Toxicological investigations on the methanol sub-fraction of the seeds of Carica papaya as a male contraceptive in albino rats

Carica papaya: Potential Implications in Human Health

Background:

Carica papaya, a tree-like herb, is cultivated in more than 50 tropical and subtropical countries worldwide. The parts [leaves, fruit (ripe and unripe), seeds and latex] are used as food as well as traditional medicine in several ways for a number of diseases. Papaya, with a variety of phytochemicals like carotenoids, polyphenols, benzyl isothiocynates, benzyl glucosinates, prunasin (cyanogenic substrate), papain and chymopapain, alkaloids, phenolic compounds, flavonoids, vitamins (A, C, E), carotenoids, cyanogenicglucosides, cystatin, and glucosinolates exhibits significant health benefits ranging from digestive to immune modulation. These compounds have antioxidant, chemoprotective, anti-diabetic, anti-bacterial, anti-plasmodial and anti-fungal activities. Papaya aqueous leaf extract was evaluated for immunomodulatory and anti-tumor activities through cytokine modulation with Th1 type shift in human immune system through molecular studies. The platelet augmenting potential of aqueous leaf extract has been reported in numerous clinical studies and deserves special mention.

Objective:

The scientific knowledge of carica papaya in the post-genomic era including molecular studies and clinical trials is discussed in the review.

Methods:

The published literature on botany, chemical composition, ethnopharmacology, and uses of papaya in food and medical industry was searched through databases like Pub- Med, Scopus, and Google scholar to comprehend the benefits of Carica papaya for human use with around more than 600 published peer- reviewed papers.

Results:

Many traditional and novel uses of Carica papaya for the human benefit are detailed in the review that significantly adds to the scientific knowledge of curious readers.

Conclusion:

Each component of the papaya plant is rich in phytochemicals and is economically important. Most of the phytochemicals are linked to biological functions and influence a variety of cellular processes; hence they have implications in refining human health.

Carica papaya seed extract slows human sperm

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional healers use Carica papaya seeds as a remedy for diseases and as a contraceptive for men and abortion in women.

MATERIAL AND METHODS

Semen samples from 35 healthy men were allowed to liquefy and subsequently incubated for 60 min in Human Tubular Fluid medium containing 1% bovine serum albumin with aqueous C. papaya seed extract at concentrations of zero, 0.025, 0.25, 2.5, 25, 250 and 2500 μg/ml. Afterwards, sperm were washed and used for assessment of capacitation and acrosome reaction, DNA fragmentation, vitality, motility, reactive oxygen species (ROS) and mitochondrial membrane potential (MMP).

RESULTS

The extract showed no effects on straight-line velocity, linearity, straightness, beat-cross frequency and the percentage of capacitated, acrosome-reacted sperm. In contrast, vitality, total motility, progressive motility, curvilinear velocity, average-path velocity and the percentages of hyper-activated, ROS-positive and MMP-intact sperm decreased significantly (P < 0.05), while the percentage of DNA-fragmented sperm increased (P < 0.05).

CONCLUSIONS

Our data show that aqueous C. papaya seed extract significantly and negatively affects sperm motility parameters crucial for fertility; and thus, poses as a likely candidate for male contraception.

The Candida albicans Inhibitory Activity of the Extract from Papaya (Carica papaya L.) Seed Relates to Mitochondria Dysfunction

The inhibitory activity of the papaya seed extract (PSE) on Candida albicans (C. albicans) was determined by turbidimetry method. The inhibitory mechanisms were also evaluated from the prospective of reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP) decrease, and the activities of four complex enzymes in mitochondria respiratory chain. Results obtained from this study indicated that the PSE exhibited an effective inhibitory activity on C. albicans and induced significant accumulation of ROS and collapse of MMP. The Complex I and Complex III exhibited continues significant decrease in mitochondrial enzyme activity assays, but the Complex II and Complex IV activities were not positively correlated. Furthermore, the GC-MS analysis demonstrated that the PSE represents a rich and high-purity source of benzyl isothiocyanate (BITC), which indicated the BITC may be responsible for the mitochondrial dysfunction.

Antibacterial activities of medicinal plants used in Mexican traditional medicine

ETHNOPHARMACOLOGICAL RELEVANCE

We provide an extensive summary of the in vitro antibacterial properties of medicinal plants popularly used in Mexico to treat infections, and we discuss the ethnomedical information that has been published for these species.

