Determination of the composition of Chinese ligustrum lucidum polysaccharide by capillary zone electrophoresis with amperometric detection

A review of botany, phytochemistry, pharmacology, and applications of the herb with the homology of medicine and food: Ligustrum lucidum W.T. Aiton

Ligustrum lucidum W.T. Aiton is an outstanding herb with the homology of medicine and food. Its ripe fruits are traditionally used as an important tonic for kidneys and liver in China. Ligustrum lucidum W.T. Aiton is rich in nutritional components and a variety of bioactive ingredients. A total of 206 compounds have been isolated and identified, they mainly include flavonoids, phenylpropanoids, iridoid glycosides, and triterpenoids. These compounds exert anti-osteoporosis, anti-tumor, liver protective, antioxidant, anti-inflammatory, and immunomodulatory effects. Ligustrum lucidum W.T. Aiton has been traditionally used to treat many complex diseases, including osteoporotic bone pain, rheumatic bone, cancer, related aging symptoms, and so on. In the 2020 Edition of Chinese Pharmacopoeia, there are more than 100 prescriptions containing L. lucidum W.T. Aiton. Among them, some classical preparations including Er Zhi Wan and Zhenqi fuzheng formula, are used in the treatment of various cancers with good therapeutic effects. Additionally, L. lucidum W.T. Aiton has also many excellent applications for functional food, ornamental plants, bioindicator of air pollution, algicidal agents, and feed additives. Ligustrum lucidum W.T. Aiton has rich plant resources. However, the application potential of it has not been fully exploited. We hope that this paper provides a theoretical basis for the high-value and high-connotation development of L. lucidum W.T. Aiton in the future.

Wedelolactone induces natural killer cell activity and the improvement to bioavailability using polysaccharides from Ligustri Lucidi Fructus

Wedelolactone (WDL) is the major bioactive component in Ecliptae Herba. This present study investigated the effects of WDL on natural killer cell functions and possible underlying mechanisms. It was proved that wedelolactone enhanced the killing ability of NK92-MI by upregulating the expression of perforin and granzyme B through the JAK/STAT signaling pathway. Additionally, wedelolactone could induce the migration of NK-92MI cells by promoting CCR7 and CXCR4 expressions. However, the application of WDL is limited due to poor solubility and bioavailability. Accordingly, this study investigated the impact of polysaccharides from Ligustri Lucidi Fructus (LLFPs) on WDL. The biopharmaceutical properties and pharmacokinetic characteristics were determined to compare WDL individually and in combination with LLFPs. The results showed that LLFPs could benefit the biopharmaceutical properties of WDL. Specifically, stability, solubility, and permeability were increased by 1.19-1.82-fold, 3.22-fold, and 1.08-fold higher than those of WDL alone, respectively. Furthermore, the pharmacokinetic study revealed that LLFPs could remarkably improve AUC_(0-t) (150.34 vs. 50.47 ng/mL ∗ h), t_1/2 (40.78 vs. 2.81 h), and MRT_(0-∞) (46.64 vs. 5.05 h) for WDL. In conclusion, WDL would be considered a potential immunopotentiator, and LLFPs could overcome the instability and insolubility, ultimately improving the bioavailability of this plant-derived phenolic coumestan.

Structural characterization and protective effect against renal fibrosis of polysaccharide from Ligustrum lucidum Ait

ETHNOPHARMACOLOGICAL RELEVANCE

Fructus Ligustri Lucidi (FLL), the fruit of Ligustrum lucidum Ait., is a traditional Chinese medicine that has been used for tonifying the kidney and liver for decades.

AIM OF THE STUDY

This study aimed to explore and identify polysaccharides from FLL and elucidate its protective effect against renal fibrosis.

