Effects of Terminalia arjuna bark extract on apoptosis of human hepatoma cell line HepG2

Ethnobotanical survey and scientific validation of liver-healing plants in northeastern Morocco

Introduction

Liver diseases represent a significant global health challenge, with primary causes including excessive alcohol consumption, infections, chemotherapy, and autoimmune disorders. Medicinal plants, due to their natural bioactive compounds, hold promise for developing effective treatments and preventive measures against liver ailments. This study aimed to document the use of herbal remedies in northeastern Morocco for liver diseases and correlate these uses with scientific evidence through a bibliometric analysis.

Methods

An ethnobotanical survey was conducted in remote communities of northeastern Morocco from October 2020 to January 2022. A total of 189 informants were interviewed using semi-structured questionnaires to gather information on local medicinal plants used for liver ailments. The data were analyzed using four ethnobotanical quantitative indices: use value (UV), familial use value (FUV), informant consensus factor (ICF), and fidelity level (FL). Additionally, a bibliometric analysis was performed to evaluate the scientific support for the ethnopharmacological uses documented.

Results

The survey identified 45 plant species from 26 different families used in the treatment of liver diseases. The most frequently utilized species were Cuminum cyminum L. (UV = 0.1065), Allium sativum L. (UV = 0.1015), Salvia officinalis L. (UV = 0.0761), Asparagus officinalis L. (UV = 0.0558), and Ziziphus lotus (L.) Lam. (UV = 0.0457). The Apiaceae family showed the highest familial use value (FUV = 0.1066), followed by Alliaceae (FUV = 0.1015). Liver congestion had the highest informant consensus factor (ICF = 0.83), followed by hepatic colic (ICF = 0.80). Bibliometric analysis revealed that 61% of the plants identified had documented pharmacological effects related to liver health.

Discussion

The study demonstrates that traditional knowledge in northeastern Morocco encompasses a rich diversity of medicinal plants used to treat liver diseases. The high ICF values indicate a strong consensus among informants on the efficacy of these remedies. The correlation between ethnopharmacological use and scientific validation for a significant portion of these plants suggests their potential as reliable therapeutic agents for liver conditions. However, further scientific investigations are necessary to confirm their efficacy and safety in clinical settings. This research contributes valuable information for future studies on the therapeutic potential of these plants.

Conclusion

This ethnobotanical survey provides a comprehensive database of medicinal plants used in northeastern Morocco for liver diseases. The findings highlight the potential of these plants in developing novel treatments for hepatic conditions, although further research is essential to substantiate their therapeutic claims.

Exploring the pharmacological potential of Lepionurus sylvestris blume: from folklore medicinal usage to modern drug development strategies using in vitro and in silico analyses

BACKGROUND

Lepionurus sylvestris Blume has a long history of folklore medicinal usage against various ailments. However, studies on these plants were neglected particularly their pharmacological potential.

METHODS

The crude extract was identified using LC-MS analysis. In vitro assays were carried out to determine the properties of antioxidant, anti-microbial, and anti-cancer. Further, network pharmacology was proposed to evaluate the potential targets of the compounds against breast cancer and type II diabetes. Molecular docking and molecular dynamic simulation were used to determine the potential compounds for the drug formulation of diabetes.

RESULTS

Various bioactive compounds were identfied using LC-MS and Galiposin, Fujikinetin, Boeravinone B, 4-Deoxybryaquinone, and Norbaeocystin were described for the first time from the plant. Determination of antioxidant potential showed that the IC50 value of ABTS, DPPH, and phosphomolybdate was 24.33 µg/ml, 37.81 µg/ml, 60.35 µg/ml, and reducing power assays 1.185. The antibacterial activity against Streptococcus pyogenes, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli was determined, and the minimum inhibition concentration (MIC) was found to be 5.3 mg/ml, 3.47 mg/ml, 3.33 mg/ml, and 2.7 mg/ml respectively, revealing the extracts as effective antibacterial agents. The IC50 values for the plant extract were determined to be 26 µg/ml, 30.52 µg/ml, and 24.39 µg/ml for HeLa, MCF-7, and K-562 cells, respectively, and the increasing concentration of the plant extract increased LDH release. Furthermore, the in silico network pharmacology, molecular docking which had the highest docking score for GAPDH and HIF-1 target proteins of -9.3 kcal/mol, and - 11.3 kcal/mol binding affinities, and molecular dynamic simulation analysis revealed the bioactive compound Boeravinone B present in the plant was significant for the treatment of various ailments.

