS). The total polyphenol strawberry leaf extracts exhibited a 122-fold-higher total polyphenol content and 13-fold higher antioxidant activity (ORAC) than strawberry fruits, and they showed evidence of possible photoprotective effects against UV damage in human melanoma cells (SK-MEL-28) and in murine embryo fibroblasts (NIH/3T3), together with promising anti-proliferative activities against the same melanoma cells. Seven polyphenols were confirmed by HPLC-DAD in the leaf extracts, with differences depending on fraction solubility. Moreover, three substituted quercetin derivatives, three substituted kaempferol derivatives, two anthocyanins, and catechin were confirmed in the soluble fraction by HPLC-MS. Given their higher total polyphenol content and bioactive activities, underutilized strawberry Festival leaves are a potential source of apparently abundant biomass with prospective bioactive applications.

Liver cells express a cytosolic α-tocopherol transfer protein (αTTP) with high binding affinity for α-tocopherol (αT) and much lower affinities for the non-αT congeners. The role of αTTP in the intracellular distribution of the different vitamin E forms is currently unknown. We therefore investigated the intracellular localization of αT, γ-tocopherol (γT), α-tocotrienol (αT3), and γ-tocotrienol (γT3) in cultured hepatic cells with and without stable expression of αTTP. We first determined cellular uptake of the four congeners and found the methylation of the chromanol ring and saturation of the sidechain to be important factors, with tocotrienols being taken up more efficiently than tocopherols and the γ-congeners more than the α-congeners, irrespective of the expression of αTTP. This, however, could perhaps also be due to an observed higher stability of tocotrienols, compared to tocopherols, in culture media rather than a higher absorption. We then incubated HepG2 cells and αTTP-expressing HepG2 cells with αT, γT, αT3, or γT3, isolated organelle fractions by density gradient centrifugation, and determined the concentrations of the congeners in the subcellular fractions. All four congeners were primarily associated with the lysosomes, endoplasmic reticulum, and plasma membrane, whereas only αT correlated with mitochondria. Neither the chromanol ring methylation or sidechain saturation, nor the expression of αTTP were important factors for the intracellular distribution of vitamin E. In conclusion, αTTP does not appear to regulate the uptake and intracellular localization of different vitamin E congeners in cultured liver cells.

The sago grub (Rhynchophorus bilineatus) [Montrouzier, Coleoptera, Dryophthoridae] is a local delicacy in the Papua Province in Indonesia. In this study, the nutrient content of the edible insect was measured using chromatographic and spectrometric methods. The results showed that it contains 10.39 g protein and 17.17 g oil/ 100 g fresh weight. The sago grub meets the FAO/WHO requirements of 40% essential amino acids and a 0.60 ratio between essential to non-essential amino acids. Its limiting amino acid is methionine + cysteine. The major fatty acids found in the sago grub are palmitic (42%), oleic (45%), and linoleic (3%) acids. Although vitamin E is exclusively produced by photosynthetic organisms, a gram of sago grub oil contains 51 μg vitamin E, which is composed mainly of tocopherols (92%). In contrast with palm oil, the sago grub oil contains δ-tocopherol (0.12 μg/g oil), and a significantly high amount of β-tocopherol (3.85 μg/g oil). It is a source of zinc and magnesium and contains safe levels of heavy metals. Based on these nutritional properties, the Indonesian sago grub can be considered as a good source of nutrients, and its propagation and utilization should be encouraged especially in other areas of Indonesia and maybe in neighboring countries where they are also endemic, and where malnutrition is prevalent. The consumption of edible insects should be considered as a component of dietary diversification – a sustainable way of alleviating the nutritional status of the population.