Flavonoids from Nelumbo nucifera Gaertn., a Medicinal Plant: Uses in Traditional Medicine, Phytochemistry and Pharmacological Activities

Evaluation of the inhibitory potential of bioactive compounds against SARS-CoV-2 by in silico approach

CONTEXT

The COVID-19 (coronavirus disease 19) pandemic brought on by the SARS-CoV-2 outbreak (severe acute respiratory syndrome coronavirus 2) has stimulated the exploration of various available chemical compounds that could be used to treat the infection. This has driven numerous researchers to investigate the antiviral potential of several bioactive compounds from medicinal plants due to their reduced adverse effects compared to chemicals. Some of the bioactive compounds used in folklore treatment strategies are reported as effective inhibitors against the proliferative and infective cycles of SARS-CoV-2. The secondary metabolites from plants are generally used to treat various diseases due to their intact medicinal properties. The present study analyzes the inhibitory potential of phytochemicals from medicinal plants like Sphaeranthus indicus, Lantana camara, and Nelumbo nucifera against SARS-CoV-2 by molecular docking.

METHODS

Ten druggable protein targets from SARS-CoV-2 are docked against the phytochemicals from the selected medicinal plants. The phytocompounds astragalin, isoquercetin, and 5-hydroxy-7-methoxy-6-c-glycosy flavone were found to have lower binding energy depicting their inhibitive potential compared with the reported inhibitors that are used in the treatment of SARS-CoV-2 infection. The phytocompounds found to have the least binding energy were selected for further analyses. To assess the compounds' potential as drugs, their ADMET characteristics were also examined. Sphaeranthus indicus, Lantana camara, and Nelumbo nucifera six possible compounds were separately screened for ADME and toxicity characteristics; then, the results were analyzed. To assess the impact of the phytocompound binding on the dynamics of SARS-CoV-2 ribonuclease protein NSP15, microsecond-level all atomistic molecular dynamics simulations were performed, and their dynamics were analyzed. Microsecond-level molecular dynamics simulations of both the ligands complexed with NSP15 revealed that the ligand induces allosteric effects on NSP15, which could lead to destabilization of NSP15 hexameric interface and loss of RNA binding. The low binding energy exhibited by the phytochemicals from Lantana camera, Sphaeranthus indicus, and Nelumbo nucifera against the protein targets of SARS-CoV-2 showed inhibitory potential by the selected molecules. Their predicted interference of the enzymes involved in the molecular mechanisms aiding the proliferation of SARS-CoV-2 indicated the inhibitive ability of the phytochemicals.

Exploring Major Flavonoid Phytochemicals from Nelumbo nucifera Gaertn. as Potential Skin Anti-Aging Agents: In Silico and In Vitro Evaluations

Nelumbo nucifera Gaertn., an aquatic medicinal plant (Nelumbonaceae family), has a history of use in traditional medicine across various regions. Our previous study demonstrated the skin anti-aging potential of its stamen ethanolic extract by effectively inhibiting collagenase and tyrosinase enzymes. While the major constituents of this extract are well documented, there is a lack of research on the individual compounds' abilities to inhibit skin aging enzymes. Therefore, this study aimed to evaluate the anti-aging potential of the primary flavonoids found in N. nucifera using both in silico and in vitro approaches. Our initial step involved molecular docking to identify compounds with the potential to inhibit collagenase, elastase, and tyrosinase. Among the seven flavonoids studied, kaempferol-3-O-robinobioside (Kae-3-Rob) emerged as the most promising candidate, exhibiting the highest docking scores for three skin aging-related enzymes. Subsequent enzyme-based inhibition assays confirmed that Kae-3-Rob displayed robust inhibitory activity against collagenase (58.24 ± 8.27%), elastase (26.29 ± 7.16%), and tyrosinase (69.84 ± 6.07%). Furthermore, we conducted extensive 200-ns molecular dynamics (MD) simulations, revealing the stability of the complexes formed between Kae-3-Rob and each enzyme along the MD simulation time. MM/PBSA-based binding free energy calculations indicated the considerably stronger binding affinity of Kae-3-Rob for collagenase and tyrosinase compared to elastase, which was related to the greater percentage of hydrogen bond occupations. These computational findings were consistent with the relatively high inhibitory activity of Kae-3-Rob against collagenase and tyrosinase observed in our in vitro experiment. In conclusion, the results obtained from this comprehensive study suggest that Kae-3-Rob, a key flavonoid from N. nucifera, holds significant potential as a source of bioactive compounds for anti-aging cosmeceutical and other phytopharmaceutical application.

Modulatory Effect of Medicinal Plants and Their Active Constituents on ATP-Sensitive Potassium Channels (KATP) in Diabetes

Hyperglycemia, which is a chronic metabolic condition caused by either a defect in insulin secretion or insulin resistance, is a hallmark of diabetes mellitus (DM). Sustained hyperglycemia leads to the onset and development of many health complications. Despite the number of available antidiabetic medications on the market, there is still a need for novel treatment agents with increased efficacy and fewer adverse effects. Many medicinal plants offer a rich supply of bioactive compounds that have remarkable pharmacological effects with less toxicity and side effects. According to published evidence, natural antidiabetic substances influence pancreatic β-cell development and proliferation, inhibit pancreatic β-cell death, and directly increase insulin output. Pancreatic ATP-sensitive potassium channels play an essential role in coupling glucose metabolism to the secretion of insulin. Although much of the literature is available on the antidiabetic effects of medicinal plants, very limited studies discuss their direct action on pancreatic KATP. The aim of this review is to focus on the modulatory effects of antidiabetic medicinal plants and their active constituents on pancreatic KATP. The KATP channel should be regarded as a key therapeutic milestone in the treatment of diabetes. Therefore, continuous research into the interaction of medicinal plants with the KATP channel is crucial.

