Chemical composition, antioxidant and antinociceptive properties of Litchi chinensis leaves

Spectrum-effect relationship between HPLC fingerprint and hypoglycemic of litchi leaves (Litchi chinensis Sonn) in vitro

Litchi chinensis Sonn (Litchi) has been listed in the Chinese Pharmacopeia, and is an economically and medicinally valuable species within the family Sapindaceae. However, the material basis of its pharmacological action and the pharmacodynamic substances associated with its hypoglycemic effect are still unclear. The predominant objective of this study was to establish the fingerprint profile of litchi leaves and to evaluate the relationship between the components of the high-performance liquid chromatography (HPLC) fingerprint of litchi leaves, assess its hypoglycemic effect by measuring α-glucosidase and α-amylase inhibition, and find the spectrum-effect relationship of litchi leaves by bivariate correlation analysis, Grey relational analysis and partial least squares regression analysis. In this study, the fingerprint of litchi leaves was established by HPLC, and a total of 15 common peaks were identified that clearly calibrated eight components, with P1 being gallic acid, P2 being protocatechuic acid, P3 being catechin, P6 being epicatechin, P12 being rutin, P13 being astragalin, P14 being quercetin and P15 being kaempferol. The similarities between the fingerprints of 11 batches of litchi leaves were 0.766-0.979. Simultaneously, the results of the spectrum-effect relationship showed that the chemical constituents represented by peaks P8, P3, P12, P14, P2, P13, and P11 were relevant to the hypoglycemic effect.

Comparative analysis of soil organic matter fractions, lability, stability ratios, and carbon management index in various land use types within bharatpur catchment, Chitwan District, Nepal

BACKGROUND

Land use and land cover changes have a significant impact on the dynamics of soil organic matter (SOM) and its fractions, as well as on overall soil health. This study conducted in Bharatpur Catchment, Chitwan District, Nepal, aimed to assess and quantify variations in total soil organic matter (TSOMC), labile organic matter fraction (CL), stable organic matter fraction (CS), stability ratio (SR), and carbon management index (CMI) across seven land use types: pastureland, forestland, fruit orchards, small-scale conventional agricultural land, large-scale conventional agricultural land, large-scale alternative fallow and conventional agricultural land, and organic farming agricultural land. The study also explored the potential use of the Carbon Management Index (CMI) and stability ratio (SR) as indicators of soil degradation or improvement in response to land use changes.

RESULTS

The findings revealed significant differences in mean values of TSOMC, CL, and CS among the different land use types. Forestland and organic farming exhibited significantly higher TSOMC (3.24%, 3.12%) compared to fruit orchard lands (2.62%), small scale conventional farming (2.22%), alternative fallow and conventional farming (2.06%), large scale conventional farming (1.84%) and pastureland (1.20%). Organic farming and Forestland also had significantly higher CL (1.85%, 1.84%) and CS (1.27%, 1.39%) compared to all other land use types. Forest and organic farming lands showed higher CMI values, while pastures and forests exhibited higher SR values compared to the rest of the land use types.

CONCLUSIONS

This study highlights the influence of various land use types on soil organic matter pools and demonstrates the potential of CMI and SR as indicators for assessing soil degradation or improvement in response to land use and land cover changes.

Antiglycoxidative Properties of Extracts and Fractions from Reynoutria Rhizomes

Hyperglycemia, when sustained over a long time in diabetes mellitus (DM), leads to biochemical and cellular abnormalities, primarily through the formation of advanced glycation end-products (AGEs). In the treatment of diabetes, beside blood-sugar-lowering medications, a consumption of herbal products that can inhibit the AGEs’ formation is recommended. This study investigated the in vitro antiglycoxidative potential of extracts and fractions from the rhizomes of Japanese, Giant, and Bohemian knotweeds (Reynoutria japonica (Houtt.), R. sachalinensis (F. Schmidt) Nakai, and R.× bohemica Chrtek et Chrtkova). Their effects on glycooxidation of bovine and human serum albumin were evaluated by incubation of the proteins with a mixture of glucose and fructose (0.5 M) and 150 µg/mL of extract for 28 days at 37 °C, followed by measuring early and late glycation products, albumin oxidation (carbonyl and free thiol groups), and amyloid-β aggregation (thioflavin T and Congo red assays). The highest antiglycoxidative activity, comparable or stronger than the reference drug (aminoguanidine), was observed for ethyl acetate and diethyl ether fractions, enriched in polyphenols (stilbenes, phenylpropanoid disaccharide esters, and free and oligomeric flavan-3-ols). In conclusion, the antiglycoxidative compounds from these three species should be further studied for potential use in the prevention and complementary treatment of DM.

