Antimicrobial potentiality of Phyllanthus amarus against drug resistant pathogens

Identification of authentic Phyllanthus amarus species in India

The Phyllanthus is a plant used in the traditional Ayurvedic Medicine system and has more than 800 species. These species grow in the same area and there are chances of adulteration of other species and, incorrect identification may also lead to wrong reports. This study was attempted by Enovate Biolife Pvt. Ltd. to identify authentic Phyllanthus amarus. The nine raw material samples were collected from different populations/suppliers from various zones of India for the study. All the samples were analysed using microscopic and macroscopic ID, and by using the High Performance Thin Layer Chromatography (HPTLC) fingerprint method. The samples collected from the Central zone (Lucknow PA-08, Uttar Pradesh) and the Southern zone (Coimbatore PA-05, and Chennai PA-09, Tamil Nadu) of India were found to be authentic P. amarus by the mentioned identification methods.

Delivery of Apoplastic Extracellular Vesicles Encapsulating Green-Synthesized Silver Nanoparticles to Treat Citrus Canker

The citrus canker pathogen Xanthomonas axonopodis has caused severe damage to citrus crops worldwide, resulting in significant economic losses for the citrus industry. To address this, a green synthesis method was used to develop silver nanoparticles with the leaf extract of Phyllanthus niruri (GS-AgNP-LEPN). This method replaces the need for toxic reagents, as the LEPN acts as a reducing and capping agent. To further enhance their effectiveness, the GS-AgNP-LEPN were encapsulated in extracellular vesicles (EVs), nanovesicles with a diameter of approximately 30-1000 nm naturally released from different sources, including plant and mammalian cells, and found in the apoplastic fluid (APF) of leaves. When compared to a regular antibiotic (ampicillin), the delivery of APF-EV-GS-AgNP-LEPN and GS-AgNP-LEPN to X. axonopodis pv. was shown to have more significant antimicrobial activity. Our analysis showed the presence of phyllanthin and nirurinetin in the LEPN and found evidence that both could be responsible for antimicrobial activity against X. axonopodis pv. Ferredoxin-NADP⁺ reductase (FAD-FNR) and the effector protein XopAI play a crucial role in the survival and virulence of X. axonopodis pv. Our molecular docking studies showed that nirurinetin could bind to FAD-FNR and XopAI with high binding energies (-10.32 kcal/mol and -6.13 kcal/mol, respectively) as compared to phyllanthin (-6.42 kcal/mol and -2.93 kcal/mol, respectively), which was also supported by the western blot experiment. We conclude that (a) the hybrid of APF-EV and GS-NP could be an effective treatment for citrus canker, and (b) it works via the nirurinetin-dependent inhibition of FAD-FNR and XopAI in X. axonopodis pv.

Gallic acid a flavonoid isolated from Euphorbia hirta antagonizes gamma radiation induced radiotoxicity in lymphocytes in vitro

OBJECTIVES

The current study was executed to isolate and evaluate gallic acid from Euphorbia hirta for in vitro radioprotective potentials against gamma irradiation caused radiotoxicity in human lymphocytes.

METHODS

The defatted E. hirta plant material was treated to methanol extraction using the soxhlet device. Bioflavonoids were isolated from the E. hirta methanol extract using column chromatography. In human cells exhibited to gamma radiation, separated flavonoid gallic acid was examined for in vitro radioprotective potentials using the micronucleus test, DNA fragmentation assay, superoxide free radical scavenging method, and apoptic assay.

RESULTS

The frequency of micronuclei was considerably declined when cells were preprocessed with gallic acid (25 g/mL) before being exhibited to 2 Gy gamma radiation, as determined by the cytokinesis blocked micronucleus test. Similarly, pre-gamma radiation treatment of human cells with gallic acid led in markedly less DNA injury, as assessed by comet metrics like olive tail moment and percent tail DNA. Gallic acid (25 g/mL) given to lymphocytes prior to gamma irradiation considerably decreased the percentage of apoptotic bodies. Gallic acid also considerably lowered the reactive oxygen species concentrations elicited by gamma radiation.

