Polyphenolics from Albizia harveyi Exhibit Antioxidant Activities and Counteract Oxidative Damage and Ultra-Structural Changes of Cryopreserved Bull Semen

A comparative untargeted metabolomic analysis and assessment of antiplasmodial potential of nine Albizia species

The genus Albizia is one of the richest genera in phenolics besides other classes of secondary metabolites including saponins, terpenes, and alkaloids with promising medicinal applications. In the current study, UHPLC-PDA-ESI-MS/MS-based metabolic profiling of leaves of Albizia lebbeck, Albizia julibrissin, Albizia odoratissima, Albizia procera, Albizia anthelmintica, Albizia guachapele, Albizia myriophylla, Albizia richardiana, and Albizia lucidior resulted in the tentative identification of 64 metabolites, mainly flavonoids, phenolic acids, saponins, and alkaloids. Some metabolites were identified in Albizia for the first time and could be used as species-specific chemotaxonomic markers, including: apigenin 7-O-dihydroferuloyl hexoside isomers, apigenin 7-O-pentosyl hexoside, quercetin 3-O-rutinoside 7-O-deoxyhexoside, quercetin 3,7-di-O-hexoside deoxyhexoside, quercetin 7-O-feruloyl hexoside, methyl myricetin 7-O-deoxyhexoside, kaempferol di-3-O-di-deoxyhexoside-7-O-hexoside, and kaempferol 3-O-neohesperidoside 7-O-hexoside. Comparative untargeted metabolomic analysis was undertaken to discriminate between species and provide a chemotaxonomic clue that can be used together with morphological and genetic analyses for more accurate classification within this genus. Moreover, the in vitro antiplasmodial activity was assessed and correlated to the metabolic profile of selected species. This was followed by a molecular docking study and absorption, distribution, metabolism, excretion, and toxicity (ADMET) prediction of the identified budmunchiamine alkaloids, revealing promising interactions with the active site of lactate dehydrogenase of Plasmodium falciparum and good pharmacokinetics and pharmacodynamics, which could help in designing novel antimalarial drugs.

Phytogenic feed additives as natural antibiotic alternatives in animal health and production: A review of the literature of the last decade

The use of antibiotics in animal production raises great public safety concerns; therefore, there is an urgent need for the development of substitutes for antibiotics. In recent decades, plant-derived feed additives have been widely investigated as antibiotic alternatives for use in animal health and production because they exert multiple biological functions and are less likely to induce resistance development. This review summarizes the research history and classification of phytogenic feed additives and their main functions, potential modes of action, influencing factors, and potential negative effects. Further, we highlight the challenges in developing sustainable, safe, and affordable plant-derived antibiotic alternatives for use in livestock production.

Molecular basis and mechanism of action of Albizia julibrissin in depression treatment and clinical application of its formulae

Albizzia julibrissin is empirically used as an antidepressant in clinical practice. Preclinical studies have indicated that its total extracts or bioactive constituents exerted antidepressant-like responses in animal models, providing the molecular basis to reveal its underlying mechanism of action. While attempts have been made to understand the antidepressant effect of A. julibrissin, many fundamental questions regarding its mechanism of action remain to be addressed at the molecular and systems levels. In this review, we conclusively discussed the mechanism of action of A. julibrissin and A. julibrissin formulae by reviewing recent preclinical and clinical studies conducted by using depressive animal models and depressive patients. Several representative bioactive constituents and formulae were highlighted as examples, and their mechanisms of action were discussed. In addition, some representative A. julibrissin formulae that have been shown to be compatible with conventional antidepressants in clinical practice were also reviewed. Furthermore, we discussed the future research directions to reveal the underlying mechanism of A. julibrissin at the molecular and systems levels in depression treatment. The integrated study using both the molecular and systematic approaches is required not only for improving our understanding of its molecular basis and mechanisms of action, but also for providing a way to discover novel agents or approaches for the effective and systematic treatment of depression.

