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Tectona grandis Linn, commonly known as teak, is traditionally used to treat a range of diseases, including the common cold, headaches, bronchitis, scabies, diabetes, inflammation, and others. The present study was conducted with the purpose of isolating and identifying the active compounds in T. grandis leaf against a panel of Vibrio spp., which may induce vibriosis in shrimp, using bioassay-guided purification. The antimicrobial activity was assessed using the microdilution method, followed by the brine shrimp lethality assay to determine toxicity. Following an initial screening with a number of different solvents, it was established that the acetone extract was the most effective. The acetone extract was then exposed to silica gel chromatography followed by reversed-phase HPLC and further UHPLC-orbitrap-ion trap mass spectrometry to identify the active compounds. Three compounds called 1-hydroxy-2,6,8-trimethoxy-9,10-anthraquinone, deoxyanserinone B, and khatmiamycin were identified with substantial anti-microbial action against V. parahaemolyticus, V. alginolyticus, V. harveyi, V. anguillarum, and V. vulnificus. The IC 50 values of the three compounds viz. 1-hydroxy-2,6,8-trimethoxy-9,10-anthraquinone, deoxyanserinone B, and khatmiamycin varied between 2 and 28, 7 and 38, and 7 and 56 μg/mL, respectively, which are as good as the standard antibiotics such as amoxicillin and others. The in vivo toxicity test revealed that the compounds were non-toxic to shrimp. The results of the study suggest that T. grandis leaf can be used as a source of bioactive compounds to treat Vibrio species in shrimp farming., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Turmeric rhizome (Curcuma longa L.) has been used without concern for safety as a culinary spice and traditional medicine under the ancient Ayurvedic medicinal system of India dating back nearly 4000 years. This preclinical safety evaluation was done to determine the safety of an oleoresin-based turmeric extract (CURCUGEN®). Guidelines from the Organization for Economic Co-operation and Development (OECD) directed the assessment of safety for the in vitro and in vivo application of CURCUGEN®. Safety of the herbal medicine was evaluated through the toxicological assessment of acute, oral, and 90-day repeated dosing, genotoxicity, and mutagenicity study. Genotoxicity tests included the in vitro bacterial reverse mutation test, chromosomal aberration test, and in vivo micronucleus test. The single dose of CURCUGEN® administered orally (gavage) to Sprague-Dawley (SD) rats resulted in a LD50 of >5000 mg/kg body weight. The subchronic assessment of CURCUGEN®, as administered to SD rats over 90 days resulted in a no observed adverse effect level (NOAEL) of 2000 mg/kg body weight/day. CURCUGEN® did not elicit any genotoxic or clastogenic effect in genotoxicity tests. The battery of safety studies carried out demonstrated that CURCUGEN® showed no evidence of general toxicity or genotoxicity., Competing Interests: Authors Somashekara Nirvanashetty and Sanjib Kumar Panda are employed by Olene Life Sciences Pvt. Ltd. Corresponding author Shavon Jackson-Michel is employed by DolCas Biotech, LLC. These authors were not involved in the analysis of data which was independently conducted by Bioneeds India Pvt. Ltd., (Copyright © 2022 Somashekara Nirvanashetty et al.)

