Antioxidant Activities of Solanum Nigrum L. Leaf Extracts Determined in in vitro Cellular Models

Bioactivities and chemical profiling comparison and metabolomic variations of polyphenolics and steroidal glycoalkaloids in different parts of Solanum nigrum L

INTRODUCTION

Solanum nigrum L. is a traditional medicinal herb and edible plant. Many studies provide evidence that S. nigrum L. is a nutritious vegetable. Polyphenols and steroidal glycoalkaloids are the main components.

OBJECTIVES

This study aimed to systemically evaluate the phytochemical profile, quantification, and bioactivities of polyphenolics and glycoalkaloids in different parts of S. nigrum L.

RESULTS

Total polyphenols (TPC) and total glycoalkaloids (TGK) were determined using the Folin-Ciocalteu and acid dye colorimetric methods, respectively. A total of 55 polyphenolic constituents (including 22 phenolic acids and 33 flavonoids) and 24 steroidal glycoalkaloids were identified from different parts using ultrahigh-performance liquid chromatography Q-exactive high-resolution mass spectrometry (UHPLC-QE-HRMS), of which 40 polyphenols (including 15 phenolic acids and 25 flavonoids) and one steroidal glycoalkaloid were characterised for the first time in S. nigrum L. Moreover, typical polyphenols and glycoalkaloids were determined using HPLC-UV and HPLC-evaporative light-scattering detector (ELSD), respectively. In addition, the TPC and TGK and their typical constituents were compared in different anatomical parts. Finally, the antioxidant capacities of polyphenolic extracts from different parts of S. nigrum L. were evaluated by ·OH, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferric-reducing antioxidant power (FRAP) assay in vitro. In addition, the antitumour effects of TGK from different parts of S. nigrum L. on the proliferation of PC-3 cells were investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Polyphenolic and glycoalkaloid extracts from different parts of S. nigrum L. showed different antioxidant and cytotoxic capacities in vitro.

CONCLUSION

This is the first study to systematically differentiate between polyphenolic and glycoalkaloid profiles from different parts of S. nigrum L.

Cytotoxic, antioxidant, and antiglycation activities, and tyrosinase inhibition using silver nanoparticles synthesized by leaf extract of Solanum aculeatissimum Jacq

The present study aimed to determine the biological properties of an extract of Solanum aculeatissimum aqueous extract (SaCE) alone as well as silver nanoparticles (AgNPs) generated by green synthesis utilizing S. aculeatissimum aqueous extract (SaCE). These synthesized SaCE AgNPs were characterized using UV-VIS spectrophotometry, scanning transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), zeta potential (ZP), dynamic light scattering (DLS). Determination of total polyphenols, flavonoids, saponins content was conducted. In addition, high performance liquid chromatography-mass spectrometry (HPLC-MS) was employed to identify constituents in this extract. Antioxidant activity was determined by DPPH radical scavenging and ferric ion reducing power (FRAP) methods. Antiglycation activity was demonstrated through relative mobility in electrophoresis (RME) and determination of free amino groups. The inhibitory activity on tyrosinase was also examined. Molecular docking analyses were performed to assess the molecular interactions with DNA and tyrosinase. The antitumor activity SaCE was also measured. Phytochemical analysis of SaCE and AgNPs showed presence polyphenols (1000.41 and 293.37 mg gallic acid equivalent/g), flavonoids (954.87 and 479.87 mg rutin equivalent/g), saponins (37.89 and 23.01% total saponins), in particular steroidal saponins (aculeatiside A and B). Both SaCE and AgNPs exhibited significant antioxidant (respectively, 73.97%, 56.27% in DPPH test, 874.67 and 837.67 μM Trolox Equivalent/g in FRAP test) and antiglycation activities (72.81 and 67.98% free amino groups, results observed in RME). SaCE and AgNPs presented 33.2, 36.1% inhibitory activity on tyrosinase, respectively. In silico assay demonstrated interaction between steroidal saponins, DNA or tyrosinase. SaCE exhibited antitumor action against various human tumor cells. Data demonstrated that extracts SaCE alone and AgNPs synthesized from SaCE presented biological properties of interest for application in new therapeutic formulations in medicine.

