Protective effect of P. fraternus against ethanol-induced mitochondrial dysfunction

An Insight Into the Modulatory Effects and Mechanisms of Action of Phyllanthus Species and Their Bioactive Metabolites on the Immune System

Phyllanthus species (family; Euphorbiaceae) have been intensively studied for their immunomodulating effects due to their wide-ranging uses to treat immune-related diseases in indigenous medicine, which are primarily lack of scientific basis. The focuses of this review are on the significance of Phyllanthus species and their bioactive metabolites particularly corilagin (1), geraniin (2), gallic acid (3), phyllanthin (4), hypophyllanthin (5), ellagic acid (6), phyltetralin (7), niranthin (8), catechin (9), quercetin (10), astragalin (11), and chebulagic acid (12) in the modulation of both innate and adaptive immune systems through various mechanisms and their possible therapeutic benefits for treatment of immune-related diseases. We have compiled all significant findings published in the literature, and the data were analyzed critically to provide perspectives and directions for future research for the plants as a prospective source of novel immunomodulating agents. Various Phyllanthus species particularly Phyllanthus amarus, Phyllanthus emblica, Phyllanthus niruri, and Phyllanthus urinaria have been documented to possess significant immunomodulatory effects. However, the possible challenges encountered by the application of extracts of various Phyllanthus species and their bioactive constituents as immunomodulators need to be addressed. Most reports on the biological and pharmacological studies of the plants were based on crude extracts. The extracts were not chemically characterized, and the contributions of their chemical constituents to the bioactivities were not identified. The underlying mechanisms involved in the immunomodulatory effects of the Phyllanthus species were not indepthly studied due to limitations in terms of design, conduct, and interpretation. Extensive experimental and preclinical studies on the immunomodulating potential of Phyllanthus species should be carried out to provide sufficient data to prove that their traditional uses are inherently effective and safe and will allow clinical trials to be pursued for their further development as therapeutic agents to treat immune-related disorders.

Protective effect of aqueous extract of Phyllanthus fraternus against bromobenzene induced changes on cytosolic glutathione S-transferase isozymes in rat liver

The aim of this study was to investigate beneficial effect of aqueous extract of Phyllanthus fraternus (AEPF) on bromobenzene (BB) induced changes on cytosolic glutathione S-transferase (GST) isozymes in rat liver. Administration of BB significantly decreased the activity of GST, however, prior administration of AEPF prevented the BB induced decrease in GST activity. Further the cytosolic GSTs were purified from 3 groups of animals (control, BB and AEPF+BB administered) and resolved into three protein bands on SDS-PAGE. Densitometric analysis showed a significant decrease in BB group compared to control. Further, 2D PAGE analysis resolved these proteins into 8 bands which were identified as five isozymes of alpha, two of Mu and one of theta by MALDI-TOF MS and also observed decreased levels of isozymes in BB group. However, on prior administration of AEPF significantly prevented the BB induced decrease in GSTs and restored to normal levels.

An overview of important ethnomedicinal herbs of Phyllanthus species: present status and future prospects

The genus Phyllanthus consists of more than 1000 species, of which many are used as traditional medicines. The plant extracts have been used since ancient times, for treating hypertension, diabetes, hepatic, urinary, and sexual disorders, and other common ailments. Modern day scientific investigations have now confirmed pharmacognostic properties of Phyllanthus herbs. The phytochemicals attributing these medicinal properties have been identified in many of the Phyllanthus herbs. The morphologically similar herbs of Phyllanthus grow together and admixture of species during collection for manufacture of herbal medicines is quite common. Hence, along with pharmacognostic and phytochemical studies, appropriate protocols for correct identification of species are also important. As the use of these herbs as green medicines is becoming more popular, it is imperative to assess its genetic diversity and phylogenetic relatedness for future conservation strategies. This review is an attempt to present an overview of the existing studies on pharmacognostics, phytochemistry, species identification, and genetic diversity of Phyllanthus herbs and consequently (i) highlight areas where further research is needed and (ii) draw attention towards extending similar studies in underutilized but potentially important herbs such as P. maderaspatensis, P. kozhikodianus, P. rheedii, P. scabrifolius, and P. rotundifolius.