CONCLUSION

Based on our findings, plant extracts could be a promising option for developing new drug formulations.

Identification of novel AKT1 inhibitors from Sapria himalayana bioactive compounds using structure-based virtual screening and molecular dynamics simulations

Through the experimental and computational analyses, the present study sought to elucidate the chemical composition and anticancer potential of Sapria himalayana plant extract (SHPE). An in vitro analysis of the plant extract was carried out to determine the anticancer potential. Further, network pharmacology, molecular docking, and molecular dynamic simulation were employed to evaluate the potential phytochemical compounds for cervical cancer (CC) drug formulations. The SHPE exhibited anti-cancerous potential through inhibition properties against cancer cell lines. The LC-MS profiling showed the presence of 14 compounds in SHPE. Using network pharmacology analysis, AKT1 (AKT serine/threonine kinase 1) is identified as the possible potential target, and EGFR (Epidermal Growth Factor Receptor) is identified as the possible key signal pathway. The major targets were determined to be AKT1, EGFR by topological analysis and molecular docking. An in silico interaction of phytoconstituents employing molecular docking demonstrated a high binding inclination of ergoloid mesylate and Ergosta-5,7,9(11),22-tetraen-3-ol, (3.beta.,22E)- with binding affinities of -15.5 kcal/mol, and -11.3 kcal/mol respectively. Further, MD simulation and PCA analyses showed that the phytochemicals possessed significant binding efficacy with CC protein. These results point the way for more investigation into SHPE compound's potential as CC treatment.

Terminalia arjuna, a Cardioprotective Herbal Medicine-Relevancy in the Modern Era of Pharmaceuticals and Green Nanomedicine-A Review

Herbal medicines were the main source of therapeutic agents in the ancestral era. Terminalia arjuna (TA) is one such medicinal plant widely known for its several medicinal properties, especially its cardiovascular properties. They have several phytochemicals, such as flavonoids, polyphenols, triterpenoids, tannins, glycosides, and several minerals, proteins, and others that are responsible for the above-mentioned medicinal properties. In this review, we have first elaborated on the various processes and their parameters for the efficient extraction of relevant phytochemicals from TA extracts. Secondly, the mechanisms behind the various medicinal properties of TA extracts are explained. We have also highlighted the role of TA extracts on the green synthesis of metallic nanoparticles, especially silver and gold nanoparticles, with an elucidation on the mechanisms behind the synthesis of nanoparticles. Finally, TA extracts-based polymeric formulations are discussed with limitations and future perspectives. We believe that this review could help researchers understand the importance of a well-known cardioprotective medicinal plant, TA, and its biomedical properties, as well as their role in green nanotechnology and various formulations explored for encapsulating them. This review will help researchers design better and greener nanomedicines as well as better formulations to improve the stability and bioavailability of TA extracts.

Terminalia arjuna induced testicular assault through Leydig cell derangement: an in vitro approach

OBJECTIVES

Terminalia arjuna (TA) has been widely used as folk medicine since ancient times. Apart from its therapeutic properties it also has anti-spermatogenic activity, but its effectiveness and mode of action on male gonadal activity remains to be revealed.

METHODS

TA bark extract was dissolved in 1% dimethyl sulfoxide and applied in primary Leydig cell culture from rat testis in dose dependent manner. After 24 h of treatment cellular toxicity marker, cytokines, steroid 5-alpha-reductase 1 (SRD5A1) and androgen receptor (AR) were measured.

RESULTS

Present study first proposed the cytotoxic impacts of TA on Leydig cells via leakage of lactate dehydrogenase and inflammatory responses by altering the pro- and anti-inflammatory cytokines in dose-dependent-manner. Furthermore, down regulation of SRD5A1 and AR indicated inhibition of normal steroidogenesis which well corroborated with cytotoxity and inflammation related parameters to promote damage of Leydig cell function. Nevertheless, it can be speculated that the inhibition of normal steroidogenesis and thereby spermatogenesis induced by TA is possibly due to the presence of β-sitosterol.

