The hepatoprotective effect and mechanism of lotus leaf on liver injury induced by Genkwa Flos

Improving the Corrosion Resistance of Aluminum Alloy by Creating a Superhydrophobic Surface Structure through a Two-Step Process of Etching Followed by Polymer Modification

A multifunctional aviation aluminum alloy with good superhydrophobicity and corrosion resistance was prepared by a two-step process of etching followed by polymer modification. Meanwhile, micro- and nanostructures formed on the processed sample. Compared with bare sample, the static liquid contact angle on the as-prepared sample was increased by 100.8°. Further polarization tests showed that the corrosion potential of such a sample increased, and the corrosion current density decreased obviously, thus suggesting that the corrosion resistance of the modified sample was significantly improved. The same conclusion was confirmed by subsequent impedance testing. The work is of great economic value and practical significance to enhance the corrosion resistance of aviation actuator materials and also lays a foundation for future hydrophobic application research in aeronautical engineering.

Study on the vasodilatory activity of lotus leaf extract and its representative substance nuciferine on thoracic aorta in rats

Lotus (Nelumbo nucifera) leaves are widely used for both edible and medicinal applications. For its further utilization, we studied the vasodilatory activity of lotus leaf extract for the first time. In this study, we obtained the extracts using different ratios of water and ethanol, which was followed by polarity-dependent extraction. We found that the CH₂Cl₂ layer exhibited better vasodilatory activity (EC₅₀ = 1.21 ± 0.10 μg/ml). HPLC and ESI-HRMS analysis of the CH₂Cl₂ layer using the standard product as a control revealed that nuciferine (E_max = 97.95 ± 0.76%, EC₅₀ = 0.36 ± 0.02 μM) was the main component in this layer. Further research revealed that nuciferine exerts a multi-target synergistic effect to promote vasodilation, via the NO signaling pathway, K⁺ channel, Ca²⁺ channel, intracellular Ca²⁺ release, α and β receptors, etc. Nuciferine exhibits good vasodilatory activity, and it exhibits the potential to be utilized as a lead compound.

Research Advances in Lotus Leaf as Chinese Dietary Herbal Medicine

Lotus leaf (Heye), the dry foliage of Nelumbo nucifera Gaertn, has been valuable as a dietary herbal medicine for thousands of years. Phytochemical studies indicated that alkaloids and flavonoids are the main components of Heye. Polysaccharides, terpenes, and amino acids are also active ingredients. The drug properties of Heye are mild and bitter. Meridian tropism is mainly distributed in the liver, spleen, and stomach meridian. In the Traditional Chinese medicine (TCM) theoretical system, it is in many formulas for the therapy of various symptoms, including wasting-thirst induced by summer heat, diarrhea caused by summer heat-dampness and spleen deficiency, hematochezia, flooding and spotting, among others. Nowadays, the extracts and active components of Heye demonstrate multiple bioactivities, for instance anti-obesity, anti-inflammatory, anti-oxidant, cardiovascular protective, anticancer, hepatoprotective, hypoglycemic, antiviral, antimicrobial, as well as hemostatic activities. This review will provide an overview of Heye serving as a typical plant with functions of both medicine and food, including its practical applications in terms of TCM and healthy diet, phytochemistry, pharmacological activity, together with its toxicity. Besides, the new points and prospects of Heye in the overview are also outlined straightforwardly.

Discovery of eight alkaloids with D1 and D2 antagonist activity in leaves of Nelumbo nucifera Gaertn. Using FLIPR assays

ETHNOPHARMACOLOGICAL RELEVANCE

Dopamine receptors are long-standing primary targets in the treatment of mental diseases and there is growing evidence that suggests relationships between obesity and the dopamine system, especially dopamine D1 and D2 receptors. Leaves of Nelumbo nucifera Gaertn. (lotus leaves) have been medically used for helping long-term maintenance of weight loss. Whether and how components of lotus leaves function through the dopamine receptors remains unclear.

AIM OF THE STUDY

This work aimed to discover dopamine receptor-active alkaloids isolated from the lotus leaves, to evaluate their potencies and to analyze their structure activity relationship.

MATERIALS AND METHODS

Dried lotus leaves were prepared and total extract was divided into alkaloids and flavones. Eight alkaloids were separated and characterized by a combination of high-performance liquid chromatography, quadrupole time-of-flight mass spectrometry and nuclear magnetic resonance, and assayed by a fluorometric imaging plate reader platform. Human embryonic kidney 239 cell lines expressing dopamine D1, D2 and serotonin 2A (5-HT2A) receptors, respectively, were cultured and used in the assay.

RESULTS

Alkaloids in the lotus leaves were the bioactive phytochemicals and inhibited dopamine from accessing the D1 and D2 receptors. All eight compounds functioned as D1-receptor antagonists and except N-nornuciferine, seven alkaloids functioned as D2-receptor antagonists. (S)-coclaurine and (R)-coclaurine are optical isomers and antagonized both D1 and D2 with equivalent potencies, suggesting that the optical rotation of the methylene linker in the monobenzyl isoquinoline backbone did not influence their activity. Among the eight alkaloids, O-nornuciferine was the potent antagonist to both receptors (the lowest IC₅₀ values, D1: 2.09 ± 0.65 μM and D2: 1.14 ± 0.10 μM) while N-nornuciferine was found to be the least potent as it moderately antagonized D1 and was inactive on D2. O-nornuciferine was also a 5-HT2A antagonist (IC₅₀~20 μM) while N-nornuciferine had no activity. These hinted the importance of a methyl group attached to the nitrogen atom in the aporphine backbone. Armepavine showed a nearly 10-fold selectivity to D2.

CONCLUSIONS

In this work, eight alkaloids were isolated from the leaves of Nelumbo nucifera Gaertn. and assayed on the D1 and D2 receptors. They were D1/D2 antagonists with IC₅₀ values in the mid- to low-micromolar range and O-nornuciferine was the most potent alkaloid among the eight. This family of alkaloids was biochemically evaluated on the dopamine receptors by the same platform for the first time.

Herbal and dietary supplement induced liver injury: Highlights from the recent literature

Herbal-induced liver injury (HILI) is an important and increasingly concerning cause of liver toxicity, and this study presents recent updates to the literature. An extensive literature review was conducted encompassing September 2019 through March 2021. Studies with clinically significant findings were analyzed and included in this review. We emphasized those studies that provided a causality assessment methodology, such as Roussel Uclaf Causality Assessment Method scores. Our review includes reports of individual herbals, including Garcinia cambogia, green tea extract, kratom as well as classes such as performance enhancing supplements, Traditional Chinese medicine, Ayurvedic medicine and herbal contamination. Newly described herbals include ashwagandha, boldo, skyfruit, and 'Thermo gun'. Several studies discussing data from national registries, including the United States Drug-Induced Liver Injury (DILI) Network, Spanish DILI Registry, and Latin American DILI Network were incorporated. There has also been a continued interest in hepatoprotection, with promising use of herbals to counter hepatotoxicity from anti-tubercular medications. We also elucidated the current legal conversation surrounding use of herbals by presenting updates from the Federal Drug Administration. The highlights of the literature over the past year indicate interest in HILI that will continue as the supplement industry in the United States grows.