Lotus (Nelumbo nucifera Gaertn.) Leaf-Fermentation Supernatant Inhibits Adipogenesis in 3T3-L1 Preadipocytes and Suppresses Obesity in High-Fat Diet-Induced Obese Rats

The lotus (Nelumbo nucifera Gaertn.) leaf is a typical homologous ingredient of medicine and food with lipid-lowering and weight-loss effects. In the present study, lotus leaves were fermented by two probiotics, Enterococcus faecium WEFA23 and Enterococcus hirae WEHI01, and the anti-adipogenic effect of Enterococcus fermented lotus leaf supernatant (FLLS) was evaluated in 3T3-L1 preadipocytes with the aim of exploring whether its anti-obesity ability will be enhanced after fermentation with Enterococcus and to dig out the potential corresponding mechanism. The FLLS fermented by E. hirae WEHI01 (FLLS-WEHI01) was selected and further investigated for its ability to inhibit obesity in vivo in high-fat diet (HFD)-induced obese rats (male, 110 ± 5 g, 4 weeks old) due to its superior inhibitory effect on adipogenesis and lipid accumulation (inhibition rate of up to 56.17%) in 3T3-L1 cells (p = 0.008 for WEHI01-L, p < 0.001 for WEHI01-H). We found that the oral administration of both the low and high doses of FLLS-WEHI01 could achieve some effects, namely decreasing body weight (p < 0.001), epididymal fat mass, adipocyte cell size, LDL-C levels (p = 0.89, 0.02, respectively), liver TC levels (p < 0.001, p = 0.01, respectively), and TG levels (p = 0.2137, p = 0.0464, respectively), fasting blood glucose (p = 0.1585, p = 0.0009), and improved insulin resistance (p = 0.33, 0.01, respectively) in rats of the model group. Moreover, the administration of both high and low doses of FLLS-WEHI01 decreased the transcription levels of adipogenic transcription factors and corresponding genes such as Pparγ (p < 0.001), Cebpα (p < 0.001), Acc (p < 0.001), and Fas (p < 0.001) by at least three times. These results indicate that FLLS-WEHI01 can potentially be developed as an healthy, anti-obesity foodstuff.

Study on the vasodilatory activity of lotus leaf extract and its representative substance nuciferine on thoracic aorta in rats

Lotus (Nelumbo nucifera) leaves are widely used for both edible and medicinal applications. For its further utilization, we studied the vasodilatory activity of lotus leaf extract for the first time. In this study, we obtained the extracts using different ratios of water and ethanol, which was followed by polarity-dependent extraction. We found that the CH₂Cl₂ layer exhibited better vasodilatory activity (EC₅₀ = 1.21 ± 0.10 μg/ml). HPLC and ESI-HRMS analysis of the CH₂Cl₂ layer using the standard product as a control revealed that nuciferine (E_max = 97.95 ± 0.76%, EC₅₀ = 0.36 ± 0.02 μM) was the main component in this layer. Further research revealed that nuciferine exerts a multi-target synergistic effect to promote vasodilation, via the NO signaling pathway, K⁺ channel, Ca²⁺ channel, intracellular Ca²⁺ release, α and β receptors, etc. Nuciferine exhibits good vasodilatory activity, and it exhibits the potential to be utilized as a lead compound.

Structures and antiosteoclastogenic activity of compounds isolated from edible lotus (Nelumbo nucifera Gaertn.) leaves and stems

One new 1,4-bis-phenyl-1,4-butanedione glycoside (14), one new eudesmane-type sesquiterpenoid (16), and 16 known compounds were isolated from the leaves and stems of Nelumbo nucifera Gaertn. The structures of the isolated compounds were elucidated by interpretation of their 1D and 2D NMR spectroscopic and HRESIMS data. Time-dependent density functional theory calculations and Electronic Circular Dichroism (ECD) spectroscopy was used to determine absolute configurations of the new eudesmane-type sesquiterpenoid (16). All the isolated compounds were examined for their antiosteoclastogenic activity. Preliminarily results of the TRAP staining on RAW 264.7 cells indicated that compounds 1 and 11 possess potential inhibitory effects on RANKL-induced osteoclast formation. Further bioassay investigation was carried out to reveal that compounds 1 and 11 suppressed RANKL-induced osteoclast formation in a concentration-dependent manner with the inhibition up to 55% and 78% at the concentration of 10 μM, respectively. In addition, the structure-activity relationship analysis showed that the 1,3-dioxole substitute and the double bond at C-6a/C-7 in the aporphine skeleton may be responsible for the antiosteoclastogenic activity. The findings provided valuable insights for the discovery and structural modification of aporphine alkaloids as the antiosteoclastogenic lead compounds.

Extraction Kinetics and Reaction Rates of Sacred Lotus Stamen Tea Infusion-Derived Flavonoids in Relation with Its Antioxidant Capacity

Stamen tea from Nelumbo nucifera Gaertn. (or the so-called sacred lotus) is widely consumed, and its flavonoids provide various human health benefits. The method used for tea preparation for consumption, namely the infusion time, may affect the levels of extractable flavonoids, ultimately affecting their biological effects. To date, there is no report on this critical information. Thus, this study aims to determine the kinetics of solid liquid extraction of flavonoid from sacred lotus stamen using the traditional method of preparing sacred lotus stamen tea. Phytochemical composition was also analyzed using high-performance liquid chromatography (HPLC). The antioxidant potential of stamen tea was also determined. The results indicated that the infusion time critically affects the concentrations of flavonoids and the antioxidant capacity of sacred lotus stamen tea, with a minimum infusion time of 5–12 min being required to release the different flavonoids from the tea. The extraction was modeled using second order kinetics. The rate of release was investigated by the glycosylation pattern, with flavonoid diglycosides, e.g., rutin and Kae-3-Rob, being released faster than flavonoid monoglycosides. The antioxidant activity was also highly correlated with flavonoid levels during infusion. Taken together, data obtained here underline that, among others, the infusion time should be considered for the experimental design of future epidemiological studies and/or clinical trials to reach the highest health benefits.