CONCLUSIONS

Therefore, the dose and duration of treatment should be carefully monitored in cases of its medicinal uses and longer duration should be avoided to protect reproductive health and fertility.

Transcriptome analysis and functional characterization of oxidosqualene cyclases of the arjuna triterpene saponin pathway

Arjuna (Terminalia arjuna) tree has been popular in Indian traditional medicine to treat cardiovascular ailments. The tree accumulates bioactive triterpene glycosides (saponins) and aglycones (sapogenins), in a tissue-preferential manner. Oleanane triterpenes/saponins (derived from β-amyrin) with potential cardioprotective function predominantly accumulate in the bark. However, arjuna triterpene saponin pathway enzymes remain to be identified and biochemically characterized. Here, we employed a combined transcriptomics, metabolomics and biochemical approach to functionally define a suite of oxidosqualene cyclases (OSCs) that catalyzed key reactions towards triterpene scaffold diversification. De novo assembly of 131 millions Illumina NextSeq500 sequencing reads obtained from leaf and stem bark samples led to a total of 156,650 reference transcripts. Four distinct OSCs (TaOSC1-4) with 54-71 % sequence identities were identified and functionally characterized. TaOSC1, TaOSC3 and TaOSC4 were biochemically characterized as β-amyrin synthase, cycloartenol synthase and lupeol synthase, respectively. However, TaOSC2 was found to be a multifunctional OSC producing both α-amyrin and β-amyrin, but showed a preference for α-amyrin product. Both TaOSC1 and TaOSC2 produced β-amyrin, the direct precursor for oleanane triterpene/saponin biosynthesis; but, TaOSC1 transcript expressed preferentially in bark, suggesting a major role of TaOSC1 in the biosynthesis of oleanane triterpenes/saponins in bark.

Effects of Hexane Root Extract of Ferula hermonis Boiss. on Human Breast and Colon Cancer Cells: An In Vitro and In Vivo Study

Breast and colon cancers are leading causes of cancer-related deaths globally. Plants are a potential source of natural products that may be used for the treatment of cancer. Ferula hermonis (FH) is reported to have diverse therapeutic effects. However, there are few reports on the in vitro anticancer potential of FH extract. Our results showed that the Ferula hermonis root hexane extract (FHRH) can induce dose-dependent cytotoxic effects in breast and colon cancer cells with MTT IC₅₀ values of 18.2 and 25 μg/ml, respectively. The FHRH extract induced apoptosis in both breast and colon cancer cells; this was confirmed by light and nuclear staining, q-PCR, and caspase 3/7 activation. This study also demonstrated the antitumor activity of FHRH in 9,10-dimethylbenz[α]anthracene DMBA-induced rodent mammary tumor model. The GC/MS analysis revealed the presence of 3,5-Dimethylbenzenemethanol, Alpha-Bisabolol, Alpha-pinene, Beta-pinene, and Baccatin III that have various pharmacological potentials. Overall, the present study suggests that FHRH extract possesses anticancer potential which is mediated through apoptotic effects in MDA-MB-231 and LoVo cells. The present study also considered a basis for further investigations into the potential use of FHRH extract as an anticancer therapy for breast and colon cancers.

Beneficial role of Terminalia arjuna hydro-alcoholic extract in colitis and its possible mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

Terminalia arjuna Roxb. (Combretaceae) is traditionally used in Ayurveda medicine and holds ethnomedicinal importance for treatment of gastrointestinal disorders. In view of its anti-inflammatory, antidiarrheal and antioxidant potential, it could be beneficial for the treatment of inflammatory bowel disease (IBD), which is associated with interaction between genetic, environmental factors and intestinal microbiome leading to dysregulated immune responses. This study evaluates the effect of hydroalcoholic extract of Terminalia arjuna bark (TAHA) in trinitrobenzenesulfonic acid (TNBS) model of rat colitis which resembles human IBD.

