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Litchi Good for Heath from Skin to Heart: an Overview of Litchi
Functional Activities and Compounds
Y. Wang, H.C. Wang, Z.Q. Hu, H.B. Chen,
G.B. Hu and X.M. Huang* Z.K. Zhou
Dongguan Campus
College of Horticulture
South China Agricultural University
Guangzhou 510642
China
*Corresponding author
Guangdong Medical University
Dongguan 532808
China
Keywords: Litchi chinensis Sonn., antioxidant, heating effect, allergens, anticancer,
antivirus, anti-diabetes
Abstract
Litchi industry in China at present suffers from seasonal overproduction,
which causes heavy burden in marketing the fresh fruit. Development of processing
industry provides a way out from this difficult situation. Large quantity of scrap
materials of skin and seed will be produced from processing and await utilization.
Health promoting effects and medical functions of litchi tissues were well
documented in ancient China. Modern phytochemistry and pharmacology provide
sound evidences of litchi’s health promoting and medical functions, and functional
compounds in the fruit are being discovered. This paper provides an overview of the
studies of antioxidant activities in various fruit tissues of litchi, ‘heating’ effect of
and allergens in the flesh, anti-cancer effect of the peel, and anticancer, antivirus
and diabetes-controlling effects of the seed.
INTRODUCTION
With its charming appearance and delicious taste, fresh litchi is loved by all
peoples. Despite this, litchi is entitled ‘heating food’ according to Chinese traditional
medicine because some people become irritated after taking litchi, which drives away
some consumers from fresh litchi.
After the rapid development of litchi in the 1990s, seasonal overproduction has
become a major problem in China. The situation demands an effort to develop a
considerable litchi processing industry. Skin and seed to be produced as scrap materials in
large amount from litchi processing await comprehensive utilization. In fact, there is a
great potential in utilization of the scrap materials. Since ancient times, Chinese people
have realized the health promoting and medical functions of various litchi tissues.
According to Ben Cao Gang Mu, an ancient monograph of herbal medicines written by
the famous doctor, Li Shizheng in Ming Dynasty, litchi flesh promotes body fluid
production and improves sense, intelligence and Qi; litchi skin can be used to cure
dysentery, metrorhagia and eczema; and litchi seed, which is ‘warm and Qi smoothening’,
can be used for killing pains in stomach, hernia and blood gas. Modern phytochemistry
and pharmacology provide sound evidences of litchi’s health promoting and medical
functions, and functional compounds in the fruit are being discovered.
FUNCTIONAL ACTIVITIES AND COMPOUNDS IN LITCHI FLESH
Litchi flesh is rich in nutritional and functional compounds. According the data
released by USDA (see http://www. nal.usda.gov/fnic/foodcomp/cgi-bin /list_nut_edit.pl),
100 g of litchi flesh contains 16.5 g sugars, 276 kj energy, 0.83 g protein, 0.44 g fat, 0.44
g ash, 1.3 g edible fiber, 5 mg Ca, 0.31 mg Fe, 10 mg Mg, 31 mg P, 171 mg K, 1 mg Na,
0.07 mg Zn, 71.5 mg vitamin C, 0.011 mg thiamin, 0.065 mg riboflavin, 0.603 mg Niacin,
0.1 mg vitamin B6, 14 mg folate, 0.07 mg vitamin E, 0.007 mg tryptophan, 0.041 mg
lysine and 0.009 mg methionine. Taking 100 g litchi flesh satisfies 2-4% of the daily
demands for P, K, Mg, Fe, Zn and Mn and 22% for Cu (Wall, 2006).
Proc. 3r
d
IS on Longan, Lychee & Other Fruit
Trees in Sapindaceae Family
Eds.: Qiu Dongliang et al.
Acta Hort. 863, ISHS 2010
646
Apart from nutrition value, litchi flesh has also such functions as improving
digestion and blood circulation, moistening skin and alleviate anaemia symptom (Chi et
al., 2005). However, active compounds and mechanisms of these functions are unknown.
