BACKGROUND: Wolfberry is rich in carotenoids, flavonoids, vitamins, alkaloids, betaines and other bioactive ingredients. For over 2,000 years, wolfberry has been used in China as a medicinal and edible plant resource. Nevertheless, the content of bioactive ingredients varies by cultivars, resulting in uneven quality across wolfberry cultivars and species. To date, research has revealed little about the underlying molecular mechanism of the metabolism of flavonoids, carotenoids, and other bioactive ingredients in wolfberry.
RESULTS: In this context, the transcriptomes of the Lycium barbarum L. cultivar \'Ningqi No. 1\' and Lycium chinense Miller were compared during the fruit maturity stage using the Illumina NovaSeq 6000 sequencing platform, and subsequently, the changes of the gene expression profiles in two types of wolfberries were analysed. In total, 256,228,924 clean reads were obtained, and 8817 differentially expressed genes (DEGs) were identified, then assembled by Basic Local Alignment Search Tool (BLAST) similarity searches and annotated using Gene Ontology (GO), Clusters of Orthologous Groups of proteins (KOG), and the Kyoto Encyclopedia of Genes and Genomes (KEGG). By combining these transcriptome data with data from the PubMed database, 36 DEGs related to the metabolism of bioactive ingredients and implicated in the metabolic pathway of carotenoids, flavonoids, terpenoids, alkaloids, vitamins, etc., were identified. In addition, among the 9 differentially expressed transcription factors, LbAPL, LbPHL11 and LbKAN4 have raised concerns. The protein physicochemical properties, structure prediction and phylogenetic analysis indicated that LbAPL and LbPHL11 may be good candidate genes involved in regulating the flavonoid metabolism pathway in wolfberry.
CONCLUSIONS: This study provides preliminary evidence for the differences in bioactive ingredient content at the transcription level among different wolfberry species, as well as a research and theoretical basis for the screening, cloning and functional analysis of key genes involved in the metabolism of bioactive ingredients in wolfberry.

Antioxidant components and properties (assayed by scavenging DPPH radicals, TEAC, reducing power, and inhibiting Cu(2+)-induced human LDL oxidation) of leaves and stems from three inbred varieties of Lycium chinense Miller, namely ML01, ML02 and ML02-TY, harvested from January to April were studied. Their flavonoid and phenolic acid compositions were also analyzed by HPLC. For each variety, the leaves and stems collected in higher temperature month had higher contents of total phenol, total flavonoid and condensed tannin. Contents of these components in the samples collected in different months were in the order: April (22.3°C)>March (18.0°C)>January (15.6°C)>February (15.4°C). Antioxidant activities of the leaves and stems for all assays also showed similar trends. The samples from different varieties collected in the same month also possessed different phenolic compositions and contents and antioxidant activities. Their antioxidant activities were significantly correlated with flavonoid and phenolic contents.

The hepatoprotective activities of Lycium chinense Miller (LC) fruit extract and its component betaine were investigated under carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. The treatment of LC fruit extract significantly suppressed the increase of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the sera of CCl4 injured rats, and restored the decreased levels of anti-oxidant enzymes such as total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and suppressed the expression of inflammatory mediators including inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-1 and -2. To visualize the potential activity of betaine, a component of LC fruit, betaine was substituted for LC extract in CCl4 injured rats. The biochemical profile in CCl4 injured rats co-treated with betaine matched those of LC fruit treated CCl4 injured rats. The ameliorative effects of LC extract, as well as betaine, were also confirmed by histopathological examination. Collectively, the present findings imply that LC fruit, via its component betaine, mitigate CCl4-induced hepatic injury by increasing antioxidative activity and decreasing inflammatory mediators including iNOS and COX-1/COX-2.

