Physicochemical characteristics and phytochemical profiles of yellow and red Physalis (Physalis alkekengi L. and P. pubescens L.) fruits cultivated in China

Unraveling the Genetic Control of Pigment Accumulation in Physalis Fruits

Physalis pubescens and Physalis alkekengi, members of the Physalis genus, are valued for their delicious and medicinal fruits as well as their different ripened fruit colors-golden for P. pubescens and scarlet for P. alkekengi. This study aimed to elucidate the pigment composition and genetic mechanisms during fruit maturation in these species. Fruit samples were collected at four development stages, analyzed using spectrophotometry and high-performance liquid chromatography (HPLC), and complemented with transcriptome sequencing to assess gene expression related to pigment biosynthesis. β-carotene was identified as the dominant pigment in P. pubescens, contrasting with P. alkekengi, which contained both lycopene and β-carotene. The carotenoid biosynthesis pathway was central to fruit pigmentation in both species. Key genes pf02G043370 and pf06G178980 in P. pubescens, and TRINITY_DN20150_c1_g3, TRINITY_DN10183_c0_g1, and TRINITY_DN23805_c0_g3 in P. alkekengi were associated with carotenoid production. Notably, the MYB-related and bHLH transcription factors (TFs) regulated zeta-carotene isomerase and β-hydroxylase activities in P. pubescens with the MYB-related TF showing dual regulatory roles. In P. alkekengi, six TF families-bHLH, HSF, WRKY, M-type MADS, AP2, and NAC-were implicated in controlling carotenoid synthesis enzymes. Our findings highlight the intricate regulatory network governing pigmentation and provide insights into Physalis germplasm's genetic improvement and conservation.

Characterization and expression analysis of a thaumatin-like protein PpTLP1 from ground cherry Physalis pubescens

Ground cherry, Physalis pubescens, is mainly cultivated as a fruit worldwide and popularly used as a food supplement and traditional Chinese medicine. Plants are challenged by external environmental stress and can initiate resistance to the stress through the regulation of pathogenesis-related (PR) proteins. Among PR proteins, PR-5, a thaumatin-like protein (TLP), was identified in many plants and found to be able to enhance stress resistance. However, PR-5 in ground cherry is not characterized and its expression is yet to be understood. In this study, a PR-5 protein PpTLP1 in P. pubescens was firstly identified. Analysis of the amino acid sequences revealed that PpTLP1 was highly similar to PR-NP24 identified in tomato with a difference in only one amino acid. Expression analysis indicated that the PpTLP1 gene was highly expressed in leaf while the PpTLP1 protein was tissue-specifically accumulated in cherry exocarp. Furthermore, the down-regulation of PpTLP1 in ground cherry was induced by NaCl treatment while the up-regulation was promoted by the infection of Sclerotinia sclerotiorum and Botrytis cinerea. This study will provide a new plant resource containing a TLP in Physalis genus and a novel insight for the improvement of postharvest management of ground cherry and other Solanaceae plants.

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.

Phenolic compound profile and gastrointestinal action of Solanaceae fruits: Species-specific differences

In this study, the presence of phenolic compounds derived from four Solanaceae fruits (tomato, pepino, tamarillo, and goldenberry) during gastrointestinal digestion and the effect of these compounds on human gut microbiota was investigated. The results indicated that the total phenolic content of all Solanaceae fruits were increased during digestion. Furthermore, the targeted metabolic analysis identified 296 compounds, of which 71 were changed after gastrointestinal digestion in all Solanaceae fruits. Among these changed phenolic compounds, 51.3% phenolic acids and 91% flavonoids presented higher bioaccessibility in pepino and tamarillo, respectively. Moreover, higher levels of glycoside-formed phenolic acids, including dihydroferulic acid glucoside and coumaric acid glucoside, were found in tomato fruits. In addition, tachioside showed the highest bioaccessibility in goldenberry fruits. The intake of Solanaceae fruits during the in vitro fermentation decreased the Firmicutes/Bacteroidetes ratio (F/B) compared with the control (∼15-fold change on average), and goldenberry fruits showed the best effect (F/B = 2.1). Furthermore, tamarillo significantly promoted the growth of Bifidobacterium and short-chain fatty acids production. Overall, this study revealed that Solanaceae fruits had different phenolic compound profiles and health-promoting effects on the gut microbiota. It also provided relevant information to improve the consumption of Solanaceae fruits, mainly tamarillo and goldenberry fruits, due to their gut health-promoting properties, as functional foods.