Antioxidant activity of litchi flesh is well documented. In addition to vitamin C and E,
litchi flesh contains antioxidant polysaccharides (Wu et al., 2004) and flavonoids
including procyanidin A2 and leucocyanidin (Van Rooyen et al., 1983). Polysaccharides
in litchi flesh is effective to eradicate O2· and was reported to significantly suppress lipid
peroxidation in liver of rat (Wu et al., 2004). Li et al. (2004) obtained a 3.3% recovery of
polysaccharides in litchi flesh.
However, based on Chinese traditional medicine, litchi flesh is a typical ‘heating’
food. Excessive taking causes ‘heating symptoms’ including sore and swell in throat,
boils in mouth, tongue and face and tonsillitis. ‘Heating’ effect of litchi, which is only
shown in some individuals, is not understood in terms of mechanism and effective
substances. Huang and Wu (2002) showed that ‘heating’ foods, including litchi flesh,
induced in vitro RAW264.7 macrophase to produce more prostaglandin E2 (PGE2), which
mediates proinflammation reaction, while ‘cooling’ foods like bitter melon did not have
this effect, suggesting that ‘heating’ effect might be an inflammation reaction in nature.
The effective substances are unknown either.
In Europe, there are records of cases where some individuals develop symptoms,
including above mentioned ‘heating symptoms’. Researchers attributed these symptoms
to allergic reaction or anaphylactic reaction to litchi flesh (Fäh et al., 1995; Niggemann et
al., 2002; Hoppe et al., 2006a, b; Raap et al., 2007). Allergic symptoms reported thus far
include mouth itch, swell of eye lip, eczema, herpes, sore and swell in throat, difficulty in
breath, rhinitis, stomachache (Hoppes et al., 2006a, b), skin itch, urticaria, agioedema
(Raap et al., 2001), allergic shock (Fäh et al., 1995). Cases of litchi takers with similar
allergic symptoms were also reported in China (Wang and Wang, 2006; Xu et al., 2005;
Gao and Wang, 2001). There is some information about allergens in litchi flesh. Fäh et al.
(1995) found that litchi flesh contained rich panallergen profilin, which was further
proved by Niggemann et al. (2002), who found interaction between latex and litchi flesh.
Zhang et al. (2006) cloned a complete length of profilin gene from litchi. Raap et al.
(2007) described one case of allergic reaction to litchi which was not caused by profilin
but might be anaphylactic reaction to mugwort. Hoppe et al. (2006a) separated series
protein allergens with molecular weight ranging from 14 to 70 kD from litchi flesh. One
of them, a 28 kD protein, was identified as triose-phosphate isomerase based on N-end
amino acid sequence. This enzyme is a key one in sugar metabolism.
Both ‘heating’ effect and allergic reaction are highly individual depended and their
symptoms have some similarities. However, there is no researcher equating the two
phenomena.
There are also reports showing over-taking causes so called ‘litchi sickness’ with
typical symptoms of hypoglycermia (Xie, 2005). Xie (2005) attributed this effect to
fructose in litchi, but his explanation lacked for clinical and pharmacological evidence. In
fact, litchi flesh is rich in sugars including sucrose, fructose and glucose, proportions of
which differ according to cultivars (Wang et al., 2006). Therefore, the assumption that
over-taking reduces blood sugar awaits absolute evidence.
FUNCTIONAL ACTIVITIES AND COMPOUNDS IN LITCHI SKIN
Antioxidant
Traditionally, litchi skin is useful to prevent the ‘heating effect’ from taking litchi
flesh. How it ‘cools’ the flesh is unknown. However, the antioxidant activity of litchi skin
is well defined (Guo et al., 2003; Surinut et al., 2005). Litchi skin contains free radical
scavenging compounds like ascorbic acid, glutathione, carotenoids, polysaccharides
(Huang and Wu, 2006; Yang et al., 2006), as well as rich phenolic substances including
flavonoids (flavonols and anthocyanins) and phenolic acids (Li and Jiang, 2007). Zhang
et al. (2000) found epicatechin, procyanidin B2, epigallocatechin and procyanidin B4 are
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among the major flavonoids in fruit skin of ‘Huaizhi’. Analysis conducted by
Sarini-Manchado et al. (2000) showed that molymerized tannins (procyanidins) were the
most abundant (0.4% fresh weight) in ‘Guiwei’ skin, followed in order by epicatechin
(0.17%) and procyanidin A2 (0.07%), anthocyanins (0.04%) and flavanols (0.04%).