MATERIALS AND METHODS

TAHA (500, 250, 125 mg/kg) was administered orally for 28 days in TNBS induced rats. Response to treatment was assessed by comparing observations in diseased and treated groups using disease activity index (DAI); macroscopic/histological damage; determining oxidative stress indicators: myeloperoxidase, malondialdehyde, nitric oxide, catalase, superoxide dismutase, and reduced glutathione; gene expression of pro-inflammatory cytokines such as IL-6, IL-1β, TNF-α and chemokine: MCP-1. Furthermore, the role of TAHA in altering the gut microbiota profile in rat feces and plasma zinc was also studied.

RESULTS

TAHA treatment in colitic rats directed decreased DAI scores, macroscopic and histologic damage. It also reduced myeloperoxidase, malondialdehyde and nitric oxide level. Whereas, prevented depletion of plasma catalase, superoxide dismutase and glutathione level. In addition, TAHA treatment down-regulated the gene expression of pro-inflammatory mediators and displayed altered beneficial effect on fecal microbiota. Furthermore, enhanced plasma zinc level supported the beneficial effect of TAHA in colitic rats. The dose of TAHA that produced most significant beneficial effect was 500 mg/kg.

CONCLUSION

TAHA administration relieved the disease activity in TNBS induced colitis by reducing expression of pro-inflammatory cytokines and chemokine, decreasing oxidative stress, and improving plasma zinc level and structure of gut microbiota.

A traditional poly herbal medicine "Le Pana Guliya" induces apoptosis in HepG2 and HeLa cells but not in CC1 cells: an in vitro assessment

"Le Pana Guliya" (LPG) is a polyherbal formulation which is used to treat different types of cancers in traditional medicine. In this study we describe in vitro efficacy and mechanism of action of LPG on two cancer cell lines (HepG2 and HeLa) compared with a normal cell line CC1. The MTT, LDH assays and protein synthesis were used to study antiproliferative activity of LPG while NO synthesis and GSH content were assayed to determine the oxidative stress exerted by LPG. Rhodamine 123 staining, caspase 3 activity, DNA fragmentation and microscopic examination of cells stained with ethidium bromide/acridine orange were used to identify the apoptosis mechanisms associated with LPG. The LPG showed the most potent antiproliferative effect against the proliferation of HepG2 and HeLa cells with an EC50 value of 2.72 ± 1.36 and 19.03 ± 2.63 µg/mL for MTT assay after 24 h treatment respectively. In contrast, CC1 cells showed an EC50 value of 213.07 ± 7.71 µg/mL. Similar results were observed for LDH release. A dose dependent decrease in protein synthesis was shown in both cancer cell types compared to CC1 cells. The reduction of GSH content and elevation of cell survival with exogenous GSH prove that the LPG act via induction of oxidative stress. LPG also stimulates the production of NO and mediates oxidative stress. Rhodamine 123 assay shows the mitochondrial involvement in cell death by depletion of Δψ inducing downstream events in apoptosis. This results in increase in caspase-3 activity eventually DNA fragmentation and LPG induced apoptotic cell death. In conclusion the present study suggested that the LPG exerted an anticancer activity via oxidative stress dependent apoptosis. Therefore present study provides the scientific proof of the traditional knowledge in using LPG as an anticancer agent.

Pelargonidin induces apoptosis and cell cycle arrest via a mitochondria mediated intrinsic apoptotic pathway in HT29 cells

Pelargonidin (PE) is an anticancer anthocyanidin that is abundant in berries.

D-pinitol promotes apoptosis in MCF-7 cells via induction of p53 and Bax and inhibition of Bcl-2 and NF-κB

Development of drugs from natural products has been undergoing a gradual evoluation. Many plant derived compounds have excellent therapeutic potential against various human ailments. They are important sources especially for anticancer agents. A number of promising new agents are in clinical development based on their selective molecular targets in the field of oncology. D-pinitol is a naturally occurring compound derived from soy which has significant pharmacological activitites. Therefore we selected D-pinitol in order to evaluate apoptotic potential in the MCF-7 cell line. Human breast cancer cells were treated with different concentrations of D-pinitol and cytotoxicity was measured by MTT and LDH assays. The mechanism of apoptosis was studied with reference to expression of p53, Bcl-2, Bax and NF-kB proteins. The results revealed that D-pinitol significantly inhibited the proliferation of MCF-7 cells in a concentration-dependent manner, while upregulating the expression of p53, Bax and down regulating Bcl-2 and NF-kB. Thus the results obtained in this study clearly vindicated that D-pinitol induces apotosis in MCF-7 cells through regulation of proteins of pro- and anti-apoptotic cascades.

