Determination of the Mineral Composition of the Pulp and Evaluation of the Acute Toxicity of the Seeds of Carica papaya L. Consumed in Lubumbashi and Kinshasa in the Democratic Republic of the Congo

This work aimed, on the one hand, to determine the mineral and phytochemical composition of Carica papaya in order to guarantee the food safety of consumers and on the other hand, to evaluate the acute toxicity of papaya seeds. The papayas were bought at the Mzée market in Lubumbashi and Selembao in Kinshasa. Fruit sampling was done according to the ISO 7002 standard on agricultural and food products;the papayas were firm, mature, and without stains or physical damage. The analysis results of the papaya pulp showed both for the samples from the city of Lubumbashi and for the city province of Kinshasa that it contains respectively 85.87% and 84.46% water, 0.59% and 0.53% ash content. The mineral evaluation of our two samples presented a potassium content of 200 ± 8 mg, magnesium 13.12 ± 3 mg, calcium 22.15 ± 2 mg, sodium 3 mg ± 0.5 for the sample from Lubumbashi and 192.32 ± 8 mg of potassium, 14.458 ± 3 mg of magnesium, 20.58 ± 2 mg of calcium and 3.58 ± 0.5 mg of sodium for the sample from Kinshasa in macroelements. Concerning the trace elements, after analysis, we found zinc content (0.29 ± 0.1 mg and 0.12 ± 0.1 mg), copper (0.02 ± 0.01 mg and 0.14 ± 0.01 mg), and iron (2.22 ± 0.5 mg and 2.04 ± 0.5 mg) respectively for Lubumbashi and Kinshasa. The chemical screening indicates the presence of alkaloids, saponosides, tannins catechics, flavonoids and anthocyanins in the palm wine and ethanolic extract of the seeds of Carica papaya and an absence of cyanogenic glycosides and gallic tannins. With mild toxicity, the seeds of the fruit of Carica papaya L. can be used with moderate risk by the population.

Content determination of benzyl glucosinolate and anti—cancer activity of its hydrolysis product in Carica papaya L.

Objective:To determine the content of benzyl glueosinolate（BG） in the pulp and the seed and investigate the anti-cuncer activity of its hydrolysis product in Curica papaya L.Methods: Determination of BG was performed on an Hypersil BDS C18 column at the wavelength of 214 nm with 0.1%trifluoroacelic acid（TFA） aqueous solution（A） and 0.1%TFA acelonilrile（B） as the mobile phase.In vitro activity test was adopted with cidtured human lung cancer H69 cell in vitro to investigate the inhibition rate of cell proliferation of benzyl isothiocyanale（BITC） againsl H69 cell.Results:The pulp has more BG before the maturation of papaya and it nearly disappeared after papaya matured,while the seed contains BG at every stage.Activity test demonstrated that the a higher concentration of BITC would have betler inhibition rate of cell proliferation on 1169 cell,and the IC50 was 6.5μmol/L.Conclusions:BG also can be produced in the pulp of papaya and it will be stored in the seed after the fruit has been matured.The hydrolysis product of BG has certain cancer-prevention anti-cancer activities for human.

Human sperm immobilization effect of Carica papaya seed extracts: an in vitro study

Aim: To examine if the seed extracts of Carica papaya, which showed anfispermatogenic/sperm immobilizationproperties in animal models, could cause human sperm immobilization in vitro. Methods: Chloroform extract, ben-zene chromatographic fraction of the chloroform extract, its methanol and ethyl acetate sub-fractions and the isolatedcompounds from the sub-fractions i. e., ECP 1 & 2 and MCP 1 & 2, of the seeds of Carica papaya were used at con-centrations of 0.1%, 0.5%, 1% and 2%. Sperm motility was assessed immediately after addition of extracts and ev-ery 5 minutes thereafter for 30 minutes. Results: There were dose-dependent spermicidal effects showing an instantfall in the sperm motility to less than 20% at 2% concentration. Isolated compounds ECP 1 & 2 were more effective in-ducing a motility of less than 10%. Many of the spermatozoa became vibratory on the spot. Total inhibition of motilitywas observed within 20-25 rain at all concentrations of all products. Scanning and transmission electron microscopyrevealed deleterious changes in the plasma membrane of the head and mid-piece of spermatozoa. Sperm viability testand the number of abnormal spermatozoa after completion of incubation suggested that the spermatozoa were infertile.The effects were spermicidal but not spermiostatic as revealed by the sperm revival test. Conclusion: The results re-veal spermicidal activity in vitro of the seed extracts of Carica papaya.

