The genus Porana (Convolvulaceae) - A phytochemical and pharmacological review

There are about 20 species of Porana Burm. f. worldwide in tropical and subtropical Asia, Africa and neighboring islands, Oceania, and the Americas. In China, India, and other places, this genus enjoys a wealth of experience in folk applications. Nevertheless, the chemical composition of only five species has been reported, and 59 compounds have been isolated and identified, including steroids, coumarins, flavonoids, quinic acid derivatives, and amides. Pharmacological studies revealed that extracts from this genus and their bioactive components exhibit anti-inflammatory, analgesic, antioxidant, anti-gout, anti-cancer, and anti-diabetic effects. Although this genus is abundant, the development of its pharmacological applications remains limited. This review will systematically summarize the traditional and current uses, chemical compositions, and pharmacological activities of various Porana species. Network analysis was introduced to compare and confirm its output with current research progress to explore the potential targets and pathways of chemical components in this genus. We hope to increase understanding of this genus’s medicinal value and suggest directions for rational medicinal development.

Investigation of the active ingredients and pharmacological mechanisms of Porana sinensis Hemsl. Against rheumatoid arthritis using network pharmacology and experimental validation

Background

Porana sinensis Hemsl. has been widely used as a substitute for Erycibes Caulis to treat rheumatoid arthritis (RA) in traditional Chinese medicine (TCM). However, little is known about the active ingredients and pharmacological mechanisms that mediate the action of P. sinensis against RA.

Methods

The compounds contained in P. sinensis were analyzed by Q Exactive Focus mass spectrometer. The active constituents and pharmacological mechanism of P. sinensis against RA were clarified using a network pharmacology-based investigation. LPS-induced RAW 264.7 cells was used to verify anti-inflammatory effects of the active compounds screened by network pharmacology. Collagen-induced arthritis model was used to further investigate the mechanism of P. sinensis against RA.

Results

The potential components and targets of P. sinensis against RA were analyzed using network pharmacology, and five compounds, twenty-five targets, and eight pathways were identified. Experimental validation suggested that P. sinensis extract and five compounds (esculetin, umbelliferone, trans-N-feruloyltyramine, caffeic acid and scopolin) could inhibit the release of inflammatory mediators (NO, TNF-α, IL-1β and IL-6) in LPS-induced RAW 264.7 cell. P. sinensis extract attenuated the severity, pathological changes, and release of cytokines (IL-6 and HIF-1α) during RA progression by regulating the PI3K/AKT and HIF-1 pathways.

Conclusion

The study provides a basis for the application of P. sinensis against RA. Our findings may provide suggestions for developing P. sinensis into a substitute for Erycibes Caulis.

Chemical compositions, pharmacological activities, quality control studies of Erycibes plants, and the development of their substitutes

Erycibes are members of the Convolvulaceae family, including more than 10 species worldwide that are distributed in tropical Asia. Some Erycibes species have long been used as traditional remedies for rheumatoid arthritis, fever, hepatitis, and liver injury in China and Thailand. A total of 152 compounds from Erycibes plants have been isolated and identified, categorized as flavonoids, coumarins, quinic acid derivatives, lignans, and alkaloids. Coumarins are the characteristic and active constituents of this species, including scopoletin and scopolin. Modern pharmacological studies have shown that the extracts and bioactive components of Erycibes plants exhibit several biological activities, including antiinflammatory, analgesic, hepatoprotective, anti-gout, antitumor, antioxidation, and other therapeutic effects. However, in recent years, due to destructive exploitation and utilization, some Erycibes plants' natural resources have become rare or endangered. Developing substitutes is a strategy to alleviate the pressure on those endangered medicinal plant resources. To provide a scientific basis for the development and protection of those threatened Erycibes species, this review summarized the current status of the chemical compositions, pharmacological activities, quality control studies, and the development of substitutes for Erycibes plants. In particular, the rationale for use of Porana sinensis currently on the market is discussed.