Disease epidemics in shrimp aquaculture increase apace with the development of aquaculture systems throughout the world. The disease caused by Vibrio spp. (vibriosis) is considered the most devastating, which has made it the most feared bacterial disease in the shrimp sector. In aquaculture, several strategies have already been applied to control Vibrio strains, including chemicals, probiotics, antibiotics, natural products from plants, including plant oils; hence, there has been considerable attention for using plants in shrimp aquaculture to provide sustainable, eco-friendly and safe compounds, such as alkaloids, saponins, terpenoids and flavonoids for replacing chemical compounds and antibiotics in current aquaculture. Medicinal plants may also have immunostimulating activity, increase growth and resistance in shrimps. The present paper aims to review the inhibition of Vibrio spp. in shrimp by medicinal plants, using both in vitro or/and in vivo techniques. Several medicinal plants appear capable of inhibiting growth of Vibrio pathogens outside living shrimp or in the body of shrimp, through enhancing growth and immune capacity when shrimps are fed or injected with them. In the current review Gracilaria spp. (Gracilariaceae family) and Sargassum spp. (family Sargassaceae) have been used most for in vitro and in vivo experiments. Among the terrestrial plants, Eucalyptus camaldulensis, Psidium guajava, Rhodomyrtus tomentosa, and Syzygium cumini (Myrtaceae family) had significant activity against Vibrio., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: Curcuminoids have been widely studied for human health and disease applications, yet bioavailability remains a hurdle to actualizing all the benefits ascribed to them. The lack of standardization in analysis method, confusion about what constitutes an ideal analyte, and conflicting thoughts around dosing strategies have made it difficult to draw parity between bioavailability and bioactivity and establish a baseline for formulation comparisons., Methods: This randomized double-blinded, 2-way cross over, single oral dose, comparative bioavailability study differentially evaluates curcumin at the time of its absorption and along various biotransformation pathways, to include free curcumin, the readily usable form of curcumin; individual and composite totals of curcumin and its analogues as exogenously cleaved conjugates, for example, total curcumin, total demethoxycurcumin (DMC), total bisdemethoxycurcumin (BDMC), and total curcuminoids respectively; and the bioactive metabolite of curcumin, total tetrahydrocurcumin (THC). As a primary study objective, the relative bioavailability of CURCUGEN, a novel dispersible, 50% curcuminoids-concentrated turmeric extract was compared to the standard curcumin reference product, curcuminoids 95% standardized extract (C-95), using the maximum concentration (Cmax), and area under the curve (AUC0-t) of free curcumin, total curcumin, total DMC, total BDMC and the curcumin active metabolite, as total THC., Results: The evaluation of free curcumin demonstrated that the Cmax and AUC0-t of the CURCUGEN was 16.1 times and 39 times higher than the Cmax and AUC0-t of C-95. Furthermore, total curcumin, total DMC, total BDMC, and total curcuminoids resulted in AUC0-t of the CURCUGEN at 49.5-, 43.5-, 46.8-, and 52.5-fold higher than C-95, respectively. The relative bioavailability of CURCUGEN for total THC was found to be 31 times higher when compared to C-95., Conclusion: As the first human pharmacokinetics study to apply best-practice recommendations and pharmaceutically-aligned guidance in the comprehensive evaluation of a novel curcuminoids formulation, we have established the novelty of said formulation while better standardizing for the common variances and discrepancies between curcuminoids and their derivatives in the literature and commercial marketing, alike., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Ethnopharmacological Relevance: Tetradenia riparia (commonly known as ginger bush) is frequently used in traditional African medicine to treat foodborne infections including diarrhoea, gastroenteritis, and stomach ache., Aim of the Study: The present study aims to identify in Tetradenia riparia the compounds active against foodborne pathogens., Materials and Methods: Dried Tetradenia riparia leaf powder was consecutively extracted with hexane, ethyl acetate, methanol and water. The hexane extract was counter-extracted with methanol:water (9:1), and after evaporation of the methanol, this phase was extracted with dichloromethane. The water extract was counter-extracted with butanol. All these fractions were tested against a panel of foodborne bacterial pathogens. A bioassay-guided purification was performed to isolate antimicrobial compounds using Staphylococcus aureus as a target organism. Further, antibiofilm activity was evaluated on S. aureus USA 300., Results: The dichloromethane fraction and ethyl acetate extract were the most potent, and therefore subjected to silica gel chromatography. From the dichloromethane fraction, one active compound was crystalized and identified using