Phytoconstituents of Nymphaea rubra flowers and their anti-diabetic metabolic targets.

Nymphaea rubra (N. rubra) flowers are prevalent in subtropical regions for both dietary and traditional medicinal purposes, attributing to their beneficial properties in supporting overall health. This study first time provides descriptions of the antidiabetic and dyslipidemic properties employing STZ induced high fat diet fed diabetic rats and inhibition of α-amylase enzyme activity first by in vitro analyses, followed by a confirmatory in silico study to create a stronger biochemical rationale. Furthermore, in 3 T3-L1 cells, this extract promoted the suppression of adipogenesis. GC-MS investigation of the ethyl acetate fraction of ethanolic extract of N. rubra flowers revealed the presence of marker compounds of N. rubra, Nuciferine, and Apomorphine, which were the focus of molecular docking studies. The acquired concentrations of Nuciferine (22.39%) and 10, 11-dimethoxy-Apomorphine (1.47%) were detected. Together with other alkaloids identified by GC-MS analysis from this extract, mechanistically suggested that it might be caused by the synergistic impact of these bioactive chemicals. Molecular docking has been done to check the binding affinities of various isolated phytochemicals with HPAA, the dose-response effect of 100 mg/kg and 250 mg/kg of flower extract after 30 days showed a significant effect on body weight, food, water intake, serum insulin, FBG, OGTT, lipid profile, glycated haemoglobin, liver and kidney function test. Kidney histopathology results show a significant effect. These findings offer a strong foundation for the potential application of the ethyl acetate fraction of ethanolic extract from Nymphaea rubra flowers and its bioactive constituent in an in vivo system for the treatment and control of diabetes and its associated condition dyslipidemia.

Biological activities, identification, method development, and validation for analysis of polyphenolic compounds in Nymphaea rubra flowers and leaves by UHPLC-Q-cIM-TOF-MS and UHPLC-TQ-MS.

INTRODUCTION: Nymphaea rubra belongs to the Nymphaea family and is regarded as a vegetable used in traditional medicine to cure several ailments. These species are rich in phenolic acid, flavonoids, and hydrolysable tannin. OBJECTIVE: This study aimed to assess the biological activities of Nymphaea rubra flowers (NRF) and leaves (NRL) by identifying and quantifying their polyphenolic compounds using ultra-performance liquid chromatography coupled to quadrupole cyclic ion mobility time-of-flight mass spectrometry (UHPLC-Q-cIM-TOF-MS) and triple quadrupole mass spectrometry (UHPLC-TQ-MS). METHODOLOGY: NRF and NRL powder was extracted with methanol and fractionated using hexane, ethylacetate, and water. Antioxidant and α-glucosidase, and tyrosinase enzyme inhibitory activities were evaluated. The polyphenolic components of NRF and NRL were identified and quantified using UHPLC-Q-cIM-TOF-MS and UHPLC-TQ-MS. The method was validated using linearity, precision, accuracy, limit of detection (LOD), and lower limit of quantification (LLOQ). RESULTS: Bioactive substances and antioxidants were highest in the ethylacetate fraction of flowers and leaves. Principal component analysis showed how solvent and plant components affect N. rubra's bioactivity and bioactive compound extraction. A total of 67 compounds were identified, and among them 21 significant polyphenols were quantified. Each calibration curve had R2 > 0.998. The LOD and LLOQ varied from 0.007 to 0.09 µg/mL and from 0.01 to 0.1 µg/mL, respectively. NRF contained a significant amount of gallic acid (10.1 mg/g), while NRL contained abundant pentagalloylglucose (2.8 mg/g). CONCLUSION: The developed method is simple, rapid, and selective for the identification and quantification of bioactive molecules. These findings provide a scientific basis for N. rubra's well-documented biological effects.

Metabolite profiling of Nymphaea rubra (Burm. f.) flower extracts using cyclic ion mobility-mass spectrometry and their associated biological activities.

Nymphaea rubra flowers (NRF) are widely used as a food and in folk medicine throughout the subtropical regions due to their health-promoting characteristics. This study characterized the phytochemical composition of various extracts/fractions of NRF by establishing a quadrupole-cyclic ion mobility-time-of-flight (Q-cIM-TOF) mass spectrometry method in both positive and negative electrospray ionization modes. Over 100 phytoconstituents were tentatively identified, among which 53 phytochemicals belonging to phenolic acids, tannins, flavonoids, terpenoids, alkaloids, xanthones, and naphthopyrones have never been documented in NRF before. Moreover, the ethyl acetate fraction of NRF demonstrated strong antioxidant potential (IC50: 9.21 ± 0.47 µg/mL in DPPH assay and 13.65 ± 0.03 µg/mL in ABTS assay) and tyrosinase, α-glucosidase, and elastase inhibition (IC50: 10.58 ± 0.20, 2.48 ± 0.02, and 38.15 ± 0.25 µg/mL, respectively). The findings highlight the value of NRF as a source of functional components and broaden its potential applications in the food and nutraceutical industries.

Immunomodulating activity of Nymphaea rubra Roxb. extracts: activation of rat dendritic cells and improvement of the T(H)1 immune response.

Polysaccharides play a key role in enhancing immune function and facilitating cellular communication. Here, we purified Nymphaea rubra Roxb. polysaccharides (NR-PS) by treating them with pullulanase. They were then cultured with immature dendritic cells (DCs) derived from rat bone marrow hematopoietic cells (BMHCs). After treatment with bioactive NR-PS with a degree of polymerization (DP) value of 359.8, we found that the DCs underwent morphological changes indicative of activation. CD80/86 (87.16% ± 8.49%) and MHC class II (52.01% ± 10.11%) expression levels were significantly up-regulated by this treatment compared to the controls (65.45% ± 0.97% and 34.87% ± 1.96%). In parallel, endocytosis was also reduced (167.94% ± 60.59%) after treatment with 25 µg/mL of NR-PS as measured by the medium fluorescence intensity compared to the control (261.67% ± 47.26%). Furthermore, the DCs after treatment with 25 µg/mL NR-PS showed increased IL-12 (102.09 ± 10.16 to 258.78 ± 25.26 pg/mL) and IFN-γ (11.76 ± 0.11 to 15.51 ± 1.66 pg/mL) secretion together with reduced IL-10 secretion (30.75 ± 3.35 to 15.37 ± 2.35 pg/mL), which indicates a T(H)1 immune response. In conclusion, NR-PS exhibits stimulatory effects on rat DCs and promotes the secretion of T(H)1 cytokines. Taken together, our studies are the first to show that NR-PS is an immunomodulator affecting the maturation and functioning of DCs.