African mistletoe ( Tapinanthus bangwensis Lor.) infestation improves the phenolic constituents, antioxidative and antidiabetic effects of almond ( Terminalia catappa Linn.) host leaf in sucrose‐rich diet‐induced diabetic‐like phenotypes in fruit fly ( Drosophila melanogaster Meigen)

An In Silico In Vitro and In Vivo Study on the Influence of an Eggplant Fruit (Solanum anguivi Lam) Diet on Metabolic Dysfunction in the Sucrose-Induced Diabetic-like Fruit Fly (Drosophila melanogaster)

Introduction: Africa faces immense food and health insecurity challenges, a problem partly attributed to food loss and waste during postharvest handling and distribution. In the context of research to meet the sustainable development goals, this project specifically addressed the postharvest loss of the ripe indigenous eggplant (Solanum anguivi lam) fruit called "Igba Yinrin" by Yoruba in South-West Nigeria, which is usually discarded in farms. The study was carried out on ripe and unripe fruits to better understand their value by comparing their effects in diabetes treatment. Methods: The study sought to assess the effects of a diet including ripe or unripe mature eggplant fruits in the sucrose-induced diabetic-like fruit fly. Bioactive compounds were identified and quantified with HPLC-UV, while the antioxidant vitamin (A, C, E), carotenoid, and mineral (Na, K, Ca, Mg, Fe, P, and Zn) content was analyzed in the fruits. Extracts were used to investigate their in vitro anti-inflammatory properties on cyclooxygenases (COX 1 and 2), 5-lipoxygenase (5-LOX), and anti-diabetes enzymes [α-amylase and α-glucosidase], while extract-supplemented diets (0.25-1% concentration) were fed to the fruit flies for 14 days. Results: Interestingly, the results showed that the ripe fruits had a significantly (p < 0.05) higher total phenol and flavonoid content, as well as a higher content of vitamins, carotenoids, and minerals, than the unripe fruits. The in vivo activities of antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), and glutathione transferase (GST)] and the total thiol level increased, while the blood glucose, reactive oxygen species (ROS), and malondialdehyde (MDA) levels decreased in Drosophila melanogaster (fruit fly). An in silico docking analysis showed strong binding affinity of the above-mentioned enzymes under investigation with the ligands hesperidin, naringin, and myricetin, which are bioactive compounds contained in the examined extracts. Conclusions: There was no significant difference in the biological effects of the ripe and unripe fruit extracts on inflammatory and anti-diabetes enzyme activities, which means that the ripe fruit, usually discarded, could serve as a sustainable alternative source of food nutrients.

Plant-Wide Target Metabolomics Provides a Novel Interpretation of the Changes in Chemical Components during Dendrobium officinale Traditional Processing

The traditional processing of Dendrobium officinale (DO) is performed in five necessary processing steps: processing fresh strips, drying at 85 °C, curling, molding, and drying at 35 °C (Fengdou). The antioxidant activity of DO is increased after it is processed into Fengdou. To comprehensively analyze the changes in the functional components, a plant-wide target metabolomics approach was employed. In total, 739 differential chemical components were identified in five processing treatments, mainly highlighting differences in the levels of phenolic acids, flavonoids, lipids, and amino acids and their derivatives, and the glycosylation of aglycone resulted in the upregulation of flavonoid glycoside levels. Temperature is a key factor in DO processing during production. In addition, the enrichment of specific differential chemical components was found mainly in five different metabolic pathways: glucosinolate biosynthesis, linoleic acid metabolism, flavonoid biosynthesis, phenylpropanoid biosynthesis, and ubiquinone and other terpene quinone biosynthesis. A correlation analysis clarified that total phenols and flavonoids show a significant positive correlation with antioxidant capacity. This study provides new insights into the influence of the processing processes on DO quality, which may provide guidance for the high-quality production of DO.