CONCLUSIONS

Our findings showed that gallic acid protects lymphocytes isolated from human blood from gamma radiation-induced DNA destruction and anti-apoptotic activity, which could be because of inhibition of free radicals formed by gamma radiation as well as the decline of gamma radiation-induced oxidative stress.

An insight into the potent medicinal plant Phyllanthus amarus Schum. and Thonn

Phyllanthus amarus Schum. and Thonn., a globally distributed herb is known for its several therapeutic potentials. P. amarus has a long history of use in the traditional system of medicine for over 2000 years owing to its wide array of secondary metabolites that confer significant medicinal attributes. Research on various aspects including ethnobotany, phytochemistry to bioactivity, or pharmacological studies has been conducted over the past several decades on this potent herb. P. amarus extracts have shown a broad range of pharmacological activities like hepatoprotective, antioxidant, antiviral, antimicrobial, antidiabetic, anti-inflammatory, anticancer, antimalarial, nephroprotective, diuretic, and several other properties. The present review compiles and covers literature and research of several groups across past decades to date and focuses on how the therapeutic significance of this plant can be further explored for future research either as herbal formulations, alternative medicine, or in the pharmaceutical industry.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13237-022-00409-z.

In Vitro Anti-Leptospiral Activity of Phyllanthus amarus Extracts and Their Combinations with Antibiotics

Despite modern medicine, there is an increasing trend for cases of the bacterial infection leptospirosis, and this has led to the exploration of alternative medicines from various sources including plants. The aim of this study was to investigate the in vitro anti-leptospiral activity of Phyllanthus amarus extracts alone and combined with penicillin G, ceftriaxone, and doxycycline. Antimicrobial susceptibility testing was performed using the microdilution broth technique upon methanol extract (ME), aqueous extract (AE), and antibiotics against the Leptospira interrogans serovars Australis, Bataviae, Canicola, and Javanica, to determine minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs). The results were analyzed using an ELISA microplate reader combined with microscopic analysis. Synergy testing using a checkerboard assay was performed to determine the fractional inhibitory concentration index values of extracts combined with antibiotics against leptospires. Scanning electron microscopy (SEM) was used to investigate morphological changes of leptospires caused by potential anti-leptospiral agents alone and combined with antibiotics. The MICs and MBCs for P. amarus extracts ranged from 100 to 400 µg/mL for AEs and from 400 to 800 µg/mL for MEs. Penicillin G was the most effective anti-leptospiral drug, with MICs and MBCs ranging from <0.01 to 0.78 and <0.01 to 3.13 µg/mL, respectively, followed by ceftriaxone, with both MICs and MBCs ranging from 0.05 to 0.78 µg/mL, and doxycycline, with MICs and MBCs ranging from 0.39 to 3.13 µg/mL and 12.5 to 25 µg/mL, respectively. Combinations of P. amarus extracts and antibiotics did not show synergistic effects on all tested Leptospira serovars, with some combinations demonstrating antagonistic effects. SEM analysis, however, showed distorted Leptospira surfaces. P. amarus AE performed better anti-leptospiral activity than P. amarus ME. The morphological effects of P. amarus extract alone and its combination with antibiotic on Leptospira cells revealed promising anti-leptospiral properties.

Phyllanthus amarus extract restored deranged biochemical parameters in rat model of hepatotoxicity and nephrotoxicity