A review on the medicinal potential, toxicology, and phytochemistry of litchi fruit peel and seed

The perception that many fruit wastes, particularly the peel, contain more phytochemicals than the edible portions has been largely supported by scientific evidence, making them potential sources of bioactive and therapeutic phytochemicals. The peel and seed of Litchi (Litchi chinensis Sonn.) contain bioactive principles and have been shown to exhibit antioxidative, antidiabetic, cancer preventive, anti-obesogenic, and anti-inflammatory properties. This review presents a critical analysis of previous and current perspectives on the medicinal, toxicological, and phytochemical profiles of litchi fruit peel and seed, thus providing an evidence-based platform to explore their medicinal potential. A literature search was done on "PubMed," "Google Scholar," and "ScienceDirect." Peer-reviewed published data on the medicinal profiles of litchi fruit peel and seed were identified and critically analyzed. The fruit peel and seed improved glycemic control and insulin signaling and downregulated lipogenic and cholesterogenic processes. Their neuroprotective, hepatoprotective, and renal protective potentials were influenced by antioxidative and anti-inflammatory actions. The anticancer effect was mediated by upregulated proapoptotic, proinflammatory, antiproliferative, and anti-metastatic processes in cancer cells. Simple flavonols, sesquiterpenes, phenolic acids, jasmonates, and proathocyanidins are the possible bioactive principles influencing the medicinal effects. Appropriate toxicity studies are, however, still lacking. Litchi fruit wastes may be further studied as useful sources of therapeutic agents that may have medicinal relevance in oxidative, metabolic, vascular, and carcinogenic ailments. PRACTICAL APPLICATIONS: Underutilized fruit wastes contribute to environmental pollution. Interestingly, these wastes contain phytochemicals that could be of medicinal relevance if their medicinal potentials are maximized. Litchi fruit is a widely consumed fruit with commercial value. Its peel and seeds contribute to fruit wastes. The review exposes the medicinal potential and bioactive principles and/or nutrients of the fruit's peel and seed while elucidating the underlying therapeutic mechanisms or modes of actions through which litchi peel and seed potentiate medicinal effects. Thus, the review provides an evidence-based platform to explore the medicinal potential of underutilized wastes from litchi fruit. Additionally, the fruit peel and seed could be low-cost residues that could afford ecofriendly opportunity if their medicinal potentials are properly maximized.

Effect of various synthesis parameters on the stability of size controlled green synthesis of silver nanoparticles

In this study, we have focused on the green method using Litchi Chinensis Leaf Extract (LCLE) for the synthesis of silver nanoparticles (AgNPs). Here, the experimental control parameters (reducing/stabilizing agent quantity, reaction time and temperature, silver ion concentrations) were studied during the size controlled synthesis of silver nanoparticles and their physicochemical properties have been studied. For biological studies, the stability of AgNPs at physiological pH is of vital importance; hence, post-synthesis solution stability of AgNPs was examined at various pH conditions. Stable AgNPs are formed by treating the aqueous solution of AgNO3 with LCLE. Formation of AgNPs was observed visually by the change in the color and further characterized by the surface Plasmon resonance (SPR) peak observed at 436 nm by UV–vis spectroscopy. The synthesized AgNPs were also characterized for their size distribution by Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM), Transmission electron microscope (TEM), crystalline nature by X-Ray Diffraction (XRD) and Fourier Transform infrared (FITR) for the functional groups present. The size of AgNPs was in the range of 40–50 nm, spherical in with face centered cubic (FCC) structure. The biomolecules (epicatechin) present in LCLE were responsible for reduction, capping, and stabilizing agent of AgNPs. Post- synthesis, the stability of AgNPs has been studied by changes in the SPR peaks at various pH (2–11) conditions using UV–vis spectroscopy. This size controlled nanoparticles are very stable at physiological pH and retain their intrinsic SPR property.