Definition of chemical markers for Hancornia speciosa Gomes by chemometric analysis based on the chemical composition of extracts, their vasorelaxant effect and α-glucosidase inhibition

ETHNOPHARMACOLOGICAL RELEVANCE

Hancornia speciosa Gomes (Apocynaceae) is a tree found in the Brazilian savannah, traditionally used to treat several diseases, including diabetes and hypertension. The anti-hypertensive activity of H. speciosa leaves (HSL) has been demonstrated in different models and is credited to the vasodilator effect and ACE (angiotensin-converting enzyme) inhibition. The hypoglycemic effect of HSL has been also reported.

AIM OF THE STUDY

To establish correlations between the biological activities elicited by H. speciosa extracts and the contents of their major compounds, aiming to define chemical markers related to the potential antihypertensive and antidiabetic effects of the species. Additionally, it aimed to isolate and characterize the chemical structure of a marker related to the α-glucosidase inhibitory effect.

MATERIALS AND METHODS

Extracts of a single batch of H. speciosa leaves were prepared by extraction with distinct solvents (ethanol/water in different proportions; methanol/ethyl acetate), employing percolation or static maceration as extraction techniques, at different time intervals. The contents of chlorogenic acid, rutin and FlavHS (a tri-O-glycoside of quercetin) were quantified by a developed and validated HPLC-PDA method. Bornesitol was determined by HPLC-PDA after derivatization with tosyl chloride, whereas total flavonoids were measured spectrophotometrically. Identification of other constituents in the extracts was performed by UPLC-DAD-ESI-MS/MS analysis. The vasorelaxant activity was assayed in rat aortic rings precontracted with phenylephrine, and α-glucosidase inhibition was tested in vitro. Principal component analysis (PCA) was employed to evaluate the contribution of each marker to the biological responses. Isolation of compound 1 was carried out by column chromatography and structure characterization was accomplished by NMR and UPLC-DAD-ESI-MS/MS analyses.

RESULTS

The contents of the chemical markers (mean ± s.d. % w/w) varied significantly among the extracts, including total flavonoids (2.68 ± 0.14 to 5.28 ± 0.29), bornesitol (5.11 ± 0.26 to 7.75 ± 0.78), rutin (1.46 ± 0.06 to 1.97 ± 0.02), FlavHS (0.72 ± 0.05 to 0.94 ± 0.14) and chlorogenic acid (0.67 ± 0.09 to 0.91 ± 0.02). All extracts elicited vasorelaxant effect (pIC₅₀ between 4.97 ± 0.22 to 6.48 ± 0.10) and α-glucosidase inhibition (pIC₅₀ between 3.49 ± 0.21 to 4.03 ± 0.10). PCA disclosed positive correlations between the vasorelaxant effect and the contents of chlorogenic acid, rutin, total flavonoids, and FlavHS, whereas a negative correlation was found with bornesitol concentration. No significant correlation between α-glucosidase inhibition and the contents of the above-mentioned compounds was found. On the other hand, PCA carried out with the areas of the ten major peaks from the chromatograms disclosed positive correlations between a peak ascribed to co-eluted triterpenes and α-glucosidase inhibition. A triterpene was isolated and identified as 3-O-β-(3'-R-hydroxy)-hexadecanoil-lupeol.

CONCLUSION

According to PCA results, the vasorelaxant activity of H. speciosa extracts is related to flavonoids and chlorogenic acid, whereas the α-glucosidase inhibition is associated with lipophilic compounds, including esters of lupeol like 3-O-β-(3'-R-hydroxy)-hexadecanoil-lupeol, described for the first time for the species. These compounds can be selected as chemical markers for the quality control of H. speciosa plant drug and derived extracts.

