Loquat Fruit - Medicinal and Delicious!
The Loquat tree and its medicinal fruit and leaves are well loved and treasured in Asian countries such as Japan and China. One Chinese legend says that when loquat fruits fall into a river, the carp fish will eat them and get strong enough to swim up waterfalls and evolve into dragons. Another folk story explains of a poor, young man who fell in love with a sick woman. He had no money or fancy clothes. The man expressed his desire to marry the woman to his mother, who gave him encouragement to use their loquat tree to make medicine and sell it at the farmer’s market. The medicine proved to be a hit and earned him enough money to dress well and woo the woman. He also gave her the loquat medicine, which made her feel well enough to leave her bed and walk. He brought her gifts of loquat and the loquat medicine every day, and soon enough she recovered from her sickness and agreed to marry him. These stories pay reverence to the value of the loquat plant and its ability to nourish and heal.
The loquat tree grows all around Hawaii as well as other tropical parts of the world. Its botanical name is Eriobotrya japonica and it belongs to the Rosaceae family. Loquat in Chinese is called Pi pa ye and it is called Biwa in Japanese. Pi pa ye is believed to originate from China and Japan in the more tropical regions, as it does not do well in temperatures below -3 degrees. Botanically, it is considered a tropical evergreen shrub with leathery green-silver leaves with hairy undersides. The loquat tree can grow up to 15 to 30 feet tall and bush out to a wide diameter. The white flowers appear in the late fall, with fruit producing throughout winter in Hawaii. In China, the fruit ripen throughout May and June. There are two main cultivars of fruit, either white or golden orange in color. The fruit is round and slightly fuzzy on the outside and fleshy on the inside with several seeds in the middle. The skin and flesh of the fruit are edible, but people often peel or boil the skin off. The fruit is loaded with vitamins and minerals, especially beta-carotenoids, which are precursors to Vitamin A and assist in immune function, eye health, and cellular growth (Kubala 2019).
In Chinese medicine, the part of the loquat used medicinally is the leaf. Pi pa ye is categorized as an herb that “Relieves Coughing and Wheezing”. It is Cool to Neutral in energy and Bitter in flavor. The fresh leaves are more cooling than the dried, and prepared Pi pa ye leaves are warmer than unprepared. Pi pa ye enters the Lung and Stomach organs. The recommended dosage is 6 – 15 grams (Bensky 446).
Pi pa ye cools Lung-Heat to transform Phlegm and alleviate cough. It is indicated for coughs with yellow phlegm (which indicates Heat). Pi pa ye is believed to direct Lung Qi downward and thus calm coughing. It also can help direct Stomach Qi downward for symptoms like hiccups and belching. It is used for nausea and vomiting due to Heat or Stomach Fire (which would be odorous and more chunky than watery). Pi pa ye can be used for coughing of blood and nosebleed, which are signs of Heat/Fire. Often these disturbances occur because of Wind-Heat, Summer Heat, or Dry Heat. Pi pa ye is contraindicated in Stomach Cold vomiting or cough due to Wind-Cold since it is cooling in nature and works to clear Heat.
Pi pa ye is often used in Chinese cough syrups like Chuan Bei Pi Pa Gao or Nin Jiom Pei Pa Koa.
It is important when preparing Pi pa ye to clean the undersides of the leaf which is covered in small hairs. Gently brush the hairs off of the leaves to prevent irritation to the throat. It is not uncommon when using Chinese syrups with Pi pa ye to see small hairs in the syrup. Although these appear to be shards of glass, it is actually the Pi pa ye hairs since it is difficult to remove them all. This small number of hairs is not concerning.
After cleaning the hairs off, the leaf can be fried with honey to strengthen its Lung-nourishing and moistening properties (Bensky 448). Pi pa ye can also be fried with ginger to create a warming effect. With the right combination of other herbs, ginger-fried Pi pa ye can work on conditions previously contraindicated for Pi pa ye, such as nausea and vomiting from Stomach Cold or Wind-cold cough (Bensky 447).
