Papaya Latex Research Articles

MOLECULAR WEIGHT PROFILE OF PROTEASE OF PINEAPPLE (Ananas comosus L.Merr) AND PAPAYA (Carica papaya L.) USING SDS-PAGE METHOD

<p>A group of protease enzymes such as papain and bromelain is able to decipher the molecular structure of the protein into amino acids which will be very useful in many fields, especially in food and pharmaceutical industries. The objective of this study to determine the molecular weight profile of enzyme bromelain from pineapple bark (<em>Ananas comosus</em> L. Merr) and papain (<em>Carica papaya</em> L.) from papaya latex with different varieties using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) method. The precipitation was performed with ammonium sulfate ((NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>)) 60 % addition and dialysized using a cellophane tubing with a pore size of 12,000 Dalton. The molecular weight of enzyme solution were determined using SDS-PAGE. The analysis results of molecular weight of enzyme bromelain of Subang and Bogor varieties were not different and were about 30.654 kDa, as well as the molecular weight of enzyme papain and Sukma California varieties were also not different and were about 23.485 kDa. It can be concluded that the different varieties of fruit of pineapple and papaya had no effect on the molecular weight of enzyme papain and bromelain.</p>

MOLECULAR WEIGHT PROFILE OF PROTEASE OF PINEAPPLE (Ananas comosus L.Merr) AND PAPAYA (Carica papaya L.) USING SDS-PAGE METHOD

<p>A group of protease enzymes such as papain and bromelain is able to decipher the molecular structure of the protein into amino acids which will be very useful in many fields, especially in food and pharmaceutical industries. The objective of this study to determine the molecular weight profile of enzyme bromelain from pineapple bark (<em>Ananas comosus</em> L. Merr) and papain (<em>Carica papaya</em> L.) from papaya latex with different varieties using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) method. The precipitation was performed with ammonium sulfate ((NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>)) 60 % addition and dialysized using a cellophane tubing with a pore size of 12,000 Dalton. The molecular weight of enzyme solution were determined using SDS-PAGE. The analysis results of molecular weight of enzyme bromelain of Subang and Bogor varieties were not different and were about 30.654 kDa, as well as the molecular weight of enzyme papain and Sukma California varieties were also not different and were about 23.485 kDa. It can be concluded that the different varieties of fruit of pineapple and papaya had no effect on the molecular weight of enzyme papain and bromelain.</p>

Purificación y caracterización preliminar de proteasas del látex de Vasconcellea candicans (A. Gray) A. DC (Mito)

Preliminary studies indicate that, the Mito fresh latex, has a specific activity of papain from 1.84 times greater than that found in the latex of papaya, so the objective of this study was to purify and characterize Mito fresh latex proteases that have activity of papain. The crude extract protease was obtained from the Mito latex which was re-suspended (1:1) in 10 mM Na acetate buffer at pH 5.0; immediately proteins were precipitated at pH 9.0 and then with 45% ammonium sulfate. Subsequently, the proteins were purified on a Sephadex G-100 column and were three fractions: A, B and C. Using as a substrate casein, the enzymatic specific activity (ESA) was measured and was found to be the fraction A was 87.74 nkat.mg-1protein, for fraction B was 14.93 nkat.mg-1protein and for fraction C it was 16.13 nkat.mg-1protein. ESA of fraction A against papain of fresh latex of C. papaya was 13.3 times greater. Electrophoretic analysis (12% denaturant gel) shows for A fraction, two protein bands having one of them a relation similar to the papain standard. In addition, there was observed that the A fraction (papain of Mito) against different concentrations of casein, used as a substrate, displays a michaeliane sigmoid curve; different volumes of enzyme shows a linear behavior; it has an optimum pH of 7.5 and is active up to 60 °C.

Effect of Pawpaw (Carica papaya) Latex on the Haemostatic Mechanism and Biochemical Profile of Male Albino Wistar Rats

Effect of Pawpaw (Carica papaya) Latex on the Haemostatic Mechanism and Biochemical Profile of Male Albino Wistar Rats

Synergistic effect of the combination of Cinnamomum burmanii, vigna unguiculata, and papain exracts derived from carica papaya latex against C. albicans biofilms degradation