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.

Phytochemical analysis of leaves and stems of Physalis alkekengi L. (Solanaceae)

Physalis alkekengi L. (Solanaceae) is encountered in different regions of Bulgaria as a wild growing or ornamental plant. The objective of this work was to characterize the phytochemical composition (macro and micro components) of the leaves and stems of two local phenotypes (PA-SB and PA-NB), with the view of revealing their use potential. The dry leaves contained (DW) protein (16.25 and 19.27%), cellulose (25.16 and 25.31%), and ash (18.28 and 16.16%) and the stems contained protein (6.83 and 7.35%), cellulose (39.34 and 38.25%), and ash (15.01 and 7.48%) for PA-SB and PA-NB, respectively. The dominant amino acids (by HPLC) in the leaves of both phenotypes were arginine (21.3–22.3 mg/g) and aspartic acid (8.8–18.4 mg/g), and those in the stems were proline and aspartic acid for PA-SB (8.8, 7.7 mg/g); isoleucine and tyrosine for PA-NB (12.8, 6.6 mg/g). Mineral elements, determined by AAS (K, Ca, Mg, Na, Cu, Fe, Zn, Mn, Pb, Cr), also varied between phenotypes and plant parts. The leaves alone were further processed by extraction with n-hexane, for the identification of leaf volatiles (by gas chromatography-mass spectrometry). The analysis identified 28 components (97.99%) in the leaf extract of PA-SB and 32 components (97.50%) in that of PA-NB. The volatile profile of PA-SB leaves was dominated by diterpenes (49.96%) and oxygenated sesquiterpenes (35.61%), while that of PA-NB was dominated by oxygenated aliphatics (40.01%) and diterpenes (35.19%). To the best of our knowledge, the study provides the first data about the phytochemical composition of the leaves and stems of P. alkekengi from Bulgaria, in a direct comparison of phenotypes from two distinct wild populations, which could be of further scientific interest.

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.

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

The calyxes and fruits of Physalis alkekengi L. var. franchetii (Mast.) Makino (P. alkekengi), a medicinal and edible plant, are frequently used as heat-clearing and detoxifying agents in thousands of Chinese medicine prescriptions. For thousands of years in China, they have been widely used in clinical practice to treat throat disease, hepatitis, and bacillary dysentery. This systematic review summarizes their structural analysis, quality control, pharmacology, and pharmacokinetics. Furthermore, the possible development trends and perspectives for future research studies on this medicinal plant are discussed. Relevant information on the calyxes and fruits of P. alkekengi was collected from electronic databases, Chinese herbal classics, and Chinese Pharmacopoeia. Moreover, information was collected from ancient documents in China. The components isolated and identified in P. alkekengi include steroids, flavonoids, phenylpropanoids, alkaloids, nucleosides, terpenoids, megastigmane, aliphatic derivatives, organic acids, coumarins, and sucrose esters. Steroids, particularly physalins and flavonoids, are the major characteristic and bioactive ingredients in P. alkekengi. According to the literature, physalins are synthesized by the mevalonate and 2-C-methyl-d-erythritol-4-phosphate pathways, and flavonoids are synthesized by the phenylpropanoid pathway. Since the chemical components and pharmacological effects of P. alkekengi are complex and varied, there are different standards for the evaluation of its quality and efficacy. In most cases, the analysis was performed using high-performance liquid chromatography coupled with ultraviolet detection. A pharmacological study showed that the crude extracts and isolated compounds from P. alkekengi had extensive in vitro and in vivo biological activities (e.g., anti-inflammatory, anti-tumor, immunosuppressive, antibacterial, anti-leishmanial, anti-asthmatic, anti-diabetic, anti-oxidative, anti-malarial, anti-Alzheimer's disease, and vasodilatory). Moreover, the relevant anti-inflammatory and anti-tumor mechanisms were elucidated. The reported activities indicate the great pharmacological potential of P. alkekengi. Similarly, studies on the pharmacokinetics of specific compounds will also contribute to the progress of clinical research in this setting.