MATERIALS AND METHODS

Polysaccharides were extracted and isolated from FLL. The purified fraction was identified by serial phytochemical work, such as gel-permeation chromatography, ion chromatography, gas chromatography-mass spectrometry, and nuclear magnetic resonance. Mice with unilateral ureteral obstruction (UUO) were applied as a renal fibrosis model. The male UUO mice were pretreated with heteropolysaccharide (Poly) 1 week prior to surgery and continuously treated for 7 days after the operation. Renal fibrosis was assessed by Periodic Acid-Schiff (PAS) staining and Masson's trichrome staining in paraffin-embedded slides. The murine mesangial cells SV40-MES13 upon angiotensin II (Ang II) treatment were developed as an in vitro fibrotic model. The cells were treated by Poly in the presence of Ang II. Molecular expression was detected by RT-PCR, immunoblotting, and immunofluorescence staining.

RESULTS

We identified a heteropolysaccharide composed of arabinose and galactose (molar ratio, 0.73:0.27) with a predicted chemical structure characterized by a backbone composed of 1,5-α-Araf, 1,3,5-α-Araf, 1,6-α-Galp, and 1,3,6-β-Galp and side chains comprised of T-α-Araf, T-α-Arap, and 1,3-α-Araf. Pretreatment of UUO mice with Poly effectively alleviated glomerulosclerosis and tubulointerstitial fibrosis. Moreover, Poly pretreatment down-regulated the expression of extracellular matrix (ECM) protein fibronectin (FN), profibrotic factor VEGF, proinflammatory cytokines MCP-1 and Rantes in the obstructed kidney. Similarly, the incubation of SV40-MES13 cells with Poly significantly inhibited Ang II-induced elevation in accumulation and expression level of FN and attenuated Ang II-evoked up-regulation in protein expression of MCP-1 and Rantes.

CONCLUSIONS

Our study isolated and identified a naturally occurring heteropolysaccharide in FLL and revealed its potential in protecting the kidneys from fibrosis.

Preliminary results on the separation of the different parts of Ligustrum lucidum Ait fruit and the main bioactive compounds analysis

Oleanolic acid (OA) and ursolic acid (UA) possess anti-inflammatory, antioxidative, antiprotozoal, antimutagenic and anticancer properties and are the main bioactive compounds in the fruit of Ligustrum lucidum Ait. The aim of this paper was to study the method of separating the whole fruit into the main ingredients containing OA and UA for the later effective extraction with reduced organic solvents and easy separation and purification. In the present study, the sarcocarps and exocarps were separated from the whole fruits (designated exo-sarcocarps, the mass percentages (w/w, dry weight basis), 33.1%), testae (13.5%) and cores (48.7%) by using methods separated. The contents of OA and UA in whole fruits, exo-sarcocarps, testae and cores were analyzed. The OA and UA extraction yields were highest in exo-sarcocarps vs. yields from whole fruits, testae or cores. The spective yields of OA and UA from exo-sarcocarps were 24.34 ± 2.09 and 7.82 ± 0.09 mg/g; these yields were about 4 times higher than OA yields and about 4 times higher than UA yields from fruit.

Ultrasound-assisted extraction of oleanolic acid and ursolic acid from Ligustrum lucidum Ait

Oleanolic acid and ursolic acid are the main bioactive compounds in fruit of Ligustrum lucidum Ait, which possess anti-inflammatory, antioxidative, antiprotozoal, antimutagenic and anticancer properties. In this study, the ultrasound-assisted extraction of oleanolic acid and ursolic acid from L. lucidum Ait was investigated with HPLC-photodiode array detection. Effects of several experimental parameters, such as type and concentration of extraction solvent, ratio of liquid to material, extraction temperature and extraction time, on extraction efficiencies of oleanolic acid and ursolic acid from L. lucidum were evaluated. The influence of experimental parameters on extraction efficiency of ursolic acid was more significant than that of oleanolic acid. The optimal extraction conditions were 95% ethanol, the ratio of material to liquid at 1:20, and extraction for 10 min at 40°C under ultrasonic irradiation. Under the optimal conditions, the yields of oleanolic acid and ursolic acid were 6.3 ± 0.25 and 9.8 ± 0.30 mg/g, respectively. The results indicated that the ultrasound-assisted extraction is a very useful method for the extraction of oleanolic acid and ursolic acid from L. lucidum.

