Explore the vast range of titles available.

Treatment of cancer has been limited by the poor efficacy and toxicity profiles of available drugs. There is a growing demand to develop alternative approaches to combat cancer such as use of nano-formulation-based drugs. Here, we report biosynthesis and characterization of silver nanoparticles (AgNPs) with papaya leaf extract (PLE) and its anti-cancer properties against different human cancer cells. Purified nanoparticles were characterized by standard techniques, such as TEM, STM, SEM, EDS, XRD, and FTIR. Furthermore, cytotoxic activity of AgNPs-PLE was carried out against different human cancer cells and non-tumorigenic human keratinocytes cells. AgNPs-PLE when compared with AgNPs-citric acid or PLE showed better efficacy against cancer cells and was also relatively less toxic to normal cells. Treatment of DU145 cells with AgNPs-PLE (0.5–5.0 μg/ml) for 24–48 h lowered total cell number by 24–36% (P < 0.05). Inhibition of cell growth was linked with arrest of cell cycle at G2/M phase at 24 h, while G1 and G2/M phase arrests at 48 h. ROS production was observed at earlier time points in presence of AgNPs-PLE, suggesting its role behind apoptosis in DU145 cells. Induction of apoptosis (57%) was revealed by AO/EB staining in DU145 cells along with induction of Bax, cleaved caspase-3, and cleaved PARP proteins. G1-S phase cell cycle check point marker, cyclin D1 was down-regulated along with an increase in cip1/p21 and kip1/p27 tumor suppressor proteins by AgNPs-PLE. These findings suggest the anti-cancer properties of AgNPs-PLE.

Papaya fruits (Carica papaya L.) are valuable both as food, including concentrates and mixed beverages and in traditional medicine. The goal of the study was to evaluate the antioxidant activity of various parts of unripe and ripe papaya fruit from the DPPH· kinetics point of view. Peel, pulp, seed, and seed-pulp of unripe and ripe papaya fruits (¼ and >¾ level of ripening) were extracted with ethanol and monitored at 517 nm in the presence of DPPH·. The radical scavenging capacity (RSC) at various time ranges and DPPH· reaction rates for specific time intervals were determined. The highest RSC values were obtained for papaya pulp extracts, consistently higher for the ripe samples in comparison with the unripe ones (86.4% and 41.3%). The DPPH· rates significantly differ for the unripe and ripe papaya extracts, especially for the first time range. They are more than double for the ripe papaya. These values were 2.70, 4.00, 3.25, 2.75 μM/s for the peel, pulp, seed, seed-pulp extracts from the ripe papaya and only 1.00, 1.65, 1.40, 1.80 μM/s for the unripe samples. DPPH· kinetic approach can be useful for a fast and simple evaluation of the overall antioxidant properties of fruit extracts.

Papaya (Carica papaya L.) is widely grown in tropical and subtropical regions. The destructive disease caused by emerging strains of Papaya ringspot virus (PRSV) demands effective transgenic resistance to target atypical virus strains threatening the crop. Papaya transformations are mainly conducted on the explants of immature zygotic or somatic embryos, which are difficult to obtain and proceed, and are largely affected by seasonal factors. Here, we attempted to develop an efficient process for organogenesis using various tissues of ex-vitro or in-vitro grown papaya seedlings. Leaf lamina, hypocotyl and stem sections of seedlings of the papaya variety Sindhi were used for establishment of callus culture through 12 different callus induction treatments (CIT 1–12), with various combinations of plant growth regulators (PGRs). Our results revealed that CIT-11 and CIT-10 enhanced callus induction from ex-vitro leaf discs with midrib, with 86% and 80% efficiency respectively, superior to 53% of CIT-10 using in-vitro leaf discs with midrib. The expression of binary vector construct pSN-PRSV CP in Agrobacterium strain GV3101 was verified in Nicotiana benthamiana and papaya by RT-PCR analysis. Calli derived from leaf tissues (with midrib) of papaya, transformed with the binary vector were successfully regenerated on the shoot induction treatment SIT-13 (Gamborg B5 medium + 0.5 mg/L TDZ + 0.01 mg/L NAA) and were subsequently rooted on root induction treatment RIT-4 (Gamborg B5 medium + 1 mg/L IBA). The transformed explants were regenerated with an efficiency of 26%. The whole process is unique in term of explant selection, source of explant (ex-vitro grown papaya plants) and media formulations as, the leaf tissue from ex-vitro grown papaya showed highest callusing and regeneration efficiency overall.Key messageSuccessful transgenic papaya regeneration is possible from transformed calli, obtained from in-vitro and ex-vitro leaf explants.