Application of Nanoparticles and Melatonin for Cryopreservation of Gametes and Embryos

Cryopreservation of gametes and embryos, a technique widely applied in human infertility clinics and to preserve desirable genetic traits of livestock, has been developed over 30 years as a component of the artificial insemination process. A number of researchers have conducted studies to reduce cell toxicity during cryopreservation using adjuvants leading to higher gamete and embryo survival rates. Melatonin and Nanoparticles are novel cryoprotectants and recent studies have investigated their properties such as regulating oxidative stresses, lipid peroxidation, and DNA fragmentation in order to protect gametes and embryos during vitrification. This review presented the current status of cryoprotectants and highlights the novel biomaterials such as melatonin and nanoparticles that may improve the survivability of gametes and embryos during this process.

Use of Purslane (Portulaca oleracea) Extracts and Cysteine in Diluents to Improve the Cryopreserved Quality of Goat Sperm

Highlights Using cysteine and purslane extracts in extenders improved significantly the post-thaw sperm characteristics. Sperm viability, DNA integrity, and mitochondrial activity demonstrate an improvement in post-thaw sperm. Malondialdehyde production was decreased based on the positive effects of treated extenders. The obtained results demonstrate that supplementation of 50 μg/mL of purslane methanolic extract with cysteine to freezing extenders was significantly superior compared with other treatments.

Two Lignan Glycosides from Albizia julibrissin Durazz. Noncompetitively Inhibit Serotonin Transporter

Albizia julibrissin Durazz. is one of the most common herbs used for depression and anxiety treatment, but its molecular basis and mechanism of action as an antidepressant or anxiolytic drug are not understood. In this study, we separated and identified two lignan glycosides that inhibit serotonin transporter (SERT) noncompetitively by decreasing Vmax with little change in Km for its fluorescence substrate. In addition, treatment with lignan glycosides did not alter total and cell surface expression levels of the transporter protein. The two compounds decreased the accessibility of a cysteine residue placed in the extracellular substrate permeation pathway by inducing a conformational shift toward an outward-closed state of SERT. These results are consistent with molecular docking for the association of the lignan glycosides to the allosteric site in SERT. The present work supports the proposal that these compounds act on SERT by a novel underlying mechanism of action different from that of conventional antidepressant drugs.

Antioxidant and Antiapoptotic Effects of a Turraea fischeri Leaf Extract on Cryopreserved Goat Sperm

This study evaluated the efficacy of Turraea fischeri leaf extract for maintaining the viability of cryopreserved goat sperm. Ejaculated semen was collected from 5 mature Baladi bucks (50-60 kg, 2-4 years of age) and those samples with mass motility ≥ 70% and sperm concentration ≥ 2.5 × 109/mL were selected, pooled, and divided into 4 aliquots. Each aliquot was diluted in Tris-citric-soybean lecithin extender containing a different concentration of T. fischeri leaf extract (0, 125, 250, or 375 µg/mL). Treated semen samples were cooled to 5 °C, transferred to 0.25-mL French straws, and stored in liquid nitrogen (LN2) at -196 °C. After thawing, membrane integrity was examined by transmission electron microscopy, apoptotic activity by Annexin/propidium iodide staining and flow cytometry, and both enzyme activities and antioxidant capacity by spectroscopic assays. The leaf extract at 375 µg/mL significantly improved semen quality as indicated by enhanced total antioxidant capacity, reduced H2O2 concentration, a greater proportion of structurally intact motile sperm, and concomitant reductions in apoptosis and necrosis. The extract also significantly increased the proportion of sperm with a contiguous plasma membrane and intact acrosome (p < 0.05). Furthermore, LC-MS revealed numerous secondary metabolites in the extract that may contribute to sperm cryopreservation.