BACKGROUND: The root bark of Lycium chinense Miller, Lycii radicis cortex, has been used in traditional Chinese medicine (TCM) to treat different inflammation-related symptoms, such as diabetes mellitus. The pro-inflammatory transcription factor nuclear factor kappa B (NF-κB) is a key regulator of inflammation, while the transcription factor peroxisome proliferator-activated receptor gamma (PPARγ) is a key modulator of genes involved in diabetes development. To identify putative active compound(s) from Lycii radicis cortex inhibiting NF-κB or activating PPARγ.
METHODS: Using activity-guided fractionation, six extracts with different polarity, isolated fractions, and purified compounds from Lycii radicis cortex were tested for NF-κB inhibition and PPARγ activation in vitro. The structure of the purified compounds was elucidated by NMR and MS techniques.
RESULTS: The ethyl acetate extract and the methanol extract of Lycii radicis cortex suppressed tumor necrosis factor alpha (TNF-α)-induced activation of NF-κB, while the dichloromethane extract activated PPARγ. Nine phenolic amide analogues, including trans-N-(p-coumaroyl)tyramine (1), trans-N-feruloyltyramine (2), trans-N-caffeoyltyramine (3), dihydro-N-caffeoyltyramine (4), three neolignanamides (5-7), and two lignanamide (8, 9), were isolated and their inhibitory potential on NF-κB was determined (1-4 were also contained in water decoction). Two of the nine isolated phenolic amides inhibited TNF-α-induced NF-κB activation. Trans-N-caffeoyltyramine was verified as the key component responsible for the NF-κB inhibition with an IC50 of 18.4μM in our cell-based test system. Activation of PPARγ was attributed to a palmitic-acid enriched fraction which displayed concentration-dependent effect ablated upon co-treatment with the PPARγ antagonist T0070907.
CONCLUSIONS: Phenolic amides were confirmed as main components from Lycii radicis cortex responsible for NF-κB inhibition. Fatty acids were identified as the major plant constituent responsible for the PPARγ activation. Structure-activity relationship analysis suggests that the NF-κB inhibitory activity of trans-N-caffeoyltyramine may be attributed to its Michael acceptor-type structure (α,β-unsaturated carbonyl group). The data of this study contribute to a better understanding of the molecular mechanism of action of Lycii radicis cortex extracts in the context of inflammation.

Four new compounds 3,4-dihydroxy benzoic acid 3-octadecanoyl-4-O-α-L-arabinopyranosyl (2a→1b)-2a-O-α-L-arabinopyranosyl-(2b→1c)-2b-O-α-L-arabinopyranoside (1), 2,6,10-trimethyl-n-dodec-2-en-1-oyl-1-O-α-L-arabinopyranosyl-(2a→1b)-2a-O-α-L-arabinopyranosyl-(2b→1c)-2b-O-α-L-arabinopyranosyl-(2c→1d)-2c-O-α-L-arabinopyranosyl-(2d→1e)-2d-O-α-L-arabinopyranosyl-(2e→1f)-2e-O-α-L-arabinopyranosyl-(2f→1g)-2f-O-α-L-arabinopyranoside (2), n-docos-9,12-dienoyl-α-D-glucopyranosyl-(2a→1b)-2a-O-α-D-glucopyranosyl-(2b→1c)-2b-O-α-D-glucopyranosyl-(2c→1d)-2c-O-α-D-glucopyranosyl-(2d→1e)-2d-O-α-D-glucopyranosyl-(2e→1f)-2e-O-α-D-glucopyranoside (3), β-D-glucopyranosyl-(2a→1b)-2a-O-β-L-arabinopyranosyl-(2b→1c)-2b-O-β-L-arabinopyranosyl-(2c→1d)-2c-O-β-L-arabinopyranosyl-(2d→1e)-2d-O-β-L-arabinopyranosyl-(2e→1f)-2e-O-β-L-arabinopyranoside (4) along with some know compounds, were isolated and identified from a methanol extract Lycium chinense fruits. Their structures were determined of the new compounds using one- and two-dimensional NMR spectroscopies in combination by IR, FAB/MS and HR-FAB/MS. The compounds 1-4 were investigated for the antioxidant potential using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, reducing power and the phosphomolybdenum activity and the results demonstrate that the compounds (2 and 3) has potential as a natural antioxidant whereas the compound (4) exhibited moderate activity and the compound (1) exhibited weak antioxidant activity.