Phyllanthus amarus has been exploited for the management of several aliments in folkloric medicine. The present study therefore investigates the restorative potential of its leaves extract on hepatic and renal assault induced by CCl4 and rifampicin respectively. Eight groups (I-VIII) containing five animals each were created for the experiments. Group I were fed with normal commercial pellet only, while group II were exposed to single intraperitoneal injection of 3 ml/kg b.w. of CCl4 only. Groups III, IV and V animals were administered 3 ml/kg b/w of CCl4 and treated with 50, 100 mg/kg b. w. of P. amarus and 100 mg/kg b.w of silymarin respectively. Group VI animals were orally exposed to 250 mg/kg b/w of rifampicin only while groups VII and VIII were treated with 50 and 100 mg/kg b. w. P. amarus respectively for 14 days after the initial exposure to 250 mg/kg b/w rifampicin . Liver and kidney function tests such as alanine amino transferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), bilirubin, urea and uric acid were determined in the serum and organs homogenates. Moreover, malonidialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD) and glutathione (GSH) as well as lipid profile were also measured. Results showed that exposure to rifampicin and CCl4 respectively caused a marked derangement in lipid profile as well as decrease in SOD and CAT activity relative to the negative control. Administration of both toxicants also caused a marked increase in serum ALT, AST, ALP, urea, uric acid and creatine kinase compared to the negative control. Treatment with P. amarus attenuated the toxicity imposed by rifampicin and CCl4 on the liver and kidney in a dose-dependent fashion. All biochemical indices measured were restored to values comparable with animals treated with silymarin. Histopathological results of the hepatic and renal tissues from the various groups of experimental animals gave credence to the curative effects of P. amarus leaf extract on damaged liver and kidney cells. Put together, P. amarus is a potential medicinal plant with similar potency to conventional drugs currently in use for the treatment liver and kidney diseases. Hence, it is a viable therapeutic alternative that can be exploited for the treatment of renal and hepatic diseases.

An Insight Into the Anxiolytic Effects of Lignans (Phyllanthin and Hypophyllanthin) and Tannin (Corilagin) Rich Extracts of Phyllanthus amarus : An In-Silico and In-vivo approaches

The extracts and the compounds isolated from Phyllanthus amarus Schumm and Thonn (Family: Euphorbiaceae) have shown a wide spectrum of pharmacological activities including antiviral, antibacterial, antiplasmodial, antimalarial, antimicrobial, anticancer, antidiabetic, hypolipidemic, antioxidant, hepatoprotective, nephroprotective and diurectic properties.

BACKGROUND

This investigation was aimed at exploring the anxiolytic potential of Phyllanthus amarus standardized extracts and predict probable role of marker phyto constitutents.

OBJECTIVE AND METHODS

Three standardized extracts of Phyllanthus amarus plant viz. standardized aqueous extract of Phyllanthus amarus whole plant (PAAE), standardized methanolic extract of P. amarus leaf (PAME) and the standardized hydro-methanolic extract of P. amarus leaf (PAHME) were tested in the classical animal models of anxiety: Elevated plus-maze model and Light & Dark Exploration test.

RESULTS

The lower doses of the tannin rich extract (PAHME) of the P. amarus possess significant anxiolytic activity compared to lignin rich (PAME) and aqueous extracts (PAAE), while at a higher dose (400mg/kg) the results of all three extracts appears to be potentially sedative. While the molecular docking studies support these probable anxiolytic, the sedative effects of the Phyllanthus amarus extracts could be due to the interaction of tannins and lignans with the GABAbenzodiazepine receptor complex.

CONCLUSION

The results of the present study indicate that the tannin-rich extract of the P. amarus may have potential clinical applications in the management of anxiety. It can be further studied for optimum dosage to be used as a future of anti-anxiety drug development or as a standardized Phytomedicine.

Evaluation of in-vivo anti-Salmonella activity of Uvaria chamae, Lantana camara and Phyllantus amarus used in Benin, West Africa

BACKGROUND

Uvaria chamae (Annonaceae), Phyllantus amarus (Phyllantaceae) and Lantana camara (Verbenaceae) are empirically alleged to be used as Beninese medicinal plants in the treatment of salmonellosis. This study aimed to produce scientific data on in vitro and in vivo efficacy of Uvaria chamae, Lantana camara and Phyllantus amarus on multiresistant Salmonella spp isolated in Benin.

RESULTS

After performing in vitro tests on aqueous and ethanolic extracts of these plants, only the aqueous extract of Uvaria chamae (leaves) showed the best anti-Salmonella's activity and was used for this in vivo experiment. The induction of salmonellosis revealed 9 × 108 CFU/ml was the optimal concentration triggering and maintaining symptoms in chicks. This infective concentration was used for in vivo assessment. Twenty-four hours post inoculation, the symptoms of salmonellosis (wet cloaca, diarrhea stools and somnolence) were observed in infected groups. After 7 days of treatment, the reduction of bacterial load at 100 mg/L, 200 mg/L, 400 mg/L of the extract was respectively 85%, 52.38% and 98% for Uvaria chamae, Phyllantus amarus and Lantana camara in the chick's groups infected with Salmonella Typhimurium ATCC 14028. On the other hand, colistin completely cancelled the bacterial load (reduction rate of 100%). With the groups infected with Salmonella spp (virulent strain), the reduction rate of bacterial load at 100 mg/L, 200 mg/L, 400 mg/L of extract was 0%, 98.66%, and 99.33%. The extracts at 200 and 400 mg/L were more active than colistin, which reduced the bacterial load by 33.33%. The toxicity tests did not show any negative effect of Colistin and the Uvaria chamae's extract on the biochemical and hematological parameters of the chicks.