Synergistic Effect of Mandarin Peels and Hesperidin with Sodium Nitrite against Some Food Pathogen Microbes

Food preservatives such as NaNO2, which are widely used in human food products, undoubtedly affect, to some extent, human organs and health. For this reason, there is a need to reduce the hazards of these chemical preservatives, by replacing them with safe natural bio-preservatives, or adding them to synthetic ones, which provides synergistic and additive effects. The Citrus genus provides a rich source of such bio-preservatives, in addition to the availability of the genus and the low price of citrus fruit crops. In this study, we identify the most abundant flavonoids in citrus fruits (hesperidin) from the polar extract of mandarin peels (agro-waste) by using spectroscopic techniques, as well as limonene from the non-polar portion using GC techniques. Then, we explore the synergistic and additive effects of hesperidin from total mandarin extract with widely used NaNO2 to create a chemical preservative in food products. The results are promising and show a significant synergistic and additive activity. The combination of mandarin peel extract with NaNO2 had synergistic antibacterial activity against B. cereus, Staph. aureus, E. coli, and P. aeruginosa, while hesperidin showed a synergistic effect against B. cereus and P. aeruginosa and an additive effect against Staph. aureus and E. coli. These results refer to the ability of reducing the concentration of NaNO2 and replacing it with a safe natural bio-preservative such as hesperidin from total mandarin extract. Moreover, this led to gaining benefits from their biological and nutritive values.

Plant Extracts as Alternative Additives for Sperm Preservation

Sperm preservation is a crucial factor for the success of assisted reproductive technology (ART) in humans, livestock, and wildlife. Irrespective of the extender and the storage conditions used, semen handling and preservation negatively affect sperm quality. Moreover, oxidative stress, which often arises during semen storage, significantly reduces sperm function and compromises the sperm fertilizing ability by inducing oxidative damage to proteins, lipids, and nucleic acids. Plant extracts have recently emerged as a cheap and natural source of additives to preserve and enhance sperm function during semen storage. The present work provides an update on the use of these natural compounds as alternative additives for sperm preservation in 13 animal species, including humans. A detailed description of the effects of 45 plant species, belonging to 28 families, on sperm function during semen storage is presented. The plant material and extraction method employed, dosage, possible toxic effects, and antimicrobial properties are provided.

A sulfated polyphenols-rich extract from Sabal yapa exhibits antitumor activities in Ehrlich ascites carcinoma

Cancer is the second leading cause of mortality accounting for one in every six deaths globally. Plant secondary metabolites, among them polyphenols, represent an effective and much safer alternative approach to the currently available medications. In this work, utilizing LC-MS/MS, we characterized the constituents of S. yapa leaves extract and evaluated its antioxidant and anticancer properties. In total, 34 secondary metabolites, mainly flavonoids (Tricin, luteolin, and apigenin and their glucosides as well as sulfated derivatives) were identified. The extract manifested substantial antioxidant activity in DPPH assay, and high total phenolic content determined by Folin Ciocalteu method. The extract was safe up to 4800 mg/kg b.wt. when administered orally in mice and neither affected the hematological parameters nor the liver enzyme levels at the studied dose (LD₅₀, 480 mg, kg b.wt.). In the treated animals, the extract surpassed the reference drug (5-flouro uracil) and significantly reduced the tumor volume and weight by 71.50 and 85.46%, respectively, increased the median survival time to 53.2 days and the lifespan by 116%. The extract improved all the hematological parameters, where it increased the hemoglobin (Hb) concentration, red blood cell (RBC) count, packed cell volume (PVC) and platelets by 58.21, 8.98, 9.89 and 120%, respectively, compared to the untreated EAC bearing animals. Additionally, the extract significantly declined the elevated levels of ALT and AST enzymes by 29.18% and 59.88%, respectively. In molecular docking, the annotated flavonoids displayed appreciable binding affinities to the active sites of VEGFR1 and VEGFR2. In conclusion, Saba yapa is a promising plant that can be introduced to further advanced clinical studies for the development of novel anticancer drugs with lower side effects.