NMR as 8(14),15-sandaracopimaradiene-7alpha, 18-diol (compound 1). Two active compounds were isolated from the ethyl acetate extract: deacetylumuravumbolide (compound 2) and umuravumbolide (compound 3). Using a microdilution method, their antimicrobial activity was tested against eight foodborne bacterial pathogens: Shigella sonnei, S. flexneri, Salmonella enterica subsp. enterica, Escherichia coli, Micrococcus luteus, S. aureus, Enterococcus faecalis, and Listeria innocua. Compound 1 had the strongest activity (IC 50 ranging from 11.2 to 212.5 μg/mL), and compounds 2 and 3 showed moderate activity (IC 50 from 212.9 to 637.7 μg/mL and from 176.1 to 521.4 μg/mL, respectively). Interestingly, 8(14),15-sandaracopimaradiene-7alpha, 18-diol is bactericidal, and also showed good antibiofilm activity with BIC 50 (8.8 ± 1.5 μg/mL) slightly lower than for planktonic cells (11.4 ± 2.8 μg/mL)., Conclusions: These results support the traditional use of this plant to conserve foodstuffs and to treat gastrointestinal ailments, and open perspectives for its use in the prevention and treatment of foodborne diseases., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Chikungunya and yellow fever virus cause vector-borne viral diseases in humans. There is currently no specific antiviral drug for either of these diseases. Banana plants are used in traditional medicine for treating viral diseases such as measles and chickenpox. Therefore, we tested selected banana cultivars for their antiviral but also cytotoxic properties. Different parts such as leaf, pseudostem and corm, collected separately and extracted with four different solvents (hexane, acetone, ethanol, and water), were tested for in vitro antiviral activity against Chikungunya virus (CHIKV), enterovirus 71 (EV71), and yellow fever virus (YFV). Extracts prepared with acetone and ethanol from leaf parts of several cultivars exhibited strong (EC 50 around 10 μg/mL) anti-CHIKV activity. Interestingly, none of the banana plant extracts (concentration 1-100 µg/mL) were active against EV71. Activity against YFV was restricted to two cultivars: Namwa Khom-Pseudostem-Ethanol (5.9 ± 5.4), Namwa Khom-Corm-Ethanol (0.79 ± 0.1) and Fougamou-Corm-Acetone (2.5 ± 1.5). In most cases, the cytotoxic activity of the extracts was generally 5- to 10-fold lower than the antiviral activity, suggesting a reasonable therapeutic window., Competing Interests: The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

Intestinal parasitic nematodes infect approximately two billion people worldwide. In the absence of vaccines for human intestinal nematodes, control of infections currently relies mainly on chemotherapy, but resistance is an increasing problem. Thus, there is an urgent need for the discovery and development of new anthelmintic drugs, especially ones with novel mechanisms of action. Medicinal plants hold great promise as a source of effective treatments, including anthelmintic therapy. They have been used traditionally for centuries and are mostly safe (if not, their toxicity is well-known). However, in most medicinal plants the compounds active against nematodes have not been identified thus far. The free-living nematode C. elegans was demonstrated to be an excellent model system for the discovery of new anthelmintics and for characterizing their mechanism of action or resistance. The compounds discussed in this review are of botanical origin and were published since 2002. Most of them need further studies of their toxicity, mechanisms and structure-activity relationship to assess more fully their potential as drugs.

Ethnopharmacological Relevance: Warburgia ugandensis Sprague subspecies ugandensis is a plant widely distributed in Eastern, Central and Southern Africa. In humans, it is used to treat respiratory infections, tooth aches, malaria, skin infections, venereal diseases, diarrhea, fevers and aches., Aim of the Study: This study aims to identify the bioactive compounds against clinically important biofilm-forming strains of Candida and staphylococci that are responsible for tissue and implanted device-related infections., Methods: Using a bioassay-guided fractionation approach, hexane -, ethanol -, acetone - and water extracts from the leaves of W. ugandensis, their subsequent fractions and isolated compounds were tested against both developing and preformed 24 h-biofilms of Candida albicans SC5314, Candida glabrata BG2, Candida glabrata ATCC 2001, Staphylococcus epidermidis 1457 and Staphylococcus aureus USA 300 using microtiter susceptibility tests. Planktonic cells were also tested in parallel for comparison purposes. Confocal scanning laser microscopy was also used to visualize effects of isolated compounds on biofilm formation., Results: Warburganal, polygodial and alpha-linolenic acid (ALA) were the major bioactive compounds isolated from the acetone extract of W. ugandensis. For both warburganal and polygodial, the biofilm inhibitory concentration that inhibits 50% of C. albicans developing biofilms (BIC 50 ) was 4.5 ± 1 and 10.8 ± 5 μg/mL respectively. Against S. aureus developing biofilms, this value was 37.9 ± 8 μg/mL and 25 