Nutrient components, health benefits, and safety of litchi (Litchi chinensis Sonn.): A review.

Litchi (Litchi chinensis Sonn.) is a tropical to subtropical fruit that is widely cultivated in more than 20 countries worldwide. It is normally consumed as fresh or processed and has become one of the most popular fruits because it has a delicious flavor, attractive color, and high nutritive value. Whole litchi fruits have been used not only as a food source but also for medicinal purposes. As a traditional Chinese medicine, litchi has been used for centuries to treat stomach ulcers, diabetes, cough, diarrhea, and dyspepsia, as well as to kill intestinal worms. Both in vitro and in vivo studies have indicated that whole litchi fruits exhibit antioxidant, hypoglycemic, hepatoprotective, hypolipidemic, and antiobesity activities and show anticancer, antiatherosclerotic, hypotensive, neuroprotective, and immunomodulatory activities. The health benefits of litchi have been attributed to its wide range of nutritional components, among which polysaccharides and polyphenols have been proven to possess various beneficial properties. The diversity and composition of litchi polysaccharides and polyphenols have vital influences on their biological activities. In addition, consuming fresh litchi and its products could lead to some adverse reactions for some people such as pruritus, urticaria, swelling of the lips, swelling of the throat, dyspnea, or diarrhea. These safety problems are probably caused by the soluble protein in litchi that could cause anaphylactic and inflammatory reactions. To achieve reasonable applications of litchi in the food, medical and cosmetics industries, this review focuses on recent findings related to the nutrient components, health benefits, and safety of litchi.

Plants with neurotoxic potential in undernourished subjects.

The consumption by humans of plants with potential to induce neurological disorders is widespread, but overt disease surfaces only when the subject's toxic threshold is exceeded. Excessive intake arising from food dependency in the setting of hunger, chronic undernutrition, vitamin deficiency, inadequate detoxication, or other individual susceptibility, can trigger acute encephalopathy (lychee, ackee fruits), sub-acute spastic paraparesis (grasspea, cassava root/leaves) or ataxic neuropathy (cassava root flour). While these disorders are very rarely encountered in high-income countries, they are not only common among impoverished populations but also often occur as outbreaks that impact a significant proportion of an affected community. Unfamiliarity with the adverse effects of plant toxins has sometimes led to the mistaken attribution of nutritional neurotoxic disease to a neurotropic viral or synthetic pesticidal etiology. The combination of human population growth, food and water insecurity, poverty and, with climate change, increased dependency on environmentally tolerant plants with neurotoxic potential, predictably may result in an increased prevalence of nutritional neurotoxic disorders, especially in certain parts of Africa and Asia.

Litchi-associated acute encephalitis in children, Northern Vietnam, 2004-2009.

Since the end of the 1990s, unexplained outbreaks of acute encephalitis in children coinciding with litchi harvesting (May-July) have been documented in the Bac Giang Province in northern Vietnam. A retrospective ecologic analysis of data for 2004-2009 involving environmental, agronomic, and climatic factors was conducted to investigate the suspected association between the outbreaks and litchi harvesting. The clinical, biological, and immunologic characteristics of the patients suggested a viral etiology. The ecologic study revealed an independent association between litchi plantation surface proportion and acute encephalitis incidence: Incidence rate ratios were 1.52 (95% CI 0.90-2.57), 2.94 (95% CI 1.88-4.60), and 2.76 (95% CI 1.76-4.32) for second, third, and fourth quartiles, respectively, compared with the lowest quartile. This ecologic study confirmed the suspected association between incidence of acute encephalitis and litchi plantations and should be followed by other studies to identify the causative agent for this syndrome.

Effects of Litchi chinensis fruit isolates on prostaglandin E(2) and nitric oxide production in J774 murine macrophage cells.

BACKGROUND: Litchi chinensis is regarded as one of the 'heating' fruits in China, which causes serious inflammation symptoms to people. METHODS: In the current study, the effects of isolates of litchi on prostaglandin E(2) (PGE(2)) and nitric oxide (NO) production in J774 murine macrophage cells were investigated. RESULTS: The AcOEt extract (EAE) of litchi was found effective on stimulating PGE(2) production, and three compounds, benzyl alcohol, hydrobenzoin and 5-hydroxymethyl-2-furfurolaldehyde (5-HMF), were isolated and identified from the EAE. Benzyl alcohol caused markedly increase in PGE(2) and NO production, compared with lipopolysaccharide (LPS) as positive control, and in a dose-dependent manner. Hydrobenzoin and 5-HMF were found in litchi for the first time, and both of them stimulated PGE(2) and NO production moderately in a dose-dependent manner. Besides, regulation of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) mRNA expression and NF-κB (p50) activation might be involved in mechanism of the stimulative process. CONCLUSION: The study showed, some short molecular compounds in litchi play inflammatory effects on human.

Exotic food allergy: anaphylactic reaction to lychee.

There are very few reports on allergic reactions to lychee fruit in the literature. We describe the case of a 26-year-old man who developed pruritus, generalized urticaria, and severe angioedema of his lips and tongue with dyspnea within 15 minutes after lychee fruit intake. Although we found no lychee-specific immunoglobulin E antibodies, a basophil activation test (BAT) and a cellular antigen stimulation test (CAST) to lychee were both positive, as was a prick-to-prick test with fresh lychee fruit. The patient also suffered from an oral food allergy syndrome to parsley and was sensitized to mugwort but not to latex or profilin. BAT and CAST are helpful tools in the diagnostic workup for exotic food allergy. Mugwort is suggested as the allergen responsible for,the cross-reactivity presented by this patient, as he had no sensitization to latex or profilin.

Anaphylactic reaction to apple, banana and lychee: what is common between botanically disparate plant families?

We present the case of a 33-year-old nonatopic woman with multiple episodes of anaphylaxis after ingestion of different fruits. The fruits implicated were apple, banana and lychee: all of which belong to different and botanically disparate plant families. The reaction to apple and banana was confirmed by prick testing. There was no history of allergy to other agents that are known to have cross reactions with fruits, viz. latex or pollen. As such patients often do not present to dermatologists, we wish to highlight the rare but potentially fatal clinical entity of type I allergy to fruits without concomitant allergy to other common airborne/contact allergens. We also discuss the possible explanation of type I reaction to apparently unrelated fruits and the allergens involved in such reactions.