There are studies showing fruit antioxidant activity is closely related to concentrations of
total phenols, esp. anthocyanins and procyanidins (Luximon-Ramma et al., 2003), hence
flavonoids in litchi skin contribute the major part of its antioxidant activity. Different
types of flavonoids differ in antioxidant activity. Zhao et al. (2006) found procyanidin B2
was stronger in scavenging hydroxyl free radical and superoxgen anion than procyanidin
B4 and epicatechin, while epicatechin is more active in eradicating DPPH than the other
two flavonoids.
Litchi fruit development is accompanied by changes in chemical compositions
including phenolic substances (Huang and Wu, 2006). Hence, antioxidant activity in skin
at different maturity differs. Zheng et al. (2003) found skin of immature fruit had a much
stronger antioxidant activity than that of mature fruit. Cultivars also differ in quantity and
quality of phenolics including flavonoids, so do their antioxidant activities.
Anti-Cancer Activity
Litchi skin is rich in insoluble fiber (40% on dry weight) (Li et al., 2006), which
prevents rectum cancer, diabetes and heamorrhoids. Wang et al. (2006a) reported that
water soluble alcohol extract from litchi skin significantly inhibited growth of human
hepatoma cells in vitro, and that feeding mice carrying liver cancer with litchi skin extract
suppressed cancer development. In both cases, the anticancer effect was dosage- and
time- depended. Dosages at 0.14, 0.3 and 0.6 g/kg/d led to a cancer inhibiting rate of 17.3,
30.8 and 44.0%, respectively. Wang et al. (2006b) further found litchi skin extract also
effective to suppress breast cancer. They found litchi skin extract caused changes in gene
express pattern, induced programmed cell death and suppressed multiplication in cancers
cells (Wang et al., 2006a, b). However, active ingredients in litchi skin were not indicated
in their studies. A study made by Zhao et al. (2007) indicated that flavonoids (epicatechin
and procynidin B2) were effective to suppress human breast cancer cells and human lung
fibroblast (HELF), although their toxicity to cancer cells was lower than that of paclitaxel.
FUNCTIONAL ACTIVITIES AND COMPOUNDS IN LITCHI SEED
Chemical Composition of Litchi Seed
Litchi kernel contains starch (40.7%), crude fiber (24.5%), proteins (4.93%) and
minerals including Mg (0.28%), Ca (0.21%) and P (0.11%). Fatty acids include 12%
palmitic acid, 27% linoleic acid, 11% linoleic acid, 42% cyclopropanoic fatty acids
(CPFA), among which dihydrosterculic acid accounts for 37%, cis-7,
8-methylenehexadecanoic acid 4%, cis-5,6-methylenetetradecanoic acid 0.4%, and cis-3,
4-methylenedodecanoic acid 0.1% (see Ding, 1999). Litchi seed contains also phenolic
acids and flavonoids such as methyl 5-O-p-coumaroylquinate, protocatechuic acid,
cyanidin-3-O-glu, cyanidin-3-O-rut and malvidin-3-acetyl-O-gluoenin (see Ding, 1999).
21 amino acids were detected by Huang and Chen (2007), among which 4 were unknown.
There were reports indicating litchi seed contains a special amino acid,
α-methylenecyclopropylglycine (see Ding, 1999). Volatile compounds including ketons,
aldehydes, esters, alcohols, enes and terpenoids with unknown functions were also
detected in litchi seed (Shen, 1988; Ding, 1999; Le and Fu, 2001; Chen et al., 2005; Guo
and Pan, 2006). Tu et al. (2006) found sterol derivatives, while Yang et al. (2004)
measured crude saponin in litchi seeds.