Phytochemical Diversity in Rhizomes of Three Reynoutria Species and their Antioxidant Activity Correlations Elucidated by LC-ESI-MS/MS Analysis

The rhizome of Reynoutria japonica is a well-known traditional herb (Hu zhang) used in East Asia to treat various inflammatory diseases, infections, skin diseases, scald, and hyperlipidemia. It is also one of the richest natural sources of resveratrol. Although, it has been recently included in the European Pharmacopoeia, in Europe it is still an untapped resource. Some of the therapeutic effects are likely to be influenced by its antioxidant properties and this in turn is frequently associated with a high stilbene content. However, compounds other than stilbenes may add to the total antioxidant capacity. Hence, the aim of this research was to examine rhizomes of R. japonica and the less studied but morphologically similar species, R. sachalinensis and R. x bohemica for their phytochemical composition and antioxidant activity and to clarify the relationship between the antioxidant activity and the components by statistical methods. HPLC/UV/ESI-MS studies of three Reynoutria species revealed 171 compounds, comprising stilbenes, carbohydrates, procyanidins, flavan-3-ols, anthraquinones, phenylpropanoids, lignin oligomers, hydroxycinnamic acids, naphthalenes and their derivatives. Our studies confirmed the presence of procyanidins with high degree of polymerization, up to decamers, in the rhizomes of R. japonica and provides new data on the presence of these compounds in other Reynoutria species. A procyanidin trimer digallate was described for the first time in, the studied plants. Moreover, we tentatively identified dianthrone glycosides new for these species and previously unrecorded phenylpropanoid disaccharide esters and hydroxycinnamic acid derivatives. Furthermore, compounds tentatively annotated as lignin oligomers were observed for the first time in the studied species. The rhizomes of all Reynoutria species exhibited strong antioxidant activity. Statistical analysis demonstrated that proanthocyanidins should be considered as important contributors to the total antioxidant capacity.

The hydroethanolic Litchi chinensis leaf extract alleviate hepatic injury induced by carbon tetrachloride (CCl4) through inhibition of hepatic inflammation

Various medicinal plants are traditionally used in a hepatoprotective manner, like, for example, the Litchi chinensis leaf infusion that is employed in Chinese medicine as liver tonics to strengthen hepatic functioning. In this context, the present study was designed to evaluate the hepatoprotective and acute toxicological effects of hydroethanolic L. chinensis leaf extract in HepG2 cells and mice. Specifically, the cytotoxicity and hepatoprotective activities of L. chinensis leaf extract were evaluated in HepG2 cells and in vivo against carbon tetrachloride (CCl₄)-induced acute liver injury. The administration of CCl₄ in mice provokes cell swelling, loss of sinusoid capillary spaces and structural disarrangement of the hepatic lobe, apoptosis and leukocyte infiltration. Further, CCl₄ evokes an increase in serum alanine aminotransferase (ALT), tumor necrosis factor (TNF) and interleukin-6 (IL-6) levels in hepatic tissue. However, Silymarin, the positive control, and the L. chinensis extract were able to restore the viability of cells treated with CCl₄ at all concentrations evaluated, reduced the inflammatory parameters, TNF and IL-6, reestablished hepatic tissue morphology and did not induce acute toxicological alterations. The data obtained underscore that the extract from L. chinensis leaves features hepatoprotective activity, corroborating with ethnopharmacological use, and does not lead to acute toxicological effects.

Hepatoprotective effects of litchi (Litchi chinensis) procyanidin A2 on carbon tetrachloride-induced liver injury in ICR mice

Drug tolerance, lacking liver regenerative activity and inconclusive inhibition of steatosis and cirrhosis by silymarin treatment during chronic liver injury have increased the demand for novel alternative or synergistic treatments for liver damage. Litchi fruit is abundant in polyphenolic compounds and is used in traditional Chinese medicine for treatments that include the strengthening of hepatic and pancreatic functions. Unique polyphenolic compounds obtained from litchi pericarp extract (LPE) were studied in vitro and in vivo for hepatoprotection. Epicatechin (EC) and procyanidin A2 (PA2) of LPE were obtained by fractionated-extraction from pulverized litchi pericarps. All fractions, including LPE, were screened against silymarin in carbon tetrachloride (CCl₄)-treated murine embryonic liver cell line (BNL). The effects of daily gavage-feeding of LPE, silymarin (200 mg/kg body weight) or H₂O in CCl₄-intoxicated male ICR mice were evaluated by studying serum chemicals, liver pathology and glutathione antioxidative enzymes. The effects of EC and PA2 on liver cell regenerative activity were investigated using a scratch wound healing assay and flow cytometric cell cycle analysis; the results of which demonstrated that LPE protected BNL from CCl₄-intoxication. Gavage-feeding of LPE decreased serum glutamic oxaloacetate transaminase and glutamic pyruvic transaminase levels, and exhibited superior retention of the hexagonal structure of hepatocytes and reduced necrotic cells following liver histopathological examinations in CCl_4-intoxicated ICR mice. Glutathione peroxidise and glutathione reductase activities were preserved as the normal control level in LPE groups. EC and PA2 were principle components of LPE. PA2 demonstrated liver cell regenerative activity in scratch wound healing assays and alcohol-induced liver cell injury in vitro. The present findings suggest that litchi pericarp polyphenolic extracts, including EC and PA2, may be a synergistic alternative to silymarin in hepatoprotection and liver cell regeneration.