Papaya, a fruit crop cultivated in tropical and subtropical regions, is known for its nutritional benefits and medicinal applications. Here we report a 3 draft genome sequence of 'SunUp' papaya, the first commercial virus-resistant transgenic fruit tree to be sequenced. The papaya genome is three times the size of the Arabidopsis genome, but contains fewer genes, including significantly fewer disease-resistance gene analogues. Comparison of the five sequenced genomes suggests a minimal angiosperm gene set of 13,311. A lack of recent genome duplication, atypical of other angiosperm genomes sequenced so far, may account for the smaller papaya gene number in most functional groups. Nonetheless, striking amplifications in gene number within particular functional groups suggest roles in the evolution of tree-like habit, deposition and remobilization of starch reserves, attraction of seed dispersal agents, and adaptation to tropical daylengths. Transgenesis at three locations is closely associated with chloroplast insertions into the nuclear genome, and with topoisomerase I recognition sites. Papaya offers numerous advantages as a system for fruit-tree functional genomics, and this draft genome sequence provides the foundation for revealing the basis of Carica's distinguishing morpho-physiological, medicinal and nutritional properties.

‘KU Gold’ is a papaya cultivar with attractive yellow fruit and paleyellow pulp during its immature stage. It can produce year-round sweet fruit containing a high amount of ascorbic acid during its ripe stage. It also has great potential as an ornamental plant due to its pale-yellow petioles and flowers.

This study was conducted to examine the effect of papaya seed on growth performance, gut morphometry, and economics in Japanese quail. Two hundred and twenty day-old quail chicks were used for the experimental purposes and were divided into four groups each with four replicates of 15 quails per replicate. Group 1 was CON (control) with normal feed while groups 2, 3, and 4 were provided with 1, 2, and 3g/kg papaya seed powder in feed respectively. The results showed no effect of papaya seed on overall feed intake, weight gain, feed conversion ratio, and mortality. The villus height and crypt depth were lower in the 3g/kg diet group ratio compared to CON and other groups. Villus width and the dressing percentage had a significantly higher value in the 3g/kg diet group than in the CON and other groups. It is concluded that papaya seed at the level of 3g/kg feed has a useful effect on growth performance, carcass traits, and gut morphology in quails.

Carica papaya L. (family: Caricaceae), also known as ‘papaya,’ is a tropical American fruit tree. Due to the bioactive components (carpaines, BITC, benzyl glucosinolates, latex, papain, zeaxanthin, choline, etc.) in its seeds, leaves, and fruits, it is revered for its excellent antioxidant, digestive, and nutraceutical benefits. Papayas are high in vitamins A, B, C, E, and K, folate, pantothenic acid, zeaxanthin, lycopene, lutein, magnesium, copper, calcium, and potassium. Being rich in fiber, antioxidants, and vitamin C, it lowers the cholesterol in the arteries; prevents arthritis; reduces aging, cancer, macular degradation, risk of cardiovascular diseases, and stress; increases platelet count; controls dengue fever; facilitates digestion, and lowers body weight. Papaya leaf extract, with many in vitro and case studies in combination therapies with modern medicine, especially for cancers and many other viral diseases, has been found to be an efficient cure. Humans have cultivated papaya cultivars for millions of years because of their significant commercial, medicinal, and agronomic value. Several reports have been published on the genetic modification of papaya for resistance to abiotic (herbicide, Al toxicity, etc.) and biotic stressors (PRSV, mites, Phytophthora, etc.), delaying ripening, and improving shelf life. However, most of these traits have not been introduced globally to all commercial papaya varieties. Unraveling the genetics of papaya has shed light on various domestication impacts, evolutionary patterns, and sex determination in fruit tree crops. It also serves as a potential step toward developing new cultivars to fight climate-oriented stress. Furthermore, extensive research on the stability of the ‘transgene’ across generations, and the ‘yield-penalty’ caused by the transgene, is required. Thus, meticulous crop improvement research on commercial papaya cultivars is necessary for long-term food and health security. This review article encompasses information on the traditional and modern medicinal uses, nutritional properties, phytochemistry, diseases and etiology, post-harvest measures, genomics, biotechnological strategies (for papaya improvement), and value-added products of papaya for food and health security.

