Camu Camu (Myrciaria dubia (Kunth) McVaugh): An Amazonian Fruit with Biofunctional Properties-A Review

Immunotherapy efficacy and toxicity: Reviewing the evidence behind patient implementable strategies

The use of immune checkpoint inhibitors (ICI) in cancer treatment is expanding, offering promising outcomes but with an important risk of immune-related adverse events (irAEs). These events, stemming from an overstimulated immune system attacking healthy cells, can necessitate immunosuppressant treatment, disrupt treatment courses, and impact patients' quality of life. The analysis of ICI efficacy data has led to a better understanding of the characteristics of responders. Similarly, we are gaining clearer insights into the characteristics of patients who develop irAEs, prompting an increasing emphasis on modifiable factors associated with irAE risk. These factors include lifestyle choices and the composition of the gut microbiome. Despite comprehensive reviews exploring the microbiome's role in therapy efficacy, understanding its connection with immune-related toxicity remains incomplete. While endeavours to identify predictive biomarkers continue, lifestyle modifications emerge as a promising avenue for enhancing treatment outcomes. This review consolidates the current evidence regarding the impact of the gut microbiome on irAE occurrence. Furthermore, it focuses on actionable strategies for mitigating these adverse events, elucidating the evidence supporting dietary adjustments, supplementation, medication management, and physical activity. With the expanding range of indications for ICI therapy, a significant proportion of oncology patients, including those in early disease stages, are now exposed to these treatments. Acknowledging the importance of averting irAEs in this context, our review offers timely insights crucial for addressing the evolving challenges associated with immunotherapy across diverse oncological settings.

Structural insights into the Smirnoff-Wheeler pathway for vitamin C production in the Amazon fruit camu-camu

l-Ascorbic acid (AsA, vitamin C) is a pivotal dietary nutrient with multifaceted importance in living organisms. In plants, the Smirnoff-Wheeler pathway is the primary route for AsA biosynthesis, and understanding the mechanistic details behind its component enzymes has implications for plant biology, nutritional science, and biotechnology. As part of an initiative to determine the structures of all six core enzymes of the pathway, the present study focuses on three of them in the model species Myrciaria dubia (camu-camu): GDP-d-mannose 3',5'-epimerase (GME), l-galactose dehydrogenase (l-GalDH), and l-galactono-1,4-lactone dehydrogenase (l-GalLDH). We provide insights into substrate and cofactor binding and the conformational changes they induce. The MdGME structure reveals a distorted substrate in the active site, pertinent to the catalytic mechanism. Mdl-GalDH shows that the way in which NAD+ association affects loop structure over the active site is not conserved when compared with its homologue in spinach. Finally, the structure of Mdl-GalLDH is described for the first time. This allows for the rationalization of previously identified residues which play important roles in the active site or in the formation of the covalent bond with FAD. In conclusion, this study enhances our understanding of AsA biosynthesis in plants, and the information provided should prove useful for biotechnological applications.

Effects of plant natural products on metabolic-associated fatty liver disease and the underlying mechanisms: a narrative review with a focus on the modulation of the gut microbiota

Metabolic-associated fatty liver disease (MAFLD) is a chronic liver disease characterized by the excessive accumulation of fat in hepatocytes. However, due to the complex pathogenesis of MAFLD, there are no officially approved drugs for treatment. Therefore, there is an urgent need to find safe and effective anti-MAFLD drugs. Recently, the relationship between the gut microbiota and MAFLD has been widely recognized, and treating MAFLD by regulating the gut microbiota may be a new therapeutic strategy. Natural products, especially plant natural products, have attracted much attention in the treatment of MAFLD due to their multiple targets and pathways and few side effects. Moreover, the structure and function of the gut microbiota can be influenced by exposure to plant natural products. However, the effects of plant natural products on MAFLD through targeting of the gut microbiota and the underlying mechanisms are poorly understood. Based on the above information and to address the potential therapeutic role of plant natural products in MAFLD, we systematically summarize the effects and mechanisms of action of plant natural products in the prevention and treatment of MAFLD through targeting of the gut microbiota. This narrative review provides feasible ideas for further exploration of safer and more effective natural drugs for the prevention and treatment of MAFLD.

The Amazonian Camu-Camu Fruit Modulates the Development of Drosophila melanogaster and the Neural Function of Adult Flies under Oxidative Stress Conditions

Camu-camu (Myrciaria dubia) is known for its antioxidant properties, although little is known about its developmental safety effects, particularly on adult neural function under basal redox and oxidative stress conditions. Therefore, this study sought to address this gap by conducting three complementary protocols using Drosophila melanogaster to investigate these effects. The initial assays revealed that second-stage larvae consumed diets supplemented with various concentrations of camu-camu uniformly, establishing a 50% lethal concentration at 4.799 mg/mL. Hence, non-lethal (0.1, 0.5, and 1 mg/mL) and sub-lethal (5 and 10 mg/mL) concentrations were then chosen to evaluate the effects of camu-camu on preimaginal development and adult neural function. Our observations showed that camu-camu impacts the expression of antioxidant enzymes, reactive species, and lipoperoxidation. Notably, sub-lethal concentrations decreased preimaginal viability and locomotor activity, negatively influenced geotaxis and acetylcholinesterase activity, and increased reactive species, catalase, and glutathione S-transferase activity in flies. Additionally, the protective effects of camu-camu against oxidative stress induced by iron (20 mM) were assessed. Flies supplemented with 0.5 mg/mL of camu-camu during the larval period showed improved neural viability and function, and this supplementation was found to protect against oxidative stress. These findings are instrumental in evaluating the safety and efficacy of commercial supplements based on camu-camu, offering significant insights for future research and application.

Edible Fruits from the Ecuadorian Amazon: Ethnobotany, Physicochemical Characteristics, and Bioactive Components

In the Ecuadorian Amazon region, there are various types of edible fruits that have distinct qualities and benefits. Understanding the uses, properties, and functions of these fruits is important for researching products that are only available in local markets. This review aims to gather and summarize the existing scientific literature on the ethnobotany, physicochemical composition, and bioactive compounds of these native fruits to highlight the potential of the region's underutilized biodiversity. A systematic review was carried out following the PRISMA methodology, utilizing databases such as Web of Science, Scopus, Pubmed, Redalyc, and SciELO up to August 2023. The research identified 55 edible fruits from the Ecuadorian Amazon and reported their ethnobotanical information. The most common uses were fresh fruit consumption, preparation of typical food, and medicine. Additionally, nine native edible fruits were described for their physicochemical characteristics and bioactive components: Aphandra natalia (Balslev and Henderson) Barfod; Eugenia stipitate McVaugh; Gustavia macarenensis Philipson; Mauritia flexuosa L.f; Myrciaria dubia (Kunth) McVaugh; Oenocarpus bataua Mart; Plukenetia volubilis L.; Pouteria caimito (Ruiz and Pav.) Radlk.; and Solanum quitoense Lam. The analyzed Amazonian fruits contained bioactive compounds such as total polyphenols, flavonoids, carotenoids, and anthocyanins. This information highlights their potential as functional foods and the need for further research on underutilized crops.