Ethnomedicinal Use, Phytochemistry, and Other Potential Application of Aquatic and Semiaquatic Medicinal Plants

Medicinal plants have been treating various ailments and diseases since ancient times. Aquatic and semiaquatic medicinal plants play an essential role in human welfare to fulfill their daily needs. They have shown biological, pharmacological, nutraceutical, and commercial applications. This review aims to collect and update all recent information on ethnomedicinal, phytochemistry, pharmacological activities, and nanoparticle synthesis and their uses in aquatic and semiaquatic medicinal plants. Original research papers, review papers, short communications, and book chapters on aquatic and semiaquatic plants have been retrieved from PubMed, Web of Science, Scopus, and Google Scholar. Keywords, ethnomedicinal studies, phytochemistry, pharmacological activities, and nanoparticle synthesis from aquatic and semiaquatic medicinal plants are used for the search. Different aquatic and semiaquatic medicinal plants belonging to the families Acanthaceae, Alismataceae, Amaranthaceae, Apiaceae, Araceae, Asteraceae, Boraginaceae, Ceratophyllaceae, Cyperaceae, Fabaceae, Hydrocharitaceae, Lythraceae, Marsileaceae, Menyanthaceae, Nelumbonaceae, Nymphaeaceae, Onagraceae, Plantaginaceae, Poaceae, Polygonaceae, Pontederiaceae, Primulaceae, Scrophulariaceae, and Zingiberaceae have been studied. They are rich in alkaloids, flavonoids, terpenoids, phenolics, saponins, tannins, dietary fiber, glycosidic derivatives, carbohydrates, and proteins. These phytochemicals have been used for their antimicrobial, antioxidant, hepatoprotective, sedative, anticonvulsant, cytotoxic, antiparasitic, and antidiabetic activities. Besides this, various parts of the plants are used as dietary supplements and green nanoparticle synthesis. These plants are also known for their commercial value and are used as an ingredient in some pharmaceutical industries.

Aboriginal medicinal plants of Queensland: ethnopharmacological uses, species diversity, and biodiscovery pathways

BACKGROUND

Aboriginal peoples have occupied the island continent of Australia for millennia. Over 500 different clan groups or nations with distinctive cultures, beliefs, and languages have learnt to live sustainably and harmoniously with nature. They have developed an intimate and profound relationship with the environment, and their use of native plants in food and medicine is largely determined by the environment they lived in. Over 1511 plant species have been recorded as having been used medicinally in Australia. Most of these medicinal plants were recorded from the Aboriginal communities in Northern Territory, New South Wales, South Australia, and Western Australia. Not much has yet been reported on Aboriginal medicinal plants of Queensland. Therefore, the main aim of this review is to collect the literature on the medicinal plants used by Aboriginal peoples of Queensland and critically assess their ethnopharmacological uses.

METHODS

The information used in this review was collected from archival material and uploaded into the Tropical Indigenous Ethnobotany Centre (TIEC) database. Archival material included botanist's journals/books and old hard copy books. Scientific names of the medicinal plant species were matched against the 'World Flora Online Plant List', and 'Australian Plant Census' for currently accepted species names to avoid repetition. An oral traditional medical knowledge obtained through interviewing traditional knowledge holders (entered in the TIEC database) has not been captured in this review to protect their knowledge.

RESULTS

This review identified 135 species of Queensland Aboriginal medicinal plants, which belong to 103 genera from 53 families, with Myrtaceae being the highest represented plant family. While trees represented the biggest habit, leaves were the most commonly used plant parts. Of 62 different diseases treated by the medicinal plants, highest number of plants are used for treating skin sores and infections. Few plants identified through this review can be found in other tropical countries but many of these medicinal plants are native to Australia. Many of these medicinal plants are also used as bush food by Aboriginal peoples.

CONCLUSION

Through extensive literature review, we found that 135 medicinal plants native to Queensland are used for treating 62 different diseases, especially skin infections. Since these medicinal plants are also used as bush food and are rarely studied using the Western scientific protocols, there is a huge potential for bioprospecting and bush food industry.

Transcriptome Analyses Revealed the Key Metabolic Genes and Transcription Factors Involved in Terpenoid Biosynthesis in Sacred Lotus

As the largest group of structurally diverse metabolites, terpenoids are versatile natural compounds that act as metabolism mediators, plant volatiles, and ecological communicators. However, few terpenoid compounds have been identified in plant parts of sacred lotus (Nelumbo nucifera Gaertn.). To elucidate the molecular genetic basis of the terpene biosynthetic pathway, terpenes from different parts of the plant, including seeds (S), young leaves (YL), mature leaves (ML), white flowers (WF), yellow flowers (YF), and red flowers (RF), were identified by LC-MS/MS and the relative contents of the same terpenes in different parts were compared. The results indicate that all plant parts primarily consist of triterpenes, with only minor quantities of sesquiterpenes and diterpenes, and there were differences in the terpene content detected in different plant parts. To illustrate the biosynthesis of various terpenoids, RNA sequencing was performed to profile the transcriptomes of various plant parts, which generated a total of 126.95 GB clean data and assembled into 29,630 unigenes. Among these unigenes, 105 candidate unigenes are involved in the mevalonate (MVA) pathway, methyl-erythritol phosphate (MEP) pathway, terpenoid backbone biosynthesis pathway, and terpenoid synthases pathway. Moreover, the co-expression network between terpene synthase (TPS) and WRKY transcription factors provides new information for the terpene biosynthesis pathway.

Optimization of alcohol extraction and spray-drying conditions for efficient processing and quality evaluation of instant tea powder from lotus and green tea leaves

Lotus and Green Tea leaves are two frequently used medicinal plants in Vietnam, utilized as food, drink, or in traditional treatments to help with weight loss and cholesterol reduction. The study’s major goal is to determine the parameters of the process preparation in order to generate instant tea powder that satisfies quality criteria for customer demand. Twenty experiments are conducted using the D-optimal model to evaluate the cause-effect relationship and optimize the production process of instant tea powder. Four independent variables are selected for the survey namely alcohol concentration (40%; 50%; 60%), carrier mass (10 g; 20 g; 30 g), inlet air temperature (160 °C; 170 °C) and flow rate (4 rpm/min; 5 rpm/min). The instant tea powder is effectively created and met quality parameters, with a drying performance, moisture content, total phenol and flavonoid content of 29.15%, 4.83%, 45.29 mg GA/g, and 70.68 mg QE/g, respectively. In conclusion, the optimal parameters of the preparation process were identified, which included an alcohol content of 60%, a carrier mass of 10 g, an inlet air temperature of 165 °C, and a flow rate of 4 rpm/min.