Background: Candidiasis is an opportunistic infection commonly occurs on host with immunodeficiency, organ transplantation, leukopenia, or radiation therapy. Biofilms are structures that protect C. albicans from antifungals treatments. C. albicans biofilms display multidrug resistance to antifungal agents. Purpose: This study aimed to know whether the combination of Cinnamomum burmannii, Vigna unguiculata, and Papain extracts derived from Carica papaya latex has inadequate inhibitory effects against C.albicans biofilms compared to the combination of Cinnamomum burmannii and Vigna unguiculata extracts. Method: C. albicans. growing on SDA were dissolved in 1 McFarland of sterile aquadest. Micro-plate was filled with 180 µL of SDB, glucose 8%, and 20 µL of C. albicans. Suspension was incubated at 37oC overnight. Extracts were added and incubated for 24 hours. Then, each well was washed with distilled water, and stained with crystal violet 0.1% for 15 minutes. Afterward, each well was washed with distilled water and immediately stained with acetic acid. After 15 minutes of staining, the suspension was transferred to a new well, then measured with micro-plate reader at 595 nm. Results: The combination of Cinnamomum burmanii and Vigna unguiculata extracts had adequate inhibitory effects which is equal to 60.75%. Inhibition increased to 72.09%, 79.06%, and 79.50% after Papain derived from Carica papaya latex was added on concentrations of 138 mg/mL, 276 mg/mL, and 552 mg/mL. Conclusion: The combination of Cinnamomum burmanii (0.25µg/mL), Vigna unguiculata (200 µg/mL), and Papain (276 µg/mL) extracts showed an optimum synergic inhibition for C. albicans biofilms.

Functional expression, extracellular production, purification, structure modeling and biochemical characterization of Carica papaya lipase 1

Abstract Carica papaya latex has been reported to contain lipolytic activity since 1925, nevertheless the efforts to isolate lipolytic enzymes directly from the latex matrix have been unsuccessful. Nowadays papaya genome is known and heterologous expression is an alternative to overcome this problem. Therefore, in this study, Carica papaya lipase 1 sequence (CpLip1) has been identified in papaya genome and for the first time, functionally expressed using Pichia pastoris as host system. Purification of the recombinant enzyme was carried out by affinity chromatography and reached a 7-fold purification factor with 25 U/mg in the purified fraction. Interestingly, homology modeling with lipases of known structure revealed homology with microbial lipases. The biochemical characterization of the purified enzyme shows that CpLip1 hydrolyzed preferentially long-chain triglycerides, it has an optimal pH of 8.5 and an optimal temperature of 35 °C. Finally, the study of its stability in organic solvents showed that, as many lipases, CpLip1 activity is affected in polar solvents. This contribution opens the possibility of studying the catalytic performance of pure CpLip1 in several reactions, and a better understanding of the role of lipases in Carica papaya .

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English

A Comparative Study of Ion Diffusion from Calcium Hydroxide with Various Herbal Pastes through Dentin.

AimThe aim of this study was to evaluate the diffusion ability of ions through dentinal tubules of different nonalcoholic calcium hydroxide-containing herbal pastes and compare it with the calcium hydroxide paste prepared with saline.Materials and methodsA total of 36 single-rooted premolar teeth were used in this study. The tooth crowns were removed and the root canals were prepared. Depending on the vehicle to be used for preparing calcium hydroxide pastes, six groups were made: Group I: Ca(OH)2 saline paste (control group), group II: Ca(OH)2 papaya latex paste, group III: Ca(OH)2 coconut water paste, group IV: Ca(OH)2 Ashwagandha (Withania somnifera) paste, group V: Ca(OH)2 Tulsi (Ocimum tenuiflorum) paste, and group VI: Ca(OH)2 garlic (Allium sativum) paste. After biomechanical preparation, calcium hydroxide herbal paste dressings were applied and sealed with resin-based cement. The teeth were placed in containers with deionized water, and the pH of the water was measured at regular intervals over 3, 24, 72, and 168 hours.ResultsWe observed that all herbal pastes allowed the diffusion of ions, but pastes prepared with Ashwagandha and papaya latex showed more ion diffusion after 168 hours and marked increase in pH, depicting better support for calcium hydroxide action.ConclusionWe conclude that Ashwagandha and papaya latex allow better diffusion of calcium hydroxide through den-tinal tubules, thus enhancing its action, and advise its use as a vehicle for placing intracanal medicament.How to cite this articleDausage P, Dhirawani RB, Marya J, Dhirawani V, Kumar V. A Comparative Study of Ion Diffusion from Calcium Hydroxide with Various Herbal Pastes through Dentin. Int J Clin Pediatr Dent 2017;10(1):41-44.