PASS-predicted Vitex negundo activity: antioxidant and antiproliferative properties on human hepatoma cells--an in vitro study

Background

Hepatocellular carcinoma is a common type of tumour worldwide with a high mortality rate and with low response to current cytotoxic and chemotherapeutic drugs. The prediction of activity spectra for the substances (PASS) software, which predicted that more than 300 pharmacological effects, biological and biochemical mechanisms based on the structural formula of the substance was efficiently used in this study to reveal new multitalented actions for Vitex negundo (VN) constituents.

Methods

Experimental studies based on antioxidant and antiproliferative assays verified the predictions obtained by the PASS-predicted design strategy. Antioxidant activity of VN extract was studied using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and Ferric reducing or antioxidant power (FRAP) assays. The antiproliferative activity of VN extract against WRL68 and HepG2 was investigated based on methylthiazol tetrazolium (MTT) spectrophotometric assay.

Results

VN extract showed 79.43% inhibition of DPPH stable radical with IC₅₀ 13.31 ± 0.18 μg/ml. This inhibition was too closed to butylated hydroxyl toluene (BHT) 82.53% (IC₅₀13.8 ± 0.14) and gallic acid 89.51% (IC₅₀ 3.1 ± 0.08). VN extract exhibited the strongest free radical scavenging power compared with two commercial antioxidants, BHT and ascorbic acid. VN increased the activities of antioxidant enzymes in normal embryonic liver cells (WRL68) including, superoxide dismutase (SOD) and glutathione peroxidase (GPX) compared with to H₂O₂ group. The ethanolic extract of VN showed cytotoxicity to HepG2 cells in a dose and time-dependent manner with IC₅₀ 66.46 μg/ml, 57.36 μg/ml and 65.12 μg/ml at 24, 48, and 72-hours incubation respectively, with no sensitivity in WRL68 cells. This was associated with significant elevation in lactate dehydrogenase (LDH) release in HepG2 cells. In addition, the activation of caspase-3 enzyme suggesting that the observed cytotoxicity was mediated via an intrinsic apoptosis pathway.

Conclusions

PASS-predicted plant activity could efficiently help in selecting a promising pharmaceutical leads with high accuracy and required antioxidant and antiproliferative properties. This is the first report on PASS-predicted VN activity.

In vitro antioxidant and anticancer activity studies on drosera indica L. (Droseraceae)

PURPOSE

The aim of present in vitro studies was performed to examine the antioxidant and anticancer activities of ethanol and aqueous extracts of Drosera indica L.

METHODS

Different concentrations (5 - 640mcg/ml) of the ethanol (EEDI) and aqueous (AEDI) extracts of D.indica L were used in various antioxidant assay methods such as hydroxyl radicals, DPPH, super oxide radical scavenging activity, chelating ability of ferrous ion, nitric oxide radical inhibition, ABTS and reducing power. Ascorbic acid (AA) was used as the standard antioxidant for the free radical scavenging assays. Dalton's Ascitic Lymphoma (DAL) and Ehrlich Ascitic Carcinoma (EAC) cell lines were used as the in vitro cancer models for the tryphan blue dye and LDH leakage assays, where 5 to 250mcg /ml of both EEDI and AEDI were tested.

RESULTS

EEDI showed antioxidant activities with the minimum IC50 values of 34.8±0.43 mcg/ml in scavenging of hydroxyl radical and moreover AEDI showed minimum IC50 values of 94.51±0.84 mcg/ml in Fe(2+)chelating assay. EEDI on the reducing power assay and ABTS showed higher IC50 than standard AA. IC50 values of AEDI on Fe(2+) chelating assay and super oxide radical assay was lesser than IC50 value of AA. Both extracts at 250mcg/ml dose showed remarkable increase in the percentage of dead cancer cells (90% by EEDI and 86% by AEDI in DAL model and 89% by EEDI and 80% by AEDI in EAC model).