Flavonoid Profiles and Antioxidant Potential of Monochoria angustifolia (G. X. Wang) Boonkerd & Tungmunnithum, a New Species from the Genus Monochoria C. Presl

Plants of the genus Monochoria have long been utilized in food, cosmetics, and traditional herbal treatments. Thailand has the highest species diversity of this genus and a new member, Monochoria angustifolia (G. X. Wang) Boonkerd & Tungmunnithum has been recently described. This plant is called “Siam Violet Pearl” as a common name or “Khimuk Si Muang Haeng Siam” as its vernacular name with the same meaning in the Thai language. Despite their importance, little research on Monochoria species has been conducted. This study, thus, provides the results to fill in this gap by: (i) determining flavonoid phytochemical profiles of 25 natural populations of M. angustifolia covering the whole floristic regions in Thailand, and (ii) determining antioxidant activity using various antioxidant assays to investigate probable mechanisms. The results revealed that M. angustifolia presents a higher flavonoid content than the outgroup, M. hastata. Our results also revealed that flavonoids might be used to investigate Monochoria evolutionary connections and for botanical authentication. The various antioxidant assays revealed that M. angustifolia extracts preferentially act through a hydrogen atom transfer antioxidant mechanism. Pearson correlation analysis indicated significant correlations, emphasizing that the antioxidant capacity is most probably due to the complex action of several phytochemicals rather than that of a single molecule. Together, these results showed that this new species provide an attractive alternative starting material with phytochemical variety and antioxidant potential for the phytopharmaceutical industry.

LC-ESI-QTOF-MS/MS Characterization and Estimation of the Antioxidant Potential of Phenolic Compounds from Different Parts of the Lotus (Nelumbo nucifera) Seed and Rhizome

Edible lotus (Nelumbo nucifera G.) is widely consumed in Asian countries and treated as a functional food and traditional medicinal herb due to its abundant bioactive compounds. Lotus rhizome peels, rhizome knots, and seed embryos are important byproducts and processing waste of edible lotus (Nelumbo nucifera G.) with commercial significance. Nevertheless, the comprehensive phenolic profiling of different parts of lotus is still scarce. Thus, this study aimed to review the phenolic contents and antioxidant potential in lotus seeds (embryo and cotyledon) and rhizomes (peel, knot, and pulp) grown in Australia. In the phenolic content and antioxidant potential estimation assays by comparing to the corresponding reference standards, the lotus seed embryo exhibited the highest total phenolic content (10.77 ± 0.66 mg GAE/g_f.w.), total flavonoid content (1.61 ± 0.03 mg QE/g_f.w.), 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity (9.66 ± 0.10 mg AAE/g_f.w.), 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging activity (14.35 ± 0.20 mg AAE/g_f.w.), and total antioxidant capacity (6.46 ± 0.30 mg AAE/g), while the highest value of ferric ion reducing antioxidant power (FRAP) activity and total tannin content was present in the lotus rhizome knot (2.30 ± 0.13 mg AAE/g_f.w.). A total of 86 phenolic compounds were identified in five parts of lotus by liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS), including phenolic acids (20), flavonoids (51), lignans (3), stilbenes (2), and other polyphenols (10). The most phenolic compounds, reaching up to 68%, were present in the lotus seed embryo (59). Furthermore, the lotus rhizome peel and lotus seed embryo exhibit significantly higher contents of selected polyphenols than other lotus parts according to high-performance liquid chromatography (HPLC) quantification analysis. The results highlighted that byproducts and processing waste of edible lotus are rich sources of phenolic compounds, which may be good candidates for further exploitation and utilization in food, animal feeding, and pharmaceutical industries.

Lotus Seed Green Embryo Extract and a Purified Glycosyloxyflavone Constituent, Narcissoside, Activate TRPV1 Channels in Dorsal Root Ganglion Sensory Neurons

Several studies have documented the broad-spectrum bioactivities of a lotus seed (Plumula nelumbinis [PN]) green embryo extract. However, the specific bioactive components and associated molecular mechanisms remain largely unknown. This study aimed to identify the ion channel-activating mechanisms of PN extracts. Using fluorometric imaging and patch-clamp recordings, PN extracts were screened for calcium channel activation in dorsal root ganglion (DRG) neurons. The TRPV1 channels in DRG neurons were strongly activated by the PN extract (mean amplitude of 131 ± 45 pA at 200 μg/mL) and its purified glycosyloxyflavone narcissoside (401 ± 271 pA at 100 μM). Serial treatment with a 200 μg/mL PN extract in TRPV1-overexpressing HEK293T cells induced robust desensitization to 10 ± 10% of the initial current amplitude. Thus, we propose that the PN extract and narcissoside function as TRPV1 agonists. This new finding may advance our knowledge regarding the traditional and scientific functions of PN in human health and disease.

Comparative Analysis of the Antioxidant and Antidiabetic Potential of Nelumbo nucifera Gaertn. and Nymphaea lotus L. var. pubescens (Willd.)

Background. Nelumbo nucifera Gaertn. and Nymphaea lotus L. var. pubescens (Willd.) are both aquatic rhizomatous perennial plants mostly found in the tropical region of Nepal, India, Bangladesh, China, and Eastern Asia. Nymphaea pubescens and Nelumbo nucifera plants are famous for their different biological activities such as antidiabetic, antioxidant, hepatoprotective, antidiarrheal, and anti-inflammatory properties. Objective. The present study majorly focused on the determination of in vitro antioxidant and antidiabetic properties of Nelumbo nucifera and Nymphaea pubescens. Methods. In vitro α-glucosidase inhibition was performed using PNPG as a substrate. Antioxidant property of the plant extract was determined by DPPH free radical scavenging assay. The aluminium trichloride method was done for the estimation of total flavonoid content. Likewise, Folin–Ciocalteu reagent was used for determining total phenolic content. Results. The total phenolic content of N. nucifera and N. pubescens was found to be 172.827 ± 0.41 and 194.87 ± 0.93 mg GAE/g, respectively, while the total flavonoid content was reported 17.12 ± 1.04 and 34.59 ± 1.73 mg QE/g, respectively. The IC50 values of the crude extract and its fractions of N. nucifera against the DPPH free radical ranged from 33.46 ± 0.6 to 3.52 ± 0.09 μg/mL, while that of the N. pubescens ranged from 14.30 ± 0.43 to 1.43 ± 0.08 μg/mL. Similarly, for the in vitro α-glucosidase inhibition activity, the IC50 of the crude extract and its fractions of N. nucifera varied from 349.86 ± 2.91 to 29.06 ± 0.24 μg/mL and that of N. pubescens ranged from 224.4 ± 6.85 to 5.29 ± 0.39 μg/mL. Conclusion. Both aquatic plants N. nucifera and N. pubescens show antioxidant properties and can inhibit α-glucosidase in in vitro. Further research is required to identify the inhibiting compounds.