The Current Trends in Using Nanoparticles, Liposomes, and Exosomes for Semen Cryopreservation

Cryopreservation is an essential tool to preserve sperm cells for zootechnical management and artificial insemination purposes. Cryopreservation is associated with sperm damage via different levels of plasma membrane injury and oxidative stress. Nanoparticles are often used to defend against free radicals and oxidative stress generated through the entire process of cryopreservation. Recently, artificial or natural nanovesicles including liposomes and exosomes, respectively, have shown regenerative capabilities to repair damaged sperm during the freeze-thaw process. Exosomes possess a potential pleiotropic effect because they contain antioxidants, lipids, and other bioactive molecules regulating and repairing spermatozoa. In this review, we highlight the current strategies of using nanoparticles and nanovesicles (liposomes and exosomes) to combat the cryoinjuries associated with semen cryopreservation.

A Polyphenol-Rich Extract From Entada abyssinica Reduces Oxidative Damage in Cryopreserved Ram Semen

The Splinter bean, Entada abyssinica, is widely used in folk medicine. In the current work, we profiled the secondary metabolites from E. abyssinica bark extract using LC-MS and investigated its effect on cryopreserved ram semen. Twenty-eight compounds, including tannins and gallic acid derivatives that prevailed in the extract, were tentatively identified. Results showed that the quality of the post-thawed semen showed a significant improvement when the extract was added to the extender at a concentration of 375 μg/mL. The progressive motility and plasma membrane integrity of sperm cells were significantly increased in the post-thawed semen; however, the total antioxidant capacity (TAC) was insignificantly increased. A significant decrease in the concentration of hydrogen peroxide was detected as well. No significant changes were observed in activities of lactate dehydrogenase (LDH), alanine aminotransaminase (ALT), and aspartate transaminase (AST) within the treated samples. Intact sperm percentage was significantly increased, while apoptotic and necrotic sperm percentages were reduced significantly. Molecular docking of some individual components from the extract revealed their potential to interfere with the apoptosis cascade in which Bcl-2 is involved. In conclusion, Entada abyssinica appears to be useful for cryopreservation presumably owing to its polyphenol content that has potent antioxidant capacity scavenging reactive oxygen species (ROS), enhancing the endogenous antioxidant system and inhibiting lipid peroxidation.

HPLC-PDA-MS/MS profiling of secondary metabolites from Opuntia ficus-indica cladode, peel and fruit pulp extracts and their antioxidant, neuroprotective effect in rats with aluminum chloride induced neurotoxicity

Opuntia ficus-indica (L.) Mill. (OFI), also known as Indian fig Opuntia or prickly pear, is a member of the family Cactaceae that produces edible, nutritionally rich sweet fruits. It has been traditionally used to treat several health disorders and is considered to possess various therapeutic properties. In this work, we have characterized 37 secondary metabolites using HPLC-MS/MS, identified the polysaccharide from the fruits and cladodes pulp, and estimated the neuroprotective activity. All tested extracts exhibited substantial antioxidant activities in-vitro and neuroprotective potential in AlCl₃ induced Alzheimer's condition. Administration of OFI extracts attenuated AlCl₃ induced learning and memory impairment as confirmed from passive avoidance test and counteracted the oxidative stress as manifested from decreasein the elevated MDA level, increased TAC, GSH, SOD and CAT levels. OFI extracts significantly decreased the elevated brain levels of proinflammatory cytokines (NF-κβ and TNF-α), increased anti-inflammatory cytokine (IL-10), and monoamine neurotransmitters (NE, DA, 5-HT) as compared to positive control group. The extracts showed a significant decrease in acetylcholinesterase level (AChE) as compared with AlCl_3. Furthermore, molecular docking was performed to investigate the ability of the major constituents of OFI extracts to interact with acetylcholinesterase (AChE) and serotonin transporter (SERT). Among the tested extracts, cladodes contain highest phenolic content and exhibited the highest antioxidant, anti-inflammatory and neuroprotective activities, which could be attributed to presence of several polyphenols, which could function as AChE and SERT inhibitors. Opuntia ficus-indica might be promising candidate for treating Alzheimer disease, which makes it a subject for more detailed studies.