Protective role ofPhyllanthus niruri against nimesulide induced hepatic damage

Present study aimed to evaluate the protective role of the aqueous extract of Phyllanthus niruri (P. niruri) against nimesulide-induced hepatic disoder in mice by determining levels of glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT) and alkaline phosphatase (ALP) in serum and also by measuring the hepatic content of the antioxidant enzymes, superoxide dismitase (SOD) and catalase (CAT); the free radical scavenger, reduced glutathione (GSH) and thiobarbituric acid reacting substances (TBARS). Aqueous extract of P. niruri was administered either orally or intraperitoneally in different doses and times as needed for the experiments. Intraperitoneal of the extract (100 mg/kg body weight for seven days) reduced nimesulide (750 mg/kg body weight for 3 days) induced increased levels of GOT (37.0±1.8 units/ml in control group vs. 91.8±2.0 units/ml in nimesulide treated group vs. 35.0±1.0 units/ml in extract treated group), GPT (30.0±2.1 units/ml in control group vs. 88.4±2.9 units/ml in nimesulide treated group vs. 34.1±1.8 units/ml in extract treated group), and ALP (7.86±0.47 KA units/ml in control group vs. 23.80±0.60 KA units/ml in nimesulide treated group vs. 7.30±0.40 KA units/ml, in extract treated group) to almost nomal. In addition, P. niruri restored the nimesulide induced alterations of hepatic SOD (550±20 units/mg total protein in control group vs. 310±13 units/mg total protein in nimesulide treated group vs. 515±10 units/mg total protein in extract treated group), CAT (99.5±2 units/mg total protein in control group vs. 25.0±1.5 units/mg total protein in nimesulide treated group vs. 81.0±0.8 units/mg total protein in extract treated group), GSH (90±3 nmoles/mg total protein in control group vs. 17±4.2 nmoles/mg total protein in nimesulide treated group vs. 81±1 nmoles/mg total protein in extract treated group) and TBARS (measured as MDA, 36.6±3.0 nmoles/g liver tissue in control group vs. 96.3±5.2 nmoles/g liver tissue in nimesulide treated group vs. 41.2±1.7 nmoles/g liver tissue in extract treated group) contents. Dose-dependent studies showed that the herb could protect liver even if the nimesulide-induced injury is severe. Intraperitoneal administration of the extract showed better protective effect than oral administration. Combining all, the data suggest that P. niruri possesses hepatoprotective activity against nimesulide-induced liver toxicity and probably acts via an antioxidant defense mechanism. To the best of our knowledge, this is the first report of the hepatoprotective action of P. niruri against nimesulide induced liver damage.

Protein Isolate from the Herb Phyllanthus niruri Modulates Carbon Tetrachloride-Induced Cytotoxicity in Hepatocytes

ABSTRACT Phyllanthus niruri is a well-known hepatoprotective herbal plant. In the present study, hepatoprotective potential of the protein isolate of P. niruri was investigated against carbon tetrachloride (CCl(4))-induced hepatoxicity in vitro. Isolated hepatocytes were treated with CCl(4) and also separately with various concentrations of the protein isolate of P. niruri along with CCl(4). Levels of different marker enzymes related to hepatic integrity and different antioxidant enzymes as well as lipid peroxidation products in hepatocytes were measured in normal, control (toxicity induced), and protein isolate-treated cells. Administration of CCl(4) increased the leakage of glutamate pyruvate transaminase (GPT) by four fold and lactate dehydrogenase (LDH) by 84% in cell suspension, along with increased lipid peroxidation (114%), and reduced the levels of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) to almost 30% and 37% of the normal values, respectively. Treatment with the protein isolate of P. niruri significantly altered these changes. GPT value almost came down to normal levels and LDH value was reduced to 32% of normal values. Depletion of SOD and CAT activities were restored significantly to 75% and 87% of normal values, respectively. Lipid peroxidation was also reduced significantly. In the DPPH free radical scavenging activity, the protein isolate was also able to quench the free radical. Results suggest that the protein isolate of P. niruri protects hepatocytes against CCl(4)-induced oxidative damage and may be used as an effective cytoprotector against CCl(4)-induced hepatotoxicity.

Protective effect of Phyllanthus fraternus against bromobenzene induced mitochondrial dysfunction in rat liver mitochondria

The objective of the current study was to investigate the protective effect of an aqueous extract of Phyllanthus fraternus (AEPF) against bromobenzene induced mitochondrial dysfunction in rat liver mitochondria. Administration of bromobenzene (10 mmol/kg body wt.) significantly decreased the rate of respiration (with glutamate+malate or succinate as substrates), abolished respiratory control ratio (RCR) and P/O ratios completely. There was a significant increase in the levels of lipid peroxides and protein carbonyls and a significant decrease in the total sulphydryl groups. The activities of antioxidant enzymes like catalase, glutathione peroxidase (GPx), glutathione reductase (GR) and superoxide dismutase (SOD) were decreased. The levels of antioxidants like reduced and oxidized glutathione were significantly decreased compared to control. Administration of rats with an AEPF (100mg/kg body wt.) prior to bromobenzene administration showed several beneficial effects like: (i) complete protection on mitochondrial respiration, RCR and P/O ratios (ii) lipid peroxides and protein carbonyl levels were significantly lowered (iii) increased the levels of sulphydryl groups and the activity of antioxidant enzymes and (iv) significant increase in the levels of reduced and oxidized glutathione. Vitamin E was used as positive control and bromobenzene induced mitochondrial dysfunction was protected better with AEPF compared to vitamin E.

