Stinging nettle (Urtica dioica L., Urticaceae) is commonly found in Asia, Africa, and Europe and has a long history of being used as food and traditional medicine. Recently, this plant is gaining attention as a highly nutritious food, where fresh leaves are dried and used as powder or in other forms. Leaves are rich in many bioactive compounds. This review aims to cover the traditional uses in food and medicine, as well as its nutritional composition, including its bioactive chemical constituents and reported food functional activities. Various bioactive chemical constituents have been isolated from stinging nettle to date, such as flavonoids, phenolic acids, amino acid, carotenoids, and fatty acids. Stinging nettle extracts and its compounds, such as rutin, kaempferol, and vitamin A, are also used for their nutritional properties and as anti-inflammatory and antioxidant agents. Future studies should focus on the proper formulation and stability testing of the functional foods containing stinging nettle and their detailed activities in clinical studies.

Leptin, a hormone that is predominantly produced by adipose tissue, is closely associated with various liver diseases. However, there is a lack of understanding as to whether leptin directly induces cytotoxic effects in hepatocytes as well as the mechanisms that are involved. Inflammasomes, which are critical components in the innate immune system, have been recently shown to modulate cell death. In this study, we examined the effect of leptin on the viability of rat hepatocytes and the underlying mechanisms, with a particular focus on the role of inflammasomes activation. Leptin treatment induced cytotoxicity in rat hepatocytes, as determined by decreased cell viability, increased caspase-3 activity, and the enhanced release of lactate dehydrogenase. NLRP3 inflammasomes were activated by leptin both in vitro and in vivo, as determined by the maturation of interleukin-1β and caspase-1, and the increased expression of inflammasome components, including NLRP3 and ASC. Mechanistically, leptin-induced inflammasome activation is mediated via the axis of ROS production, ER stress, and autophagy. Notably, the inhibition of inflammasomes by treatment with the NLRP3 inhibitor or the IL-1 receptor antagonist protected the hepatocytes from leptin-induced cell death. Together, these results indicate that leptin exerts cytotoxic effects in hepatocytes, at least in part, via the activation of NLRP3 inflammasomes.

Muscle satellite (stem) cells (MSCs) reside in skeletal muscle and are essential for myogenesis. Thus, MSCs are widely used in cultured meat research. This study aimed to identify substances that promote MSC proliferation and differentiation while maintaining their intrinsic properties, with the long-term goal of replacing fetal bovine serum (FBS) for bovine MSC cultivation. Therefore, this study evaluated the effects of six growth factors (TGF-β, HGF, PDGF, insulin, IGF-1, and EGF) and the cytokine IL-2 on bovine MSCs. Each factor was applied during the proliferation and differentiation of MSCs, and the proliferation rate, differentiation rate, and expression of relevant mRNA and proteins were analyzed. Insulin most effectively promoted MSC proliferation and differentiation. Specifically, insulin increased cell proliferation rates, proliferation markers Ki67 and PCNA expressions, and markers of differentiation, such as myotube formation and creatine kinase activity, alongside the expressions of MYOD, MYOG, and MYH. Furthermore, insulin suppressed low FBS-induced reductions in proliferation and differentiation markers. This study suggests insulin can promote MSC proliferation and differentiation and reduce FBS usage. Thus, this study provides a potential means of cultivating MSCs on a large scale for cultured meat production.

Albumin is the most abundant protein synthesized exclusively by the hepatocytes in the liver. Once secreted into plasma, it helps in the maintenance of osmotic pressure, as well as the exertion of defensive roles such as anti-oxidative and anti-inflammatory functions. Dysregulation in the synthesis and clearance of albumin is observed in various hepatic and extra-hepatic diseases. Abnormal levels of albumin could be either a cause or an effect of various pathological ailments, including hepatic, cardiac, renal, neurological, etc. Owing to its long half-life and multiple binding sites in its heart-shaped structure, it interacts with various internal agents, such as hormones, or external substances like drugs, which is why transportation can be one of its many functions. Additionally, albumin’s drug interactions, as well as displacement of albumin–drug binding, could have serious clinical consequences, and careful considerations should be made in determining an appropriate drug regimen to achieve a desired therapeutic outcome with minimal side effects. Moreover, albumin also undergoes several post-translational modifications that can influence its physiological roles, including drug binding and antioxidant functions. Furthermore, it has a complicated role in physiology, where it can help in maintaining plasma oncotic pressure and prevent endothelial cell apoptosis but can have adverse effects on the lungs and kidneys. These adverse effects are mainly attributed to ER stress and inflammasome activation. This narrative review provides an overview of the general biology of albumin and its effects in physiology, with a focus on its beneficial and adverse effects and the underlying molecular mechanisms.

The endoplasmic reticulum (ER) is a vital cell organelle that is primarily involved in the processes of protein folding, maintenance of intracellular calcium storage and lipid synthesis in order to maintain cellular homeostasis. To achieve this meticulous order, several ER-dependent processes have to be in unison and perfect harmony. However, a persistent supply of newly synthesized proteins strains the ER mainly due to the accumulation of unfolded proteins, thus ultimately leading to an imbalance termed ER stress. Although the accumulation of misfolded proteins is a frequent reason for the initiation of ER stress, it is also induced by the hyper-production of reactive oxygen species, aberrant calcium leakage from the ER and due to the effect of cytokines. ER stress signals are conveyed via three arms of ER, namely PERK, IRE1 and ATF6. Signal transduction form these signaling molecules often converges on the transcriptional upregulation of CHOP and its related signaling mechanisms. If the ER stress is unresolved, then it can lead to cell death through different cell death mechanisms, including apoptosis, proptosis, etc. In the liver, it has been observed that ER stress plays a critical role in hepatic damage under different experimental conditions. This review highlights the role of ER stress in liver pathologies.