Effect of food processing on the antioxidant activity of flavones from Polygonatum odoratum (Mill.) Druce

Neuroinflammation of Microglial Regulation in Alzheimer's Disease: Therapeutic Approaches

Alzheimer's disease (AD) is a complex degenerative disease of the central nervous system that is clinically characterized by a progressive decline in memory and cognitive function. The pathogenesis of AD is intricate and not yet fully understood. Neuroinflammation, particularly microglial activation-mediated neuroinflammation, is believed to play a crucial role in increasing the risk, triggering the onset, and hastening the progression of AD. Modulating microglial activation and regulating microglial energy metabolic disorder are seen as promising strategies to intervene in AD. The application of anti-inflammatory drugs and the targeting of microglia for the prevention and treatment of AD has emerged as a new area of research interest. This article provides a comprehensive review of the role of neuroinflammation of microglial regulation in the development of AD, exploring the connection between microglial energy metabolic disorder, neuroinflammation, and AD development. Additionally, the advancements in anti-inflammatory and microglia-regulating therapies for AD are discussed.

Gastroprotective effects of Polygonatum odoratum in rodents by regulation of apoptotic proteins and inflammatory cytokines

In an increasing interest in natural antiulcer compounds that may have gastric healing effects and possibly prevent ulcer recurrence, Polygonatum odoratum appears as a strong candidate. The gastroprotective potentials of P. odoratum rhizome extract (PORE) were explored on ethanol-induced gastric ulceration in rats. Sprague Dawley rats were caged in 5 groups, normal and ulcer control rats received CMC (1% carboxymethyl cellulose). Omeprazole (20 mg/kg) was given to reference Rats. Experimental rats were treated with 250 mg/kg and 500 mg/kg PORE, respectively. After an hour, the normal control rats received 1% CMC, whereas rat groups 2-5 were given absolute ethanol by oral gavage. After 60 min, rats received anesthesia and were sacrificed. Dissected gastric tissue was analyzed by histopathological and immunohistochemical techniques. PORE treatment significantly lowered the ethanol-induced gastric injury, as shown by up-surging gastric pH and mucus content, reduced leukocyte infiltration, lower ulcerative areas in mucosal layers, and increased antioxidants (SOD and CAT) and (MDA) levels. Furthermore, PORE pre-treated rats showed significantly increased expression of the Periodic acid-Schiff (PAS), HSP-70 protein, and decreased Bax protein in their gastric epithelial layers. PORE treatment showed an important regulation of inflammatory cytokines shown by decreasing the TNF-a, and IL-6 and increasing the IL-10 values. The detected biological activity of PORE is encouraging and presents the scientific evidence for its traditional use as a gastroprotection agent however further studies are required to determine the exact phytochemicals and mechanism pathway responsible for this bioactivity.

Qualitative and quantitative studies on two commercial specifications of Polygonatum odoratum

The rhizoma of Polygonatum odoratum (PO) is used to treat yin injuries of the lung and stomach in traditional Chinese medicine. The chemical constituents of this herb are steroidal saponins, homoisoflavanones, and alkaloids. Xiangyuzhu (XPO) and Guanyuzhu (GPO) are available in the market as two specifications of the commodity. Nonetheless, systematic research on the identification and comparison of chemical constituents of these two commercial specifications is yet lacking. Herein, an integrated method combing ultra-high-performance liquid chromatography-quadruple time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) with ultra-high-performance liquid chromatography-charged aerosol detection (UHPLC-CAD) was employed for the comprehensively qualitative and quantitative analyses of PO. A total of 62 compounds were identified by UHPLC-Q-TOF/MS, among which 13 potential chemical markers were screened out to distinguish two commercial specifications. Subsequently, the absolute determination method for polygodoraside G, polygonatumoside F, and timosaponin H1 was established and validated by UHPLC-CAD. The contents of the three compounds were 13.33-236.24 μg/g, 50.55-545.04 μg/g, and 13.34-407.83 μg/g, respectively. Furthermore, the ratio of timosaponin H1/polygodoraside G could be applied to differentiate the two specifications. Samples with a ratio <2 are considered XPO and >5 are considered GPO. Therefore, the above results provide a valuable means for the quality control of PO.

A Review of Polygonatum Mill. Genus: Its Taxonomy, Chemical Constituents, and Pharmacological Effect Due to Processing Changes

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Polygonatum Tourn, ex Mill. contains numerous chemical components, such as steroidal saponins, polysaccharides, flavonoids, alkaloids, and others, it possesses diverse pharmacological activities, such as anti-aging, anti-tumor, immunological regulation, as well as blood glucose management and fat reducing properties.

AIM OF THE REVIEW

This study reviews the current state of research on the systematic categorization, chemical composition, pharmacological effects, and processing changes of the plants belonging to the genus Polygonatum, to provide a theoretical foundation for their scientific development and rational application.

MATERIALS AND METHODS

The information was obtained by searching the scientific literature published between 1977 and 2022 on online databases (including PubMed, CNKI, SciFinder, and Web of Science) and other sources (such as the Chinese Pharmacopoeia 2020 edition, and Chinese herbal books).

RESULTS

The genus Polygonatum contains 79 species, and 233 bioactive chemical compounds were identified in them. The abundance of pharmacological activities, such as antioxidant activities, anti-fatigue activities, anti-inflammatory activities, etc., were revealed for the representatives of this genus. In addition, there are numerous processing methods, and many chemical constituents and pharmacological activities change after the unappropriated processing.

CONCLUSIONS

This review summarizes the taxonomy classification, chemical composition, pharmacological effects, and processing of the plants belonging to the genus Polygonatum, providing references and research tendencies for plant-based drug development and further clinical applications.