Dietary regulation of peroxisome proliferator-activated receptors in metabolic syndrome

BACKGROUND

Peroxisome proliferator-activated receptors (PPARs) are a class of ligand-activated nuclear transcription factors, members of the type nuclear receptor superfamily, with three subtypes, namely PPARα, PPARβ/δ, and PPARγ, which play a key role in the metabolic syndrome. In the past decades, a large number of studies have shown that natural products can act by regulating metabolic pathways mediated by PPARs.

PURPOSE

This work summarizes the physiological importance and clinical significance of PPARs and reviews the experimental evidence that natural products mediate metabolic syndrome via PPARs.

METHODS

This study reviews relevant literature on clinical trials, epidemiology, animals, and cell cultures published in NCBI PubMed, Scopus, Web of Science, Google Scholar, and other databases from 2001 to October 2022. Search keywords were "natural product" OR "botanical" OR "phytochemical" AND "PPAR" as well as free text words.

RESULTS

The modulatory involvement of PPARs in the metabolic syndrome has been supported by prior research. It has been observed that many natural products can treat metabolic syndrome by altering PPARs. The majority of currently described natural compounds are mild PPAR-selective agonists with therapeutic effects that are equivalent to synthetic medicines but less harmful adverse effects.

CONCLUSION

PPAR agonists can be combined with natural products to treat and prevent metabolic syndrome. Further human investigations are required because it is unknown how natural products cause harm and how they might have negative impacts.

Quercetin ameliorates hepatic fat accumulation in high-fat diet-induced obese mice via PPARs

As a natural pigment in food, quercetin possesses multiple biological activities and plays a crucial role in regulating metabolic syndrome. Herein, we aim to explore the potential mechanism of quercetin to ameliorate hepatic fat accumulation. In vivo experiments showed that quercetin significantly relieved inflammation response by decreasing the serum TNF-α and IL-6 levels and also improved high-fat diet-induced hepatic steatosis without other organ injuries. Quercetin can effectively reduce lipid aggregation and down-regulate the protein expression of PCK1 in HepG2 cells induced by oleic acid and palmitic acid, indicating that inhibiting gluconeogenesis leads to hepatic fat accumulation reduction. Furthermore, molecular docking results suggested that quercetin can bind to both PPARα and PPARγ, with an even more potent binding affinity than indeglitazar, a pan-agonist of PPARs. In conclusion, quercetin may regulate gluconeogenesis to ameliorate hepatic fat accumulation via targeting PPARα/γ.

Ultra-High Hydrostatic Pressure Pretreatment on White Que Zui Tea: Chemical Constituents, Antioxidant, Cytoprotective, and Anti-Inflammatory Activities

Herbal tea has numerous biological activities and exhibits broad benefits for human health. In China, the flower buds of Lyonia ovalifolia are traditionally processed as herbal tea, namely White Que Zui tea (WQT). This study was aimed to evaluate the effect of ultra-high hydrostatic pressure (UHHP) pretreatment on the chemical constituents and biological activities of free, esterified, and insoluble-bound phenolic fractions from WQT. A total of 327 chemical constituents were identified by a quasi-targeted metabolomics analysis. UHHP pretreatment extremely inhibited reactive oxygen species (ROS) production and cell apoptosis in H2O2-induced HepG2 cells, and it increased the activities of intracellular antioxidant enzymes (SOD and CAT) and GSH content in different phenolic fractions from WQT. In addition, after UHHP pretreatment, the anti-inflammatory effects of different phenolic fractions from WQT were improved by inhibiting the production of nitric oxide (NO) and pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) in LPS-induced RAW264.7 cells. Thus, the UHHP method might be a potential pretreatment strategy for improving the bioavailability of phytochemicals from natural plants.

Mistletoe infested Moringa oleifera and Terminalia catappa leaves supplemented diet enhances antioxidant and insulin-like peptide mRNA levels in Drosophila melanogaster

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This research reports the influence of mistletoe infested moringa and almond leaves supplemented diet on antioxidant and insulin-like peptide mRNA levels in diabetic-like flies.