Microwave-assisted extraction of oleanolic acid and ursolic acid from Ligustrum lucidum Ait

Oleanolic acid and ursolic acid are the main active components in fruit of Ligustrum lucidum Ait, and possess anticancer, antimutagenic, anti-inflammatory, antioxidative and antiprotozoal activities. In this study, microwave-assisted extraction of oleanolic acid and ursolic acid from Ligustrum lucidum was investigated with HPLC-photodiode array detection. Effects of several experimental parameters, such as type and concentration of extraction solvent, ratio of liquid to material, microwave power, extraction temperature and microwave time, on the extraction efficiencies of oleanolic acid and ursolic acid from Ligustrum lucidum were evaluated. The influence of experimental parameters on the extraction efficiency of ursolic acid was more significant than that of oleanolic acid (p < 0.05). The optimal extraction conditions were 80% ethanol aqueous solution, the ratio of material to liquid was 1:15, and extraction for 30 min at 70 °C under microwave irradiation of 500 W. Under optimal conditions, the yields of oleanolic acid and ursolic acid were 4.4 ± 0.20 mg/g and 5.8 ± 0.15 mg/g, respectively. The results obtained are helpful for the full utilization of Ligustrum lucidum, which also indicated that microwave-assisted extraction is a very useful method for extraction of oleanolic acid and ursolic acid from plant materials.

Novel determination of the total phenolic content in crude plant extracts by the use of 1H NMR of the -OH spectral region

A novel method for the determination of the total phenolic content using (1)H NMR spectroscopy in the -OH spectral region is presented. The use of DMSO-d(6), which is an aprotic and strongly hydrogen bonding solvent, allows the "appearance" of the relative sharp resonances of phenolic hydroxyl protons in the region of 8-14 ppm. The determination of the total phenolic -OH content requires three steps: (i) a 1D (1)H NMR spectrum is obtained in DMSO-d(6); (ii) a subsequent 1D (1)H NMR spectrum is recorded with irradiation of the residual water signal which results in the elimination or reduction of the phenolic -OH groups, due to proton exchange; and (iii) 1D (1)H NMR spectra are recorded with the addition of a progressively increased amount of salt, NaHCO(3), which results in extensive linebroadening of the COOH resonances thus allowing the discrimination of the phenolic from the carboxylic acid signals. Integration, with respect to the internal standard TSP-d(4), of the signal resonances between 14 and 8 ppm in spectrum (i) which are either eliminated or reduced in intensity in steps (ii) and (iii) allows the quantitation of the total phenolic content. The method was applied to model compounds, a mixture of them and several extracts of natural products. The results of the proposed (1)H NMR method were compared to the Folin-Ciocalteu (FC) reagent method. Additionally, since (1)H NMR refers to the total phenolic hydroxyl protons, a reaction factor, A(e), is proposed that corresponds to the hydroxyl reactivity. The (1)H NMR method is rapid and accurate bearing the inherent advantages of the NMR spectroscopy and can be applied directly in complex extracts. Furthermore, it can be applied in a wide range of matrixes from crude plant extracts and food products to biological samples.

Anticancer activity of rhamnoallosan against DU-145 cells is kinetically complementary to coexisting Polyphenolics in Psidium guajava budding leaves