Dengue fever treatment with Carica papaya leaves extracts

The main objective of the current study is to investigate the potential of Carica papaya leaves extracts against Dengue fever in 45 year old patient bitten by carrier mosquitoes.For the treatment of Dengue fever the extract was prepared in water.25 mL of aqueous extract of C.papaya leaves was administered to patient infected with Dengue fever twice daily i.e.morning and evening for five consecutive days.Before the extract administration the blood samples from patient were analyzed.Platelets count(PLT),White Blood Cells(WBC) and Neutrophils(NEUT) decreased from 176×10~3/μ L,8.10×10~3/μ L,84.0%to 55×10~3/μ L,3.7×10~3/μL and 46.0%.Subsequently,the blood samples were rechecked after the administration of leaves extract.It was observed that the PLT count increased from 55×10~3/μ L to 168×10~3/μ L,WBC from 3.7×10~3/μ L to 7.7×10~3/μ L and NEUT from 46.0%to 78.3%.From the patient feelings and blood reports it showed that Carica papaya leaves aqueous extract exhibited potential activity against Dengue fever.Furthermore,the different parts of this valuable specie can be further used as a strong natural candidate against viral diseases.

Sperm characteristics and ultrastructure of testes of rats after long-term treatment with the methanol subfraction of Carica papaya seeds

The contraceptive efficacy of Carica papaya seeds after short-term evaluation has been well established. We have examined the safety and mechanism of contraception in rats after long-term treatment with the methanol subfraction （MSF） of C. papaya seeds. The test substance was administered orally to the male albino rats （n = 40） at 50 mg per kg body weight each day for 360 days. Control animals （n = 40） received olive oil as a vehicle. Recovery was assessed up to 120 days after treatment withdrawal. Sperm parameters, serum testosterone levels, fertility, histology and ultrastructure of the testis, haematology and serum clinical chemistry were evaluated to establish the safety and efficacy of the test substance. Safety of long-term treatment was evidenced by unaltered health status, organ weight, haematology and clinical chemistry, and by an increase in body weight. The mechanism of contraception was shown by reduction in nuclear and cytoplasmic volume, normal nuclear characteristics and vacuolization in the cytoplasmic organelles of the Sertoli cells, as well as nuclear degeneration in spermatocytes and spermatids indicating disturbed spermatogenesis. Leydig cells were normal. Initial effects were observed in Sertoli cells at 60 days of treatment. Spermatocytes and spermatids were affected after 120-240 days of treatment. A significant decline in sperm count and viability, total inhibition of sperm motility, increased numbers of sperm abnormalities, normal serum testosterone levels and 100% sterility were evident after 60 days of treatment. All the altered parameters, including percent fertility, were restored to control level 120 days after treatment withdrawal. It is concluded that the MSF is safe for long-term treatment and the mechanism of contraception is shown by its effect on spermatid differentiation in the testis, possibly mediated by the Sertoli cell factors.