Redox State Modulatory Activity and Cytotoxicity of Olea europaea L. (Oleaceae) Leaves Extract Enriched in Polyphenols Using Macroporous Resin

The food products derived from Olea europaea are a fundamental part of the Mediterranean diet, and their health-promoting effects are well known. In this study, we analyzed the phytochemical characteristics, the redox state modulatory activity, and the cytotoxic effect of an olive leaf aqueous extract enriched by macroporous resin on different tumor and normal cell lines (LNCaP, PC3, HFF-1). HPLC-DAD analysis, the Folin-Ciocalteu and aluminum chloride methods confirmed the qualitatively and quantitatively high content of phenolic compounds (130.02 ± 2.3 mg GAE/g extract), and a DPPH assay (IC50 = 100.00 ± 1.8 μg/mL), the related antioxidant activity. The biological investigation showed a significant cytotoxic effect, highlighted by an MTT test and the evident cellular morphological changes, on two prostate cancer cell lines. Remarkably, the extract was practically non-toxic on HFF-1 at the concentrations (100, 150, 300 µg/mL) and exposure times tested. Hence, the results are selective for tumor cells. The underlying cytotoxicity was associated with the decrease in ROS production (55% PC3, 42% LNCaP) and the increase in RSH levels (>50% PC3) and an LDH release assay (50% PC3, 40% LNCaP, established necrosis as the main cell death mechanism.

Solanum nigrum L. in COVID-19 and post-COVID complications: a propitious candidate

COVID-19 is caused by severe acute respiratory syndrome coronavirus-2, SARS-CoV-2. COVID-19 has changed the world scenario and caused mortality around the globe. Patients who recovered from COVID-19 have shown neurological, psychological, renal, cardiovascular, pulmonary, and hematological complications. In some patients, complications lasted more than 6 months. However, significantly less attention has been given to post-COVID complications. Currently available drugs are used to tackle the complications, but new interventions must address the problem. Phytochemicals from natural sources have been evaluated in recent times to cure or alleviate COVID-19 symptoms. An edible plant, Solanum nigrum, could be therapeutic in treating COVID-19 as the AYUSH ministry of India prescribes it during the pandemic. S. nigrum demonstrates anti-inflammatory, immunomodulatory, and antiviral action to treat the SARS-CoV-2 infection and its post-complications. Different parts of the plant represent a reduction in proinflammatory cytokines and prevent multi-organ failure by protecting various organs (liver, kidney, heart, neuro, and lung). The review proposes the possible role of the plant S. nigrum in managing the symptoms of COVID-19 and its post-COVID complications based on in silico docking and pharmacological studies. Further systematic and experimental studies are required to validate our hypothesis.

Steroidal constituents from Solanum nigrum

Three previously undescribed steroidal constituents including two sterols (1-2) and one pregnane-type steroidal glycoside (6), along with nineteen known ones (3-5, 7-22), were isolated from the 80% alcohol extraction of Solanum nigrum L. Their structures and the absolute configurations were established by analysis of the extensive spectroscopic data (1H/13 NMR, 1H1H COSY, HSQC, HMBC, and NOESY), and/or by comparisons of the experimental electronic circular dichroism (ECD) spectra with those calculated ones by TDDFT method. Further, a MTT assay was applied to demonstrate that compounds 1-4, 6-12, 18, and 22 exhibited significant cytotoxic activities against SW480 cells, and compounds 1-4, 6-14, and 16-22 showed significant cytotoxic activities against Hep3B cells.

Formulation of Resveratrol-Loaded Polycaprolactone Inhalable Microspheres Using Tween 80 as an Emulsifier: Factorial Design and Optimization

Resveratrol (RSV) is a bioactive phytoconstituent that has potential applications in respiratory diseases. However, poor oral bioavailability is the major hurdle to its clinical use. In the present work, resveratrol-loaded polycaprolactone (PCL) inhalable microspheres (MSs) were formulated to improve their therapeutic potential. The inhalable microspheres were formulated using the emulsion-solvent evaporation method. In this research, inhalable resveratrol microspheres were prepared using Tween 80 in place of polyvinyl alcohol which formed insoluble lumps. A 3² factorial design was applied taking polymer (PCL) and emulsifier (Tween 80) as independent variables and drug loading (DL) and encapsulation efficiency (EE) as dependent variables. The DL and EE of the optimized formulation were found to be 30.6% and 63.84% respectively. The in vitro aerosolization study performed using the Anderson cascade impactor showed that the fine particle fraction (FPF) of optimized resveratrol polycaprolactone microspheres (RSV-PCL-MSs) blended with lactose, and RSV-PCL-MSs were significantly higher than those of the pure drugs. The MMAD_T (theoretical mass median aerodynamic diameter) of optimized RSV-PCL-MSs was found to be 3.25 ± 1.15. The particle size of microspheres was within the inhalable range, i.e., between 1 and 5 µm. The morphological analysis showed spherical-shaped particles with smooth surfaces. The in vitro release study showed sustained drug release from the microspheres for up to 12 h. The study concluded that resveratrol-loaded inhalable microspheres may be an efficient delivery system to treat COPD.