MATERIALS AND METHODS

We carried out a bibliographic investigation by analyzing local and international peer-reviewed papers selected by consulting internationally accepted scientific databases from 1995 to 2014. We provide specific information about the evaluated plant parts, the type of extracts, the tested bacterial strains, and the inhibitory concentrations for each one of the species. We recorded the ethnomedical information for the active species, as well as their popular names and local distribution. Information about the plant compounds that has been identified is included in the manuscript. This review also incorporates an extensive summary of the available toxicological reports on the recorded species, as well as the worldwide registries of plant patents used for treating bacterial infections. In addition, we provide a list with the top plant species with antibacterial activities in this review RESULTS: We documented the in vitro antibacterial activities of 343 plant species pertaining to 92 botanical families against 72 bacterial species, focusing particularly on Staphylococcus aureus, Mycobacterium tuberculosis, Escherichia coli and Pseudomonas aeruginosa. The plant families Asteraceae, Fabaceae, Lamiaceae and Euphorbiaceae included the largest number of active species. Information related to popular uses reveals that the majority of the plants, in addition to treating infections, are used to treat other conditions. The distribution of Mexican plants extended from those that were reported to grow in just one state to those that grow in all 32 Mexican states. From 75 plant species, 225 compounds were identified. Out of the total plant species, only 140 (40.57%) had at least one report about their toxic effects. From 1994 to July 2014 a total of 11,836 worldwide antibacterial patents prepared from different sources were recorded; only 36 antibacterial patents from plants were registered over the same time period. We offered some insights on the most important findings regarding the antibacterial effects, current state of the art, and research perspectives of top plant species with antibacterial activities in vitro.

CONCLUSIONS

Studies of the antibacterial in vitro activity of medicinal plants popularly used in Mexico to treat infections indicate that both the selection of plant material and the investigation methodologies vary. Standardized experimental procedures as well as in vivo pharmacokinetic studies to document the effectiveness of plant extracts and compounds are necessary. This review presents extensive information about the medicinal plants possessing antibacterial activity that has been scientifically studied and are popularly used in Mexico. We anticipate that this review will be of use for future studies because it constitutes a valuable information tool for selecting the most significant plants and their potential antibacterial properties.

Indian folklore medicine in managing men's health and wellness

India is a home for a large variety of plants with remarkable medicinal and pharmacological value. Traditional medicine in the form of Ayurveda, Siddha and Unani has used many of these plants since ancient days for treating and curing various ailments of the body. When it comes to issues related to reproductive health, people still hesitate to discuss and/or accept it openly and hence look for alternate and natural remedies. The various tribal populations distributed across different parts of the country still use these plant extracts in various formulations for maintenance of good health. The medical utilities of several of these plants have been documented; however, there are many more, whose potential is yet to be explored. This review discusses the role of various plants grown in the Indian subcontinent that have been widely used in maintaining various aspects of reproductive health in men such as infertility, aphrodisiac, contraception, libido, sexually transmitted infections and reproductive tract cancers as well as in treating chronic disorders.

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 (SGOT) 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 SGOT, SGPT and serum creatinine levels were detected 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)×10⁵/µL (P=0.00004) and the RBC count (7.97±0.61)×10⁶/µL (P=0.00003) were significantly 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±0.18×10⁵/µL), reaching almost a fourfold higher at Day 21 (11.3×10⁵/µL), while it was 3.8×10⁵/µL and 5.5×10⁵/µL at Day 3 and Day 21 respectively in the control. Likewise, the RBC count in the test group increased from 6×10⁶/µL to 9×10⁶/ µL at Day 21 while it remained near constant in the control group (6×10⁶/µL).

CONCLUSIONS

Fresh C. papaya leaf extract significantly 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.

Repeated dose 28-days oral toxicity study of Carica papaya L. leaf extract in Sprague Dawley rats

Carica papaya L. leaves have been used in ethnomedicine for the treatment of fevers and cancers. Despite its benefits, very few studies on their potential toxicity have been described. The aim of the present study was to characterize the chemical composition of the leaf extract from ‘Sekaki’ C. papaya cultivar by UPLC-TripleTOF-ESI-MS and to investigate the sub-acute oral toxicity in Sprague Dawley rats at doses of 0.01, 0.14 and 2 g/kg by examining the general behavior, clinical signs, hematological parameters, serum biochemistry and histopathology changes. A total of twelve compounds consisting of one piperidine alkaloid, two organic acids, six malic acid derivatives, and four flavonol glycosides were characterized or tentatively identified in the C. papaya leaf extract. In the sub-acute study, the C. papaya extract did not cause mortality nor were treatment-related changes in body weight, food intake, water level, and hematological parameters observed between treatment and control groups. Some biochemical parameters such as the total protein, HDL-cholesterol, AST, ALT and ALP were elevated in a non-dose dependent manner. Histopathological examination of all organs including liver did not reveal morphological alteration. Other parameters showed non-significant differences between treatment and control groups. The present results suggest that C. papaya leaf extract at a dose up to fourteen times the levels employed in practical use in traditional medicine in Malaysia could be considered safe as a medicinal agent.