A comparative study of the ovicidal and larvicidal activities of aqueous and ethanolic extracts of pawpaw seeds Carica papaya(Caricaceae) on Heligmosomoides bakeri

Objective:To assess the ovicidal and larvicidal activities of aqueous and ethanolic extracts of pawpaw seeds Carica papaya（Caricaceae） on the eggs and first stage larvae（L1） of Heligmosomoides bakeri.Methods:Eggs of this parasite were obtained from experimentally infested mice（Mus musculus） and larvae were from eggs after incubation at 25℃for about 72 hours.The eggs and larvae were exposed to ten different concentrations（0.125,0.25,0.375,0.5, 0.75,1.0,1.25,1.75,2.25 and 2.75 mg/mL） of both aqueous and ethanolic extracts respectively for 72 hours.Distilled water and 0.05%ethanol used as placebo and negative control,respectively. Results:Placebo and negative control group all showed average 92%embryonnation,98%egg hatching and 2%larval mortality,and did not affect development and larval survival.The extracts inhibited embryonic development,egg hatching and larval survival.In general,the ovicidal and larvicidal activities increased with increasing concentration of different extracts.The aqueous extract was found to be more potent on eggs than on larvae.At 2.75 mg/mL,only 8%of eggs embryonnated and 50%hatched to L1 vs 57%embryonic development and 79%hatching occurred in the ethanolic extract.However,this later extract was more efficient in preventing larval development producing 96%mortality as against 68%with the aqueous extract.Conclusions: These results shows the ovicidal and larvicidal properties of aqueous and ethanolic pawpaw seeds extracts.

Reduction of hydrogen peroxide-induced erythrocyte damage by Carica papaya leaf extract

Objective:To investigate thein vitroantioxidant potential of Carica papaya(C. papaya) leaf extract and its effect on hydrogen peroxide-induced erythrocyte damage assessed by haemolysis and lipid peroxidation.Methods:Hydroxyl radical scavenging activities, hydrogen ion scavenging activity, metal chelating activity, and the ferrous ion reducing ability were assessed as antioxidant indices. In the other experiment, human erythrocytes were treated with hydrogen peroxide to induce erythrocyte damage. The extract(at various concentrations) was subsequently incubated with the erythrocytes and later analysed for haemolysis and lipid peroxidation as indices for erythrocyte damage.Results:Preliminary investigation of the extract showed that the leaf possessed significant antioxidant and free radical scavenging abilities usingin vitro models in a concentration dependent manner(P<0.05). The extract also reduced hydrogen peroxide induced erythrocyte haemolysis and lipid peroxidation significantly when compared with ascorbic acid(P<0.05). The IC50values were 7.33 mg/mL and 1.58 mg/mL for inhibition of haemolysis and lipid peroxidation, respectively. In all cases, ascorbic acid(the reference antioxidant) possessed higher activity than the extract.Conclusions:The findings show that C. papayaleaves possess significant bioactive potential which is attributed to the phytochemicals which act in synergy.Thus, the leaves can be exploited for pharmaceutical and nutritional purposes.

Sperm motility inhibitory effect of the benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya in langur monkey, Presbytis entellus entellus

Aim： To assess the contraceptive efficacy of the benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya in langur monkeys. Methods： The test substance was given p.o. to five monkeys at 50 mg/kg body weight/day for 360 days. Control animals （n = 3） received olive oil as vehicle. Sperm parameters as per World Health Organization standards, sperm functional tests, morphology of testis and epididymis, haematology, clinical biochemistry, serum testosterone and libido were evaluated. Following completion of 360 days treatment the animals were withdrawn from the treatment and the recovery pattern was assessed by semen analysis and sperm functional tests. Results： Total inhibition of sperm motility was observed following 60 days of treatment that continued until 360 days study period. Sperm count, percent viability and percent normal spermatozoa showed a drastic decline following 30 days of treatment. Sperm morphology showed predominant mid piece abnormalities. Sperm functional tests scored in sterile range. Histology and ultrastructure of testis revealed vacuolization in the Sertoli cells and germ cells. Loss of cytoplasmic organelles was evident in spermatocytes and round spermatids. Histology and ultrastructure of epididymis of treated animals were comparable to those of control animals. Hematological and serum clinical parameters and testosterone levels fluctuated within the control range throughout the study period. Recovery was evident following 60--120 days of treatment withdrawal. Conclusion- The results suggest that the benzene chro- matographic fraction of the chloroform extract of the seeds of Carica papaya shows contraceptive efficacy without adverse toxicity, mediated through inhibition of sperm motility. （Asian JAndro12008 Mar; 10： 298-306）