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.

Solanum nigrum Linn.: An Insight into Current Research on Traditional Uses, Phytochemistry, and Pharmacology

Solanum nigrum Linn., is a common edible medicinal herb of the Solanaceae family which is native to Southeast Asia and is now widely distributed in temperate to tropical regions of Europe, Asia, and America. Traditionally, it has been used to treat various cancers, acute nephritis, urethritis, leucorrhea, sore throat, toothache, dermatitis, eczema, carbuncles, and furuncles. Up to now, 188 chemical constituents have been identified from S. nigrum. Among them, steroidal saponins, alkaloids, phenols, and polysaccharides are the major bioactive constituents. Investigations of pharmacological activities of S. nigrum revealed that this edible medicinal herb exhibits a wide range of therapeutic potential, including antitumor, anti-inflammatory, antioxidant, antibacterial, and neuroprotective activities both in vivo and in vitro. This article presents a comprehensive and systematic overview of the botanical, traditional uses, phytochemical compositions, pharmacological properties, clinical trials, and toxicity of S. nigrum to provide the latest information for further exploitation and applications of S. nigrum in functional foods and medicines.

Evaluation of Antimicrobial and Chemopreventive Properties and Phytochemical Analysis of Solanum nigrum L. Aerial Parts and Root Extracts

This study evaluated in vitro antibacterial, antifungal, anticancer and antioxidant activities of methanolic leaf and root extracts from Solanum nigrum L. and determined its chemical composition. The chemical profile of S. nigrum L. extract was tested using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Disc diffusion and microdilution assays were used for the antibacterial activities. Antifungal activity was measured using the poisoned food technique. In vitro activity on the cell culture model was assessed by MTT assay, viability measurement and by determination of cellular ROS by DCFDA assay. The minimal inhibitory concentrations for extracts from aerial parts ranged from 125 to 500 μg/mL for gram-positive cocci and Pectobacterium strains. The growth inhibition coefficient ranged from 17–56%, depending on the dosage. The antifungal effect of S. nigrum extracts on the tested filamentous fungi depended on the dose. An inhibitory effect of 50–56% on fungi was observed against Alternaria alternata and Chaetomium globosum. The study showed a reduction in cellular vitality of THP1, A549, MCF7 and HeLa cancer lines using both extracts. In addition, there was a decrease in the number of viable cells in cultures incubated with the extract of aerial parts and a reduction in oxygen radicals in the cells. The obtained results indicate the possibility of using S. nigrum extracts from the aerial part as antimicrobial factors. Both extracts show chemopreventive properties by inhibiting the growth of cancer cells and reducing the level of free radicals. Both extracts show chemopreventive properties by inhibiting cancer cell growth and lowering free radical levels. The broad biological activity of the studied extracts can be used in agriculture, veterinary usages and medicine.

The powerful Solanaceae: Food and nutraceutical applications in a sustainable world

The Solanaceae family is considered one of the most important families among plant species because, on one hand encompasses many staple food crops of the human diet while, on the other hand, it includes species rich in powerful secondary metabolites that could be valorized in medicine or drug formulation as well as nutraceuticals and food supplements. The main genera are Solanum, Capsicum, Physalis, and Lycium which comprise several important cultivated crops (e.g., tomato, pepper, eggplant, tomatillo, and goji berry), as well as genera notable for species with several pharmaceutical properties (e.g., Datura, Nicotiana, Atropa, Mandragora, etc.). This chapter discusses the nutritional value of the most important Solanaceae species commonly used for their edible fruit, as well as those used in the development of functional foods, food supplements, and nutraceuticals due to their bioactive constituents. The toxic and poisonous effects are also discussed aiming to highlight possible detrimental consequences due to irrational use. Finally, considering the high amount of waste and by-products generated through the value chain of the main crops, the sustainable management practices implemented so far are presented with the aim to increase the added-value of these crops.