Papaya (Carica papaya) latex- an alternative to rennet for cottage cheese preparation

Objective: The study was conducted to standardize the desire level of papaya latex on quality of cheese prepared from cow milk. Materials and methods: Cheese sample was prepared using whole milk collected from Dairy Farm, Bangladesh Agricultural University. This experiment was conducted on five treatments from cow milk named as sample CC1: cow control; A1: 2 drops (0.06 gm); B1: 3 drops (0.10 gm); C1: 4 drops (0.14 gm); D1: 5 drops (0.16 gm) of papaya latex. All experimental cheeses were judged by a panel of judges for organoleptic evaluation using a score card. The total solids and ash content of the different types of cheese were determined by oven drying method according to AOAC. Fat per cent, protein and acidity were determined by Babcock method, procedure and titrating with N/10 sodium hydroxide solution, respectively described by Aggarwala and Sharma. Results: There was significant difference within the overall physical score of different samples except color score. Overall score of sample B1 was highest (93.67±1.53) and score of sample D1 was lowest (72.33±12.01). In case of chemical analysis, the highest protein value was 17.14±0.34% found in B1 and lowest value was 14.94±0.16% found in D1. The highest fat value of sample B1 was 23.00±1.00% and lowest value was 16.00±1.00% found in C1. Highest carbohydrate was found in A1 (9.44±2.25) and lowest in D1 (5.02±0.04). Total solids and moisture content of cheese differed significantly (P

Optimasi Sintesa Ester Maltitol Asam Lemak Dari Minyak Kelapa Sawit Menggunakan Lipase Getah Pepaya sebagai Katalisator

Research optimization of the ester Maltlitol Fatty Acid (EMALTAL) synthesis from palm as biosurfactant has been conducted. Papaya latex lipase used as a catalyst in the synthesis. This research aims to study the optimization of biosurfactant synthesis Maltitol Fatty Acid Esters (EMALTAL) from palm oil using papaya latex lipase as a catalyst. Before the synthesis carried out, palm oil is converted into methyl esters Fatty Acids (EMAL). Optimal conditions needed to form EMALTAL determined by Response Surface Method / RSM. To get the optimum conversion EMALTAL synthesis, the reaction is affected by three variables: time, papaya latex lipase levels and temperature as well as the response variable is called the optimum conversion EMALTAL synthesis. By using response surface methods (RSM), the optimal synthesis conditions obtained at a temperature of 0C 39.4490, 53.2440 minutes of time and concentration of crude papaya latex 7.6600% to 28.6806% conversion of surfactant in the form of monoester. Characterization of EMALTAL shows the melting point of 24.5-27 o C, 180 o C smoke point and refractive index of 1.441. EMALTAL produced a monoester that serves as an emulsifier

Papaya latex supernatant has a potent effect on the free-living stages of equid cyathostomins in vitro

The control of equid gastrointestinal nematodes in developed countries, in particular the cyathostomins, is threatened by high levels of anthelmintic resistance. In recent years, there has been increasing interest in the evaluation of traditional ‘ethnoveterinary’ medicines as alternatives to chemical anthelmintics. The cysteine proteinases (CPs), a group of enzymes derived from fruits such as papaya (Carica papaya), pineapple (Ananas comosus) and figs (Ficus spp.), have shown good efficacy against adult stages of a range of parasitic nematodes, in vitro and in vivo. The efficacy of CPs against cyathostomins remains to be explored. In this study, the efficacy of a crude preparation of CPs, papaya latex supernatant (PLS), against the free-living stages of cyathostomins was evaluated using two in vitro tests, the egg hatch test (EHT) and the larval migration inhibition test (LMIT). It was demonstrated that PLS had a potent effect in the EHT, with EC-50 values in the range of 0.12–0.22μM. At concentrations above 6.25μM the eggs did not develop, below this concentration the L1 developed but they lost integrity of the cuticle upon hatching. These effects were inhibited by pre-incubation of PLS with the CP inhibitor L-trans-epoxysuccinyl-l-leucylamido-(4-guanidino butane) (E64), indicating that CPs were responsible for the anti-parasitic activity. A dose-dependent inhibition of migration of third stage larvae (L3) in the LMIT was demonstrated at higher concentrations of PLS, with EC-50 values in the range of 67.35–106.31μM. Incubation of PLS with E64 prior to use in the LMIT did not reverse the anti-migratory effect, suggesting that CPs were not responsible for the reduced migration of cyathostomin L3 and that PLS also contains an additional active compound. This is the first report of PLS and/or CPs showing activity against the free-living stages of a parasitic helminth. In addition, it suggests that cyathostomins are highly sensitive to the effects of CPs and further evaluation of their efficacy against parasitic stages and in vivo are strongly indicated.