CONCLUSION

It is concluded from this study that D.indica L exhibited excellent antioxidant activity against the different in vitro antioxidant models and anticancer activity against the two different cell lines tested.

Isolation and purification of a peptide from Bullacta exarata and its impaction of apoptosis on prostate cancer cell

Bullacta exarata was hydrolyzed with trypsin to prepare peptides; Hydrolysates were isolated by ultrafiltration and purified using G-25 gel filtration. The purity of the Bullacta exarata was demonstrated by HPLC and its peptide sequence analysis was detected. The effects of BEPT II and BEPT II-1 on the proliferation of PC-3 cells were examined using a MTT assay. BEPT II and BEPT II-1 significantly inhibited the proliferation of PC-3 cells in a time- and dose-dependent manner. Annexin V/PI double staining studies showed exposing PC-3 cells to 5, or 15 mg/mL BEPT II-1 for 24 h increased the percentage of the early stage of apoptotic cells from 11.22% to 22.09%. In addition, typical morphologic changes were observed in the cells with acridine orange/ethidium bromide staining. These data support that BEPT II-1 has anticancer properties and merits further investigation to understand the mechanisms of BEPT II-1-induced apoptosis in PC-3 cells.

Effect ofAchyranthes asperaRoot andTerminalia arjunaBark on Aerotolerant Responses inStreptococcus mutans

In the present study, the effect of hydroalcoholic extract ofAchyranthes asperaroot (AAR) andTerminalia arjunabark (TAB) on the aerotolerant capacities ofStreptococcus mutanswas examined. AAR and TAB extracts were found to inhibit the prime antioxidant enzymes like manganese superoxide dismutase (MnSOD), NADH oxidases, and glutathione peroxidase (GPx), altering the aerotolerant responses inS. mutans. Consequently,S. mutansare unable to withstand the oxidative stress and thus are made more susceptible to the antimicrobial activity.

The aqueous extract, not organic extracts, of Terminalia arjuna bark exerts cardiotonic effect on adult ventricular myocytes

The bark of Terminalia arjuna (TA) has been used for centuries in ayurvedic medicine as cardiotonics for treatment of cardiac disorders. It became recently available as over-the-counter supplements marketed for maintaining a healthy heart. However, the cellular mechanism of its cardiotonic effect remains undefined. The present study was designed to investigate the physicochemical property and inotropic effect of the aqueous extract of TA bark (TA(AqE)) on adult rat ventricular myocytes in comparison with extracts prepared sequentially with organic solvents (organic extracts). The kinetics of myocyte contraction and caffeine-induced contraction were analyzed to assess the effect of TA(AqE) on sarcoplasmic reticular (SR) function. The inotropic effect of TA(AqE) was also compared with that of known cardiotonics, isoproterenol (ISO) and ouabain (Ouab). We found that TA(AqE) decoctions exerted positive inotropy, accelerated myocyte relaxation and increased caffeine-induced contraction concentration-dependently. In contrast, TA organic extracts caused interruption of excitability and arrhythmias without consistent inotropic action. In conclusion, TA(AqE)-induced cardiotonic action via enhancing SR function, a unique action minimizing the occurrence of arrhythmias, makes TA(AqE) a promising and relatively safe cardiotonic beneficial to the healthy heart and the treatment for chronic heart disease. The cardiotonic effect of TA(AqE) is consistent with the therapeutic property of TA bark used in ayurvedic medicine. The method of administration and/or selective omission of hydrophobic components from bark powder could be crucial to the efficacy and safety of TA bark in cardiac therapy and uses as over-the-counter supplements.

Intrinsic anticarcinogenic effects of Piper sarmentosum ethanolic extract on a human hepatoma cell line

Background

Piper sarmentosum, locally known as kaduk is belonging to the family of Piperaceae. It is our interest to evaluate their effect on human hepatoma cell line (HepG2) for the potential of anticarcinogenic activity.