Anticancer L-Asparaginase and Phytoactive Compounds From Plant Solanum nigrum Against MDR (Methicillindrug resistant) Staphylococcus aureus and Fungal Isolates

L-asparaginase is used in chemotherapy for acute lymphoblastic leukemia and other cancers. L-asparaginase derived from bacterial source triggers immune responses. The current study investigates Solanum nigrum as a novel and latent source of L-asparaginase to minimize immunological reactions. The antitumor activity of SN methanol extract was determined using the potato disc assay. InterPro Chimera and InterPro were used to predict the amino acid sequence of L-asparaginase and its anticancer activity. Purification of the enzyme was carried out to homogeneity of 1.51-fold with a recovery of 61.99%. At optimal conditions of 36.5°C, pH 8.6, and 8.5 g/mL substrate, fruit (crude extract) revealed an L-asparaginase titer of 48.23 U/mL. The molecular weight of the enzyme was calculated to be 32 ± 5 kDa using SDS PAGE. The fruit’s total flavonoids and phenolic contents are 0.42 ± .030 g/mL and 94 ± 1.9 mg CAE, respectively. Anti-tumorigenic efficacy was determined to be 66% against Agrobacterium tumefaciens. Additionally, the extract possesses potent antifungal and antibacterial properties. Molecular docking provided the structural motifs and underlying interactions between L-asparaginase, N-acetylglucosamine, murine, and chitin. SN contains high levels of the enzyme L-asparaginase and phytochemicals, making it a potential source of anticancer drugs.

Solanum nigrum Line inhibits osteoclast differentiation and suppresses bone mineral density reduction in the ovariectomy‑induced osteoporosis model

Bone homeostasis is maintained by osteoclasts that absorb bone and osteoblasts that form bone tissue. Menopausal osteoporosis is a disease associated with aging and hormonal changes due to menopause causing abnormal activation of osteoclasts, resulting in a decrease in bone density. Existing treatments for osteoporosis have been reported to have serious side effects, such as jawbone necrosis and breast and uterine cancer; therefore, their use by patients is decreasing, whilst studies focusing on alternative treatments are increasingly popular. Solanum nigrum Line (SL) has been used as a medicinal plant that possesses several pharmacological effects, such as anti‑inflammatory and hepatotoxic protective effects. To the best of our knowledge, however, its effects on osteoporosis and osteoclasts have not been demonstrated previously. In the present study, the anti‑osteoporotic effect of SL was investigated using a postmenopausal model of osteoporosis in which Sprague‑Dawley rat ovaries were extracted. In addition, the inhibitory effects on osteoclast differentiation and function of SL was confirmed using an osteoclast model treated with receptor activator of NF‑κB ligand (RANKL) on murine RAW 264.7 macrophages. In vivo experiments showed that SL reduced the decrease in bone mineral density and improved changes in the morphological index of bone microstructure, such as trabecular number and separation. In addition, the number of tartrate resistant acid phosphatase‑positive cells in the femur and the expression levels of nuclear factor of activated T‑cells cytoplasmic 1 (NFATc1) and cathepsin K protein were inhibited. In vitro, SL suppressed RANKL‑induced osteoclast differentiation and bone resorption ability; this was mediated by NFATc1/c‑Fos, a key transcription factor involved in osteoclast differentiation, ultimately inhibiting expression of various osteoclast‑associated genes. These experimental results show that SL may be an alternative treatment for osteoporosis caused by abnormal activation of osteoclasts in the future.

In vitro cytotoxic potential of Solanum nigrum against human cancer cell lines

Plants have natural products which use to possess antiproliferative potential against many cancers. In the present study, six isolated fractions (ethyl acetate, petroleum ether, chloroform, n-butanol, ethanol and aqueous) from Solanum nigrum were evaluated for their cytotoxic effect on different cell lines. Hepatic carcinoma cell line (HepG2), cervical cancer cell line (HeLa) and baby hamster kidney (BHK) used as normal non-cancerous cells were evaluated for cytotoxicity against isolated fractions. Cell viability assay was performed to evaluate the cytotoxicity of all fractions on different cell lines followed by the lactate dehydrogenase and vascular endothelial growth factor assays of most active fraction among all screened for cytotoxic analysis. HPLC analysis of most active fractions against cytotoxicity was performed to check the biological activity of compounds. Results displayed the potent cytotoxic activity of ethyl acetate fraction of S. nigrum against HepG2 cells with IC50 value of 7.89 μg/ml. Other fractions exhibited potent anticancer activity against HepG2 cells followed by HeLa cells. Fractions in our study showed no cytotoxicity in BHK cells. Cytotoxic activity observed in our current study exposed high antiproliferative potential and activity of ethyl acetate fraction against HepG2 cells. The results demonstrated that S. nigrum fractions exhibited anticancer activity against hepatic and cervical cancer cell lines with non-toxic effect in normal cells. These results reveal significant potential of S. nigrum for the therapeutic of cancers across the globe in future.