CONCLUSION

The aqueous extract of Uvaria chamae is active in vitro and in vivo on multiresistant strains of Salmonella enterica. This plant is a good candidate for the development of an improved traditional medicine for the management of salmonellosis.

Antimicrobial activity of Phyllanthus amarus Schumach. & Thonn and inhibition of the NorA efflux pump of Staphylococcus aureus by Phyllanthin

The aim of this study was to evaluate the antimicrobial activity of ethanoic extract of P. amarus (PAEE) and its compound Phyllanthin, as well as, investigate if these natural products could modulate the fluoroquinolone-resistance in S. aureus SA1199-B by way of overexpression of the NorA efflux pump. Microdilution tests were carried out to determine the minimal inhibitory concentration (MIC) of the PAEE or Phyllanthin against several bacterial and yeast strains. To evaluate if PAEE or Phyllanthin were able to act as modulators of the fluoroquinolone-resistance, MICs for Norfloxacin and ethidium bromide were determined in the presence or absence of PAEE or Phyllanthin against S. aureus SA1199-B. PAEE showed antimicrobial activity against Gram-negative strains, meanwhile Phyllanthin was inactive against all strains tested. Addition of PAEE or Phyllanthin, to the growth media at sub-inhibitory concentrations enhanced the activity of the Norfloxacin as well as, Ethidium Bromide, against S. aureus SA1199-B. These results indicate that Phyllanthin is able to modulate the fluoroquinolone-resistance possibly by inhibition of NorA. This hypothesis was supported by in silico docking analysis which confirmed that Phyllantin is a NorA ligand. Thus, this compound could be used as a potentiating agent of the Norfloxacin activity in the treatment of infections caused by fluoroquinolone-resistant S. aureus.

Pharmacological and polyphenolic profiles of Phyllanthus phillyreifolius var. commersonii Müll. Arg: An unexplored endemic species from Mauritius

Phyllanthus phillyreifolius var. commersonii Müll. Arg is an endemic plant of Mauritius. To date, no study has been performed concerning its polyphenolic profile and pharmacological properties. In this study, a decoction (water), ethyl acetate and methanol extracts of the aerial parts of P. phillyreifolius, obtained from different extraction procedures (maceration and Soxhlet), were studied for antibacterial, antioxidant, anticancer, and enzyme inhibitory properties along with their polyphenolic profile. The ethyl acetate macerated extract showed high antibacterial activity against B. cereus (MIC = 0.293 mg/mL) and E. coli (MIC = 0.417 mg/mL) while S. epidermidis was most susceptible to the ethyl acetate-Soxhlet extract (MIC = 0.521 mg/mL). The methanol-Soxhlet extract displayed the most potent cupric and ferric reducing power, and metal chelating effect, while the macerated methanolic extract was the most effective DPPH and ABTS scavenger, and BChE inhibitor. Only the ethyl acetate-Soxhlet extract exhibited α-glucosidase inhibition. All extracts exhibited a strong anti-tyrosinase activity, which was further investigated by molecular docking and molecular dynamic. After 48 h exposure to the extracts for HeLa cell lines, the ethyl acetate-Soxhlet extract showed the highest inhibition (IC₅₀ = 533.1 μg/mL) while the decoction extract was more cytotoxic to MDA-MB-231 cells (IC₅₀ = 337.4 μg/mL). Treatment of cancer cell lines with all P. phillyreifolius extracts resulted in a time-dependent reduction of cell viability for HeLa and dose-and time-dependent reduction for MDA-MB-231. Gene expression ratio of Bcl-2 to Bax was higher for all Soxhlet-extracts. Total phenolics (TPC) and flavonoids (TFC) content were highest in the decoction and methanol-Soxhlet extract, respectively (122.43 mg GAE/g extract and 31.28 mg RE/g extract, respectively). The extracts were abundant in ellagitannins, although phenolic acids and flavonoids were also detected. Granatin B was detected for the first time in Phyllanthus species. Overall, the aerial parts of P. phillyreifolius exemplify a potent reservoir of bioactive phytochemicals for therapeutic applications.