Biological and Phytopharmacological Descriptions of Litchi Chinensis

Plants remain a vital source of drugs and at present, much emphasis is given to nutraceuticals. Herbal medicines have been the basis of treatment and cure for various diseases and physiological conditions in the traditional methods practiced such as ayurveda and homeopathy. Litchi chinensis belongs to the Sapindaceae family and is well-known in the Indian traditional system for its traditional uses. The parts of the plant used are leaves, flowers, fruits, seed, pulp, and pericarp. All parts of the plant are rich sources of phytochemicals--epicatechin; procyanidin A2 and procyanidin B2; leucocyanidin; cyanidin glycoside, malvidin glycoside, and saponins; butylated hydroxytoluene; isolariciresinol; kaempferol; rutin; and stigmasterol. In the present review, we explore the lychee's description, traditional medicinal uses, and phytoconstituents, and investigate the pharmacological activities in various parts of the lychee to show its importance in ethanopharmacology. This is so that this review can serve as a ready-to-use material for further research on the plant.

Litchi chinensis: medicinal uses, phytochemistry, and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Litchi chinensis Sonn. (Sapindaceae) has been widely used in many cultures for the treatment of cough, flatulence, stomach ulcers, diabetes, obesity, testicular swelling, hernia-like conditions, and epigastric and neuralgic pains. The ethnopharmacologial history of L. chinensis indicated that it possesses hypoglycemic, anticancer, antibacterial, anti-hyperlipidemic, anti-platelet, anti-tussive, analgesic, antipyretic, hemostatic, diuretic, and antiviral activities.

AIM OF THE REVIEW

The aim of this review is to provide up-to-date information on the botanical characterization, distribution, traditional uses, and chemical constituents, as well as the pharmacological activities and toxicity of L. chinensis. Moreover, the focus of this review is the possible exploitation of this plant to treat different diseases and to suggest future investigations.

MATERIALS AND METHODS

To provide an overview of the ethnopharmacology, chemical constituents, and pharmacological activities of litchi, and to reveal their therapeutic potentials and being an evidence base for further research works, information on litchi was gathered from scientific journals, books, and worldwide accepted scientific databases via a library and electronic search (PubMed, Elsevier, Google Scholar, Springer, Scopus, Web of Science, Wiley online library, and pubs.acs.org/journal/jacsat). All abstracts and full-text articles were examined. The most relevant articles were selected for screening and inclusion in this review.

RESULTS

A comprehensive analysis of the literature obtained through the above-mentioned sources confirmed that ethno-medical uses of L. chinensis have been recorded in China, India, Vietnam, Indonesia, and Philippines. Phytochemical investigation revealed that the major chemical constituents of litchi are flavonoids, sterols, triterpenens, phenolics, and other bioactive compounds. Crude extracts and pure compounds isolated from L. chinensis exhibited significant antioxidant, anti-cancer, anti-inflammatory, anti-microbial, anti-viral, anti-diabetic, anti-obesity, hepato-protective, and immunomodulatory activities. From the toxicological perspective, litchi fruit juice and extracts have been proven to be safe at a dose 1 g/kg.

CONCLUSIONS

Phytochemical investigations indicated that phenolics were the major bioactive components of L. chinensis with potential pharmacological activities. The ethnopharmacological relevance of L. chinensis is fully justified by the most recent findings indicating it is a useful medicinal and nutritional agent for treating a wide range of human disorders and aliments. Further investigations are needed to fully understand the mode of action of the active constituents and to fully exploit its preventive and therapeutic potentials.

New bioactive chromanes from Litchi chinensis

Seven new δ-tocotrienols, designated litchtocotrienols A-G (1-7), together with one glorious macrocyclic analogue, macrolitchtocotrienol A (8), and one new meroditerpene chromane, cyclolitchtocotrienol A (9), were isolated from the leaves of Litchi chinensis. Their structures were mainly determined by extensive spectroscopic analysis, and their biological activities were evaluated by cytotoxicity against human gastric adenocarcinoma cell lines (AGS, ATCC CRL-1739) and hepatoma carcinoma cell line (HepG2 2.2.1.5). The structure-activity relationship of the isolated compounds was also discussed.