Effect of Nelumbo nucifera Petals Extract on Antioxidant Activity and Sperm Quality in Charolais Cattle Sperm Induced by Mancozeb

The white Nelumbo nucifera petals aqueous extraction (NAE) was prominent in phytochemical content, antioxidant activity, and enhanced rat sperm viability induced by FeSO₄, a heavy metal. Mancozeb (MZ) contains heavy metals and is widely used for fungal control in agriculture and industry. It induces oxidative stress and causes of spermatogenesis and reproductive organs’ abnormalities in both humans and animals. The aims of the present study were to investigate the effects of white Nelumbo nucifera petals aqueous extraction (WNAE) on sperm quality in cattle sperm induced by MZ. Moreover, this study investigated phytochemical compounds by liquid chromatography-mass spectrometry. A protein profile related to sperm quality with SDS-page and sperm energy preservation for each treatment was determined. The results found nine phytochemical compounds, in which quercetin-3-O-arabinoglycoside was a major flavonoid that was found in the WNAE. MZ induced free radicals in cells, leading to LPO and protein oxidation, while decreasing sperm motility, sperm viability, acrosome integrity, and normal sperm morphology. The cattle sperm found four proteins related to sperm quality including MWs of 17, 31, 34, and 55 kDa. The WNAE effectively increased energy preservation, sperm motility, sperm viability, acrosome integrity, and normal sperm morphology. The WNAE enhanced sperm qualities by reducing oxidative stress. It might be suggested that WNAE has benefits for sperm preservation which may be used to guard against toxicity in animals or humans exposed to MZ contaminants.

Flavonoids from Sacred Lotus Stamen Extract Slows Chronological Aging in Yeast Model by Reducing Oxidative Stress and Maintaining Cellular Metabolism

Nelumbo nucifera is one of the most valuable medicinal species of the Nelumbonaceae family that has been consumed since the ancient historic period. Its stamen is an indispensable ingredient for many recipes of traditional medicines, and has been proved as a rich source of flavonoids that may provide an antiaging action for pharmaceutical or medicinal applications. However, there is no intense study on antiaging potential and molecular mechanisms. This present study was designed to fill in this important research gap by: (1) investigating the effects of sacred lotus stamen extract (LSE) on yeast lifespan extension; and (2) determining their effects on oxidative stress and metabolism to understand the potential antiaging action of its flavonoids. A validated ultrasound-assisted extraction method was also employed in this current work. The results confirmed that LSE is rich in flavonoids, and myricetin-3-O-glucose, quercetin-3-O-glucuronic acid, kaempferol-3-O-glucuronic acid, and isorhamnetin-3-O-glucose are the most abundant ones. In addition, LSE offers a high antioxidant capacity, as evidenced by different in vitro antioxidant assays. This present study also indicated that LSE delayed yeast (Saccharomyces cerevisiae, wild-type strain DBY746) chronological aging compared with untreated control yeast and a positive control (resveratrol) cells. Moreover, LSE acted on central metabolism, gene expressions (SIR2 and SOD2), and enzyme regulation (SIRT and SOD enzymatic activities). These findings are helpful to open the door for the pharmaceutical and medical sectors to employ this potential lotus raw material in their future pharmaceutical product development.

Validation of a High-Performance Liquid Chromatography with Photodiode Array Detection Method for the Separation and Quantification of Antioxidant and Skin Anti-Aging Flavonoids from Nelumbo nucifera Gaertn. Stamen Extract

Nelumbo nucifera Gaertn., or the so-called sacred lotus, is a useful aquatic plant in the Nelumbonaceae family that has long been used to prepare teas, traditional medicines as well as foods. Many studies reported on the phytochemicals and biological activities of its leaves and seeds. However, to date, only few studies were conducted on its stamen, which is the most important ingredient for herbal medicines, teas and other phytopharmaceutical products. Thus, this present study focuses on the following: (1) the application of high-performance liquid chromatography with photodiode array detection for a validated separation and quantification of flavonoids from stamen; (2) the Nelumbo nucifera stamen’s in vitro and in cellulo antioxidant activities; as well as (3) its potential regarding the inhibition of skin aging enzymes for cosmetic applications. The optimal separation of the main flavonoids from the stamen ethanolic extract was effectively achieved using a core-shell column. The results indicated that stamen ethanolic extract has higher concentration of in vitro and in cellulo antioxidant flavonoids than other floral components. Stamen ethanolic extract showed the highest protective effect against reactive oxygen/nitrogen species formation, as confirmed by cellular antioxidant assay using a yeast model. The evaluation of potential skin anti-aging action showed that the stamen extract has higher potential to inhibit tyrosinase and collagenase compared with its whole flower. These current findings are the first report to suggest the possibility to employ N. nucifera stamen ethanolic extract as a tyrosinase and collagenase inhibitor in cosmetic applications, as well as the utility of the current separation method.

Lotus (Nelumbo nucifera Gaertn.) and Its Bioactive Phytocopounds: A Tribute to Cancer Prevention and Intervention

Simple Summary

The plant Nelumbo nucifera (Gaertn.), commonly known as lotus, sacred lotus, Indian lotus, water lily, or Chinese water lily, is an aquatic perennial crop belonging to the family of Nelumbonaceae. N. nucifera has traditionally been used as an herbal medicine and functional food in many parts of Asia. It has been found that different parts of this plant consist of various bioactive phytocompounds. Within the past few decades, N. nucifera and its phytochemicals have been subjected to intense cancer research. In this review, we critically evaluate the potential of N. nucifera phytoconstituents in cancer prevention and therapy with related mechanisms of action.