Exploring Phytochemicals of Traditional Medicinal Plants Exhibiting Inhibitory Activity Against Main Protease, Spike Glycoprotein, RNA-dependent RNA Polymerase and Non-Structural Proteins of SARS-CoV-2 Through Virtual Screening

Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) being a causative agent for global pandemic disease nCOVID’19, has acquired much scientific attention for the development of effective vaccines and drugs. Several attempts have been made to explore repurposing existing drugs known for their anti-viral activities, and test the traditional herbal medicines known for their health benefiting and immune-boosting activity against SARS-CoV-2. In this study, efforts were made to examine the potential of 605 phytochemicals from 37 plant species (of which 14 plants were endemic to India) and 139 antiviral molecules (Pubchem and Drug bank) in inhibiting SARS-CoV-2 multiple protein targets through a virtual screening approach. Results of our experiments revealed that SARS-CoV-2 M^Pro shared significant disimilarities against SARS-CoV M^Pro and MERS-CoV M^Pro indicating the need for discovering novel drugs. This study has screened the phytochemical cyanin (Zingiber officinale) which may exhibit broad-spectrum inhibitory activity against main proteases of SARS-CoV-2, SARS-CoV and MERS-CoV with binding energies of (−) 8.3 kcal/mol (−) 8.2 kcal/mol and (−) 7.7 kcal/mol respectively. Amentoflavone, agathisflavone, catechin-7-o-gallate and chlorogenin were shown to exhibit multi-target inhibitory activity. Further, Mangifera indica, Anacardium occidentale, Vitex negundo, Solanum nigrum, Pedalium murex, Terminalia chebula, Azadirachta indica, Cissus quadrangularis, Clerodendrum serratum and Ocimum basilicumaree reported as potential sources of phytochemicals for combating nCOVID’19. More interestingly, this study has highlighted the anti-viral properties of the traditional herbal formulation “Kabasura kudineer” recommended by AYUSH, a unit of Government of India. Short listed phytochemicals could be used as leads for future drug design and development. Genomic analysis of identified herbal plants will help in unraveling molecular complexity of therapeutic and anti-viral properties which proffer lot of chance in the pharmaceutical field for researchers to scout new drugs in drug discovery.

Role of Nutraceuticals in COVID-19 Mediated Liver Dysfunction

COVID-19 is known as one of the deadliest pandemics of the century. The rapid spread of this deadly virus at incredible speed has stunned the planet and poses a challenge to global scientific and medical communities. Patients with COVID-19 are at an increased risk of co-morbidities associated with liver dysfunction and injury. Moreover, hepatotoxicity induced by antiviral therapy is gaining importance and is an area of great concern. Currently, alternatives therapies are being sought to mitigate hepatic damage, and there has been growing interest in the research on bioactive phytochemical agents (nutraceuticals) due to their versatility in health benefits reported in various epidemiological studies. Therefore, this review provides information and summarizes the juncture of antiviral, immunomodulatory, and hepatoprotective nutraceuticals that can be useful during the management of COVID-19.

Chinese herbal medicines for prevention and treatment of colorectal cancer: From molecular mechanisms to potential clinical applications

Worldwide, colorectal cancer (CRC) is one of the most common malignant tumors, leading to immense social and economic burdens. Currently, the main treatments for CRC include surgery, chemotherapy, radiotherapy and immunotherapy. Despite advances in the diagnosis and treatment of CRC, the prognosis for CRC patients remains poor. Furthermore, the occurrence of side effects and toxicities severely limits the clinical use of these therapies. Therefore, alternative medications with high efficacy but few side effects are needed. An increasing number of modern pharmacological studies and clinical trials have supported the effectiveness of Chinese herbal medicines (CHMs) for the prevention and treatment of CRC. CHMs may be able to effectively reduce the risk of CRC, alleviate the adverse reactions caused by chemotherapy, and prolong the survival time of patients with advanced CRC. Studies of molecular mechanisms have provided deeper insight into the roles of molecules from CHMs in treating CRC. This paper summarizes the current understanding of the use of CHMs for the prevention and treatment of CRC, the main molecular mechanisms involved in these processes, the role of CHMs in modulating chemotherapy-induced adverse reactions, and CHM's potential role in epigenetic regulation of CRC. The current study provides beneficial information on the use of CHMs for the prevention and treatment of CRC in the clinic, and suggests novel directions for new drug discovery against CRC.