μg/mL with warburganal and ALA respectively. Eradication of preformed 24 h biofilms was also observed. Interestingly, synergy between the sesquiterpenoids and azoles against developing C. albicans biofilms resulted in an approximately ten-fold decrease of the effective concentration required to completely inhibit growth of the biofilms by individual compounds. The hydroxyl group in position C-9 in warburganal was identified as essential for activity against staphylococcal biofilms. We also identified additional promising bioactive sesquiterpenoids; drimenol and drimendiol from the structure-activity relationship (SAR) studies., Conclusions: ALA and four sesquiterpenoids: polygodial, warburganal, drimenol and drimendiol, have shown biofilm-inhibitory activity that has not been reported before and is worth following up. These compounds are potential drug candidates to manage biofilm-based infections, possibly in combination with azoles., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Despite the advancement of the pharmaceutical industry, medicinal plants are still a reliable source of traditional medicines to cure a number of diseases. Various parts of Dillenia pentagyna are used in traditional medicine in India for treatment of various disorders including cancers, but detailed mechanisms are still unknown. Dried leaves of D. pentagyna were extracted with ethanol and termed as an ethanolic extract of leaves of D. pentagyna (EELDP). Our aim was to elucidate the role of EELDP in in-vitro cell migration and apoptosis in highly metastatic human lung adenocarcinoma A549 cells. We measured cell viability and in-vitro cell migration in three different human cancer cells A549, HeLa and U2OS treated with EELDP (0-0.6 mg/mL). However, A549 cells showed higher sensitivity to EELDP treatment. Hence we studied several key markers of metastasis and apoptosis pathway in A549 cells treated with EELDP. EELDP treatment significantly reduced in-vitro cell migration, wound healing, expression and activity of MMP-2, MMP-9 via reduction of nuclear factor kappa Beta (NF-κβ). EELDP also reduced vimentin, N-cadherin and increased claudin-1. The intrinsic pathway of apoptosis was triggered by EELDP via the NF-κβ pathway through the increase of the Bax to Bcl 2 ratio, leading to the fall of mitochondrial membrane potential and subsequently induced release of cytochrome c, activation of caspase-3 followed by nuclear fragmentation in A549 cells. Furthermore, we observed change of a few markers of metastasis and apoptosis in other two cell types HeLa and U2OS treated with EELDP. These data implicate that the effect of EELDP is not cell-specific. Since only 0.1 mg/mL EELDP significantly reduces in-vitro cell migration and increases apoptosis, the active compound(s) present in EELDP is very much potent to control highly metastatic cancer., (© 2019 Wiley Periodicals, Inc.)

Ethnopharmacological Relevance: Knowledge on the use of plants for different ailments by the tribals of the Chirang Reserve Forest (CRF, Northeast India) was used to assess the potential of these plants for treating viral, bacterial and fungal infections., Materials and Methods: Fieldwork in the CRF documented the use of plants for the treatment of various human ailments. The ethnobotanical data were analysed using different quantitative indices viz. Informant Consensus Factor (ICF), Relative Frequency Citation (RFC), Fidelity Level (FL), Relative Popularity Level (RPL) and Rank Order Priority (ROP). For each plant, four extracts were prepared with different solvents (water, ethanol, acetone and hexane) and tested for bioactivity such as antiviral (Enterovirus 71) and antimicrobial (E. coli, S. aureus, C. albicans) effects. To develop fingerprints, thin layer chromatography (TLC) was carried out with at least one extract of each active plant., Results: Thirty-seven plant species belonging to 26 families used frequently in the CRF were categorised into twenty disease(s) and markedly high ICF values (0.5-1) were found. The FL of the 19 most important plant species ranged from 10% to 100%. Aglaia spectabilis, Actinodaphne obovata, Bischofia javanica, Gmelina arborea, Hodgsonia macrocarpa and Mesua ferrea were the most popular plant species with RPL values > 0.4. The most commonly treated diseases were skin infections, worm infections, diarrhoea, dysentery, common cold and throat infections, cough and respiratory problems, fever, malaria, rheumatism, pain, stomach ache and gastric problems. Among the taxonomic families, the most represented are Lauraceae (4 species); Meliaceae (3 species), Euphorbiaceae, Elaecarpoceae, Magnoliaceae, Malvaceae, Moraceae and Myrtaceae (2 species each). Of these, 35 plants (95%) with 91 of their extracts were found to be active against S. aureus (inhibition > 50%). Similarly, over half of the tested plants inhibited growth of E. coli (19 plants with 31 extracts) while 9 plants with 14 extracts were active against C. albicans. Moreover, one-third (12) of the plants showed anti-enteroviral activity. TLC analysis of the extracts indicates the presence of different phytochemical classes such as