Psidium guajava L. is a valuable farm fruit plant having many medicinal uses. Previously its budding leaves (PE) were shown to contain huge amounts of soluble polyphenolics (SP) including (in mg/g) gallic acid (348), catechin (102), epicatechin (60), rutin (100), quercetin (102), and rutin (100) and to exhibit potent anticancer activity. However, reconstitution of these polyphenolics recovered only 40% of the original bioactivity, and the soluble carbohydrate (SC) portion in PE was suspected to contribute the remaining. PE contained a novel rhamnoallosan, which had a carbohydrate/protein (w/w) ratio = 29.06%/10.27% (=2.83, average molecular mass of 5029 kDa), characteristically evidencing a peptidoglycan, consisting of a composition (mole % ratio) of rhamnose/allose/arabinose/tallose/xylose/fucose/glucose/mannose/galactose = 36.05:24.24:8.76:7.95:7.37:5.90:3.69:3.19:2.85 and of amino acid (in wt %) glycine/leucine/proline/alanine/methionine/isoleucine/valine/histidine/tyrosine/phenylalanine/cysteine/aspartic acid/lysine/glutamic acid = 37.12:12.68:10.05:8.97:5.99:4.89:4.83:4.25:4.05:2.78:1.86:1.10:0.73:0.70. Kinetic analysis showed comparable apparent cell-killing rate coefficients (k(app)) to be 4.03 x 10(3) and 2.92 x 10(3) cells mg(-1) h(-1), respectively, by SP and SC, evidencing the complementary anti-DU-145 bioactivity in nature.

Optimization of CZE for analysis of phytochemical bioactive compounds

Advantages of CZE such as high efficiency, low cost, short analysis time, and easy implementation result in its wide applications for analysis of phytochemical bioactive compounds (e.g. flavonoids, alkaloids, terpenoids, phenolic acid, saponins, anthraquinones and coumarins). However, several aspects, including sample preparation, separation, and detection have significant effects on CZE analysis. Therefore, optimization of these procedures is necessary for development of the method. In this review, sample preparation such as extraction method and preconcentration, separation factors including buffer type, concentration and pH, additives, voltage and temperature, as well as detection, e.g. direct and indirect UV detection, LIF and MS were discussed for optimization of CZE analysis on phytochemical bioactive compounds. The optimized strategies were also reviewed.

Enantiomeric separation of synthetic 2,3-dihydroxy-3-phenylpropionate compounds by β-cyclodextrin-modified capillary electrophoresis

A new capillary electrophoretic method was developed for enantiomeric separation and optical impurity analysis of three synthetic 2,3-dihydroxy-3-phenylpropionate compounds using native beta-cyclodextrin (beta-CD) as chiral selector and borate as a background electrolyte. The separation was carried out in uncoated capillary (58.5 cm x 75 microm I.D., effective length 48.5 cm). The results showed that beta-CD as the chiral selector exhibited good enantioselectivity and the baseline separation was obtained at pH 9.8, 200 mM borate buffer containing 1.7% beta-CD at applied voltage 15 kV and capillary temperature 20 degrees C within 15 min. The precision of each tested compound was less than 1.0% at migration time and 5.0% in corrected peak area and the accuracy of the method was in the range of 98.7-105%. Furthermore, the developed method was successfully applied to the determination of the undesirable trace (2S,3R)-(+)-form impurity in the synthetic (2R,3S)-(-)-2,3-dihydroxy-3-phenylpropionate samples.

Chiral Separation of Synthetic Vicinal Diol Compounds by Capillary Zone Electrophoresis with Borate Buffer and .BETA.-Cyclodextrin as Buffer Additive

The investigation on capillary electrophoretic enantioseparation of six synthetic compounds containing vicinal diol groups has been undertaken to acquire the optimum conditions using native beta-cyclodextrin (beta-CD) as chiral selector and borate as a background electrolyte. The separation was carried out in an uncoated capillary (58.5 cm x 75 microm i.d., effective length 48.5 cm) and the effects of several important factors were investigated in detail. The results showed that beta-CD as a chiral selector exhibited good enantioselectivity and that the enantioseparation was greatly influenced by the structure of the diols, the borate concentration and the buffer pH. The optimum performance was obtained for the chiral vicinal diols under the conditions of 200 mM borate buffer of pH 9.8 containing 1.7% beta-CD at an applied voltage of 15 kV and a capillary temperature of 20 degrees C. Under the conditions, four diols were baseline separated with fast analysis time and the good theoretical plate numbers (above 10 x 10(4)) and favorable migration-time reproducibilities (RSDs below 3.0%) were obtained. The separation results were satisfactory.