Antiinflammatory activity of the methanolic extract of the seeds of Carica papaya in experimental animals

Objective:To scientifically verify the claims of our traditional healers on the anti-inflammatory activity of Carica papaya(C.papaya) and possibly deduce its activities.Methods:0.1 mL of fresh egg albumin was injected into the right hind-paw of adult white Wistar rats to induce inflammation an hour post intraperitoneal(IP) administration of 50-200 mg/kg doses of the extract to 3 groups of 5 rats per group.The 4th group of 5 rats was used as negative control and received 2 mL/kg(IP) of physiological saline,while the 5th group of 5 rats was used as positive-comparative control and received(IP) 150 mg/kg of aspirin.Increases in diameter of the paw were measured with the aid of Veneer Calipers before extract administration and at interval of 30 minutes post administration for further 2 hours.Percentage inhibition of oedema was calculated for each dose group and results were subjected to statistical analysis using student /-test and analysis of variance(ANOVA).Results:All doses of extract showed a dose and time dependent inhibition effects of oedema(P【0.05).Conclusions:This work is at present though limited to animals,the anti-inflammatory activity of the seeds of C.papaya is perhaps proven.

Does Carica papaya leaf-extract increase the platelet count? An experimental study in a murine model

Objective:To investigate the potential role of fresh Carica papaya(C.papaya)leaf extract on haematological and biochemical parameters and toxicological changes in a murine model.Methods:In total 36 mice were used for the trial.Fresh C.papaya leaf extract[0.2 mL(2 g)/mouse]was given only to the test group(18 mice).General behavior,clinical signs and feeding patterns were recorded.Blood and tissue samples were collected at intervals.Haematological parameters including platelet,red blood cell(RBC),white blood cell<(WBC),packed cell volume(PCV),serum biochemistry including serum creatinine,serum glutamic-oxaloacetic transaminase(SCOT)and serum glutamic-pyruvic transaminase(SGPT)were determined.Organs for possible histopathological changes were examined.Results:Neither group exhibited alteration of behavior or reduction in food and water intake.Similarly,no significant changes in SCOT,SGPT and serum creatinine levels were delected in the test group.Histopathological organ changes were not observed in either group of mice except in three liver samples of the test group which had a mild focal necrosis.The platelet count(11.33±0.35)×10~5VμL(P=0.00004)and the RBC count(7.97±0.61)×10~/μL(P=0.00003)were significandy increased in the test group compared to that of the controls.However,WBC count and PCV(%)values were not changed significantly in the test group.The platelet count in the test group started to increase significantly from Day 3(3.4±0.18×10~5/μL),reaching almost a fourfold higher at Day 21(11.3×10~5/μL),while it was 3.8X10^5/μL and 5.5×10~5/μL at Day 3 and Day 21 respectively in the control.Likewise,the RBC count in the test group increased from 6×10~6/μL to 9×10~6/μL at Day 21 while it remained near constant in the control group(6×10~6μL).Conclusions:Fresh C.papaya leaf extract significandy increased the platelet and RBC counts in the test group as compared to controls.Therefore,it is very important to identify those chemicals of C.papaya leaves as it can be recommended to be used as a medication to boost thrombopoiesis and erythropoiesis in humans and in animals in which these cell lineages have been compromised.

Identification and quantification of flavonoids in Carica papaya leaf and peroxynitrite-scavenging activity