Functional Activities and Pharmacological Studies
Dried litchi seed is characterized by traditional Chinese medicine as slightly bitter,
warming, Qi flow promoting, cold-driving, pain-killing, and liver- and kidney–tonifying
(see Tian, 2005). There are abundant information on the health promoting and medical
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functions of litchi seed, including antioxidant, anti-cancer, anti-virus, controlling diabetes,
and reducing blood lips.
Antioxidant Activity
As mentioned above, litchi seed contains flavonoids, which contribute to the
antioxidant activity of the seed. Water and ethanol extracts from litchi seed were found to
reduce the damage caused by free radicals and promoted SOD activity in alloxan
momohydrate (ALX) treated mice (Pan et al., 1999).
Anti-Cancer Eeffect
Xiao et al. (2007) and Wang et al. (2007) reported in the same year that water
extract of litchi seed or litchi seed pellets were effective to suppress tumor and hepatoma.
Water extract of litchi seed at dosage of 62.5 kg/kg.d obtained 30% suppression on
hepatoma tumor in mice (Wang et al., 2007). Xiao et al. (2007) found that extract from
litchi seed inhibited the formation of telomere in heptoma cells and thus their cell
division.
Reducing Blood Sugars and Lipids
There have been reports about the effects of litchi seed in reducing blood sugars
and lipids and in promoting the function of liver (Wu et al., 1991; Zheng et al., 1998; Pan
et al., 1999; Guo et al., 2003). Results obtained by Wu et al. (1991), Zheng et al. (1998)
and Pan et al. (1999) showed that the water extracts of litchi seeds reduced blood sugar in
rat suffering from diabetes induced by ALX and that the effect was similar to that of the
anti-diabetes drug, biguanides. And it was found that litchi seed extract was safer and the
effect lasted longer (over 1 week) than biguanides (Zheng et al., 1998). Pan et al. (1999)
suggested that litchi seed extract reduced blood sugar because it inhibited glucose uptake
by blood capillary but promote glucose uptake in ambient tissues. Guo et al. (2003) also
found that litchi seed extract alleviated sugar metabolism disorder and improved
sensitivity to insulin in rat suffering from insulin resistant Type 2 diabetes (T2DM)
induced by streptomycin, and therefore reduced blood sugar.
There is little information about active anti-diabetes and lipid-reducing substances
in litchi seed. Ning (1996) attributed the abundant unsaturated fatty acids to blood
lipid-reducing effect of litchi seed. Some authors suggested that
α-methylenecyclopropylglycine in litchi seed was the effective to reduce the blood sugar
and glucogen in liver in mice treated with ALX (Huang, 1994); while others believed
anti-diabetes activity was related to saponins (Guo et al., 2003; Yang and Liang, 2004).
Anti-Virus Effects
There have been not a few reports about the anti-virus effects of litchi seed
extracts, which were effective to hepatitis B virus (Zheng and Zheng, 1992; Li, 1997; Pan
et al., 2000; Xu et al., 2004; Xiao et al., 2005; Jiang et al., 2008), respiratory syncytial
virus (RSV) (Liang et al., 2006), influenza virus (Luo et al., 2006) and SARS coronavirus
(Gong et al., 2008). Zheng and Zheng (1992) found that litchi seed was the second most
effective to control hepatitis B among 1000 tested herbal medicines. Pan et al. (2000)
found direct inhibition on in vitro expression of HbsAg and HBV-DNA. Yang et al.
(2001) showed that both water and alcohol (50%) extracts from litchi seeds were effective
to inhibit HbsAg and HbeAg, but water extract was more effective on HbeAg, while
alcohol extract more effective on HbsAg. Xu et al. (2004) examined 6 extraction fractions
of litchi seed, all showing strong effects in inhibiting the expression of HBsAg and
HbeAg in Hep G 2.2.15 cell line, with an inhibiting rate reaching 90.9 and 84.3% on
HBsAg and HbeAg, respectively. Most authors attribute anti-virus effect of litchi seed
extracts to its flavonoids (Luo et al., 2006; Liang et al., 2006; Gong et al., 2008), while
Jiang et al. (2008) suggested that saponins in litchi seed was the effective component.