Investigation of the mechanism of action of Porana sinensis Hemsl. against gout arthritis using network pharmacology and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Porana sinensis Hemsl. has been widely used to treat joint pain and rheumatoid arthritis in traditional Chinese medicine (TCM). Although evidence exists to support a pharmacological action of P. sinensis for the treatment of gout arthritis (GA), the underlying mechanism of action remains unknown due to it being a multi-component and multi-target agent.

AIM OF THE STUDY

To clarify the active compounds and mechanism of P. sinensis against GA.

MATERIALS AND METHODS

The present study combined network pharmacology with experiments to clarify the mechanism of P. sinensis against GA. A protein-protein interaction network for gout was constructed to identify the potential drug targets, and molecular docking was subsequently performed to determine whether the protein was a target for the compounds of P. sinensis. KEGG pathway analysis was then conducted to elucidate the pathway involved in the P. sinensis-mediated treatment of gout. A rat model of GA was used to further investigate the mechanism of P. sinensis against GA.

RESULTS

The network pharmacology study indicates that coumarins and chlorogenic acids of P. sinensis may serve as additives to GA treatment. P. sinensis played a role in the treatment of GA by regulating the PI3K-Akt, MAPK, NF-kappa B and toll-like receptor pathways and so on. Moreover, experimental validation suggests that P. sinensis extract significantly suppressed the expression of TLR2 and MyD88 mRNA, regulating the release of cytokines (IL-1β, IL-4 and TGF-β), lowering lipid peroxidation (MDA) and increasing antioxidant status (SOD).

CONCLUSION

The present study clarifies the mechanism of P. sinensis against GA, and provides evidence to support its clinical use.

Promotion of a quality standard for Porana sinensis Hemsl. based on the efficacy-oriented Effect-Constituent Index

Multicompound determination for the quality control of traditional Chinese medicine (TCM) may often be inadequate, since these compounds may not be associated with, or fully represent, the clinical effects of TCM. Moreover, the individual contributions of each constituent to the pharmacological effect are often not considered. In China, Porana sinensis is widely used as a substitute for Erycibe sources to treat joint pain and rheumatoid arthritis. The existing quality control methods for P. sinensis neither consider the individual contributions of various compounds nor control the actual quality associated with different clinical efficacies. In the present study, a novel efficacy-oriented approach, named the effect-constituent index (ECI), was established for P. sinensis. Analyses of the spectrum-effect relationship and components in rat plasma were conducted to systematically and scientifically select quality markers. Quantitative analysis of multicomponents via a single marker method was introduced to enhance the practical application value of the established ECI. The established ECI shows a good ability to distinguish and predict the bioeffect-based quality of P. sinensis. The present study also provides a reference for the establishment and application of ECI as a quality control method for TCMs.

Phenolic Compounds and Ginsenosides in Ginseng Shoots and Their Antioxidant and Anti-Inflammatory Capacities in LPS-Induced RAW264.7 Mouse Macrophages

We conducted this study for the first time to evaluate changes in the composition and contents of phenolic compounds and ginsenosides in ginseng shoot extracts (GSEs) prepared with different steaming times (2, 4, and 6 h) at 120 °C, as well as their antioxidant and anti-inflammatory activities in lipopolysaccharide (LPS)-induced RAW264.7 mouse macrophages (RAW264.7 cells). The results show that total phenol and flavonoid contents were both significantly higher in steamed versus raw GSEs, and the same trend was found for 2,2'-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2'-azobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) scavenging capacities. Among the 18 ginsenosides quantified using high-performance liquid chromatography (HPLC) with the aid of pure standards, polar ginsenosides were abundant in raw GSEs, whereas less-polar or rare ginsenosides appeared after steaming at 120 °C and increased with steaming time. Furthermore, steamed GSEs exhibited a greater ability to inhibit the production of inflammatory mediators and pro-inflammatory cytokines, such as nitric oxide (NO), interleukin (IL)-6, and tumor necrosis factor (TNF)-α in LPS-induced RAW264.7 cells at the same concentration. Relative expression levels of inducible nitric oxide synthase (iNOS), IL-6, TNF-α, and cyclooxygenase-2 (COX-2) mRNAs were attenuated by the GSEs, probably due to the enrichment of less-polar ginsenosides and enhanced antioxidant activity in steamed GSEs. These findings, combined with correlation analysis, showed that less-polar ginsenosides were major contributors to the inhibition of the overproduction of various inflammatory factors, while the inhibitory effects of total phenols and total flavonoids, and their antioxidant abilities, are also important.

