INTRODUCTION:

Dengue is the most common anthropod borne infection caused by Flaviviridae family. It is one of the causative agent for fever (4). It is caused by 4 serotypes. It is worldwide disease. The dengue virus is a single stranded RNA virus. It is the most important emerging viral diseases in human. Infection by one serotype will provide lifelong immunity to that particular strain but not to the remaining three. Cross-strain infections are common and can have severe consequences, with extreme cases leading to death. Dengue fever has strong spatial and temporal patterns which have been linked to climatic and environmental conditions (8). It is mostly found in tropical and subtropical areas predominantly found in urban and semiurban area (5). It is common in atleast 100 countries in Asia, the Pacific, the Americans, Africa and the Caribbean. Thailand, Vietnam, Singapore and Malaysia have all reported an increase in cases. An estimated 50 million dengue infection cases occur globally with around 500,000 cases of severe dengue and 20,000 deaths per year (7).

DENGUE FEVER:

Dengue fever is a viral disease that is spread through Aedes aegypti mosquito vector, but dengue has been transmitted through blood transfusion and organ transplantation.

Infection with any of the DENV serotypes may be asymptomatic in the majority of cases or may result in a wide spectrum of clinical symptoms ranging from a mild flu-like syndrome the most severe forms of the disease, which are characterized by coagulopathy, increased vascular fragility, and permeability. It also develops into severe forms of illness like dengue haemorrhagic fever and dengue shock syndrome (1). There is no specific treatment and no vaccine. Later it is found that dengue fever can be cured by Carica papaya leaves extract. Early diagnosis and management of symptoms is critical to reduce the risk of complications and avoid further spread of the virus. After being bitten by a mosquito carrying the virus, the incubation period ranges from 3 to 15 days. Dengue starts with chills, headache and pain during moving eyes and low backache. Painful aching in the legs and joints occurs during first four of illness. The temperature rises quickly as high as 104 F (40 C) with bradycardia and hypotension. The eyes become reddened. A flushing or pale pink rash comes over the face and disappears. The glands in the neck and groin are often swollen.

PATHOGENESIS OF DENGUE VIRAL INFECTION:

Cell and tissue tropism of DENV may have a major impact on the outcome of DENV infections. In vitro data and autopsy studies suggest that three organ systems play an important role in the pathogenesis of DHF/DSS: the immune system, the liver, and endothelial cell linings of blood vessels. During the feeding of mosquitoes on humans, DENV is presumably injected into the blood- stream, with spill over in the epidermis and dermis, resulting in infection of immature Langerhans cells and keratinocytes. Infected cells then migrate from site of infection to lymph nodes, where monocytes and macrophages are recruited, which become targets of infection. This infection is amplified and virus is disseminated through the lymphatic system (2). As a result of this primary viremia, several cells of the mononuclear lineage, including blood-derived monocytes, myeloid and splenic and liver macrophages are infected. The liver is commonly involved in DENV infections in humans. Although DENV was found in a significant proportion of human hepatocytes and Kupffer cells, little inflammation was seen within the liver, indicating that much of the observed apoptosis and necrosis was virally induced.

DIAGNOSIS AND TREATMENT OF DENGUE FEVER:

Dengue can be diagnosed by isolation of virus by serological methods or by molecular methods. Diagnosis of acute or recent dengue infection can be established by testing serum samples after first 5 days of symptoms. Methods such as one step, real time RT-PCR or nested RT-PCR are widely used to detect dengue viral genes in acute phase serum samples. There are three basic methods used in laboratory to diagnosis of dengue viral infection are viral isolation and charecteristics, detection of genomic sequence by a nucleic acid amplification technology assay and detection of dengue virus specific antibodies. These laboratory methods are used to diagnose dengue, including detection of the dengue virus, viral antigens and antibiotics against the virus in the patient’s blood or tissue (6). The virus can be detected in the blood for only four to five days after the onset of symptoms. During this early stage of dengue is caused by virus there is no specific medicine or antibiotic to treat dengue. Rest and fluid intake for adequate hydration is important. Aspirin and non steriodal anti inflammatory drugs are used for worsening bleeding complications. Acetaminophen and codeine is used for headache and for joints and muscles pain. Aspirin and Brufen should not be given for fever. Before evidence of haemorrhage and bleeding we should avoid intravenous therapy. Antibiotics and steroids should not be used because they don’t have any benefits against dengue.

NATURAL THERAPY FOR DENGUE FEVER:

Papaya (Carica papaya) and Neem are naturally used to cure dengue fever.