Objective: To characterize the types, contents, and peroxynitrite-scavenging activities of flavonoids in the leaf of Carica papaya(C. papaya).Methods: Chromatographic and spectroscopic techniques along with high performance liquid chromatography quantitative analysis and peroxynitrite-scavenging assay were performed to isolate and quantify flavonoid compounds in the flavonoid-rich fraction(Bu OH fraction) derived from Me OH extract of C. papaya leaves and evaluate their peroxynitrite-scavenging activities.Results: Seven flavonoids were isolated from the leaves of C. papaya, including quercetin 3-(2~G-rhamnosylrutinoside), kaempferol 3-(2~G-rhamnosylrutinoside), quercetin 3-rutinoside, myricetin 3-rhamnoside, kaempferol 3-rutinoside, quercetin, and kaempferol. All of the substances exhibited potent activities on peroxynitrite scavenging(IC50 4.15 mmol/L), which were stronger than the positive control, L-penicillamine(6.90 mmol/L). The content of kaempferol 3-(2~G-rhamnosylrutinoside) was significantly higher than other identified compounds(123.18 mg/g Bu OH fraction and 7.23 mg/g Me OH extract).Conclusions: The results of the present study demonstrate the potent antioxidant flavonoids of C. papaya leaf, with kaempferol 3-(2~G-rhamnosylrutinoside) as the major one.

Studies on the Antioxidant Potential of Extracts from Unripe Fruit of Carica papaya

The antioxidant activities of the ethyl acetate fraction and aqueous extract of unripe fruit of Carica papaya were compared and investigated in vitro using thiobarbituric reactive species （TBARS） assay, total phenol content, evaluation of reactive oxygen species （ROS） in liver mitochondria, Fe2＋ chelating and 2,2-diphenyl-lpicrylhydrazyl （DPPH） scavenging activities. Both extracts had high antioxidant properties and could inhibit FeE＋ and sodium nitroprusside lipid peroxidation in the liver. Total phenol content of ethyl acetate fraction and aqueous extract were 4.50 ±2.26 and 1.21±3.12 mg/g, respectively. Both extracts had a maximal effect at the lowest concentrations tested （15 μg/mL for ethyl acetate and 150 μg/mL for the aqueous）. Ethyl acetate fraction showed that the highest values of antioxidant activity is probably associated with its high phenolic content, Fe2＋ chelating and DPPH scavenging activities. It is therefore concluded that ethyl acetate fraction and to a less extent the aqueous fractions are potent inhibitor of lipid peroxidation.

Effects of the methanolic seeds extract of Carica Papaya on plasmodium Berghei infected mice