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Other Functions
Litchi seed is especially effective to cure haemorrhoids (Deng, 2006).
PROBLEMS AND PROSPECTS
There is no doubt that litchi fruit possesses health promoting and some medical
functions. However, research in their mechanisms and active substances are still in its
infantry. Except for antioxidants in the skin and allergens in the flesh which are well
understood, other functions, such as anti-virus, anti-cancer and anti-diabetes, have been
studied based on crude components rather than purified substances. Litchi fruit is
ill-reputated as ‘heating’ food in China, which drives away numerous consumers from
taking litchi. In fact, ‘heating’ symptoms occur only on small percentage of people. What
are ‘heating’ substances in litchi? What are the mechanisms of ‘heating’ effect of litchi?
Why different people respond differentially to litchi? What is the relation between
‘heating effect’ and allergic reaction? Answering these questions will help to prevent
‘heating’ symptoms by taking litchi, and clear the ill reputation of ‘litchi heating’.
Solving the problems of seasonal overproduction of litchi has now become the
biggest issue in litchi industry in China. Development of processing industry, which is
one of the most important solutions, will generate large quantities of skin and seed as
scrap materials. As mentioned above, these are potential materials for anti-cancer,
anti-virus and anti-diabetes drugs. Their utilizations await a joint effort in understanding
these functions from researchers in fruit science, medicine, phytochemistry and
pharmacology.
ACKNOWLEDGEMENTS
This study has been supported by Ministry of Agriculture (Project No.
nyhyzx08-031 and 2006G31) and Dongguan Bureau of Science and Technology (Project
No. 2008108101051).
Literatures Cited
Chen, J., Feng, X.F., Pan, J.Q., Xu, Z.L. and Liu, D. 1988. Identification of volatile oils in
litchi stone. Chinese Traditional Medicine Bulletin 13(8):31-32.
Chen, L., Liu, Z.P., Shi, W.B., Liu, L. and Deng, Q.Y. 2005. GC/MS identification of
essential oils from the seed and the membrane of Litchi chinesis Sonn. Acta
Scientiarum Naturalium Universitatis Sunyatseni 44(2):53-56.
Chi, J.W., Tang, X.J., Zhang, M.W., Xu, Z.H., Zhang, Y., Wei, Z.C., Li, J.X. and Zhang,
R.F. 2005. Study on the processing technology of litchi health oral solution. Food
Science and Technology 26(7):63-65.
Deng, Z. 2006. Alcohol and vinegar extract of litchi seed is especially effective for
external haemorrhoids. Rural New Technology 6:46.
Ding, G. 1999. The research progress of Litchi chinensis. Lishizhen Medicine and
Materia Medica Research 10(2):145-146.
Fäh, J., Wüthrich, B. and Vieths, S. 1995. Anaphylatic reaction to lychee fruit: evidence
for sensitization to profiling. Clinical and Experimental Allergy 25:1018-1023.
Gao, J.T. and Wang, Q.L. 2001. Analysis of litchi-induced allergic asthma among 23
cases. Chinese Journal of Microbiology and Immunology 21(additional issue):76-78.
Gong, S.J., Su, X.J., Wu, H.P., Li, J., Qin, Y.J., Xu, Q. and Luo, W.S. 2008. A study on
anti-SARS-CoV 3CL protein of flavonoids from litchi chinensis sonn core. Chinese
Pharmacology Bulletin 24(5):699-700.
Guo, C.J., Yang, J.J., Wei, J.Y., Li, Y.F., Xu, J. and Jiang, Y.G. 2003. Antioxidant
activities of peel, pulp and seed fractions of common fruits as determined by FRAP
assay. Nutrition Research 23(12):1719-1726.