Potential P-glycoprotein-mediated herb-drug interaction of phyllanthin at the intestinal absorptive barrier

Objectives

This study investigated the absorptive potential of phyllanthin across the polarized Caco-2 monolayers and the potential role of phyllanthin in P-glycoprotein (P-gp)-mediated drug interaction.

Methods

The absorptive potential of phyllanthin was predicted from its apparent permeability (Papp) across the Caco-2 monolayers under the pH gradient condition (pH 6.5AP–7.4BL) at 37°C. Integrity of paracellular transport was assessed by monitoring transepithelial electrical resistance (TEER) and lucifer yellow (LY) leakage. P-gp-mediated interaction was evaluated by transport studies of phyllanthin and rhodamine-123.

Key findings

The absorptive Papp of phyllanthin (34.90 ± 1.18 × 10−6 cm/s) was in the same rank order as the high permeable theophylline and antipyrine. Phyllanthin transport in the absorptive and secretive directions was comparable (the efflux ratio (ER) of 1.19 ± 0.01). Phyllanthin caused no changes in TEER nor LY leakage in the monolayers. However, phyllanthin increased rhodamine-123 ER in a concentration-dependent manner, suggesting its inhibition on P-gp function. In addition, phyllanthin aqueous solubility was &lt;5 μg/ml at 37°C.

Conclusions

Phyllanthin is a highly permeable compound that could passively diffuse through the absorptive barrier via transcellular pathway with little hindrance from P-gp. Phyllanthin could interfere with transport of P-gp drug substrates, when concomitantly administered. In addition, aqueous solubility could be a limiting factor in phyllanthin absorption.

Sequencing, De novo Assembly, Functional Annotation and Analysis of Phyllanthus amarus Leaf Transcriptome Using the Illumina Platform

Phyllanthus amarus Schum. and Thonn., a widely distributed annual medicinal herb has a long history of use in the traditional system of medicine for over 2000 years. However, the lack of genomic data for P. amarus, a non-model organism hinders research at the molecular level. In the present study, high-throughput sequencing technology has been employed to enhance better understanding of this herb and provide comprehensive genomic information for future work. Here P. amarus leaf transcriptome was sequenced using the Illumina Miseq platform. We assembled 85,927 non-redundant (nr) "unitranscript" sequences with an average length of 1548 bp, from 18,060,997 raw reads. Sequence similarity analyses and annotation of these unitranscripts were performed against databases like green plants nr protein database, Gene Ontology (GO), Clusters of Orthologous Groups (COG), PlnTFDB, KEGG databases. As a result, 69,394 GO terms, 583 enzyme codes (EC), 134 KEGG maps, and 59 Transcription Factor (TF) families were generated. Functional and comparative analyses of assembled unitranscripts were also performed with the most closely related species like Populus trichocarpa and Ricinus communis using TRAPID. KEGG analysis showed that a number of assembled unitranscripts were involved in secondary metabolites, mainly phenylpropanoid, flavonoid, terpenoids, alkaloids, and lignan biosynthetic pathways that have significant medicinal attributes. Further, Fragments Per Kilobase of transcript per Million mapped reads (FPKM) values of the identified secondary metabolite pathway genes were determined and Reverse Transcription PCR (RT-PCR) of a few of these genes were performed to validate the de novo assembled leaf transcriptome dataset. In addition 65,273 simple sequence repeats (SSRs) were also identified. To the best of our knowledge, this is the first transcriptomic dataset of P. amarus till date. Our study provides the largest genetic resource that will lead to drug development and pave the way in deciphering various secondary metabolite biosynthetic pathways in P. amarus, especially those conferring the medicinal attributes of this potent herb.