Abstract

Cancer is one of the major leading causes of death worldwide. Accumulating evidence suggests a strong relationship between specific dietary habits and cancer development. In recent years, a food-based approach for cancer prevention and intervention has been gaining tremendous attention. Among diverse dietary and medicinal plants, lotus (Nelumbo nucifera Gaertn., family Nymphaeaceae), also known as Indian lotus, sacred lotus or Chinese water lily, has the ability to effectively combat this disease. Various parts of N. nucifera have been utilized as a vegetable as well as an herbal medicine for more than 2000 years in the Asian continent. The rhizome and seeds of N. nucifera represent the main edible parts. Different parts of N. nucifera have been traditionally used to manage different disorders, such as fever, inflammation, insomnia, nervous disorders, epilepsy, hypertension, cardiovascular diseases, obesity, and hyperlipidemia. It is believed that numerous bioactive components, including alkaloids, polyphenols, terpenoids, steroids, and glycosides, are responsible for its various biological and pharmacological activities, such as antioxidant, anti-inflammatory, immune-modulatory, antiviral, hepatoprotective, cardioprotective, and hypoglycemic activities. Nevertheless, there is no comprehensive review with an exclusive focus on the anticancer attributes of diverse phytochemicals from different parts of N. nucifera. In this review, we have analyzed the effects of N. nucifera extracts, fractions and pure compounds on various organ-specific cancer cells and tumor models to understand the cancer-preventive and therapeutic potential and underlying cellular and molecular mechanisms of action of this interesting medicinal and dietary plant. In addition, the bioavailability, pharmacokinetics, and possible toxicity of N. nucifera-derived phytochemicals, as well as current limitations, challenges and future research directions, are also presented.

Phytochemical Diversity and Antioxidant Potential of Natural Populations of Nelumbo nucifera Gaertn. throughout the Floristic Regions in Thailand

Asian lotus has long been consumed as a food and herbal drug that provides several health benefits. The number of studies on its biological activity is significant, but research at the population level to investigate the variation in phytochemicals and biological activity of each population which is useful for a more efficient phytopharmaceutical application strategy remains needed. This present study provided the frontier results to fill-in this necessary gap to investigating the phytopharmaceutical potential of perianth and stamen, which represent an important part for Asian traditional medicines, from 18 natural populations throughout Thailand by (1) determining their phytochemical profiles, such as total contents of phenolic, flavonoid, and anthocyanin, and (2) determining the antioxidant activity of these natural populations using various antioxidant assays to examine different mechanisms. The result showed that Central is the most abundant floristic region. The stamen was higher in total phenolic and flavonoid contents, whereas perianth was higher in monomeric anthocyanin content. This study provided the first description of the significant correlation between phytochemical contents in perianth compared with stamen extracts, and indicated that flavonoids are the main phytochemical class. This analysis indicated that the stamen is a richer source of flavonoids than perianth, and provided the first report to quantify different flavonoids accumulated in stamen and perianth extracts under their native glycosidic forms at the population level. Various antioxidant assays revealed that major flavonoids from N. nucifera prefer the hydrogen atom transfer mechanism when quenching free radicals. The significant correlations between various phytochemical classes and the different antioxidant tests were noted by Pearson correlation coefficients and emphasized that the antioxidant capability of an extract is generally the result of complex phytochemical combinations as opposed to a single molecule. These current findings offer the alternative starting materials to assess the phytochemical diversity and antioxidant potential of N. nucifera for phytopharmaceutical sectors.

Ethnobotanical investigation of medicinal plants used in Lingchuan county, Shanxi, China

Abstract Medicinal plants are the primary sources of healthcare among the people of developing countries in villages and local towns. Documenting and reporting the traditional knowledge of medicinal plants may contribute to pharmaceutical research development. For this reason, we present our findings on ethnomedicinal plants from Lingchuan County, Shanxi, China, an unexplored area rich in medicinal plant resources. Information of ethnomedicinal plants were collected through questionnaire/semi-structured interviews from 180 informants, including traditional healers. Field surveys were conducted in 53 villages of Lingchuan County from 2017 to 2018. Informed consent was obtained from each participant before conducting the interview process. Quantitative analysis was performed for each recorded species, such as Relative Frequency Citation (RFC), Use Value (UV), and Factor of Informant Consensus (FIC). Diseases were categorized into twelve groups. A total 138 species of medicinal plants were recorded, belonging to 123 genera of 58 families. Asteraceae was the dominant plant family with 19 species, followed by Rosaceae and Fabaceae. Herbs were dominant among plant life-forms with 96 species, followed by shrubs and trees (15 species each). Roots were the most commonly used plant parts with 58 species, followed by whole plants and fruits (28 species each). Most plant species were reported non-toxic (84, 60%), followed by unknown toxicity (35, 25%), poisonous, and less toxic (19, 14%). Quantitative analysis revealed that Forsythia suspensa was with higher (0.33) RFC value, and Scutellaria baicalensis was recorded with a higher (0.91) UV. Treated diseases were categorized in 12 groups and evaluated by their FIC value, in which gynecological diseases have higher (0.93) FIC value followed by urinary system diseases. Most medicinal plants are used to clear away heat and relieve the surface. The present study revealed that local people of Lingchuan County confidently use ethnomedicinal plants for their healthcare needs. The higher indices value of a plant species resulted from quantitative analysis warrants further investigation, which may possess valuable phytochemical compounds that may result in new drugs for treating various human disorders.

Pectic polysaccharide from Nelumbo nucifera leaves promotes intestinal antioxidant defense in vitro and in vivo

In this study, the Nelumbo nucifera leaf polysaccharide (NNLP) was isolated by hot water extraction and ethanol precipitation. DEAE anion exchange chromatography and gel filtration were further performed to obtained the purified fraction NNLP-I-I, the molecular weight of which was 16.4 kDa. The monosaccharide composition analysis and linkage units determination showed that the fraction NNLP-I-I was a pectic polysaccharide. In addition, the NMR spectra analysis revealed that NNLP-I-I mainly consisted of a homogalacturonan backbone and rhamnogalacturonan I, containing a long HG region and short RG-I region, with AG-II and 1-3 linked rhamnose as side chains. The biological studies demonstrated that NNLP-I-I displayed antioxidant properties through mediating the Nrf2-regulated intestinal cellular antioxidant defense, which could protect cultured intestinal cells from oxidative stress and improve the intestinal function of aged mice.