Grape-Leaf Extract Attenuates Alcohol-Induced Liver Injury via Interference with NF-κB Signaling Pathway

Grape (Vitis vinifera) leaf extracts (GLEs) are known to be rich in phenolic compounds that exert potent antioxidant effects. Given the vulnerability of the liver to oxidative damage, antioxidants have been proposed as therapeutic agents and coadjuvant drugs to ameliorate liver pathologies. The current study was designed to characterize secondary metabolites and investigate the hepatoprotective effects of GLE and its underlying mechanisms. The secondary metabolites were profiled using HPLC–PDA–ESI-MS, and forty-five compounds were tentatively identified. In experimental in vivo design, liver injury was induced by oral administration of high doses of ethanol (EtOH) for 12 days to male Sprague Dawley rats that were split into five different groups. Blood samples and livers were then collected, and used for various biochemical, immunohistochemical, and histopathological analyses. Results showed that GLE-attenuated liver injury and promoted marked hepatic antioxidant effects, in addition to suppressing the increased heat-shock protein-70 expression. Moreover, GLE suppressed EtOH-induced expression of nuclear factor-κB (NF-κB) p65 subunit and proinflammatory cytokine tumor necrosis factor-α. Caspase-3 and survivin were enhanced by EtOH intake and suppressed by GLE intake. Finally, EtOH-induced histopathological changes in liver sections were markedly normalized by GLE. In conclusion, our results suggested that GLE interferes with NF-κB signaling and induces antioxidant effects, which both play a role in attenuating apoptosis and associated liver injury in a model of EtOH-induced liver damage in rats.

Polyphenols from Salix tetrasperma Impair Virulence and Inhibit Quorum Sensing of Pseudomonas aeruginosa

Bacterial resistance represents one of the emerging obstacles in plants, animals, and humans that impairs treatment with antibacterial agents. Targeting of the bacterial quorum sensing system is one of the strategies to overcome this problem. Recently, research has been focused on natural and food components which can function as quorum sensing inhibitors. In this study, a methanol extract from Salix tetrasperma stem bark was phytochemically profiled by LC-MS analysis. This resulted in the identification of 38 secondary metabolites with (epi)catechin-(epi)catechin, epicatechin, tremulacin, salicortin, and trichocarposide as the major constituents. The extracts of both stem bark and the previously profiled flower of S. tetrasperma were tested for anti-quorum sensing activity in a common and widely distributed pathogen Pseudomonas aeruginosa. The natural products inhibited swimming and swarming motilities, as well as proteolytic and hemolytic activities in a dose-dependent manner. Molecular docking of the constituents from both extracts against the quorum sensing controlling systems Lasl/LasR, rhll/rhlR, and PQS/MvfR showed that epicatechin, (epi)catechin-(epi)catechin, p-hydroxy benzoyl galloyl glucose, p-hydroxy benzoyl protocatechuic acid glucose, and caffeoylmalic acid could be the main active components. This study supports the importance of secondary metabolites, especially polyphenols, as quorum sensing inhibitors.

Albizia anthelmintica: HPLC-MS/MS profiling and in vivo anti-inflammatory, pain killing and antipyretic activities of its leaf extract

In the current work, the phytochemical composition of a leaf methanol extract from Albizia anthelmintica was thoroughly investigated. The antioxidant, anti-inflammatory, analgesic, and antipyretic activities of the extract were investigated. In the carrageenan induced hind paw edema bioassay; the extract significantly reduced the edema thickness in rats and diminished the leukocyte migration to the peritoneal cavity in mice. The extract exhibited central and peripheral anti-nociceptive effects; it significantly decreased the number of acetic acid induced writhes and prolonged the latency time in the hot plate test. The extract showed a substantial antipyretic activity as it decreased significantly the elevated rectal temperature in mice after intraperitoneal injection of Brewer's yeast. Molecular docking of some major compounds in the extract to COX-1, COX-2 and 5-LOX, enzymes involved in the inflammation cascade, revealed appreciable interactions with the conserved amino acid residues in these target proteins. These findings were confirmed with in vitro enzyme inhibitory assays in which the extract showed IC₅₀ values of 4.11, 0.054, and 1.74 μg/mL towards COX-1, COX-2 and 5-LOX, respectively. The extract displayed solid antioxidant properties as well with a TAC value of 35.13 U/L and EC₅₀of 5.36 μg/mL in DPPH assay. These findings suggested that Albizia anthelmintica is a good antioxidant with potential therapeutic efficacy for treating inflammation, pain and related oxidative stress disorders.