Medicinal plants with potential anti-arthritic activity

ETHNO PHARMACOLOGICAL RELEVANCE

Traditional medicinal plants are practiced worldwide for treatment of arthritis especially in developing countries where resources are meager. This review presents the plants profiles inhabiting throughout the world regarding their traditional usage by various tribes/ethnic groups for treatment of arthritis.

MATERIALS AND METHODS

Bibliographic investigation was carried out by analyzing classical text books and peer reviewed papers, consulting worldwide accepted scientific databases from the last six decades. Plants/their parts/extracts/polyherbal formulations, toxicity studies for arthritis have been included in the review article. The profiles presented also include information about the scientific name, family, dose, methodology along with mechanism of action and toxicity profile. Research status of 20 potential plant species has been discussed. Further, geographical distribution of research, plants distribution according to families has been given in graphical form.

RESULTS

485 plant species belonging to 100 families, traditionally used in arthritis are used. Among 100 plant families, malvaceae constitute 16, leguminasae 7, fabaceae 13, euphorbiaceae 7, compositae 20, araceae 7, solanaceae 12, liliaceae 9, apocynaceae, lauraceae, and rubiaceae 10, and remaining in lesser proportion. It was observed in our study that majority of researches are carried mainly in developing countries like India, China, Korea and Nigeria.

CONCLUSION

This review clearly indicates that list of medicinal plants presented in this review might be useful to researchers as well as practioners. This review can be useful for preliminary screening of potential anti-arthritis plants. Further toxicity profile given in the review can be useful for the researchers for finding the safe dose.

Green silver nanoparticles of Phyllanthus amarus: as an antibacterial agent against multi drug resistant clinical isolates of Pseudomonas aeruginosa

BACKGROUND

Pseudomonas aeruginosa infection is a leading cause of morbidity and mortality in burn and immune-compromised patients. In recent studies, researchers have drawn their attention towards ecofriendly synthesis of nanoparticles and their activity against multidrug resistant microbes. In this study, silver nanoparticles were synthesized from aqueous extract of Phyllanthus amarus. The synthesized nanoparticles were explored as a potent source of nanomedicine against MDR burn isolates of P. aeruginosa.

RESULTS

Silver nanoparticles were successfully synthesized using P. amarus extract and the nature of synthesized nanoparticles was analyzed by UV-Vis spectroscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, dynamic light scattering, zeta potential, X- ray diffraction and fourier transform infra-red spectroscopy. The average size of synthesized nanoparticles was 15.7, 24 ± 8 and 29.78 nm by XRD, TEM and DLS respectively. The antibacterial activity of AgNPs was investigated against fifteen MDR strains of P. aeruginosa tested at different concentration. The zone of inhibition was measured in the range of 10 ± 0.53 to 21 ± 0.11mm with silver nanoparticles concentration of 12.5 to 100 μg/ml. The zone of inhibition increased with increase in the concentration of silver nanoparticles. The MIC values of synthesized silver nanoparticles were found in the range of 6.25 to12.5 μg/ml. The MIC values are comparable to the standard antibiotics.

CONCLUSION

The present study suggests that silver nanoparticles from P. amarus extract exhibited excellent antibacterial potential against multidrug resistant strains of P. aeruginosa from burn patients and gives insight of their potential applicability as an alternative antibacterial in the health care system to reduce the burden of multidrug resistance.

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.

Effects of cocktail of four local Malaysian medicinal plants (Phyllanthus spp.) against dengue virus 2

Background

The absence of commercialized vaccines and antiviral agents against dengue has made the disease a major health concern around the world. With the current dengue virus transmission rate and incidences, the development of antiviral drugs is of vital need. The aim of this project was to evaluate the possibility of developing a local medicinal plant, Phyllanthus as an anti-dengue agent.

Methods

Cocktail (aqueous and methanolic) extracts were prepared from four species of Phyllanthus (P.amarus, P.niruri, P.urinaria, and P.watsonii) and their polyphenolic compounds were identified via HPLC and LC-MS/MS analysis. MTS assay was then carried out to determine the maximal non-toxic dose (MNTD) of the extracts, followed by screening of the in vitro antiviral activity of aqueous cocktail extracts against DENV2 by means of time-of-addition (pre-, simultaneous and post-) using RT-qPCR. The differentially expressed proteins in the treated and infected cells were analysed with two dimensional gel electrophoresis experiments.