Green Papaya as a Potential Source for Antidiabetic and Diabetic-Wound Healing Therapy

The use of dietary antioxidants and nutraceuticals is one of the strategies often pursued as low cost remedies to reduce oxidative stress for preventing diabetes and its chronic complications [2]. Different parts of papaya (seeds, roots, leaves, barks, flowers, latex, and fruit) have been used in folk medicine to treat various diseases, including diabetes, cancer, and cardiovascular and infectious diseases [3]. Papaya (Carica papaya) is a perennial plant of tropical and subtropical regions, which requires temperatures between 21 and 33 °C and cannot tolerate temperatures less than 15 °C [4,5]. The papaya tree can grow to about 6-10 feet in high tunnels and produces unripe green papaya, which are harvested before the temperature drops below 15 °C. Recent scientific studies have validated many of the traditional uses and reported antiviral, antibacterial, antiprotozoal, antifungal, anti-inflammatory, antitumor, antihypertensive, wound healing, neuroprotective, diuretic, abortifacient, antifertility, hypoglycemic, and hypolipidemic properties [3,6-8]. This wide range of biological activities from papaya is attributed to its content of a number of phytochemicals including, flavonoids, polyphenols, alkaloids, glycosides, triterpenes, lectins, saponins, polysaccharides, vitamins, minerals, enzymes, proteins, and oils [3]. Editorial

A sustainable affinity partitioning process to recover papain from Carica papaya latex using alginate as macro-ligand

The role of the natural biodegradable polymer alginate (ALG) as affinity macro-ligand for papain (PAP) was evaluated in order to design a new sustainable two-phase affinity strategy for recovering this enzyme from Carica papaya latex. In presence of PAP, decreased values of intrinsic viscosity and hydrodynamic radius of ALG were observed. These results suggested a neutralizing effect of PAP on the polymer negative charges which caused a decrease of intra-chain repulsion forces in ALG molecules and a consequent shrinkage of the polymer size. Calorimetric measurements demonstrated a cooperative interaction between PAP and ALG which was enthalpy-entropically driven. When partitioned C. papaya latex into aqueous two-phase systems (ATPSs) formed by polyethylene glycol (PEG) of MW 8000 and the biodegradable salt sodium citrate pH 5.20, only 20% of PAP was recovered at the PEG-enriched phase with a purification factor (PF) of 2.48. The addition of ALG 0.1% (w/w) into the system doubled the PAP partition coefficient (Kp, PAP), showing the ability of this polymer to enhance the enzyme recovery at the PEG-enriched phase and therefore, increasing the extraction efficiency. The subsequent addition of calcium chloride at a final concentration of 80 mM allowed the precipitation of the target enzyme and the recovering of PEG phase for recycling. The overall process showed a PAP recovery of 72% and a PF of 2.41. The proposed strategy not only conserved all the advantages of the reported extractions with PEG/ammonium sulfate (or phosphate) ATPSs, i.e., low cost, scalability and integration of the clarification and extraction steps, but also allowed overcoming their main drawbacks, i.e., the separation of the target molecule from the phase-polymer and the environmental impact caused by the disposal of these salts.

Formulation of Carica papaya latex-functionalized silver nanoparticles for its improved antibacterial and anticancer applications

In the present study, commercially important crop Carica papaya latex extract was used as potential bioreductant to fabricate high-stable silver nanoparticles (CPAgNPs). The reduction of Ag+ in Ag0 nanostructures was initially observed with a color change from light to dark brown and further confirmed through SPR spectra at 410nm in UV–vis spectroscopy. Fourier transform infrared spectroscopy (FTIR) analysis reveals that protein moieties present in the latex extract act as reducing/capping agent for nanoparticle synthesis. Interestingly, X-ray diffraction (XRD) study confirms that synthesized CPAgNPs were face centered cubic crystalline (fcc) in structure. High resolution transmission electron microscope (HRTEM) micrographs display polydispersed spherical CPAgNPs with an average size of 12±6nm. The CPAgNPs display tremendous antibacterial activity against human pathogens such as Bacillus subtilis, Enterococcus faecalis, Escherichia coli, Vibrio cholerae, Klebsiella pneumoniae and Proteus mirabilis. On the other hand, in vitro anticancer studies were performed to assess the chemotherapeutic potential of formulating NPs against human breast carcinoma cell line (MCF-7). It was observed that fabricated CPAgNPs show excellent anticancer effect in a dose-dependent manner with the IC50 value 19.88μg/ml. These results clearly impelled that biogenic CPAgNPs can be used as promising nano-drug formulation to combat against bacterial infections and also for breast cancer chemotherapy