Technological Maturity and Systematic Review of Medicinal Plants with Pharmacological Activity in the Central Nervous System

BACKGROUND

Medicinal plants present activities against neurodegenerative diseases with potential for the pharmaceutical industries. Therefore, the objective of this study was to investigate the current panorama of patents and articles of Brazilian medicinal plants with pharmacological activities in the Central Nervous System (CNS), regarding such aspects as the number of patents by countries, areas of knowledge, and technological maturity.

METHODS

We carry out a technological exploration on the Questel Orbit® platform with the descriptors: Agave sisalana P., Amburana cearenses A., Dimorphandra mollis B., Jatropha curcas L., Poincianella pyramidalis T. and Prosopis juliflora (Sw.) DC. with pharmacological activity and scientific exploration in PubMed and Science Direct associated with the CNS in the title, abstract, and methodology.

RESULTS

A total of 642 patents were identified between the years 1999-2019. India, China, and Brazil are highlighted, 6th place, out of a total of 48 countries. Of these, 30 patents were not in the National Institute of Industrial Property, and 10% are Brazilian in biotechnology and pharmaceutical products. Eleven articles were used in PubMed and Science Direct with scientific domains (anticancer, neuroprotection and anti-inflammatory). The Federal University of Bahia is highlighted, showing Technology Readiness Levels (TRL4), basic skills of pre-clinical research.

CONCLUSION

Brazilian public universities have a significant role in the scientific, technological and innovative development of therapeutic assets for CNS.

Nontargeted Metabolomics as a Screening Tool for Estimating Bioactive Metabolites in the Extracts of 50 Indigenous Korean Plants

Many indigenous Korean plants have been used in medicinal preparations and health-promoting foods. These plant species contain beneficial metabolites with various bioactivities, such as antioxidant and anti-inflammatory activities. Herein, we suggest a new screening strategy using metabolomics to explore the bioactive compounds in 50 Korean plants. Secondary metabolites were analyzed using UHPLC-LTQ-Orbitrap-MS/MS. The plant extracts were subjected to antioxidant and anti-inflammatory assays. We identified metabolites that contributed to bioactivities according to the results of bioassays and multivariate analyses. Using Pearson’s correlation, phenolics (e.g., casuarictin, 3-O-methylellagic acid) showed positive correlation with antioxidant activity, while biflavonoids (e.g., amentoflavone, rosbustaflavone) were correlated with nitric oxide (NO) inhibition activity. To compensate for the limitation of this new strategy, we further validated these by investigating three parts (branches, fruits, leaves) of Platycladus orientalis which showed high activities on both bioassays. Unlike the above observation, we identified significantly different metabolites from different parts, which was not the results of bioassays. In these validation steps, interestingly, biflavonoids (e.g., robustaflavone, sciadopitysin) contributed to both activities in P. orientalis. The findings of this work suggest that new strategy could be more beneficial in the identification of bioactive plant species as well as that of their corresponding bioactive compounds that impart the bioactivity.

Phytochemical Screening, Antioxidant and Sperm Viability of Nelumbo nucifera Petal Extracts

Sacred lotus (Nelumbo nucifera Gaertn.; N. nucifera) is a common ingredient in traditional medicine and Thai recipes. Its petal is an agricultural waste from stamen production. There are limitations in the used and pharmacological data of the petals resulting in more petals waste. The aims of this study were to investigate the phytochemical contents, antioxidant activity, and potential effects on sperm viability of aqueous (NAE) and ethanolic extracts (NEE) of both red and white N. nucifera petals. The white NAE had the highest total phenolics content, total tannins content and maximal antioxidant activity. The white NEE had the highest concentration of total flavonoids. Quercetin was a major flavonoid and was found in the aqueous extracts. Both red and white of NAE in the range of 0.22 to 1.76 mg/mL increased sperm viability. The white NAE was prominent in phytochemical content, antioxidant activity, and both red and white NAE effectively increased rat sperm viability in the in vitro model. The white NAE enhanced sperm viability by decreasing oxidative stress. It might be suggested that the N. nucifera petals have benefits for sperm viability health promotion and may increase the economic value of agricultural waste.

Benzylisoquinoline alkaloids from Nelumbo nucifera Gaertn. petals with antiausterity activities against the HeLa human cervical cancer cell line

Ethanolic extract of Nelumbo nucifera petals showed preferential cytotoxic activity against HeLa human cervical cancer cell line with a PC₅₀ value of 10.4 μg/mL. This active extract was subjected to a phytochemical investigation study which led to the isolation of nine benzylisoquinoline alkaloids (1-9). The isolated compounds exhibited potent antiausterity activities. Moreover, under nutrient-deprived conditions, (-)-lirinidine (8) induced remarkable alterations in HeLa cell morphology including cell shrinkage and plasma blebbing leading to total cell death within 10 h. Mechanistically, 8 was found to inhibit Akt/mTOR signaling pathway. It also induced apoptosis by promoting caspase-3 activation and inhibiting Bcl-2 expression. Therefore, benzylisoquinoline alkaloids skeleton can be considered as a promising scaffold for the anticancer drug development against cervical cancer.

Ameliorative effect of a standardized polyherbal combination in methotrexate-induced nephrotoxicity in the rat