Lycium barbarum and Laminaria japonica polysaccharides improve Cashmere goat sperm quality and fertility rate after cryopreservation

Cashmere goat is known for the highest cashmere yield and best fiber quality. Here, the effects of Lycium barbarum polysaccharide (LBP) and Laminaria japonica polysaccharide (LJP) on goat sperm quality were investigated. Results showed that the sperm motility, mitochondrial activity, and membrane and acrosome integrity were significantly higher with 4.0 mg/mL LBP and 1.0 mg/mL LJP supplementations than in the control (P < 0.05), respectively. Higher SOD, CAT, and GSH-Px levels were observed in 4.0 mg/mL LBP and 1.0 mg/mL LJP groups than control group (P < 0.05). Sperm characteristics with 2.0 + 1.0 mg/mL LBP + LJP supplementation significantly improved compared to that with other treatments (P < 0.05). Compared to the control treatment, the non-return rate (NRR) were higher in the LBP + LJP (2.0 + 1.0 mg/mL) group (P < 0.05). These results suggest that LBP and LJP enhance cryo-protective effects on goat spermatozoa, and that 2.0 + 1.0 mg/mL LBP + LJP addition to the extender during cryopreservation is beneficial to the Cashmere goat breeding industry.

Identification, Quantification, and Antioxidant Activity of Hydroalcoholic Extract of Artemisia campestris from Algeria

Objectives

Our study aimed to investigate the chemical profile of hydroalcoholic extract of Algerian Artemisia campestris and its antioxidant activity.

Materials and Methods

The hydroalcoholic extract of Algerian A. campestris was investigated for its phenolic constituents using high performance liquid chromatography (HPLC)-diode array detection (DAD)-electrospray ionization (ESI)-mass spectrometer (MS)/MS. The in vitro antioxidant activity and total phenolic content were also evaluated via oxygen radical absorbance capacity and Folin-Ciocalteu assays, respectively.

Results

HPLC-DAD-ESI-MS/MS analysis revealed that the main tentatively identified compounds were caffeoylquinic acid isomers, flavonoids, and benzoic acid derivatives. Additionally, the hydroalcoholic extract exhibited a promising antioxidant activity value of 120.5±10.4 μmol Trolox equivalent antioxidant capacity/g dry weight (DW), and a strong correlation exists between this activity and the total phenolic content value of 102.09±1.65 mg/g gallic acid equivalents DW.

Conclusion

The hydroalcoholic extract of A. campestris is a promising candidate for the production of naturally occurring antioxidant agents.

Chemical composition, antioxidant and hepatoprotective activities of methanol extracts from leaves of Terminalia bellirica and Terminalia sericea (Combretaceae)

Background

Plants belonging to the genus Terminalia such as Terminalia bellirica and Terminalia sericea are used traditionally to treat several diseases and health disorders. Up to this date, the roots of Terminalia sericea and the fruits of Terminalia bellirica are the mostly studied plant parts. The phytochemical composition and the biological activities of the leaves of both species are not well identified so far.

Methods

The secondary metabolites of Terminalia bellirica and Terminalia sericea leaves were identified using HPLC-PDA-MS/MS. The antioxidant activities of the leaves extracts were determined by DPPH and FRAP assays. The hepatoprotective potential was evaluated in rats with D-galactosamine induced liver damage. The effect of the extracts on the expression of the anti-apoptotic marker Bcl-2 was measured in an immunohistochemical study. The most abundant compounds identified in the studied extracts were docked into Bcl-2: Bim (BH3) interaction surface using molecular operating environment software.