Guo, J.W. and Pan, J.Q. 2006. Chemical compositions, biological activities and
pharmacological effects of litchi or litchi seeds. Chinese Journal of New Drugs
15(8):585-588.
Guo, J.W., Pan, J.Q., Qiu, G.Q., Li, A.H., Xiao, L.Y. and Han, C. 2003. Effects of litchi
650
seed on enhancing insulin sensitivity in type 2 diabetic-insulin resistant rats. Chinese
New Drug Journal 12(7):536-539.
Huang, C.J. and Wu, M.C. 2002. Differential effects of foods traditionally regarded as
‘heating’ and ‘cooling’ on prostaglandin E2 production by a macrophage cell line.
Journal Biomed Sci. 9:596-606.
Huang, T.K. 1994. Handbook for component analysis and pharmacology of common
chinese traditional medicine. Chinese Medical Science and Technology Press 1292.
Huang, X.M. and Wu, Z.X. 2006. Maturation and senescence of litchi fruit and their
regulations. p.315-340. In: B. Nouredddine and S. Norio (eds.), Advances in
Postharvest Technologies for Horticultural Crops. Research Sunpost, Keralaa, India.
Huang, X.S. and Chen, J. 2007. Determination of free amino acids in litchi stone. Amino
Acids and Biotic Resources 29(2):11-14.
Jiang, W.F., Chen, J.Z., Zhang, J., Zhang, J. and Peng, J. 2008. Inhibitory effects of total
saponin extracted from the semen litchi against hepatitis B virus in vitro. Journal of
the Fourth Military Medical University 29(2):100-103.
Le, C.G. and Fu, H.L. 2001. Volatile compounds in litchi peel and seed. Chinese
Traditional and Herbal Drugs 32(8):688-689.
Li, J. and Jiang, Y. 2007. Litchi flavonoids: isolation, identification and biological
activity. Molecules 12:745-758.
Li, W. 1997. Experimental study of the inhibitory effect of Chinese herbal medicine on
HBV-DNA. Journal of Traditional Chinese Medicine 39(1):46.
Li, X.H., Long, S.J., Xie, Y.F. and Wei, W. 2004. The extraction of Euphoria longan
(Lour) and Litchi chinensis Sonn polysaccharides and its effect of cleaning oxygen
radicals. Journal of Guangxi Medical University 21(3):342-344.
Li, Y.H., Wang, X.L. and Qiu, N. 2006. Extracting technology of dietary fibre from
lichee shell. Journal of GuiLin University of Technology 26(3):385-387.
Liang, R.G., Liu, W.B., Tang, Z.N. and Xu, Q. 2006. Inhibition on respiratory syncytial
virus in vitro by flavonoids extracted from the core of Litchi chinensis. Journal of the
Fourth Military Medical University 27(20):1881-1883.
Liu, A.W., Chen, X. and Zheng, J.Y. 2003. Inhibitory effect of litchi seed extract on
NDMA. Science and Technology in Food Industry 24(12):27-29.
Luo, W.S., Gong, S.J., Liang, R.G. and Xu, Q. 2006. A study of the action of flavonoids
from litchi seed against influenza virus. China Journal of Chinese Materia Medica
31(6):1379-1380.
Luximon-Ramma, A., Bahorun, T. and Crozier, A. 2003. Antioxidant actions and
phenolic and vitamin C contents of common Mauritian exotic fruits. Journal of the
Science of Food and Agriculture 83:496-502.
Niggemann, B., Reibel, S., Hipler, C. and Wahn, U. 2002. Anaphylactic reaction to
lychee in a 12-year-old girl: cross-reactivity to latex? Pediatr Allergy Immunol
12(1):64-67.
Ning, Z.X., Peng, K.W., Qing, Y., Wang, J.X. and Tan, X.H. 1996. Effects of the kernel
oil from Litchi chinensis Sonn. seed on the level of serum lipids in rats. Acta
Nutrimenta Sinica 18(2):159-162.
Pan, J.Q., Gui, J.W., Han, C. and Liu, H.C. 2000. Survey of pharmacological
experimental studies in litchi seed. Chinese New Drug Journal 9(1):14-16.