Results

The anticarcinogenic activity of an ethanolic extract from Piper sarmentosum in HepG2 and non-malignant Chang's liver cell lines has been previously determined using (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) (MTT) assays, where the IC₅₀ value was used as a parameter for cytotoxicity. The ethanolic extract that showed anticarcinogenic properties in HepG2 cells had an IC₅₀ of 12.5 μg mL^-1, while IC₅₀ values in the non-malignant Chang's liver cell line were greater than 30 μg mL^-1. Apoptotic morphological changes in HepG2 cells were observed using an inverted microscope and showed chromatin condensation, cell shrinkage and apoptotic bodies following May-Grunwald-Giemsa's staining. The percentage of apoptotic cells in the overall population (apoptotic index) showed a continuously significant increase (p < 0.05) in 12.5 μg mL^-1 ethanolic extract-treated cells at 24, 48 and 72 hours compared to controls (untreated cells). Following acridine orange and ethidium bromide staining, treatment with 10, 12 and 14 μg mL^-1 of ethanolic extracts caused typical apoptotic morphological changes in HepG2 cells. Molecular analysis of DNA fragmentation was used to examine intrinsic apoptosis induced by the ethanolic extracts. These results showed a typical intrinsic apoptotic characterisation, which included fragmentation of nuclear DNA in ethanolic extract-treated HepG2 cells. However, the non-malignant Chang's liver cell line produced no DNA fragmentation. In addition, the DNA genome was similarly intact for both the untreated non-malignant Chang's liver and HepG2 cell lines.

Conclusion

Therefore, our results suggest that the ethanolic extract from P. sarmentosum induced anticarcinogenic activity through an intrinsic apoptosis pathway in HepG2 cells in vitro.

Neurotoxicity from glutathione depletion is mediated by Cu-dependent p53 activation

Loss of intracellular neuronal glutathione (GSH) is an important feature of neurodegenerative disorders including Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. The consequences of GSH depletion include increased oxidative damage to proteins, lipids, and DNA and subsequent cytotoxic effects. GSH is also an important modulator of cellular copper (Cu) homeostasis and altered Cu metabolism is central to the pathology of several neurodegenerative diseases. The cytotoxic effects of Cu in cells depleted of GSH are not well understood. We have previously reported that depletion of neuronal GSH levels results in cell death from trace levels of extracellular Cu due to elevated Cu(I)-mediated free radical production. In this study we further examined the molecular pathway of trace Cu toxicity in neurons and fibroblasts depleted of GSH. Treatment of primary cortical neurons or 3T3 fibroblasts with the glutathione synthetase inhibitor buthionine sulfoximine resulted in substantial loss of intracellular GSH and increased cytotoxicity. We found that both neurons and fibroblasts revealed increased expression and activation of p53 after depletion of GSH. The increased p53 activity was induced by extracellular trace Cu. Furthermore, we showed that in GSH-depleted cells, Cu induced an increase in oxidative stress resulting in DNA damage and activation of p53-dependent cell death. These findings may have important implications for neurodegenerative disorders that involve GSH depletion and aberrant Cu metabolism.

Ulcer protective effect of Terminalia arjuna on gastric mucosal defensive mechanism in experimental rats

The methanol extract of the bark of Terminalia arjuna (Combretaceae) (TAE) showed marked antiulcer and ulcer healing activity against 80% ethanol (ETH), diclofenac sodium (DIC) and dexamethasone (DEX) induced ulcer models dose dependently at doses of 100, 400 and 200 mg/kg body weight respectively. Pre-, post and co-administration of TAE offered 100% protection to the gastric mucosa against ETH, DIC and DEX induced ulcers as observed from the ulcer score. Gastric mucosal analysis of DEX induced rats were associated with changes in the levels of protein, protein bound carbohydrate complexes, lipid peroxides (LPO), glutathione (GSH) and activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) compared with control rats. Co-administration with TAE in DEX rats (DEX + TAE) favorably altered the levels of LPO, GSH and also the activities of SOD and CAT in gastric mucosa, whereas the activities of GPx remained unaltered in all groups. In DEX + TAE rats, the levels of protein and protein bound carbohydrate complexes were increased when compared with DEX rats. The results indicate that the gastroprotective effect of TAE is probably related to its ability to maintain the membrane integrity by its antilipid peroxidative activity that protects the gastric mucosa against oxidative damage and its ability to strengthen the mucosal barrier, the first line of defense against exogenous and endogenous ulcerogenic agents.