Effects of drying methods on the characterization of fatty acids, bioactive compounds and antioxidant capacity in a thin layer of physalis (Physalis peruviana L.) pulp

Physalis peruviana L. fruits are rich in bioactive compounds with health benefits. Processing of physalis into pulp with further dehydration has been proposed as a method to increase shelf life and preserve bioactive compounds. Here, the effect of three drying methods on the physico-chemical properties, color, antioxidant capacity, tocopherol and fatty acids content of physalis pulp thin layers were evaluated. The radical scavenging activity showed higher antioxidant activity at high temperatures rather than at low temperatures. Both, DPPH and ORAC assay showed a high antioxidant capacity of the physalis pulp. Chromatic parameters as well as Chroma and Hue angle were affected by drying temperature, which contributed to the discoloring of physalis pulp during this process. Based on these results, both convective drying and infrared drying at 80 °C were proved to be viable drying options for physalis pulp.

Phenolic Compounds in Mesoamerican Fruits-Characterization, Health Potential and Processing with Innovative Technologies

Diets rich in phenolic compounds have been associated to reducing the risk of metabolic syndrome and its derived disorders. Fruits are healthy components of the human diet because of their vitamin, mineral, fiber and phenolic profile. However, they have a short shelf-life which is limited by microbiological growth and enzymatic activity. Innovative preservation methods such as high hydrostatic pressure, pulsed electric fields, ultrasound, microwave, cold plasma and ultraviolet light have become popular for the processing of fruits because they can preserve nutritional quality. In this review, the phenolic profile and health potential of 38 Mesoamerican fruits were assessed. Phenolic compounds were classified based on their contribution to the diet as flavonoids, phenolic acids, tannin, lignins and stilbenoids. Due to this composition, fruits showed a wide range of bioactivities which included anti-inflammatory, anti-diabetic, anti-hypertensive and anti-obesity activities, among others. Phenolic content in fruits submitted to innovative food processing technologies depended on parameters such as enzymatic activity, antioxidant capacity, microstructure integrity and cell viability. Innovative technologies could increase phenolic content while assuring microbiological safety by (i) promoting the release of bound phenolic compounds during processing and (ii) inducing the synthesis of phenolic compounds by activation of phenylpropanoid pathway during storage.

Physalis alkekengi L. Extract Reduces the Oxidative Stress, Inflammation and Apoptosis in Endothelial Vascular Cells Exposed to Hyperglycemia

To find new natural remedies in diabetes, this study investigated the biological activity of two extracts obtained from the fruits (PhyF) and herba (PhyH) of Physalis alkekengi var. franchetii L. on human umbilical vein endothelial cells (HUVECs) exposed to normo- and hyperglycemic conditions. The biological effect was quantified by malondialdehyde, IL-31 and IL-33 levels in correlation with physico-chemical characterization and antioxidant activity. Additionally, from PhyP extract, the caspase-3, IL-6, IL-10, tumor necrosis factor (TNF)-α and nuclear transcription factor NFkB expressions were evaluated. HPLC analysis revealed a significant number of phenolic compounds, especially in PhyF extract, with a good antioxidant activity as highlighted by TEAC, CUPRAC or DPPH methods. On HUVECS cells, the extracts were not toxic even at high concentrations. Particularly PhyF extract, diminished lipid peroxidation and inhibited the IL-31 and IL-33 secretions induced by hyperglycemia. The inhibitory effect on proinflammatory cytokines was noticed after both doses of PhyF extract in parallel with the upregulation of anti-inflammatory cytokine IL-10. Moreover, PhyF, especially in a low dose, reduced caspase-3 active form. These experimental findings suggest that Physalis fruits extract exerted beneficial effects in hyperglycemia by inhibition of oxidative stress, inflammation and apoptosis being a good adjuvant option in diabetes.