Development of Food Chemistry, Natural Products, and Nutrition Research: Targeting New Frontiers

The Special Issue entitled: "Development of Food Chemistry, Natural Products, and Nutrition Research" is focused on the recent development of food chemistry research, including natural products' sources and nutrition research, with the objectives of triggering interest towards new perspectives related to foods and opening a novel horizon for research in the food area. The published papers collected in this Special Issue are studies that refer to different aspects of food, ranging from food chemistry and analytical aspects, to composition, natural products, and nutrition, all examined from different perspectives and points of view. Overall, this Special Issue gives a current picture of the main topics of interest in the research and proposes studies and analyses that may prompt and address the efforts of research in the food area to find novel foods and novel applications and stimulate an environmentally-friendly approach for the re-use of the by-products of the agro-food area. This notwithstanding, the main challenge is currently addressed to achieve a full comprehension of the mechanisms of action of food components, the nutrients, outlining their high potential impact as preventive and/or therapeutic tools, not only as a source of macro- and/or micro-nutrients, which are necessary for all the metabolic and body functions.

Antiviral effect of Chinese herbal prescription JieZe-1 on adhesion and penetration of VK2/E6E7 with herpes simplex viruses type 2

ETHNOPHARMACOLOGICAL RELEVANCE

The Chinese Herbal Prescription JieZe-1(JZ-1), added and subtracted from Yihuang Decoction, a famous formula in the 12th year of Kangxi in Qing Dynasty, has a clear effect on Genital Herpes (GH) and no obvious adverse reactions occur clinically. JZ-1 also has preventive and therapeutic effects on Trichomonas vaginitis, Candida albicans vaginitis and GH in vitro and in vivo experiments.

AIM OF STUDY

The effect and mechanism of JZ-1 on anti-herpes simplex virus type 2(HSV-2) in vitro focusing on adhesion and penetration stages were investigated.

MATERIALS AND METHODS

A model of HSV-2 infection of VK2/E6E7 was developed. In order to explore JZ-1's anti-HSV-2 effect in vitro, cell morphology, ultrastructural pathology, cell viability and expression of viral glycoprotein D (gD) were assessed at 6 h, 12 h, 18 h, and 24 h of JZ-1 treatment. Then we measured the exact time required for adhesion and penetration of HSV-2 into VK2/E6E7 among a series of times at room temperature and under temperature control techniques. We treated VK2/E6E7 with JZ-1, penciclovir, or berberine and explored the mechanism of JZ-1 in blocking HSV-2 adhesion and penetration of host cells by assessing the cell ultrastructural pathology, viability, viral proteins gB, gD, VP16, ICP5, and ICP4 and host cell proteins HVEM, Nectin-1, and Nectin-2.

RESULTS

HSV-2 can fully adhere and penetrate into VK/E6E7 within 5 mins at room temperature while it takes 60mins under temperature control techniques. JZ-1 and penciclovir showed significant anti-HSV-2 effects, with improved host cell morphologies and increased host cell viabilities observed after treatment for 24 h. The anti-HSV-2 effect of JZ-1 can be detected after treatment for 6 h while that of penciclovir was not obvious until treatment for 12 h. JZ-1 showed distinct effect on HSV-2 adhesion and penetration stages by significantly reducing the expression of viral proteins gB, gD, VP16, ICP5, and ICP4, improving cell morphology and increasing cell viability. However, these effects were not exerted via downregulated expression of membrane fusion-related proteins such as HVEM, Nectin-1, or Nectin-2. The specific anti-HSV-2 mechanism of JZ-1 need to be further explored.

CONCLUSION

The anti-HSV-2 effect of JZ-1 was superior to that of penciclovir and berberine in vitro, and was mainly mediated by enhancing host cell defense and blocking adhesion and penetration of HSV-2.