Objective:The leaves extract of Carica Papaya（C.Papaya）papaya has been shown to possess antimalarial activity, thus this work aims at finding out if the plants antimalarial activity is present in or extended to the seeds.Methods:The seeds of C.papaya were collected from its fruit,air dried for 5 days and ground into fine powder.80.65 g of the powder was then soaked for 48hours in 300 mL of methanol.Filtration was carried out using Whatman No.1 filter paper.The filtrate was evaporated to dryness by a three-day continuous heating on a hot plate of 30℃.The dry extract yield was scraped out of the Petri dish weighed and refrigerated until required. The percentage extract yield was calculated out from the initial powder weight.A preliminary phytochemical study was done by re-dissolving the appropriate amount of the dry extract in distilled water and appropriate test reagent added.The LD50 of the seeds of C.papaya was carried out using arithmetic method.Swiss albino Mice of both sexes and of average weight of 18-25 g were used as animals for antimalarial activity.They were housed in standard animal house,fed on Rats/Mice pellets and had non restricted excess to both feed and water throughout the 60day study period.While the non pregnant female Mice were used as test animals,the male animals were used as malaria parasite donors.Precautions were taken to ensure that all animals in the study groups were free from infection with Eperythrozoon coocoides.The female animals were then divided into three main groups（A-C） of 25 animals per group.Group A was used for malaria suppressive study（early infection -day 0-3） and was further subdivided to 5 subgroups（a-e） of 5animals per group.Group B was used for malaria curative study（established malaria infection-day 3-7） and was further subdivided to 5subgroups（a-e） of 5animals per group.Group C was used for malaria prophylactic study（repository-4days treatment prior to malaria parasite infection） and was also further subdivided into 5subgroups（a-e） of 5animals per group.At the appropriate time,50 mg/kg/day,100 mg/kg/day and 200 mg/kg/day of crude extract of C.papaya were administered orally to the different subgroups（b-d） within the three main groups.One subgroup（a） in each main group also received orally,5 mg/kg/day of chloroquine phosphate as positive control while one subgroup （e） in each main group also received orally,0.2 mL/kg/day of distilled water as negative control.Malaria parasites infected red blood cells numbering 1×10 and suspended in 0.2 mL of physiological saline was inoculated intraperitoneally,to each animal of the subgroups（a-d） in each of the three main groups at the appropriate time.Blood smears were made from animals’tail,stained with Lieshman and examined microscopically at 100×for the presence of malaria parasite.Percentage malaria parastaemia was calculated as well as average percentage malaria parasitaemia suppression.Results:Extraction yield of 25.29%was obtained while the LD50 was 620 mg/kg.The phytochemistry showed the richly presence of alkaloids,as well as glycosides,carbohydrates, resins,fats and fixed oils.The suppressive study at doses of 200,100 and 50mg/kg/day showed 53.02%,43.43%and 19.83%suppressive activity against Plasmodium berghei respectively.This activity compared to that of chloroquine,a standard antimalaria drug that gave 95.95%suppressive anti-parasitaemia. The prophylactic study at doses of 200,100 and 50 mg/kg/day showed 63.85%,61.12%and 48.08%prevention to malaria parasitaemia respectively as against 94.78%showed by chloroquine.The curative study however,at doses of 200,100 and 50 mg/kg/day failed to suppress malaria parasitaemia with a mean survival range of 6-8days as against 27.2 days showed by chloroquine.The seeds extract of C.papaya showed a significant malaria parasitaemia suppressive activity（P≤0.05）.These activities are dose dependent and comparable to those of Chloroquine phosphate.Conclusion:The results above suggest that the seeds extracts of C.papaya possess antimalarial activity like the leaf extracts.The antimalarial activity may be attributable to the richly presence of alkaloids and or the presence of its proteolytic enzyme（Papain）.The present finding justifies the inclusion of the seeds of C.papaya in the treatment of malaria by local herbalists.The seeds extracts therefore,if well purified and characterized may be used in treatment of very early plasmodiasis as well as a good prophylactic drug in human.This work at the moment is limited to animals,thus clinical trials in humans is be recommended particularly,when C.papaya seeds are non harmful/non toxic.

Long-term spatial memory and morphological changes in hippocampus of Wistar rats exposed to smoke from Carica papaya leaves

Objective:To investigate the effects of smoking of dried leaves of Carica papaya(pawpaw)based on ethnopharmacological information which indicated that smoking of papaya leaves could influence motor performance and learning.Methods:Twenty-four rats were used for the study,and were grouped into four groups.Groups 1served as the control(not exposed to papaya leaves smoke),while Groups 2,3 and 4 were exposed to smoke from 6.25 g,12.50 g and 18.75 g of dry pawpaw leaves respectively in a smoking chamber twice daily for 21 d with each exposure lasting for 3 min.Lastly,hippocampus was harvested in each group for histological study.Result:The results showed that there were significant(P<0.05)increases in mean of recall latencies of long-term spatial memory in the animal administered the high dose while the other groups had significantly(P<0.05)lower frequencies.Histological investigation showed signs of mild neural degeneration in high dose group and hypochromic appcarance of the Nissl substance in all treated groups.Conclusions:In conclusion,the findings from this study has demonstrated that smoking of papaya leaves has the ability to maintain an intact long-term spatial memory at all doses but retrieving such memory is faster with the low and medium dosages.

Evaluation of Phenolic Content and Antioxidant Activity of Aqueous Extracts of Three Carica papaya Varieties Cultivated in Senegal