PAPAYA (Carica papaya):

The young leaves from a fruit bearing papaya plant should be used. The leaves of the Red Lady Papaya Plant found commonly in India are more effective. Fresh Papaya leaves should be mixed with a little cold water and ground and filtered. The important fact that the leaves are not too old neither too young. The leaves are crushed by using Mortar and Pestle and juice is taken from it. An adult should have 10ml of juice twice daily and children’s should have 2.5ml to 5ml of juice. This extract was administered to infected patient twice daily. Before administration of the extract blood samples were analysed. Platelets count, White Blood Cells and Neutrophils count were decreased, because Carica papaya leaves exhibit potential activity against dengue fever. After infection, patient feels fatigue and fever. Carica papaya contains two biologically active compound chymopapain and papain. It shows that papaya derived papain,carcain,chymopapain and glycine endopeptidase will improve PH conditions and pepsin degradation. Although all parts of Carica papaya are used as antimicrobial, antimalarial, antifungal, male and female antifertility and immunomodulatory (3).

NEEM (Azadirchata indica):

The Neem tree, Azadirachta indica, is a tropical evergreen with a wide adaptability. The neem tree contains more than 100 bio active ingredients and it is rich in proteins. Its bitter taste is due to an array of complex compounds called “limonoids”. Young neem leaves contain 60% water,23% carbohydrates,7% proteins,3% minerals and 1% fat. Neem seeds contain 45% of brown and bitter oil known as Oil of Margosa. In case of dengue fever, fresh Neem leaves should be mixed with a little cold water and ground and filtered. It should consume 10ml 2-3 times a day. After consuming fever will subside on consumption for five days. Even after recovery from fever this can consume for another 2 days. It is a homemade natural medicine.

PROGRESS OF CURRENT VACCINE FOR DENGUE FEVER:

Although no licensed dengue vaccine is available, several vaccines are under progress. Such as live attenuated virus vaccines, live chimeric virus vaccine, inactivated virus vaccine and live recombinant, DNA and subunit vaccines. Non viral vaccines are also proposed and developed.NS1 is another subunit vaccine candidate that is not a virion associated protein and it has no ADE effects. Although recovery of dengue can be identified by stable pulse, blood pressure. Patients leads to normal temperature and appetite (7).

CONCLUSION:
The main objective of the current review is to investigate the potential of C. papaya leaves extracts against Dengue fever. The secondary metabolite of plants origin makes up a vast repository of compounds with a wide range of biological activities. There have been many reports of higher plant extracts possessing relatively good potential to inhibit viruses. Many plants extracts including Spilanthes calva, Sterculia guttata, Balanites aegyptiaca, Vitex negundo, Solanum xanthocarpum, Artemisia annua, Fagonia indica, Nerium indicum, Trigonella foenum, in different solvents have been reported to exhibit activity against Aedes aegypti; a vector of dengue fever (5).

REFERENCE:

1 Byron E.E.Martina, Penelope Korata. Dengue virus pathogenesis. Clinical Microbiology Reviews, Oct. 2009, p. 564–581

2 Durbin, A. P., M. J. Vargas, K. Wanionek, S. N. Hammond, A. Gordon, C. Rocha, A. Balmaseda, and E. Harris. 2008. Phenotyping of peripheral blood mononuclear cells during acute dengue illness demonstrates infection and increased activation of monocytes in severe cases compared to classic dengue fever. Virology 376:429–435.

3 Karishna KL, Paridhavi M, Patel JA. Review on nutritional, medicinal and pharmacological properties of papaya (Carica papaya Linn.) Nat Prod Radiance. 2008;7:364–373.

4 Murthy JM, Rani PU. Biological activity of certain botanical extracts as larvicides against the yellow fever mosquito, Aedes aegypti L. J Biopest. 2009;2:72–76

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7 Shu- Wen Wan, Robert Anderson, Chiou- Feng Lin. Current progress in dengue vaccines. Journal of Biomedical Science 2013,20:37 doi: 10.1180/1423-0127-20-37

8 Vanessa Racloz, Rabecca Ramsey, Shilu Tong, Wenbiao Hu. Surveillance of Dengue Fever Virus: A Review of Epidemiological Models and Early Warning Systems. 2012.doi: 10.1371/journal.pntd.0001648

9 World Health Organization. 1999. Strengthening implementation of the global strategy for dengue fever and dengue haemorrhagic fever, prevention and control. Report of the informal consultation, 18-20 October. World Health Organization, Geneva, Switzerland.

Received on 07.12.2013 Modified on 06.01.2014

Research J. Pharm. and Tech. 7(2): Feb. 2014; Page 269-271