Pan, J.Q., Liu, H.C., Liu, G.N., Hu, Y.L., Chen, L.X. and Qiu, Z.Q. 1999. A study in
blood sugar reducing, blood lipid controlling and antioxidant activities in litchi seed.
Guangdong Pharmaceutical Journal 9(1):47-50.
Poppe, S., Neidhart, S., Zunker, K., Hutasingh, P., Carle, R., Steinhart, H. and Paschke,
A. 2006b. The influences of cultivar and thermal processing on the allergenic potency
of lychee (Litchi chinensis Sonn.). Food Chemistry 96:209-29.
Poppe, S., Steinhart, H. and Paschke, A. 2006a. Identification of a 28 kDa lychee allergen
as a triose-phosphate isomerase. Food and Agricultural Immunology 17(1):9-19.
Raap, U., Schaefer, Kapp A. and Wedi, B. 2007. Exotic food allergy:anaphylactic
reaction to lychee. Journal of Investigation of Allergol Clin Immuno. 17(3):199-201.
651
Sarini-Manchado, P., Le, Roux E., Le, Guerneve C., Lozano, Y. and Cheynier, V. 2000.
Phenolic composition of litchi fruit pericarp. J. Agric. Food Chem. 48(12):5995-6002.
Surinut, P., Kaewsutthi, S. and Surakarnkul, R. 2005. Radical scavenging activity in fruit
extracts. Acta Hort. 679:201-203.
Tian, J. 2005. Progress in research of anti-diabetes herbal medicines. Journal of
Hangzhou Teachers College 4(6):470-472.
Tu, P.F., Luo, Q. and Zheng, J.H. 2002. Studies on chemical constituents in seed of Litchi
chinensis. Chinese Traditional and Herbal Drugs 33(4):300-303.
Van Rooyen Petrus H., et al. 1983. Crystal structure and molecular conformation of
proanthocyanidin-A2, a bitter substance in litchi. S Afr Chem. 36(2):49.
Wall, M.M. 2006. Ascorbic acid and mineral composition of longan (Dimocarpus
longan), lychee (Litchi chinensis) and rambutan (Nephelium lappaceum) cultivars
grown in Hawaii. Journal of Food Composition & Analysis 19:655-663.
Wang, H.C., Huang, H.B., Huang, X.M. and Hu, Z.Q. 2006. Sugar and acid compositions
in the arils of Litchi chinensis Sonn.:cultivar differences and evidence for the absence
of succinic acid. Journal of Horticultural Science and Biotechnology 81(1):57-62.
Wang, J. and Wang, Z.Q. 2006. A case of allergic reaction to litchi with symptoms of
urticaria and twitch. Abstracts of Chinese Medicine 25(2):92.
Wang, X., Wei, Y., Yuan, S., Liu, G., Zhang, Y.L.J. and Wang, W. 2006a. Potential
anticancer activity of litchi fruit pericarp extract against hepatocellular carcinoma in
vitro and in vivo. Cancer Letter 239:144-50.
Wang, X., Yuan, S., Wang, J., Lin, P., Liu, G., Lu, Y., Zhang, J., Wang, W. and Wei, Y.
2006b. Anticancer activity of litchi fruit pericarp extract against human breast cancer
in vitro and in vivo. Toxicol. Appl. Pharmacol. 215:168-78.
Wang, X.Y., Xiao, L.Y., Pan, J.Q., Lu, J.H. and Zhang, S.P. 2007. Experimental studies
of effects of antitumor of litchi seed Ke li and the activity of in the tissue-end of EAC,
S180 and hepatic carcinoma of rats. China Healthcare Innovation 2(12):54-56.
Wu, H.H., Li, X.H. and Qiu, L. 2004. Studies on superoxide scavenging capability on
litchi and longan fruit pulp by its polysaccharides. Food Science and Technology
25(5):166-169.