alkaloids, flavonoids, glycosides, terpenoids and saponins based on observing characteristic spots under visible or UV light (254 or 360 nm), with or without derivatisation., Conclusions: Thirty-seven plants commonly used by the tribes of the CRF as anti-infective agents offer perspectives for further research, as the phytochemistry and phytopharmacology for most of these plants have not been published to date., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Curene® is a bioavailable formulation of turmeric  Curcucma longa extract comprising naturally derived curcuminoids formulated with proprietary Aquasome® technology. Curcuminoids were found to have anti-inflammatory properties by inhibiting Cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) enzyme and hence have potential application in the treatment of Osteoarthritis (OA). To evaluate the safety and efficacy of Curene® a randomized, double blind, placebo controlled, parallel-group study was conducted in subjects with knee OA. Significant improvements in clinical endpoints were observed during the trial along with excellent safety profile., Methods: Fifty (50) subjects aged between 40 and 75 years who were suffering from unilateral or bilateral OA of the knee for greater than 3 months according to American College of Rheumatology (ACR) criteria were enrolled. They were randomized into two treatment groups; one group received Curene® 500 mg once daily and the other group received placebo. Efficacy was evaluated using change from baseline in Visual Analogue Scale (VAS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. Biochemical and hematological parameters including urine analysis were performed to evaluate the safety of Curene® in OA patients., Result: Forty-six (46) subjects completed the study. The reduction from baseline in total WOMAC score (also subscale scores) and VAS score resulted in statistically significant difference when compared to placebo. It was also found to be safe and well tolerated as there was no incidence of treatment related AEs., Conclusion: Curene® results in statistically significant and clinically meaningful reduction in pain, stiffness, and improvement in physical functioning in subjects suffering from knee OA. Curene® also demonstrates excellent safety profile during the study., Trial Registration: This trial is registered with Clinical Trial Registry, India, CTRI/2017/07/009044, registered on 14th July 2017, http://ctri.nic.in/Clinicaltrials/showallp.php?mid1=19264&EncHid=&userName=ocius%20life%20sciences.

The purpose of this review is to survey the antiparasitic plants of the Asteraceae family and their applicability in the treatment of parasites. This review is divided into three major parts: (a) literature on traditional uses of Asteraceae plants for the treatment of parasites; (b) description of the major classes of chemical compounds from Asteraceae and their antiparasitic effects; and (c) antiparasitic activity with special reference to flavonoids and terpenoids. This review provides detailed information on the reported Asteraceae plant extracts found throughout the world and on isolated secondary metabolites that can inhibit protozoan parasites such as Plasmodium, Trypanosoma, Leishmania, and intestinal worms. Additionally, special attention is given to the Asteraceae plants of Odisha, used by the tribes of the area as antiparasitics. These plants are compared to the same plants used traditionally in other regions. Finally, we provide information on which plants identified in Odisha, India and related compounds show promise for the development of new drugs against parasitic diseases. For most of the plants discussed in this review, the active compounds still need to be isolated and tested further., (© S.K. Panda and W. Luyten, published by EDP Sciences, 2018.)

Bio- synthesis of silver nanoparticles (AgNPs) was made by using the aqueous leaf extract of Ardisia solanacea. Rapid formation of AgNPs was observed from silver nitrate upon treatment with the aqueous extract of A. solanacea leaf. The formation and stability of the AgNPs in the colloidal solution were monitored by UV-visible spectrophotometer. The mean particle diameter of AgNPs was calculated from the DLS with an average size ∼4 nm and ∼65 nm. ATR-FTIR spectroscopy confirmed the presence of alcohols, aldehydes, flavonoids, phenols and nitro compounds in the leaf which act as the stabilizing agent. Antimicrobial activity of the synthesized AgNPs was performed using agar well diffusion and broth dilution method against the Gram-positive and Gram-negative bacteria. Further, robust anti-oxidative potential was evaluated by DPPH assay. The highest antimicrobial activity of synthesized AgNPs was found against Pseudomonas aeruginosa (28.2 ± 0.52 mm) whereas moderate activity was found against Bacillus subtilis (16.1 ± 0.76), Candida kruseii (13.0 ± 1.0), and Trichophyton mentagrophytes (12.6 ± 1.52). Moreover, the potential wound healing activity was observed against the BJ-5Ta normal fibroblast cell line. Current research revealed that A. solanacea was found to be a suitable source for the green synthesis of silver nanoparticles.