Carbohydrate and protein digestion of palm kernal cake using Mannanase BS4 and papain cocktail enzymes

Supplementation of the mannanase BS4 enzyme on palm kernel cake (PKC) increased its metabolisable energy (ME), and supplementation with protease is expected to increase its protein digestibility. Therefore, the purpose of this research is to determine the optimum proportion of cocktail enzymes between BS4 β-mannanase (produced by Eupenicillium javanicum) and protease (papain) and their degradation activities on carbohydrate and protein of PKC. The β-Mannanase was produced by the mold through solid substrate fermentation (SSF) using coconut meal as the substrate. The papain was extracted from papaya latex (PL), collected by longitudinal incisions on unripe papaya fruit and oven dried overnight. The evaluation of enzyme cocktails for PKC hydrolysis was done at pH 5.8 and 40°C which are similar with poultry intestine condition and both enzymes are still active. The β- mannanase BS4 : papain were mixed with some proportions, i.e.: 100 : 0; 75 : 25; 50 : 50; 25 : 75 and 0 : 100% (by volume) in order to study the optimum cocktail composition ratio. The activities of β-mannanase towards gum locust bean was 86 U.ml -1 and papains PL activity was 18,000 U.g -1 respectively. PL was chosen for synergistic reaction and compared with a commercial Merck papain (CMP, 20,000 U.g -1 ) as positive control. β-Mannanase BS4 showed carbohydrate digestion activity, and protein digestion activity was not detected. Papain showed protein digestion activity and no carbohydrate digestion activity. Enzyme cocktails of 50 : 50 from PL protease showed slightly increased in synergistic protein digestion activity in PKC. However, its reduction sugar production was much lower than 100 : 0 and 75 : 25. Amino acids production by enzyme cocktails 75 : 25 were higher than that of 100 : 0. As a result, the best volume composition of β-mannanase BS4 and papaya latex was 75 : 25 (v:v) or 14 : 10 (U:U). Key W ords : Mannanase BS4, Papain, Cocktail-Enzymes, Palm Kernel Cake

PENGARUH PEMBERIAN GEL KOMBINASI EKSTRAK GETAH PEPAYA (Carica papaya L) DAN EKSTRAK DAGING LIDAH BUAYA (Aloe vera) TERHADAP PROSES PENYEMBUHAN ULKUS TRAUMATIKUS PADA MALE WISTAR RATS YANG MENDERITA DIABETES MELITUS

Introduction: Research on the use of papaya and aloevera sap on wound healing each been done, but effects the combination of the two extracts on wound healing in diabetes mellitus condition has not been done.Purpose: This study aims to determine the effect of a gel combination of papaya latex and aloevera flesh extracts on the traumatics ulcer healing process in diabetic rats.Methods: True experimental laboratory research with the post-test-only control group design that performed on 28 male wistar rats which were divided intofour groups: DM and non-DM rat that treatment with povidone iodine and gel combination of papaya latex and aloevera flesh extract. The treatment was done for 7 days with smearing that was given 2x/day. Traumatics ulcer healing seen from the number of fibroblasts that then were analyzed by One WayAnova and post hoc LSD test.Results: The results showed the number of fibroblasts in DM and non-DM rat with povidone iodine were 44.6 and 42.73; in the DM and non-DM rat with a gel combination of papaya latex and aloe vera flesh extracts were 61.10 and 77.03. One Way Anova test resulted p-value = 0.000, it was mean that there were at least a significant difference on the number of fibroblasts in the two groups. Differences of the number fibroblasts was shown in all groups, except in the group DM and non-DM rats with povidone iodine (p = 0.764).Conclusion: Conclusion of the study was the provision of a gel combination of papaya latex and aloevera flesh extracts effect on the traumatics ulcer healing process in diabetic rats.

The anthelmintic efficacy of natural plant cysteine proteinases against the equine tapeworm, Anoplocephala perfoliata in vitro.