Intervention with the crude polysaccharides of Physalis pubescens L. mitigates colitis by preventing oxidative damage, aberrant immune responses, and dysbacteriosis

In this study, a colitis mouse model induced by dextran sulfate sodium (DSS) was used to investigate the mechanisms of action of an extract of crude polysaccharides (POL) from Physalis pubescens L. as a dietary intervention for colitis. Our results showed that the administration of POL prior to DSS-induced colitis protected the colon mucosal layer; maintained intestinal barrier integrity; alleviated oxidative damage; and lowered neutrophil infiltration by downregulating intercellular cell adhesion molecule-1 and monocyte chemoattractant protein-1 expression. More importantly, POL pretreatment reduced the expression of the proinflammatory factors tumor necrosis factor-α, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2), thereby modulating the nuclear factor-κB/iNOS-COX-2 signal transduction pathway. In addition, POL reversed DSS-induced gut dysbiosis, accompanied by reducing the relative abundance of Helicobacter, Mucispirillum, and Erysipelatoclostridium. In conclusion, POL ameliorated DSS-induced intestinal injury in mice, indicating that POL could be a useful dietary nutrient to protect against colitis. PRACTICAL APPLICATION: Physalis pubescens L. is an edible fruit. The results of this study show that the intervention with Physalis pubescens L. crude polysaccharides may help prevent ulcerative colitis.

Carotenogenesis and chromoplast development during ripening of yellow, orange and red colored Physalis fruit

Formation of specific ultrastructural chromoplastidal elements during ripening of fruits of three different colored Physalis spp. is closely related to their distinct carotenoid profiles. The accumulation of color-determining carotenoids within the chromoplasts of ripening yellow, orange, and red fruit of Physalis pubescens L., Physalis peruviana L., and Physalis alkekengi L., respectively, was monitored by high-performance liquid chromatography/diode array detector/tandem mass spectrometry (HPLC-DAD-MS/MS) as well as light and transmission electron microscopy. Both yellow and orange fruit gradually accumulated mainly β-carotene and lutein esters at variable levels, explaining their different colors at full ripeness. Upon commencing β-carotene biosynthesis, large crystals appeared in their chromoplasts, while large filaments protruding from plastoglobules were characteristic elements of chromoplasts of orange fruit. In contrast to yellow and orange fruit, fully ripe red fruit contained almost no β-carotene, but esters of both β-cryptoxanthin and zeaxanthin at very high levels. Tubule bundles and unusual disc-like crystallites were predominant carotenoid-bearing elements in red fruit. Our study supports the earlier hypothesis that the predominant carotenoid type might shape the ultrastructural carotenoid deposition form, which is considered important for color, stability and bioavailability of the contained carotenoids.

Metabolomic Profiling of Carotenoid Constituents in Physalis peruviana During Different Growth Stages by LC-MS/MS Technology

With the current ongoing changes in global food demands, natural carotenoids are preferred by consumers and are gaining attention among food scientists and producers alike. Metabolomic profiling of carotenoid constituents in Physalis peruviana during distinct on-tree growth stages was performed with liquid chromatography-tandem mass spectrometry (LC-MS/MS) technology. The results show that the β rings of β-carotene are hydroxylated with great efficiency, and there is a continual synthesis of zeaxanthin at half-ripe and full-ripe stages, which is confirmed by relating the zeaxanthin content to that of its precursor (β-carotene). Lutein was, in terms of mass intensity, the most abundant carotenoid constituent (64.61 µg/g at the half-ripe stage) observed in this study. In addition, γ-carotene, which is rare in dietary fruits and vegetables, was detected in the mature and breaker stages, albeit at a relatively low level. The results suggest that when we consider the variation in carotenoid content during different growth stages, Physalis peruviana can be considered a good source of natural carotenoids.