Results

Several active compounds including gallic acid, geraniin, syringin, and corilagen have been identified. The MNTD of both aqueous and methanolic extracts on Vero cells were 250.0 μg/ml and 15.63 μg/ml respectively. Phyllanthus showed strongest inhibitory activity against DENV2 with more than 90% of virus reduction in simultaneous treatment. Two-dimensional analysis revealed significantly altered levels of thirteen proteins, which were successfully identified by tandem MS (MS/MS). These altered proteins were involved in several biological processes, including viral entry, viral transcription and translation regulations, cytoskeletal assembly, and cellular metabolisms.

Conclusions

Phyllanthus could be potentially developed as an anti-DENV agent.

Phyllanthus amarus: ethnomedicinal uses, phytochemistry and pharmacology: a review

ETHNOPHARMACOLOGICAL RELEVANCE

Phyllanthus amarus Schum. & Thonn. belongs to the family Euphorbiaceae is a small herb well known for its medicinal properties and widely used worldwide. P. amarus is an important plant of Indian Ayurvedic system of medicine which is used in the problems of stomach, genitourinary system, liver, kidney and spleen. It is bitter, astringent, stomachic, diuretic, febrifuge and antiseptic. The whole plant is used in gonorrhea, menorrhagia and other genital affections. It is useful in gastropathy, diarrhoea, dysentery, intermittent fevers, ophthalmopathy, scabies, ulcers and wounds.

MATERIALS AND METHODS

The present review covers a literature across from 1980 to 2011. Some information collected from traditional Ayurvedic texts and published literature on ethanomedicinal uses of Phyllanthus amarus in different countries worldwide.

RESULTS

Phytochemical studies have shown the presence of many valuable compounds such as lignans, flavonoids, hydrolysable tannins (ellagitannins), polyphenols, triterpenes, sterols and alkaloids. The extracts and the compounds isolated from P. amarus show a wide spectrum of pharmacological activities including antiviral, antibacterial, antiplasmodial, anti-inflammatory, antimalarial, antimicrobial, anticancer, antidiabetic, hypolipidemic, antioxidant, hepatoprotective nephroprotective and diurectic properties.

CONCLUSION

The present review summarizes information concerning the morphology, ecology, ethnopharmacology, phytochemistry, biological activities, clinical applications and toxicological reports of P. amarus. This review aims at gathering the research work undertaken till date on this plant in order to provide sufficient baseline information for future works and commercial exploitation.

Phyllanthus spp. induces selective growth inhibition of PC-3 and MeWo human cancer cells through modulation of cell cycle and induction of apoptosis

BACKGROUND

Phyllanthus is a traditional medicinal plant that has been used in the treatment of many diseases including hepatitis and diabetes. The main aim of the present work was to investigate the potential cytotoxic effects of aqueous and methanolic extracts of four Phyllanthus species (P.amarus, P.niruri, P.urinaria and P.watsonii) against skin melanoma and prostate cancer cells.

METHODOLOGY/PRINCIPAL FINDINGS

Phyllanthus plant appears to possess cytotoxic properties with half-maximal inhibitory concentration (IC(50)) values of 150-300 µg/ml for aqueous extract and 50-150 µg/ml for methanolic extract that were determined using the MTS reduction assay. In comparison, the plant extracts did not show any significant cytotoxicity on normal human skin (CCD-1127Sk) and prostate (RWPE-1) cells. The extracts appeared to act by causing the formation of a clear "ladder" fragmentation of apoptotic DNA on agarose gel, displayed TUNEL-positive cells with an elevation of caspase-3 and -7 activities. The Lactate Dehydrogenase (LDH) level was lower than 15% in Phyllanthus treated-cancer cells. These indicate that Phyllanthus extracts have the ability to induce apoptosis with minimal necrotic effects. Furthermore, cell cycle analysis revealed that Phyllanthus induced a Go/G1-phase arrest on PC-3 cells and a S-phase arrest on MeWo cells and these were accompanied by accumulation of cells in the Sub-G1 (apoptosis) phase. The cytotoxic properties may be due to the presence of polyphenol compounds such as ellagitannins, gallotannins, flavonoids and phenolic acids found both in the water and methanol extract of the plants.