Papaya latex has been demonstrated to be an efficacious anthelmintic against murine, porcine, ovine and canine nematode parasites, and even those infecting poultry, and it has some efficacy against rodent cestodes. The active ingredients of papaya latex are known to be cysteine proteinases (CPs). The experiments described in this paper indicate that CPs in papaya latex, and also those in pineapples, are highly efficacious against the equine cestode Anoplocephala perfoliata in vitro, by causing a significant reduction in motility leading to death of the worms. The susceptibility of A. perfoliata to damage by CPs was considerably greater than that of the rodent cestodes Hymenolepis diminuta and H. microstoma. Our results are the first to report anthelmintic efficacy of CPs against an economically important equine helminth. Moreover, they provide further evidence that the spectrum of activity of CPs is not restricted to nematodes and support the idea that these plant-derived enzymes can be developed into useful broad-spectrum anthelmintics.

Factors affecting the anthelmintic efficacy of papaya latex in vivo: host sex and intensity of infection

The development of plant-derived cysteine proteinases, such as those in papaya latex, as novel anthelmintics requires that the variables affecting efficacy be fully evaluated. Here, we conducted two experiments, the first to test for any effect of host sex and the second to determine whether the intensity of the worm burden carried by mice would influence efficacy. In both experiments, we used the standard C3H mouse reference strain in which papaya latex supernatant (PLS) consistently shows >80% reduction in Heligmosomoides bakeri worm burdens, but to broaden the perspective, we also included for comparison mice of other strains that are known to respond more poorly to treatment with papaya latex. Our results confirmed that there is a strong genetic influence affecting efficacy of PLS in removing adult worm burdens. However, there was no effect of host sex on efficacy (C3H and NIH) and no effect of infection intensity (C3H and BALB/c). These results offer optimism that plant-derived cysteine proteinases (CPs), such as these from papaya latex, can function as effective anthelmintics, with neither host sex nor infection intensity presenting further hurdles to impede their development for future medicinal and veterinary usage.

A current overview of the Papaya meleira virus, an unusual plant virus.

Papaya meleira virus (PMeV) is the causal agent of papaya sticky disease, which is characterized by a spontaneous exudation of fluid and aqueous latex from the papaya fruit and leaves. The latex oxidizes after atmospheric exposure, resulting in a sticky feature on the fruit from which the name of the disease originates. PMeV is an isometric virus particle with a double-stranded RNA (dsRNA) genome of approximately 12 Kb. Unusual for a plant virus, PMeV particles are localized on and linked to the polymers present in the latex. The ability of the PMeV to inhabit such a hostile environment demonstrates an intriguing interaction of the virus with the papaya. A hypersensitivity response is triggered against PMeV infection, and there is a reduction in the proteolytic activity of papaya latex during sticky disease. In papaya leaf tissues, stress responsive proteins, mostly calreticulin and proteasome-related proteins, are up regulated and proteins related to metabolism are down-regulated. Additionally, PMeV modifies the transcription of several miRNAs involved in the modulation of genes related to the ubiquitin-proteasome system. Until now, no PMeV resistant papaya genotype has been identified and roguing is the only viral control strategy available. However, a single inoculation of papaya plants with PMeV dsRNA delayed the progress of viral infection.

The anthelmintic efficacy of natural plant cysteine proteinases against the rat tapeworm Hymenolepis diminuta in vivo.

Hymenolepis diminuta is a natural parasite of the common brown rat Rattus norvegicus, and provides a convenient model system for the assessment of the anthelmintic activity of novel drugs against cestodes. The experiments described in this paper indicate that treatment of rats infected with H. diminuta with a supernatant extract of papaya latex, containing a mixture of four cysteine proteinases, was moderately efficacious, resulting in a significant, but relatively small, reduction in worm burden and biomass. However, faecal egg output was not affected by treatment. In our experiments these effects were only partially dose-dependent, although specific inhibition by E-64 confirmed the role of cysteine proteinases as the active principles in papaya latex affecting worm growth but not statistically reducing worm burden. Data collected for a further 7 days after treatment indicated that the effects of papaya latex supernatant on worm loss and on worm growth were not enhanced. Our findings provide a starting point for further refinement in formulation and delivery, or assessment of alternative natural plant-derived cysteine proteinases in efforts to develop these naturally occurring enzymes into broad-spectrum anthelmintics, with efficacy against cestodes as well as nematodes.