Chemical Constituents from Albiziae Cortex and Their Ability to Ameliorate Steatosis and Promote Proliferation and Anti-Oxidation In Vitro

A comparison review of Hehuan flowers and Hehuan bark on the traditional applications, phytochemistry and pharmacological effects

ETHNOPHARMACOLOGICAL RELEVANCE

Albizia julibrissin Durazz is a well-known medicinal plant with the Chinese name Hehuan []. Hehuan bark and Hehuan flowers have long been recognized as traditional Chinese herbal medicine for treating anxiety, melancholy, insomnia, bruises, pulmonary abscess, fractures, carbuncle, amnesia, acute conjunctivitis, blurred vision, neonatal tetanus and stroke for thousands of years. They are recorded in Chinese Pharmacopoeia separately with different properties. Until now, new chemical constituents and pharmacological activities of Hehuan have been continuously studied and revealed.

THE AIM OF THE REVIEW

This review aims to provide a comprehensive summary of traditional applications, phytochemistry, pharmacology effects, and toxicology of Hehuan bark and Hehuan flowers, and give critical assessment and point out the promising direction for further research on Hehuan.

MATERIAL AND METHODS

A literature search was undertaken on Hehuan bark and Hehuan flowers by analyzing the information from scientific databases (SciFinder, Pubmed, Elsevier, Google Scholar, Web of Science, and Baidu Scholar). We also gathered the information of Hehuan from classic herbal literatures and conference papers on ethnopharmacology.

RESULTS

According to Chinese and English documents, the medicinal history of Hehuan in China can be traced back to ad 25. Meanwhile, its medicinal history as a kind of herbal medicine can also be found in other Asian countries. So far about 140 compounds have been isolated from Hehuan bark and Hehuan flowers, including triterpenoids, flavonoids, lignans, phenolic acids, alkaloids, etc. Among them, flavonoids mainly exist in Hehuan flowers, while Hehuan bark contains lignans and saponins. The composition differences between the barks and flowers of Hehuan account for the different effects and applications. Modern pharmacological studies have indicated that crude extracts and pure compounds of Hehuan flowers and Hehuan bark have multiple pharmacological activities, such as antineoplastic, immunomodulatory, anti-inflammatory, anxiolytic, antidepressant, metabolic regulation, anti-insomnia, neuroprotective, hepatoprotective, sedative, and anti-osteolytic activities.

CONCLUSIONS

Hehuan (Albizia julibrissin Durazz) is traditionally used to relieve depression, calm nerves, promote blood circulation and reduce swelling. Modern pharmacological studies have revealed that natural products from Hehuan bark and Hehuan flowers possess extensive pharmacological activities in treating cancer, enhancing immunity, regulating metabolism, improving mental state, etc. These properties make it great clinical application potential. Further research on natural pharmaceutical chemistry, pharmacology, toxicology, pharmacokinetics, and quality standards of Hehuan are still required to verify the efficacy and safety for future clinical applications.

Constituents of Tinospora sinensis and their nitric oxide inhibitory activities

One new phenylpropanoid glycoside, tinosinen A (1) and 13 known compounds, tinosinen (2), citrusin B (3), picraquassioside C (4), erythro-guaiacylglycerol-β-O-4'-coniferyl alcohol (5), erythro-guaiacylglycerol-8-O-4'-(sinapyl alcohol) ether (6), erythro-syringylglycerol-8-O-4'-(sinapyl alcohol) ether (7), seco-isolariciresinol 9-O-D-β-glucopyranoside (8), tinosposide A (9), pinoresinol-4'-O-β-D-glucopyranoside (10), syringaresinol-4'-O-β-D-glucopyranoside (11), pinoresinol (12), syringaresinol (13), and lirioresino-β-dimethyl ether (14) were isolated from the stems of Tinospora sinensis (Lour.) Merr. Their structures were established by detailed spectroscopic studies and comparisons with those reported in the literature. Compound 13 showed significant inhibitory NO production (IC₅₀ value of 38.53 ± 1.90 μM) in RAW264.7 macrophages, LPS-stimulated. Compounds 3-7, 11, 12, and 14 inhibited NO production with IC₅₀ values ranging from 38.53 to 99.07 μM.

Two Lignan Glycosides from Albizia julibrissin Durazz. Noncompetitively Inhibit Serotonin Transporter

Albizia julibrissin Durazz. is one of the most common herbs used for depression and anxiety treatment, but its molecular basis and mechanism of action as an antidepressant or anxiolytic drug are not understood. In this study, we separated and identified two lignan glycosides that inhibit serotonin transporter (SERT) noncompetitively by decreasing Vmax with little change in Km for its fluorescence substrate. In addition, treatment with lignan glycosides did not alter total and cell surface expression levels of the transporter protein. The two compounds decreased the accessibility of a cysteine residue placed in the extracellular substrate permeation pathway by inducing a conformational shift toward an outward-closed state of SERT. These results are consistent with molecular docking for the association of the lignan glycosides to the allosteric site in SERT. The present work supports the proposal that these compounds act on SERT by a novel underlying mechanism of action different from that of conventional antidepressant drugs.

Chinese Pharmacopoeia Revisited: A Review of Anti-Depression Herbal Sources

Depression, which can be accompanied by many fatal diseases and a low life quality, has become the leading cause of ill health and disability worldwide. However, Chinese Pharmacopoeia, the most authoritative and evidence-based encyclopedia of Traditional Chinese Medicine (TCM), could contain leads and insights into the development of new antidepressant drugs. In this work, nine herbal medicines with ‘dispel melancholy functions’ specifically documented in Chinese Pharmacopoeia have been comprehensively reviewed with respect to clinical trials, and phytochemical and pharmacological aspects. The nine drugs are Rosae Chinensis Flos, Croci Stigma, Albiziae Cortex and Flos, Roase Rugosae Flos, Curcumae Radix, Hyperici Perforati Herba, Cyperi Rhizoma and Bupleuri Radix. The mechanisms of action of their functional antidepressant compounds, including gallic acid, hypericin, kaempferol, crocetin, crocin, quercetin, luteolin, isorhamnetin, curcumin, hyperforin, adhyperforin, catechin, rutin, puerarin, and saikosaponins A and D, have been collected and discussed. These traditional Chinese herbs and their active compounds provide a promising resource to develop effective new antidepressant drugs in future. Moreover, mechanistic investigations, safety verification and large-scale clinical trials are still expected to finally transform such TCM-based antidepressant resources to new drugs for patients suffering from depression.