Context: Nephrotoxicity is a renal dysfunction that arises from direct exposure to environmental chemicals or as a side effect of therapeutic drugs. Boerhaavia diffusa Linn. (Nyctaginaceae), Rheum emodi Wall. Ex. Meissn. (Polygonaceae), Nelumbo nucifera Gaertn. (Nelumbonaceae) and Crataeva nurvala Buch-Ham. (Capparidaceae) are well-recognized medicinal plants of Indian traditional system of medicine used for kidney disorders.Objectives: The present investigation was undertaken to develop a chromatographically characterized polyherbal combination and to evaluate its nephroprotective activity.Materials and methods: Roots of B. diffusa and R. emodi, flowers of N. nucifera and stem bark of C. nurvala were extracted by decoction using 70% ethanol. Response surface methodology (RSM) was used for the optimization of extraction parameters. Polyherbal combinations with different doses (150-300 mg/kg) were tested against methotrexate-induced nephrotoxicity in Wistar rats.Results: The optimized extract contained 27% phenols and 15% flavonoids, which showed 75% 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging potential. Based on the retention time of high-performance liquid chromatography (HPLC) analysis, 17 out of 122 constituents were found common in all extracts and combinations. Two combinations showed significantly higher (p ≤ 0.05) DPPH scavenging potential and xanthine oxidase inhibition. The half maximal inhibitory concentration (IC₅₀) of the best combination for DPPH scavenging and xanthine oxidase inhibition were 80 and 74 µg/mL, respectively. Treatment of methotrexate-induced nephrotoxic rats with polyherbal combination significantly (p ≤ 0.05) improved the kidney function markers, oxidative stress markers and histological parameters.Discussion and conclusion: The developed combination was found to be effective in nephrotoxicity; it can be explored further for the management of drug-induced nephrotoxicity and other chronic kidney diseases.

The Effect of Sacred Lotus (Nelumbo nucifera) and Its Mixtures on Phenolic Profiles, Antioxidant Activities, and Inhibitions of the Key Enzymes Relevant to Alzheimer's Disease

Sacred lotus (Nelumbo nucifera) has long been used as a food source and ingredient for traditional herbal remedies. Plant parts contain neuroprotective agents that interact with specific targets to inhibit Alzheimer's disease (AD). Organic solvents including methanol, ethyl acetate, hexane, and n-butanol, are widely employed for extraction of sacred lotus but impact food safety. Seed embryo, flower stalk, stamen, old leaf, petal, and leaf stalk of sacred lotus were extracted using hot water (aqueous extraction). The extractions were analyzed for their bioactive constituents, antioxidant and anti-AD properties as key enzyme inhibitory activities toward acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-secretase 1 (BACE-1). Results showed that the sacred lotus stamen exhibited significant amounts of phenolics, including phenolic acids and flavonoids, that contributed to high antioxidant activity via both single electron transfer (SET) and hydrogen atom transfer (HAT) mechanisms, with anti-AChE, anti-BChE, and anti-BACE-1 activities. To enhance utilization of other sacred lotus parts, a combination of stamen, old leaf and petal as the three sacred lotus plant components with the highest phenolic contents, antioxidant activities, and enzyme inhibitory properties was analyzed. Antagonist interaction was observed, possibly from flavonoids-flavonoids interaction. Further in-depth elucidation of this issue is required. Findings demonstrated that an aqueous extract of the stamen has potential for application as a functional food to mitigate the onset of Alzheimer's disease.

Plant Polyphenols, More than Just Simple Natural Antioxidants: Oxidative Stress, Aging and Age-Related Diseases

The present editorial serves as an introduction to the Special Issue "Antioxidant and Anti-aging Action of Plant Polyphenols". It also provides a summary of the polyphenols, their biological properties and possible functions as medicines, the importance of traditional medicines as a source of inspiration, the rationalization of new uses of plant extracts which lead to applications in modern medicine, the status of modern green-chemistry extraction methods, and some reflections on future prospects. Here, the articles from this Special Issue, and the main aspects of the antioxidant and anti-aging effects of plant polyphenols are discussed in the form of seven questions.

Multitarget Activities of Kleeb Bua Daeng, a Thai Traditional Herbal Formula, Against Alzheimer's Disease

The Kleeb Bua Daeng formula (KBD) is a Thai traditional medicine for brain health promotion. On the basis of the activities of its individual components, the KBD could have good potential for the treatment of Alzheimer’s disease (AD). Herein, we investigated the KBD as an AD treatment. The ethanol extracts of KBD and its components, i.e., Nelumbo nucifera (NN), Piper nigrum fruits (BP), and the aerial part of Centella asiatica (CA) exhibited antioxidant activity, as determined by both ABTS and DPPH assays. The Ellman’s assay revealed that the KBD, NN, and BP showed an ability to inhibit acetylcholinesterase. The thioflavin T assay indicated that the KBD, NN, BP, and CA inhibited beta-amyloid aggregation. The neuroprotection and Western blot analysis revealed that the KBD reduced H₂O₂-induced neuronal cell death by inhibiting the expression of pro-apoptotic factors, i.e., cleaved caspase-9 and -3, p-P65, p-JNK, and p-GSK-3β, as well as by inducing expression of anti-apoptotic factors, i.e., MCl₁, BCl_xl, and survivin. Furthermore, the KBD could improve scopolamine induced memory deficit in mice. Our results illustrate that the KBD with multimode action has the potential to be employed in AD treatment. Thus, the KBD could be used as an alternative novel choice for the prevention and treatment of patients with AD.

Role of Whole Plant Extract of Nelumbo nucifera Gaertn in the Treatment of Thrombolysis

AIM

This study aims to find out the components responsible for the antithrombotic activity of Nelumbo nucifera.

MATERIAL AND METHODS

Petroleum ether, chloroform and hydroalcoholic extracts of whole plant of Nelumbo nucifera (Lotus) were prepared and assessed for its thrombolytic, anti-platelet aggregation activity and bleeding time. The extracts were further analyzed through HPTLC and GC-MS. Statistical analysis was conducted through ANOVA trailed by Tukey's multiple comparison test test.

RESULTS

Hydroalcoholic extract showed the highest activity at the concentration of 400µg/ml in thrombolytic assay (42.03 ± 5.76), anti-platelet aggregation assay (57.93 ± 1.68) and bleeding time (70.17 ± 2.16) in comparison to clopodigrel (33.76 ± 3.43), aspirin (66.55 ± 1.86) and aspirin (93.85 ± 2.75) at the concentration of 100 µg/ml respectively. 25 peaks were identified through GC-MS, out of which, ferulic acid (14.2µ/g) and quercetin (5.4 µ/g) are active chemical compounds. HPTLC showed different chromatograms in hydroalcoholic extracts like (1) chlorogenic, (2) quercetin, (3) benzoic acid, (4) caffeic acid, (5) ferulic acid, (6) kaempferol, and (7) gallic acid.

CONCLUSION

Based on these findings, flavonoids present in hydroalcoholic extract may be developed into a drug for clinical application for the treatment of thrombosis in patients.