Natural Products from Physalis alkekengi L. var. franchetii (Mast.) Makino: A Review on Their Structural Analysis, Quality Control, Pharmacology, and Pharmacokinetics

Physalin H, physalin B, and isophysalin B suppress the quorum-sensing function of Staphylococcus aureus by binding to AgrA

The virulence of Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), depends on the expression of toxins and virulence factors controlled by the quorum-sensing (QS) system, encoded on the virulence accessory gene regulator (agr) locus. The aim of this study was to identify a phytochemical that inhibits Agr-QS function and to elucidate its mechanism. We screened 577 compounds and identified physalin H, physalin B, and isophysalin B--phytochemicals belonging to physalins found in plants of the Solanaceae family--as novel Agr-QS modulators. Biological analyses and in vitro protein-DNA binding assays suggested that these physalins suppress gene expression related to the Agr-QS system by inhibiting binding of the key response regulator AgrA to the agr promoters, reducing the function of hemolytic toxins downstream of these genes in MRSA. Furthermore, although physalin F suppressed gene expression in the Agr-QS system, its anti-hemolytic activity was lower than that of physalins H, B, and isophysalin B. Conversely, five physalins isolated from the same plant with the ability to suppress Agr-QS did not reduce bacterial Agr-QS activity but inhibited AgrA binding to DNA in vitro. A docking simulation revealed that physalin interacts with the DNA-binding site of AgrA in three docking states. The carbonyl oxygens at C-1 and C-18 of physalins, which can suppress Agr-QS, were directed to residues N201 and R198 of AgrA, respectively, whereas these carbonyl oxygens of physalins, without Agr-QS suppression activity, were oriented in different directions. Next, 100-ns molecular dynamics simulations revealed that the hydrogen bond formed between the carbonyl oxygen at C-15 of physalins and L186 of AgrA functions as an anchor, sustaining the interaction between the carbonyl oxygen at C-1 of physalins and N201 of AgrA. Thus, these results suggest that physalin H, physalin B, and isophysalin B inhibit the interaction of AgrA with the agr promoters by binding to the DNA-binding site of AgrA, suppressing the Agr-QS function of S. aureus. Physalins that suppress the Agr-QS function are proposed as potential lead compounds in the anti-virulence strategy for MRSA infections.

Metabolite Profiling, through LC-ESI/LTQOrbitrap/MS Analysis, of Antioxidant Extracts from Physalis alkekengi L

Due to the increasing use of Physalis alkekengi L. as a food supplement and starting material for tea preparation, a comprehensive analysis of green extracts was performed. Two different extraction methods were applied to yellow Physalis alkekengi L. fruit and calyx and compared: hydroalcoholic extraction and decoction. Characterization of the metabolome of the calyx and fruit of yellow Physalis alkekengi L. was performed by LC-ESI/LTQOrbitrap/MS followed by LC-ESI/LTQOrbitrap/MS/MS to identify 58 phytocompounds using the two different extraction techniques. Subsequently, through preliminary spectrophotometric assays followed by cell studies, the antioxidant activity of the different Physalis alkekengi L. extracts were evaluated. It was found that Physalis alkekengi L. extracts are a good source of metabolites such as flavonoids, organic acids, phenylpropanoids, physalins and carotenoids, with various biological activities, in particular, antioxidant activity capable of reducing the production of free radicals in intestinal Caco-2 cells. For the first time, an integrated approach (metabolomics approach and antioxidant evaluation) was applied to the study of Physalis alkekengi green extracts and decoctions, the green extraction method mostly used in herbal preparations. An interesting finding was the high antioxidant activity shown by these extracts.

Research progress on the chemical components and pharmacological effects of Physalis alkekengi L. var. franchetii (Mast.) Makino

Physalis Calyx seu Fructus is the dry calyx or the calyx with fruit of the Solanaceae plant Physalis alkekengi L. var. franchetii (Mast.) Makino, with a long history of use in medicine and food. However, despite its many potential therapeutic and culinary applications, P. alkekengi is not being exploited for these applications on a large scale. This study analysed various research related to the different chemical components of P. alkekengi, including steroids, flavonoids, alkaloids, phenylpropanoids, sucrose esters, piperazines, volatile oils, polysaccharides, amino acids, and trace elements. In addition, research related to the pharmacological activities of P. alkekengi, including its anti-inflammatory, anti microbial, antioxidative, hypoglycaemic, analgesic, anti-tumour, and immunomodulatory effects were investigated. Research articles from 1974 to 2023 were obtained from websites such as Google Scholar, Baidu Scholar, and China National Knowledge Infrastructure, and journal databases such as Scopus and PubMed, with the keywords such as Physalis alkekengi, components, effects, and activities. This study aims to provide a comprehensive understanding of the progress of phytochemical and pharmacological research on the phytochemical and pharmacological aspects of P. alkekengi and a reference for the better exploitation of P. alkekengi in the food and pharmaceutical industries.