The aqueous extracts of different parts (old leaves (OL), young leaves (YL), peels (PE) and delipidated seed residues (DS)) of three varieties of papaya are studied. Extraction conditions are optimized: an extraction time of 20 minutes, a temperature of 70°C and a plant material/water mixture of 1% give the best yield of polyphenol. The amount of polyphenols, flavonoids, saponins and proanthocyanins of each aqueous extract was investigated. Antioxidant activities are measured using two different methods (DPPH and ABTS). The delipidated seeds (DS) of V1 have the highest total phenolic content (TPC = 72.56 ± 3.16 mg GAE/g) while they have the lowest total flavonoid content (TFC = 0.22 ± 0.01). With regard to saponins, the PE of V3 is much richer in saponins (194.03 ± 15.78 mg AeE/g) than all the other extracts studied. The OL of V2 and PE of V1 contain the most proanthocyanidins with very similar values of 2.51 ± 0.03 mg CE/g and 2.53 ± 0.34 mg CE/g respectively. The study of the antioxidant activities of the extracts showed a correlation between the amount of polyphenols and IC50. DPPH OL and YL V2, which are rich in polyphenols, have the lowest IC50 of 0.072 mg/ml and 0.080 mg/ml respectively, whereas for ABTS we have PE of V1 that is very rich in polyphenols which has the smallest IC50 value of 0.218 mg/ml.

Chemical Analysis of <i>Carica papaya</i>L. Crude Latex

Crude latex of Carica papaya L. has been known to offer a lot of benefits and potentials especially in the agricultural industry and human health. This study focuses on the latex coming from its fruits of Papaya CX variety. Seven to eight longitudinal incisions were made in order to allow latex to appear and drain in the collecting devices. 439.5 g dried latex was stored in plastic containers and freezed. Results showed that dried latex contained higher amount of crude protein (57.24 ± 0.69%), followed by moisture (17.76 ± 0.09%), ash (7.00 ± 0.01%), crude fat (5.21 ± 0.13%) and crude fiber (0.67 ± 0.09%) based on the complete proximate analysis. In the enzyme analysis, papain had protease activity of 2655 units·g-1 at pH 5.5 and 285 units·g-1 at pH 9.0. These results provided evidence that papain as a protease enzyme is found in the crude latex of papaya which is a major constituent in various proteolytic activities. Crude latex from C. papaya L. can be utilized to address the issues in agricultural farms to accelerate production and reduce environmental hazards.

Inhibition of Proliferation of Breast Cancer Cells MCF7 and MDA-MB-231 by Lipophilic Extracts of Papaya (<i>Carica papaya</i>L. var. Maradol) Fruit

Several epidemiological studies have suggested that carotenoids have antineoplasic activities. The objective of this study was to determine the antiproliferative effect of rich carotenoid lipophilic extracts of papaya fruit pulp ( Carica papaya L., cv Maradol) in breast cancer cells, MCF-7 (estrogen receptor positive) and MDA-MB-231 (estrogen receptor negative), and in non-tumoral mammary epithelial cells MCF-12F. Antiproliferative effect was evaluated using the methylthiazolydiphenyl-tetrazolium bromide (MTT) assay and testing lipophilic extracts from different papaya fruit ripening stages (RS1, RS2, RS3, RS4), at different times (24, 48 and 72 h). Papaya lipophilic extracts do not inhibit cell proliferation of MCF-12F and MDA-MB-231 cells. However, MCF-7 cells showed a significant reduction in proliferation at 72 h with the RS4 papaya extract. Results suggested that lipophilic extracts had different action mechanisms on each type of cells and therefore, more studies were required to elucidate such mechanisms.

Effect of <i>Carica papaya</i>Leaf Extract on Serum Lipids and Liver Metabolic Parameters of Rats Fed a High Cholesterol Diet

Hyperlipidemia plays an important role in the development of atherosclerosis, the main cause of death in the world. In this study, the lipid-lowering effect of Carica papaya leaf in rats fed with a high cholesterol diet was evaluated. Daily doses of C. papaya extract 0, 31, 62 or 125 mg/kg body weight were orally administered in 300 μl polyethylene glycol to hypercholesterolemic rats;it was also administered 62 mg/kg body weight of the extract to rats with normal diet. After a 20-day treatment, the animals were sacrificed;blood and liver were analyzed. Hypercholesterolemic rats showed an increased serum and liver cholesterol, triacylglycerols, and atherogenic index. The C. papaya extract produced a significant decrease of serum and liver cholesterol concentrations in hypercholesterolemic rats, but did not modify serum or liver triacylglycerols;however, the extract reduced the atherogenic index in a dose-dependent manner. C. papaya treatment decreased LDL-C and increased HDL-C in serum significantly. When the oxygen consumption was evaluated in phosphorylating and resting states, the respiratory control in hypercholesterolemic rats mitochondria was lower than in normal diet rats. However, a higher respiratory control in hypercholesterolemic rats mitochondria was observed after C papaya treatment. The liver morphological data are in accordance with serum and liver biochemical values. Our data support that C. papaya has a significant hypocholesterolemic action and HDL-C raising effect on rats fed with a cholesterol-rich diet, however, the precise metabolites responsible of this effect remain unknown.