Protein isolate from the herb, Phyllanthus niruri L. (Euphorbiaceae), plays hepatoprotective role against carbon tetrachloride induced liver damage via its antioxidant properties

Phyllanthus niruri L. (Euphorbiaceae) (P. niruri) is a well-known hepatoprotective herbal plant. In the present study, hepatoprotective potential of the protein isolate of P. niruri was investigated against carbon tetrachloride (CCl(4)) induced liver damage in vivo. Protein isolate of P. niruri was intraperitoneally injected in mice either prior to (preventive) or after the induction of toxicity (curative). Levels of different liver marker enzymes in serum and different anti-oxidant enzymes, as well as lipid peroxidation products and glutathione (GSH) in liver homogenates were measured in normal, control (toxicity induced) and protein isolate treated mice. Administration of CCl(4) increased the serum glutamate pyruvate transaminase (GPT) and alkaline phosphatase (ALP) levels of mice sera along with increased lipid peroxidation and reduced levels of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) in the liver. Treatment with the protein isolate of P. niruri significantly altered these changes to almost normal. The protein isolate also showed protective properties as was evidenced in histopathological studies. Results suggest that the protein isolate of P. niruri protects liver tissues against oxidative damage and somehow helps stimulating repair mechanism present in liver. It could be used as an effective hepatoprotector against CCl(4) induced liver damage.

Herbal (Phyllanthus niruri) protein isolate protects liver from nimesulide induced oxidative stress

Present study was conducted to evaluate the role of a protein fraction (PI, protein isolate) of the herb, Phyllanthus niruri (P. niruri) against nimesulide-induced oxidative stress in vivo using a murine model. Mice were intraperitoneally treated with that at a dose of 5mg/kg body weight for 7 days before and separately 1-5 days after nimesulide (at a dose of 10mg/kg body weight for 7 days) administration to evaluate its preventive and curative role. Levels of reduced glutathione (GSH), antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), as well as thiobarbituric acid reactive substances (TBARS) were measured in the liver homogenates of all study groups. Pretreatment with isolated P. niruri protein fraction significantly enhanced nimesulide-induced reduced levels of antioxidant enzymes and GSH as well as reduced the enhanced level of lipid peroxidation. Post-treatment studies showed that the recovery after nimesulide induced oxidative stress was more rapid if PI was administered compared to the spontaneous recovery of liver. Histological studies also suggest that this protein fraction could prevent as well as cure liver from nimesulide induced oxidative stress. DPPH radical scavenging assay showed that it could scavenge free radicals. Its antioxidant property was compared with that of a known potent antioxidant, Vitamin E. Besides, the effect of a non-relevant protein, BSA, was also included in the study. Heat treatment and trypsin digestion destroyed the biological activity of this protein fraction. In conclusion, data obtained suggest that the P. niruri protein fraction may protect liver from nimesulide-induced oxidative stress probably via promotion of antioxidant defense.

Protective effect of Phyllanthus fraternus against allyl alcohol-induced oxidative stress in liver mitochondria

The effect of administration of allyl alcohol on the oxidative stress and the protective effect due to administration of an aqueous extract of Phyllanthus fraternus against allyl alcohol-induced damage in liver mitochondria were studied. When rats were treated with allyl alcohol, the rate of mitochondrial respiration was decreased significantly with both NAD(+)- and FAD-linked substrates. The respiratory control ratio, an index of membrane integrity and the P/O ratio, a measure of phosphorylation efficiency also decreased significantly. There was a significant increase in the lipid peroxide level and the protein carbonyl content. A significant decrease was observed in the total sulphydryl groups and a significant increase in the generation of superoxide radicals. Administration of rats with an aqueous extract of Phyllanthus fraternus (100 mg/kg) prior to allyl alcohol administration showed protection of 72, 40 and 80% using glutamate+malate (NADH oxidation) and 77, 54 and 20% using succinate as substrate on state 3, RCR and P/O ratio, respectively. The protection on lipid peroxide level was 88 and 91% in homogenate and mitochondria, respectively. In case of protein carbonyls, total sulphydryl groups and on the generation of superoxide radicals the protection was 99, 59 and 53%, respectively.