Physalis alkekengi L. var. franchetii combined with hormone therapy for atopic dermatitis

Atopic dermatitis (AD) is a common, chronic, and recurring inflammatory skin disease. Physalis alkekengi L. var. franchetii (Mast) Makino (PAF), a traditional Chinese medicine, is primarily used for the clinical treatment of AD. In this study, a 2,4-dinitrochlorobenzene-induced AD BALB/c mouse model was established, and a comprehensive pharmacological method was used to determine the pharmacological effects and molecular mechanisms of PAF in the treatment of AD. The results indicated that both PAF gel (PAFG) and PAFG+MF (mometasone furoate) attenuated the severity of AD and reduced the infiltration of eosinophils and mast cells in the skin. Serum metabolomics showed that PAFG combined with MF administration exerted a synergistic effect by remodeling metabolic disorders in mice. In addition, PAFG also alleviated the side effects of thymic atrophy and growth inhibition induced by MF. Network pharmacology predicted that the active ingredients of PAF were flavonoids and exerted therapeutic effects through anti-inflammatory effects. Finally, immunohistochemical analysis confirmed that PAFG inhibited the inflammatory response through the ERβ/HIF-1α/VEGF signaling pathway. Our results revealed that PAF can be used as a natural-source drug with good development prospects for the clinical treatment of AD.

Discovery of physalin biosynthesis and structure modification of physalins in Physalis alkekengi L. var. Franchetii

Physalins, active ingredients from the Physalis alkekengi L. var. franchetii (P. alkekengi) plant, have shown anti-inflammatory, antioxidant and anticancer activities. Whereas the bioactivity of physalins have been confirmed, their biosynthetic pathways, and those of quite a few derivatives, remain unknown. In this paper, biosynthesis and structure modification-related genes of physalins were mined through transcriptomic and metabolomic profiling. Firstly, we rapidly and conveniently analyzed physalins by UPLC-Q-TOF-MS/MS utilizing mass accuracy, diagnostic fragment ions, and common neutral losses. In all, 58 different physalin metabolites were isolated from P. alkekengi calyxes and berries. In an analysis of the physalin biosynthesis pathway, we determined that withanolides and withaphysalins may represent a crucial intermediate between lanosterol and physalins. and those steps were decanted according to previous reports. Our results provide valuable information on the physalin metabolites and the candidate enzymes involved in the physalins biosynthesis pathways of P. alkekengi. In addition, we further analyzed differential metabolites collected from calyxes in the Jilin (Daodi of P. alkekengi) and others. Among them, 20 physalin metabolites may represent herb quality biomarkers for Daodi P. alkekengi, providing an essential role in directing the quality control index of P. alkekengi.

Chemical Composition Assessment of Structural Parts (Seeds, Peel, Pulp) of Physalis alkekengi L. Fruits

In recent years there has been an extensive search for nature-based products with functional potential. All structural parts of Physalis alkekengi (bladder cherry), including fruits, pulp, and less-explored parts, such as seeds and peel, can be considered sources of functional macro- and micronutrients, bioactive compounds, such as vitamins, minerals, polyphenols, and polyunsaturated fatty acids, and dietetic fiber. The chemical composition of all fruit structural parts (seeds, peel, and pulp) of two phenotypes of P. alkekengi were studied. The seeds were found to be a rich source of oil, yielding 14–17%, with abundant amounts of unsaturated fatty acids (over 88%) and tocopherols, or vitamin E (up to 5378 mg/kg dw; dry weight). The predominant fatty acid in the seed oils was linoleic acid, followed by oleic acid. The seeds contained most of the fruit’s protein (16–19% dw) and fiber (6–8% dw). The peel oil differed significantly from the seed oil in fatty acid and tocopherol composition. Seed cakes, the waste after oil extraction, contained arginine and aspartic acid as the main amino acids; valine, phenylalanine, threonine, and isoleucine were present in slightly higher amounts than the other essential amino acids. They were also rich in key minerals, such as K, Mg, Fe, and Zn. From the peel and pulp fractions were extracted fruit concretes, aromatic products with specific fragrance profiles, of which volatile compositions (GC-MS) were identified. The major volatiles in peel and pulp concretes were β-linalool, α-pinene, and γ-terpinene. The results from the investigation substantiated the potential of all the studied fruit structures as new sources of bioactive compounds that could be used as prospective sources in human and animal nutrition, while the aroma-active compounds in the concretes supported the plant’s potential in perfumery and cosmetics.

Phytonutrient Composition of Two Phenotypes of Physalis alkekengi L. Fruit

Physalis alkekengi L. is the only representative of the genus Physalis (Solanaceae) that is native to Bulgaria, found in wild habitats under different climatic and soil conditions. The plant is poisonous, but produces edible fruit, which are a source of functional nutrients—vitamins, phenolic antioxidants, minerals, etc. Therefore, the objective of this work was to determine the presence of certain nutrient and bioactive substances in two phenotypes of P. alkekengi fruit from Bulgaria, in order to better reveal the prospects of fruit use in nutrition. Different macro and micronutrients were determined in the fruit—protein, ash, lipids, fiber, natural pigments, sugars, amino acids, minerals—and the results showed differences between the phenotypes. Fruit energy values were low and identical in the samples, 43 kcal/100 g. The fruits were rich in extractable phenolics (TPC, 17.74–20.25 mg GAE/100 g FW; flavonoids, 15.84–18.03 mg QE/100 g FW) and demonstrated good antioxidant activity (DPPH, 171.55–221.26 mM TE/g; FRAP, 193.18–256.35 mM TE/g). P. alkekengi fruits were processed to obtain a dry extract with ethanol (yield 47.92–58.6%), and its individual composition was identified (GC-MS). The results in this study supported the presumed phytonutritive potential of P. alkekengi fruit, thus, opening doors for further research.