CONCLUSIONS/SIGNIFICANCE

Phyllanthus plant exerts its growth inhibition effect in a selective manner towards cancer cells through the modulation of cell cycle and induction of apoptosis via caspases activation in melanoma and prostate cancer cells. Hence, Phyllanthus may be sourced for the development of a potent apoptosis-inducing anticancer agent.

Radioprotective properties of polyphenols from Phyllanthus amarus Linn

Radioprotective activity of pure compounds isolated from the plant Phyllanthus amarus was studied using rat liver mitochondria and pBR322 plasmid DNA as an in vitro model system. These compounds were ellagitannins namely amariin, 1-galloyl-2,3-dehydrohexahydroxydiphenyl (DHHDP)-glucose, repandusinic acid, geraniin, corilagin, phyllanthusiin D, and flavonoids namely rutin, and quercetin 3-O-glucoside. The activity was then correlated with their hydroxyl and superoxide radical scavenging activity. Both ellagitannins and flavonoids effectively prevented lipid peroxidation and protein oxidation in mitochondria. The compounds also prevented radiation induced single strand breaks in pBR322 plasmid DNA. The radioprotective activity of ellagitannins and flavonoids could be due to their ability to scavenge different radicals more or less efficiently, relieving the oxidative stress. Protection conferred by flavonoids, rutin and quercetin 3-O-glucoside to rat liver mitochondria and plasmid pBR322 DNA from radiation induced damage was due to their strong hydroxyl radical scavenging activity. The inhibitory effect of ellagitannins on lipid peroxidation in liver mitochondria was due to their efficient superoxide radical scavenging ability. This is the first report about the radioprotective activity of pure ellagitannins from Phyllanthus amarus.

Two new lignans from Phyllanthus amarus

Two new lignans, 3-(3,4-dimethoxy-benzyl)-4-(7-methoxy-benzo[1,3]dioxol-5-yl-methyl)-dihydrofuran-2-one (1) and 4-(3,4-dimethoxy-phenyl)-1-(7-methoxy-benzo[1,3]dioxol-5-yl)-2,3-bis-methoxymethyl-butan-1-ol (2), were isolated from the leaves of Phyllanthus amarus and their structures were established by spectral analysis. Additionally, eight known lignans were also isolated and characterized.

Antioxidant potential of aqueous extract of Phyllanthus amarus in rats

OBJECTIVE

Increased levels of oxidative stress may be implicated in the etiology of many pathological conditions. Protective antioxidant action imparted by many plant extracts and plant products make them promising therapeutic drugs for free radical induced pathologies. In this study we assessed the antioxidant potential of Phyllanthus amarus (Euphorbiaceae).

MATERIALS AND METHODS

EXPERIMENTAL RATS WERE DIVIDED INTO TWO GROUPS: Control and Phyllanthus amarus (P. amarus) treated. Treated rats received P. amarus aqueous extract (PAAEt) at a dose of 200 mg/kg body wt/day for 8 weeks. After the treatment period of 8 weeks lipid peroxidation (LPO), vitamin C, uric acid and reduced glutathione (GSH) were estimated in plasma and antioxidant enzymes: Glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD) were also assayed. Genotoxicity of PAAEt was assessed by single cell gel electrophoresis (SCGE) of lymphocytes under both in vitro and in vivo conditions. The protective role of PAAEt against hydrogen peroxide (H(2)O(2)), streptozotocin (STZ) and nitric oxide generating system induced lymphocyte DNA damage was also assessed by SCGE.

RESULTS

PAAEt treated rats showed a significant decrease in plasma LPO and a significant increase in plasma vitamin C, uric acid, GSH levels and GPx, CAT and SOD activities. SCGE experiment reveals that PAAEt was devoid of genotoxicity and had a significant protective effect against H(2)O(2), STZ and nitric oxide (NO) induced lymphocyte DNA damage.

CONCLUSION

The results suggest the non-toxic nature of PAAEt and consumption of PAAEt can be linked to improved antioxidant status and reduction in the risk of oxidative stress.