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Mistletoe infestation on moringa and almond leaves caused upregulation of superoxide dismutase mRNA levels and downregulation of heat shock protein-70 gene.

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The mistletoe infested moringa and almond leaves also resulted in significant downregulation of drosophila insulin-like peptide-2 mRNA levels.

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Consumption of mistletoe infested Moringa and Almond leaves could possibly offer better antioxidative and hypoglycemic effects.

Moringa and Almond are common plants of medicinal and economic value which are often infested with mistletoe. Host plants’ infestation could result in major differences in their phytoconstituents and biological activities. Thus, effects of mistletoe infestation on Moringa and Almond host plants supplemented diets on mRNA expression levels of Drosophila insulin-like peptide-2 (Dilp2), heat shock protein-70 (Hsp70) and superoxide dismutase (Sod) in diabetic-like flies were evaluated using quantitative real-time PCR system. Mistletoe infestation on host leaves caused significant upregulation of Sod and significant downregulation of Hsp70 and Dilp2 genes. Hence, we opined that infestation of Moringa and Almond trees with mistletoe resulted in improved expression level of antioxidant and insulin-like peptide genes. This may be the mechanism by which host plants caused enhanced regulation of circulating glucose and oxidative stress. Therefore, consumption of mistletoe infested Moringa and Almond host leaves could possibly offer better antioxidant and hypoglycemic effects.

Tapinanthus species: A review of botany and biology, secondary metabolites, ethnomedical uses, current pharmacology and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Tapinanthus species are hemiparasites that grow on diverse hosts in African regions. Tapinanthus species are locally known as "all purpose herbs" as they are traditionally used to treat various diseases such as diabetes, hypertension, cancer, inflammation, malaria, anemia, anxiety, itching, and so on.

AIM OF THE STUDY

A comprehensive review on research outcomes and future perspectives of Tapinanthus species are presented to provide a reference for relevant researchers.

MATERIALS AND METHODS

The references regarding Tapinanthus species were retrieved from Google Scholar, Web of Science, Sci-finder, PubMed, Elsevier, Wiley, China National Knowledge Infrastructure, Open Access Library, and SpringerLink between 1963 and 2022. Scientific plant names were provided by "The Plant List" (www.theplantlist.org) and "The world Flora Online" (www.worldfloraonline.org).

RESULTS

Even though Tapinanthus species are regarded as notorious pests that can undermine various hosts, they are, as omnipotent herbs in folklore, meaningful for the development of potential phytomedicine sources. Phytochemistry screening has revealed the presence of glycosides, triterpenoids, flavonoids, alkaloids, tannins, steroids, anthraquinones. Among them, the chemical structures of 40 compounds have been elucidated by phytochemical methods without alkaloids and anthraquinones. These secondary metabolites might be responsible for ethnomedical uses and bioactivities of Tapinanthus species. Current research has provided scientific evidence for traditional uses of Tapinanthus species, especially unraveling hypoglycemic, hepatoprotective, antioxidant, antibacterial, anti-anxiety, anti-depression, anti-inflammatory, and other pharmacological properties. Given the fact that ethnomedical uses served as a valuable reference for pharmacology, however, some records to treat arthritis, fever, itching, dysentery, stomach pain, and anemia, have not been confirmed in current research. Furthermore, the toxic effects of Tapinanthus species were susceptible to the dosages, with relative safety across a wide range.

CONCLUSIONS

To reasonably yield Tapinanthus species, artificial culture might be a promising method to develop in the future. The discrepancies between phytochemistry screening and structure elucidation, as well as between ethnomedical uses and current pharmacology, need to be further clarified. The identification of bioactive compounds in crude extracts and fractions, the illustration of the underlying mechanisms of pharmacology, along with the addition of cytotoxicity, genotoxicity, and clinical trials of toxic tests, should be carried out in depth. This review highlights that Tapinanthus species can be considered promising phytomedicine sources as long as we adhere to digging more deeply into their potential role.