The present study reports on biogenic-synthesised silver nanoparticles (AgNPs) derived by treating Ag ions with an extract of Cassia fistula leaf, a popular Indian medicinal plant found in natural habitation. The progress of biogenic synthesis was monitored time to time using a ultraviolet-visible spectroscopy. The effect of phytochemicals present in C. fistula including flavonoids, tannins, phenolic compounds and alkaloids on the homogeneous growth of AgNPs was investigated by Fourier-transform infrared spectroscopy. The dynamic light scattering studies have revealed an average size and surface Zeta potential of the NPs as, -39.5 nm and -21.6 mV, respectively. The potential antibacterial and antifungal activities of the AgNPs were evaluated against Bacillus subtilis, Staphylococcus aureus, Candida kruseii and Trichophyton mentagrophytes . Moreover, their strong antioxidant capability was determined by radical scavenging methods (1,1-diphenyl-2-picryl-hydrazil assay). Furthermore, the AgNPs displayed an effective cytotoxicity against A-431 skin cancer cell line by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, with the inhibitory concentration (IC 50 ) predicted as, 92.2 ± 1.2 μg/ml. The biogenically derived AgNPs could find immense scope as antimicrobial, antioxidant and anticancer agents apart from their potential use in chemical sensors and translational medicine.

Ethnopharamcological Relevance: The present study examined the variety and the extent of medicinal plants used in the health care system of tribal inhabitants of Similipal Biosphere Reserve. In addition to this, such plants were also screened for antibacterial properties against common pathogenic bacteria., Material and Methods: Semi-structured interview was carried out with 42 informants (mean age 42, 86% male, 14% female) at 24 locations in and around SBR, regarding the use of plants for the treatment of various human ailments. Antibacterial screening is adopted with the documented ethnomedicinal plants using methanol and aqueous extracts against eight bacterial strains., Results: A total of 187 plant species belonging to 74 families were documented for frequent medicinal uses against common ailments such as stomach problems, fever, skin diseases, diarrhea and dysentery. Although all parts of plant are used, leaves and bark are most common. Tribals used the plant parts both in form of decoction (taken orally as in internal problems) and paste (external use). Out of 187 plant species, 120 plants recorded antibacterial activity against test bacterial strain., Conclusions: This study revealed that self care using medicinal plants is a common practice by the tribes of SBR. About 64% of the used plants have scientifically proved medicinal values with respect to the antibacterial properties., (© 2013 Elsevier Ireland Ltd. All rights reserved.)

Extracts of the two traditional Indian herbs, Phyllanthus amarus (P. amarus) and Phyllanthus maderaspatensis (P. maderaspatensis), described by others as useful in the treatment of chronic hepatitis B virus infection were studied for antiviral properties on duck hepatitis B virus infection. One hundred and fourteen ducks infected posthatch with the duck hepatitis B virus (DHBV) were divided into groups at three months of age and treated intraperitoneally with the aqueous, butanol, and alcoholic extracts of these two plants at doses of 25, 50, or 200 mg/kg body weight. Saline-treated animals served as controls. In the ducks negative for DHBV in serum after treatment, we observed replicative intermediates in the liver. There was no definite antiviral property observed in the treated ducks.

The therapeutic potential of plant extracts of Phyllanthus amarus and Phyllanthus maderas patensis for postexposure prophylaxis against infection by Hepadnaviruses was studied in ducklings infected by the duck hepatitis B virus (DHBV). Forty-four Pekin ducklings were inoculated intraperitoneally with DHBV at 24 hr post-hatch. They were treated by intraperitoneal injection of Phyllanthus amarus (aqueous extract) (100 mg/kg body weight) or Phyllanthus mad eraspatensis (alcoholic extract) (100 mg/kg body weight) for a period of 4 weeks. Infected ducklings treated with saline served as controls. Weekly serum samples obtained before, during, and after treatment were analysed for the presence of DHBV DNA in serum by dot blot hybridisation using alpha 32P-labelled probes. Liver tissue was collected after killing the ducks at various time intervals and was studied for replicative status of the viral DNA and liver histopathology; 17 of 21 ducks were viraemic on completion of treatment with Phyllanthus amarus. At 16 week posttreatment follow-up four of seven animals remained viraemic. Similar results were obtained with Phyllanthus maderaspatensis. There was no alteration in DHBV replication in the liver. No toxicity was observed with this treatment. These observations suggest that Phyllanthus amarus and Phyllanthus maderaspatensis are not useful as therapeutic agents for postexposure prophylaxis against DHBV infection.