Effect of papaya seed extract on microenvironment of cauda epididymis. (1/108)

AIM: To evaluate the effect of aqueous Carica papaya seed extract on microenvironment of cauda epididymis. METHODS: Adult male albino rats were intramuscularly administered with 0 (control) or 0.5 mg papaya seed extract/kg body weight for 7 days. Cauda epididymal tubular content was collected by micropuncture technique; epididymal luminal fluid and sperm pellets were separately analyzed. RESULTS: The results revealed that the extract treatment caused significant reduction, as compared with control, in total protein and sialic acid contents in both epididymal fluid and sperm pellet. As compared with control, significantly lowered acid phosphatase activity was recorded in sperm pellet but was higher in epididymal fluid after the treatment. The extract treatment also caused significant reduction in level of inorganic phosphorus in the epididymal fluid. CONCLUSION: It is concluded that the aqueous papaya seed extract alters cauda epididymal microenvironment.  (+info)

Comparative reactions of recombinant papaya ringspot viruses with chimeric coat protein (CP) genes and wild-type viruses on CP-transgenic papaya. (2/108)

Transgenic papaya cultivars SunUp and Rainbow express the coat protein (CP) gene of the mild mutant of papaya ringspot virus (PRSV) HA. Both cultivars are resistant to PRSV HA and other Hawaii isolates through homology-dependent resistance via post-transcriptional gene silencing. However, Rainbow, which is hemizygous for the CP gene, is susceptible to PRSV isolates from outside Hawaii, while the CP-homozygous SunUp is resistant to most isolates but susceptible to the YK isolate from Taiwan. To investigate the role of CP sequence similarity in overcoming the resistance of Rainbow, PRSV HA recombinants with various CP segments of the YK isolate were constructed and evaluated on Rainbow, SunUp and non-transgenic papaya. Non-transgenic papaya were severely infected by all recombinants, but Rainbow plants developed a variety of symptoms. On Rainbow, a recombinant with the entire CP gene of YK caused severe symptoms, while recombinants with only partial YK CP sequences produced a range of milder symptoms. Interestingly, a recombinant with a YK segment from the 5' region of the CP gene caused very mild, transient symptoms, whereas recombinants with YK segments from the middle and 3' parts of the CP gene caused prominent and lasting symptoms. SunUp was resistant to all but two recombinants, which contained the entire CP gene or the central and 3'-end regions of the CP gene and the 3' non-coding region of YK, and the resulting symptoms were mild. It is concluded that the position of the heterologous sequences in the recombinants influences their pathogenicity on Rainbow.  (+info)

In vitro antimalarial activity of extracts of three plants used in the traditional medicine of India. (3/108)

In an attempt to search for new antimalarial drugs, we studied plants used by traditional healers of southwest India to treat malaria. Aqueous and organic solvent extracts obtained from specific parts of the plants Swertia chirata, Carica papaya, and Citrus sinensis were tested on malaria strain Plasmodium falciparum FCK 2 in vitro. The temperatures of extraction were the same as that used by the traditional healers in their plant preparations. Visual evaluation of the antimalarial activity of the plant extracts on thin blood smears was followed by quantification of the activity by use of [35S]-methionine incorporation into parasite proteins to determine the value that inhibits 50% (IC50). Among the 3 plants tested, 2 had significant inhibitory effect on P. falciparum in vitro.  (+info)

Chloroform extract of Carica papaya seeds induces long-term reversible azoospermia in langur monkey. (4/108)

AIM: To evaluate the antifertility activity of the chloroform extract of Carica papaya seeds by oral administration in langur monkey, Presbytis entellus entellus. METHODS: The chloroform extract of Carica papaya seeds, 50 mg/kg/day, was administered orally for 360 days to adult male langur monkeys. The sperm characteristics by light and electron microscopy, the sperm functional tests, the semen biochemistry, the serum testosterone level, the Leydig cell function, and the histology and ultrastructure of testis were determined to evaluate the antifertility activity and the blood biochemistry and hematology, to evaluate the toxicology. RESULTS: The extract gradually decreased the sperm concentration since days 30-60 of treatment with a total inhibition of sperm motility, a decrease in sperm viability and increase in sperm abnormality. Azoospermia was observed after day 90 of treatment and continued during the whole treatment period. Treatment withdrawal resulted in a gradual recovery in these parameters and 150 days later they reverted to nearly the pretreatment values. Morphological observation of the ejaculated sperm by light and scanning electron microscopy showed deleterious changes, particularly on the mid-piece. Sperm functional tests, viz., sperm mitochondrial activity index, acrosome intactness test and hypo-osmotic swelling test scored in the infertile range during treatment and returned to the fertile values 150 days after drug withdrawal. Histology of the testis revealed shrunken tubules, germ cell atrophy and normal Leydig cells. Ultrastructure of the testis showed vacuolization in the cytoplasm of Sertoli cells and germ cells. Loss of cytoplasmic organelles were evident in the spermatocytes and spermatids. Round spermatids showed loss of Golgi bodies, peripheral mitochondria and vacuolated cytoplasm, indicating maturational arrest. Leydig cell functional test indicated a mild inhibition of steroidogenic function. Haematology and serum biochemistry study disclosed no significant toxicological effect and the serum testosterone level was not affected. CONCLUSION: Carica papaya seed extract may selectively act on the developing germ cells, possibly mediated via Sertoli cells, leading to azoospermia.  (+info)