Analysis of Simple Sequence Repeats Information from Floral Expressed Sequence Tags Resources of Papaya (<i>Carica papaya</i>L.)

Papaya (Carica papaya L.) is one of the most economically, medicinally and nutritionally important tropical fruit crops. Expressed sequence tags (ESTs) derived simple sequence repeat (SSR) markers are more valuable as they are derived from conserved genic portion. Development of EST-SSRs markers through in silico approach is cheaper, less time consuming and labour-intensive. In this study, we aimed to mine SSRs and developed EST-SSR primers from papaya floral ESTs. A total of 75,846 papaya floral ESTs were downloaded from public database National Centre for Biotechnology Information (NCBI). A total of 26,039 floral unigenes (7961 contigs and 18,078 singletons) were generated after assembly of these ESTs. From these floral unigenes, 433,782 perfect SSRs, 204,968 compound SSRs and 6061 imperfect SSRs were mined, respectively. In perfect SSRs, mononucleotide repeats were most abundant (94.7%) followed by tri- (3.1%) and di-nucleotide repeats (1.7%). The frequencies of tetra-, hexa- and penta-nucleotide repeats accounted for only (0.17%), (0.04%) and (0.03%), respectively. In mononucleotide repeats, the most abundant motif was A/T (69.3%) and in di- and tri-nucleotide repeats were AG/CT (61%) and AAG/CTT (31%), respectively. In imperfect SSRs, mononucleotide repeats (56.5%) were most abundant. 176 different types of motifs were identified. A total of 3807 primer pairs for floral papaya ESTs were successfully designed. These developed EST-SSR primers are being used for the genetic improvement of papaya such as study of cross-transferability across genera/species, evaluation of genetic diversity, and identification of sex-specific markers. These EST derived SSRs can also be used in filling gaps in existing linkage maps in papaya.

Bilirubin Lowering Potential of Aqueous Carica Papaya Extract in Induced Jaundice in Rats

Background： The mature unripe fruit of aqueous Carica papaya （ACP） is used in Nigerian traditional medicine for the treatment of jaundice. Work done on aqueous extract of the unripe C. papaya in an acute oral toxicity study in rats showed the LD50 to be 2,520 mg/kg in rats. Current study evaluated the bilirubin-lowering potential of ACP extract in phenylhydrazine （40 mg/kg） induced jaundice in adult rats. Method： Jaundice was assessed by measuring the levels of TB （total bilirubin） and DB （direct bilirubin） in phenylhydrazine-treated animals with or without drug treatment, with CUR （curative）, PRO （prophylactic study）, and in animals with RLC （reduced liver capacity）. Results： Result demonstrated that TB level of 24.0 μmols/L, 22.0 μmols/L and 45.0 μmols/L in the jaundiced group of the CUR, PRO and RLC respectively was significantly lowered （p 〈 0.05） to 10.0, 13.0, and 17.0 respectively by 400 mg/kg of the extract. Total bilirubin level of 24.0 btmols/L, 22.0 lamols/L and 45.0 μmols/L in the jaundiced group of the CUR, PRO and RLC respectively was significantly lowered （p 〈 0.05） to 7.0, 10.0, and 17.0 respectively by 800 mg/kg extract. Conclusion： The study concluded that ACP fruit extract has ability to lower elevated bilirubin level and confer hepatoprotective effect as seen from the liver function test indices thus justifying its ethnomedicinal use.