Wu, Q.H., Liang, S.M., Li, Y.J., Zhao, S.H., Jian, Z.H. and Chen, S.Y. 1991. Screening
study of TCM simple and proved recipes on diabetes. Jouranl of Guangzhou Uiversity
of Traditional Chinese Medicine (Z1):218-223.
Xiao, L.Y., Hong, H.J., Pan, J.Q., Lu, J.H. and Zhang, S.P. 2007. Anti-tumor effect of
semen litchi and its effect on telomerase activation of hepatoma tissue. China
Pharmacy 18(18):1366-1368.
Xiao, L.Y., Zeng, W.T., Ma, P.Q., Zhu, K.L., Liang, J.X., Huang, Y.H., Yang, H.H. and
Ou, Y.Y. 2005. Clinical study on the effect of litchi seed pellet on chronic hepatitis B.
China Journal of Traditional Chinese Medicine and Pharmacy 20(7):444-445.
Xie, R.H. 2005. Excessive taking of litchi causes disease of low blood sugar. China
Health Monthly 10:106.
Xu, H.B., Guo, X.X. and Liu, Y. 2005. A case of allergic purpura after taking litchi.
Medical Journal of National Defending Forces in North China 17(2):89.
Xu, Q., Chen, Q.B., Yi, X.H. and Chen, Z.Y. 2004. Inhibitory effect of extracts of the
core of litchi on the expression of HBsAg and HBeAg in the HepG 2.2.15 cells.
Chinese Journal of Hospital Pharmacy 24(7):393-395.
Yang, B., Wang, J., Zhao, M., Liu, Y., Wang, W. and Jiang, Y. 2006. Identification of
polysaccharides from pericarp tissues of litchi (Litchi chinensis Sonn.) fruit in relation
to their antioxidant activities. Carbohydrate Research 341(5):634-638.
Yang, Y., Luo, Z.H. and Yan, Q. 2004. Estimation of content on total saponins from
semen litchi. Chemical Industry Times 18(1):45-46.
Yang, Y., Yi, X.H., Chen, Q.B. and Tan, M. 2001. Inhibition of semen litchi on HbsAG
and HbeAG. Chemical Industry Times 7:24-26.
Yang, Y.J. and Liang, B.M. 2004. Determination of anti-diabete saponins from Litchi
chinensis Sonn. Guangdong Pharmaceutical Journal 14(6):12-15.
652
Zhang, D.L., Quantick, P.C. and Grigor, J.M. 2000. Changes in phenolic compounds in
litchi (Litchi chinensis Sonn.) fruit during postharvest storage. Postharvest Biology
and Technology 19(2):165-172.
Zhang, H.Y., Song, J.J., Liu, Z.G. and Kang, M.X. 2006. Expression and purification of
profilin from lychee fruit and its cross-reactivity with birch pollen profilin Bet v 2.
Journal of Tropical Medicine 6(6):620-623.
Zhao, M., Yang, B., Wang, J.S., Li, B.Z. and Jiang, Y.M. 2006. Identification of the
major flavonoids from pericarp tissues of lychee fruit in relation to their antioxidant
activities. Food Chem. 98:737-742.
Zhao, M.M., Yang, B., Wang, J.S., Liu, Y., Yu, L.M., and Jiang, Y.M. 2007.
Immunomodulatory and anticancer activities of flavonoids extracted from litchi
(Litchi chinensis Sonn.) pericarp. International Immunopharmacology 7:162-166.
Zheng, G.M., Yi, Z.Z., Zhang, J.B. and Zhong, D.H. 2003. Studies on the antioxidative
effect of extract from mature and premature litchi pericarp 15(4):341-344.
Zheng, L.Y., Han, C. and Pan, J.Q. 1998. Chemical, pharmacological and clinical studies
of litchi seed. Acta Chinese Medicine and Pharmacology 5:51-53.
Zheng, M.S. and Zheng, Y.F. 1992. Experimental studies on the inhibition effects of 1000
Chinese medicinal herbs on the surface antigen of hep2 atitis B virus. Journal of
Traditional Chinese Medicines 12(3):193.