Zinc oxide nanoparticles (ZnO NPs) were synthesized by Carica papaya leaf extract. The nanoparticles were characterized by UV–Vis spectrum, Fourier Transform Infrared spectroscopy (FTIR), X-ray Diffraction (XRD), Dynamic light scattering (DLS) analyser and Energy-dispersive X-ray spectroscopy analysis with a scanning electron microscope (SEM–EDX). The ZnO NPs were assessed using 2,2′-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay with varying ZnO NP concentration, showed scavenging activity with the half maximal inhibitory concentration (IC 50 ) = 130.1 and 104.9 µg/mL −1 respectively. Antifungal studies were conducted for ZnO NPs against S. sclerotiorum , R. necatrix and Fusarium species, which demonstrated a higher inhibition rate for S. sclerotiorum (59.7%). Seeds of chickpea were separately treated with various concentrations of ZnO NPs. An exposure to ZnO NPs (25%, 50%, 75% and 100%) and control caused significant changes in seed germination, root length, shoot length and antioxidant enzyme were studied. Compared with control the maximum seed germination, root and plant growth was observed with the treatment of ZnO NPs. Superoxide dismutase and catalase activity increased due to ZnO NPs treatment. This suggest that ZnO NPs may significantly alter antioxidant metabolism during seed germination.

Papaya ringspot virus (PRSV) limits papaya production worldwide. Previously, we generated transgenic lines of hybrid Tainung No.2 (TN-2) carrying the coat protein (CP) gene of PRSV with broad resistance to PRSV strains. Unfortunately, all of them were female, unacceptable for growers and consumers in practical applications. With our reported flanking sequences and the newly released papaya genomic information, the CP-transgene insert was identified at a non-coding region in chromosome 3 of the papaya genome, and the flanking sequences were verified and extended. The female transgenic line 16-0-1 was first used for backcrossing with the parental Sunrise cultivar six times and then followed by selfing three times. With multi-level molecular markers developed from the PRSV CP transgene and the genomic flanking sequences, the presence and zygosity of the CP transgene were characterized at the seedling stage. Meanwhile, hermaphrodite genotype was identified by a sex-linked marker. With homozygotic transgene and horticultural properties of Sunrise, a selected hermaphrodite individual was propagated by tissue culture (TC) and used as maternal progenitor to cross with non-transgenic parental cultivar Thailand to generate a new hybrid cultivar TN-2 with a hemizygotic CP-transgene. Three selected hermaphrodite individuals of transgenic TN were micropropagated by TC, and they showed broad-spectrum resistance to different PRSV strains from Taiwan, Hawaii, Thailand, and Mexico under greenhouse conditions. The selected clone TN-2 #1, with excellent horticultural traits, also showed complete resistance to PRSV under field conditions. These selected TC clones of hermaphrodite transgenic TN-2 provide a novel cultivation system in Taiwan and elsewhere.

High temperatures can interfere with plant metabolism and physiology, compromising productivity. One tactic to minimize the effects of heatwaves on agriculture is the use of bio-stimulants. This study evaluated two commercial products (Baltiko® and Acadian®) containing Ascophyllum nodosum in ‘Aliança’ papaya (Carica papaya L.) seedlings. Six doses (0, 1, 2, 3, 4, and 8 mL L−1) were applied weekly for four weeks at two distinct times, considering moderate and high temperatures. The results indicated distinct effects on gas exchange, seedling development, and nutrient content in leaves and roots. During the moderate temperature period, increasing doses enhanced gas exchange and aerial development, along with increases in potassium and boron levels in the leaves, while root growth decreased. Acadian® provided higher levels of boron in leaves and roots compared to Baltiko®. During the period of elevated temperature, increases were observed in leaf area, root dry mass, and leaf content of phosphorus, potassium, sulfur, and zinc, along with potassium in the roots. These increases were primarily attributed to the effects of the applied biostimulants. A lower dose (3 mL L−1) is recommended during mild temperatures, while a higher dose (6 mL L−1) is suggested for elevated temperatures.