Effect of papaya seed extract on contractile response of cauda epididymal tubules. (5/108)

AIM: To evaluate the administration of Carica papaya seed extract on the contractility of cauda epididymal tubules in male rats. METHODS: Adult male albino rats were administered intramuscularly papaya seed extract at a dose of 0.5 mg/kg/day for 7 days. Animals were killed, cauda epididymal tubules of 5 cm length were isolated and the contractile response to different concentrations of adrenalin (1-500 microg/25mL) was examined. In another group of animals, the contractile response was assayed 3 months after withdrawal of the treatment. RESULTS: Papaya seed extract brought about a significant decrease in the contractile response of epididymal tubules as compared with the control. After three months of papaya withdrawal, a nearly normal pattern of contraction was regained. CONCLUSION: Papaya seed treatment reversibly reduces the contractile response of cauda epididymal tubules.  (+info)

On the evolution and molecular epidemiology of the potyvirus Papaya ringspot virus. (6/108)

The potyvirus Papaya ringspot virus (PRSV) is found throughout the tropics and subtropics. Its P biotype is a devastating pathogen of papaya crops and its W biotype of cucurbits. PRSV-P is thought to arise by mutation from PRSV-W. However, the relative impact of mutation and movement on the structure of PRSV populations is not well characterized. To investigate this, we have determined the coat protein sequences of isolates of both biotypes of PRSV from Vietnam (50), Thailand (13), India (1) and the Philippines (1), and analysed them together with 28 PRSV sequences already published, so that we can better understand the molecular epidemiology and evolution of PRSV. In Thailand, variation was greater among PRSV-W isolates (mean nucleotide divergence 7.6%) than PRSV-P isolates (mean 2.6%), but in Vietnamese populations the P and W biotypes were more but similarly diverse. Phylogenetic analyses of PRSV also involving its closest known relative, Moroccan watermelon mosaic virus, indicate that PRSV may have originated in Asia, particularly in the Indian subcontinent, as PRSV populations there are most diverse and hence have probably been present longest. Our analyses show that mutation, together with local and long-distance movement, contributes to population variation, and also confirms an earlier conclusion that populations of the PRSV-P biotype have evolved on several occasions from PRSV-W populations.  (+info)

Effect of dried fruits of Carica papaya Linn on hepatotoxicity. (7/108)

Ethanol and aqueous extracts of Carica papaya has been evaluated for its anti hepatotoxic activity. The ethanol and aqueous extracts of Carica papaya showed remarkable hepatoprotective activity against CCl(4) induced hepatotoxicity. The activity was evaluated by using biochemical parameters such as serum aspartate amino transferase (AST), alanine amino transferase (ALT), alkaline phosphatase, total bilirubin and gamma glutamate transpeptidase (GGTP). The histopathological changes of liver sample was compared with respect to control.  (+info)

Comparison of cross inoculation potential of South African avocado and mango isolates of Colletotrichum gloeosporioides. (8/108)

Three hundred and eighteen Colletotrichum gloeosporioides isolates from stem-end rot and anthracnose infected avocados as well as from stem-end rot/anthracnose and soft brown rot on mango, were compared using fruit inoculations. Isolates could be categorised according to lesion size and both avocado and mango isolates produced larger lesions when inoculated on their own hosts. Cross-inoculation potential of these isolates was also compared on strawberries, peppers, guavas, papayas and citrus. All isolates produced lesions on all hosts except citrus. Factors such as area of origin and symptom type from which original isolations were made, could not be correlated with lesion development on these hosts.  (+info)

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