Results

A total of 85 secondary metabolites were identified in the leaf extracts of both species. Ellagitannins such as corilagin, chebulagic acid, galloylpunicalagin, and digalloyl-hexahydroxydiphenoyl-hexoside were found to be the major components in Terminalia bellirica whereas flavonoid glycosides including quercetin rutinoside and quercetin galloyl-glucoside were highly abundant in Terminalia sericea. The studied extracts exhibited pronounced antioxidant activities, moderate anti-apoptotic and hepatoprotective potential. In silico docking experiments revealed that the compounds abundant in the extracts were able to bind to Bcl-2: Bim (BH3) interaction surface with an appreciable binding free energy.

Discussion

The antioxidant and hepatoprotective activities exhibited by the studied extracts might be attributed to the high content of the polyphenols. The anti-apoptotic activity could be due to the interference with the apoptotic pathway mediated by Bcl-2: Bim interaction. These findings support the medicinal relevance of Terminalia bellirica and Terminalia sericea and provide a rational base for their utilization in folk medicine.

Tannin-rich extracts from Lannea stuhlmannii and Lannea humilis (Anacardiaceae) exhibit hepatoprotective activities in vivo via enhancement of the anti-apoptotic protein Bcl-2

The potential hepatoprotective activities of two Lannea species were explored in vivo. Furthermore, the binding activities of their main polyphenols to the antiapoptotic protein Bcl-2 were investigated. Based on HPLC-MS/MS results, 22 secondary metabolites were characterized in L. stuhlmannii (mainly tannins), while 20 secondary metabolites (mainly sulphated tannins) were identified in L. humilis. Both extracts exhibited substantial antioxidant activities in vitro and counteracted D-galactosamine induced intoxication in rats in vivo and increased the total antioxidant capacity (TAC) of liver tissues. In addition to reducing the elevated levels of AST and total bilirubin, both extracts significantly attenuated the deleterious histopathologic changes in liver after D-galactosamine-intoxication. Also, both extracts protected hepatocytes from apoptotic cell death and increased the expression of the anti-apoptotic protein Bcl-2. The identified compounds from both extracts can bind to the Bcl-2: Bim (BH3) interface with an appreciable binding free energy. Hydrogen and ionic bonds and hydrophobic interactions with amino acid residues in the hydrophobic face of Bim (BH3) domain were discovered. To sum up, L. humilis and L. stuhlmanni exhibited promising hepatoprotective activities in vivo against D-GalN-induced liver injury and their hepatoprotection is due to the antioxidant and anti-apoptotic effects of tannins and proanthocyanidins.

Rheum palmatum root extract inhibits hepatocellular carcinoma in rats treated with diethylnitrosamine

Objectives

The aim of this study was to investigate the potential anticancer properties of a methanol extract of Rheum palmatum roots against diethylnitrosamine (DENA)-induced hepatocellular carcinoma (HCC) in rats and to characterize its phytoconstituents.

Methods

HPLC-PDA-MS/MS was used to profile the secondary metabolites in R. palmatum root extract. HCC was induced using diethylnitrosamine (DENA). The activity of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT), alpha-fetoprotein (AFP), total proteins, serum albumin and serum globulin was determined. DNA fragmentation and histopathological examination and GST-P immunostaining were also studied.

Key findings

LC-MS/MS analysis identified 16 compounds belonging to anthraquinones, flavonoids and tannins. The root extract significantly reduced the elevated liver enzymes ALT and AST and increased total proteins, albumin and globulin in HCC-rats. Also, the tumour markers AFP and GGT levels were significantly reduced in HCC-rats treated with the extract. In addition, the extract significantly reduced elevated DNA fragmentation and decreased the numbers and areas of GST-P positive putative foci in HCC-rats.

Conclusions

Rheum palmatum is a potential candidate to be explored for the treatment of hepatocellular carcinoma.