Fertility, developmental toxicity and teratogenicity in albino rats treated with methanol sub-fraction of Carica papaya seeds

Objective:

To evaluate the status of fertility, developmental stages during gestation and teratological changes, if any, following oral administration of methanol sub-fraction (MSF) of the benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya in rats.

Materials and Methods:

The MSF was administered at the doses of 50 mg contraceptive dose (CD), 100 mg (2× CD), 250 mg (5× CD) and 500 mg (10× CD)/kg body wt/day along with vehicle-treated control using 10 male and 20 female Wistar rats in each group. Necropsies were performed one day before the expected parturition. Status of gravid/non-gravid uterus, the number of corpora lutea in the ovary, implantation status, fetal wellbeing, fetal resorption, fetal body weight, external, visceral and skeletal malformations were recorded.

Results:

Pregnancies were recorded in vehicle-treated control animals and in the animals treated with 50 mg/kg body wt/day. The animals treated with 2× CD, 5× CD and 10× CD did not get pregnant. The fetuses and the status of the ovary, uterus and implantation, fetal body weight, soft tissues and skeletal structures were recorded normal. Data were comparable to those of control.

Conclusion:

The results suggest that the test substance had no developmental toxicity and teratogenicity which could affect pregnancy, implantation and gestation.

Safety evaluation of long term oral treatment of methanol sub-fraction of the seeds of Carica papaya as a male contraceptive in albino rats

ETHNOPHARMACOLOGICAL RELEVANCE

The manuscript is one of the series of attempts in authenticating scientific documentation of the seeds of Carica papaya being traditionally used for contraception.

AIMS OF THE STUDY

To establish safety of the methanol sub-fraction (MSF) of the seeds of Carica papaya as a male contraceptive following long term oral treatment.

MATERIALS AND METHODS

MSF was administered orally to albino rats at multiples of contraceptive dose (CD) at 50 (1x), 100 (2x), 250 (5x) and 500 (10x)mg/kg body weight daily for 52 weeks. Body weight, organs weight, morbidity, mortality, clinical chemistry, sperm analysis, histopathology and serum testosterone were evaluated to assess the safety and contraceptive efficacy.

RESULTS

MSF treatment at various dose regimens, daily for 52 weeks did not show significant changes in body weight, organs weight, food and water intake and pre-terminal deaths compared to those of control animals. Sperm count and viability in 50mg/kg body weight treated animals and the weight of epididymis, seminal vesicle and prostate of all the treated animals showed significant reduction compared to control. Cauda epididymal spermatozoa of 50mg/kg body weight treated animals were immotile. Azoospermia was observed in 100, 250 and 500 mg/kg body weight treated animals. Serum clinical parameters, serum testosterone and histopathology of vital organs were comparable to those of control animals. Histology of testis revealed adverse effects on the process of spermatogenesis, while the histology of epididymis, seminal vesicles and ventral prostate showed no changes compared to control.

CONCLUSION

The long term daily oral administration of MSF affects sperm parameters without adverse side effects and is clinically safe as a male contraceptive.

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.

Reproductive and Fertility Effects of an Extract of Andrographis paniculata in Male Wistar Rats

The possible effect of extract of Andrographis paniculata Nees ( A paniculata) standardized to ≥10% andrographolide, the main bioactive component, on male fertility in albino Wistar rats was evaluated, by orally administering 0, 20, 200, and 1000 mg/kg of body weight per day, for 65 days prior to mating and 21 days during mating. The treated groups showed no signs of dose-dependent toxicity. The body weight gain and feed consumption were not affected at any of the dose levels. The testosterone levels and fertility indices in treatment groups were found to be comparable with that of the control indicating no effect on fertility. Total sperm count and sperm motility were not affected. The testes and epididymides did not show any gross and histopathological changes. Based on these findings, it can be concluded that the no-observed adverse effect level of extract of A paniculata (≥10% andrographolide) was found to be more than 1000 mg/kg per day.