Phyllanthus amarus has anti-inflammatory potential by inhibition of iNOS, COX-2, and cytokines via the NF-kappaB pathway

BACKGROUND/AIMS

Phyllanthus amarus is a herbal medicine traditionally applied in the treatment of viral hepatitis. Aim of this study was to investigate potential anti-inflammatory properties of standardized P. amarus extracts concerning a potential influence of P. amarus on endotoxin-induced nitric oxide synthase (iNOS), cyclooxygenase (COX-2), and cytokine production in vivo and in vitro.

METHODS

Investigations were performed in rat Kupffer cells (KC), in RAW264.7 macrophages, in human whole blood, and in mice. Cells were stimulated with lipopolysaccharides (LPS) in the presence or absence of P. amarus extracts (hexane, EtOH/H(2)O), mice were treated with galactosamine/LPS as a model for acute toxic hepatitis. Nitrite was measured by Griess assay, prostaglandin E(2) (PGE(2)) by radioimmunoassay, and cytokines by enzyme-linked immunosorbent assay. iNOS and COX-2 were determined by Western blot, activation of NF-kappaB and AP-1 by EMSA.

RESULTS

P. amarus EtOH/H(2)O and hexane extracts showed an inhibition of LPS-induced production of NO and PGE(2) in KC and in RAW264.7. The extracts also attenuated the LPS-induced secretion of tumor necrosis factor (TNF-alpha) in RAW264.7 as well as in human whole blood. Both extracts reduced expression of iNOS and COX-2 and inhibited activation of NF-kappaB, but not of AP-1. P. amarus inhibited induction of interleukin (IL)-1beta, IL-10, and interferon-gamma in human whole blood and reduced TNF-alpha production in vivo.

CONCLUSIONS

This work shows that standardized extracts of P. amarus inhibit the induction of iNOS, COX-2, and TNF-alpha. Therefore, we report for the first time an anti-inflammatory potential of this traditionally employed herbal medicine both in vitro and in vivo.

Clinical manifestations and management of antiretroviral nucleoside analog-related mitochondrial toxicity

OBJECTIVES

This article reviews the clinical manifestations of mitochondrial toxicity associated with the use of nucleoside analog reverse transcriptase inhibitors (NRTIs) and outlines strategies to manage these sequelae.

BACKGROUND

NRTIs are the key components of the antiretroviral combinations used in the management of patients infected with HIV. The available NRTIs differ in their convenience of administration, frequency of dosing, resistance profiles, and side-effect profiles. NRTIs act as competitive inhibitors of the RNA/DNA polymerase reverse transcriptase of HIV and cause chain termination in the growing viral DNA chain. Many of the important and treatment-limiting side effects of NRTIs may be related to the effect of these agents on human DNA polymerases, in particular, mitochondrial DNA polymerase gamma. Depletion of mitochondrial DNA during chronic NRTI therapy may lead to cellular respiratory dysfunction and generalized and tissue- and drug-specific toxicities, including myopathy, peripheral neuropathy, and lactic acidosis. Recently, it has been proposed that the fat redistribution syndrome, or lipodystrophy, reported during chronic antiretroviral therapy is a manifestation of the differential impact of at least some NRTIs on peripheral and visceral adipocytes. Management of potential mitochondrial toxicity during NRTI therapy remains a challenge. A range of nutritional supplements, both as treatments and prophylaxes, have been proposed, and some have been investigated in vitro; no in vivo studies have yet been conducted.

METHODS

The information in this review was compiled using MEDLINE and AIDSLINE searches of the literature, including conference abstracts.

CONCLUSIONS

At present, interruption of NRTI therapy or substitution of the probable causative agent with alternative NRTIs that appear to be better tolerated represents the mainstay of management for mitochondrial toxicity and its clinical manifestations.

Protective effect of Phyllanthus fraternus against carbon tetrachloride-induced mitochondrial dysfunction

The effect of carbon tetrachloride administration on liver mitochondrial function and the protective effect of an aqueous extract of Phyllanthus fraternus were studied in rats. The following changes were observed in mitochondria due to the administration of carbon tetrachloride. 1) A decrease in the rate of respiration, respiratory control ratio and P/O ratio using glutamate and malate or succinate as substrates. 2) A decrease in the activities of NADH dehydrogenase (35%), succinate dehydrogenase (76%) and cytochrome c oxidase (51%). The rate of electron transfer through site I, site II and site III was studied independently and found to be significantly decreased. 3) A decrease in the content of cytochrome aa3 (34%). 4) A significant decrease in the levels of phospholipids particularly cardiolipin and a significant increase in the lipid peroxide level was observed. The carbon tetrachloride induced toxicity may be partly due to the lipid peroxidation and partly due to the effect on protein synthesis. Administration of rats with an aqueous extract of P. fraternus prior to carbon tetrachloride administration showed significant protection on the carbon tetrachloride induced mitochondrial dysfunction on all the parameters studied.