Qualitative and quantitative analysis of Porana sinensis Hemsl by UHPLC-Q-Exactive MS, TLC autographic method and DART-MS

INTRODUCTION

Erycibe obtusifolia and E. schmidtii are widely used in traditional Chinese medicine (TCM) to treat joint pain and rheumatoid arthritis. With the reduction of wild E. obtusifolia and E. schmidtii resources, Porana sinensis has been widely used as a substitute. However, few studies have been conducted on the chemical composition and quality control of P. sinensis.

OBJECTIVE

To clarify the chemical composition and improve the quality control of P. sinensis.

METHODOLOGY

We developed an ultra-high performance liquid chromatography electrospray ionisation Q-Exactive Focus tandem mass spectrometry (UHPLC-ESI-Q-Exactive Focus-MS/MS) method to characterise the chemical constituents of P. sinensis. A strategy based on a combination of high-performance thin-layer chromatography (HPTLC) and direct analysis in real-time (DART) ion source was proposed for the identification of alkaloid components in P. sinensis. Thin-layer chromatography (TLC) autography for 2,2'-diphenyl-1-picrylhydrazyl free radical (DPPH˙) and TLC bioautography for xanthine oxidase were used to rapidly screen marker compounds for high-performance liquid chromatography (HPLC) determination of P. sinensis. Based on the selected marker compounds, a HPLC method for the quantitative determination of eight marker compounds in P. sinensis was developed.

RESULTS

Eighteen compounds in P. sinensis were identified by UHPLC-Q-Exactive MS. Taken together with the results of TLC autography and TLC bioautography, eight compounds were chosen as marker compounds for HPLC determination of P. sinensis. The alkaloid components in P. sinensis were identified as Baogongteng A and Baogongteng C by DART-MS.

CONCLUSION

We systematically clarified the chemical composition of P. sinensis for the first time, and potentially improved its quality control. These results should promote the application of P. sinensis as a new resource for Caulis Erycibes.

Sweeping-micelle to solvent stacking for the on-line preconcentration and determination of organic acids in Angelica sinensis by capillary electrophoresis

A novel on-line two-step stacking preconcentration method by sweeping plus micelle to solvent stacking in capillary zone electrophoresis was developed for the simultaneous determination of three organic anions (vanillic acid, ferulic acid and cinnamic acid) in Angelica sinensis. Hexadimethrine bromide was used for electroosmotic flow reversal. The main experimental parameters that affected the separation and sensitivity were investigated and optimized. The best separation was achieved in 50 mM ammonium acetate (pH 12.0) containing 50% methanol (v/v) under a negative voltage of 20 kV. The micellar solution was a mixed solution comprised of 12 mM cetyltrimethyl ammonium bromide and 20 mM ammonium acetate. After injecting a short plug (0.5 psi, 30 s) of micellar solution, the sample was introduced into the capillary at 0.5 psi for 45 s. Under the optimal conditions, the sensitivity enhancement factors obtained by the developed method were between 42 and 77. The intra-day (n = 6) and inter-day (n = 5) precisions of the method expressed as their relative standard deviations were found to be less than 7.2%. The Angelica sinensis sample was pulverized and then refluxed in 95% ethanol and filtered. After an aliquot of the extractant was dried, it was reconstituted in 20 mM ammonium acetate for capillary electrophoresis analysis. The recoveries of the analytes by this method for the analysis of Angelica sinensis were in the range of 94.4% to 108.4%.