Numerous studies confirm that Pi pa ye is a valuable medicine. First, Pi pa ye has been shown to have anti-inflammatory benefits. The leaf and seed extract as well as the loquat fruit juice inhibits cytokines, NF-KB activation (similar to turmeric), prostaglandins, and leukotrienes, which all play a significant role in the inflammatory process. Loquat seed extract has specifically inhibited these inflammatory markers in the alveoli of the lung, confirming its value in treating lung issues (Ge et. Al 2009). The extract also promotes antifibrosis by improving the lung structure of rats with induced pulmonary fibrosis and helping to reduce inflammatory expressions such as TNF-alpha cytokine activation (Yang et. Al 2012).
Pi pa ye is also being studied for its antioxidant properties. Research shows that loquat extract can help protect against Reactive Oxygen Species (Kwon et. Al 2000). It has been shown to increase antioxidants Superoxide Dismutase (S.O.D.) and glutathione perioxidase in liver tissue, as well as increase Nitric oxide concentration, which is necessary for vasodilation of the blood vessels to enhance circulation (Chang et. Al 2011).
The terpenes and flavonoids found in the loquat leaf, seed, and fruit inhibit an increase in serum glucose, suggesting that Pi pa ye has anti-diabetic properties. Liu et. Al (2016) suggests that loquat leaf and seed extracts may prevent and control development of type I and II diabetes. Loquat leaf extract showed promising hypoglycemic effects on mice tests, effectively lowering blood glucose levels. Another study found that loquat leaf extract inhibits glucocorticoid-elevating enzymes. Elevated glucocorticoids are associated with hyperglycemia (high blood sugar), insulin resistance and type II diabetes (Gumy et. Al 2009). In addition to lowering blood glucose levels, the loquat leaf extract also lowered total cholesterol and triglyceride levels in fish fed a high cholesterol diet.
Ethanol and methanol extracts of loquat seed show promise in improving liver function by inhibiting development of liver fibrosis, as well as providing hepatoprotective action through constituents such as b-sitoserol and unsaturated fatty acids. The loquat seed extract decreased ALT and AST levels and the formation of fat droplets in the liver of rats. Elevated antioxidant enzyme activity was also found to combat oxidative stress in rats with induced hepatitis (Nishioka et. Al 2002).
Other studies have found the seed extract useful for protection of renal and neuronal cells due to its antioxidant properties. The seed extract has demonstrated neuroprotective benefits against oxidative stress and neuronal cell death, which resulted in reversed memory impairment in mice. The extract also inhibited lipid peroxidation and restored S.O.D. activity (Kim et. Al 2011).
Loquat leaf extracts were shown to suppress cell carcinogenesis at different progression stages of cancer, such as “cancer initiation, proliferation, and metastasis” (Kim et. Al 2011). The same study by Kim et. Al (2011) demonstrated anti-cancer properties in loquat leaf specifically targeting breast cancer cells. Both water and ethanol extracts of the loquat leaf were shown to decrease the incidence of tumors, with the water extract having more of an inhibitory effect. Another study showed that loquat tea extract induced apoptosis in human promyelocytic leukemia cells, making loquat a promising natural medicine for chemoprevention (Zar et. Al 2014).
Pi pa ye is a resource that can be useful in providing delicious food as well as valuable medicine. Modern studies confirm traditional usage of Pi pa ye for its lung ameliorating and gives better insight into its general health-promoting benefits. Traditional and modern explorations have both proven that Pi pa ye is a wondrous medicinal herb. Practitioners and laypeople worldwide would strongly benefit in furthering their experience with Pi pa ye and its various offerings.
—
References:
Bensky, Dan, et al. Chinese Herbal Medicine: Materia Medica . Eastland Press, 2015.
Chang CT;Huang SS;Lin SS;Amagaya S;Ho HY;Hou WC;Shie PH;Wu JB;Huang GJ; “Anti-Inflammatory Activities of Tormentic Acid from Suspension Cells of Eriobotrya Japonicaex Vivo and in Vivo.” Food Chemistry, U.S. National Library of Medicine, https://pubmed.ncbi.nlm.nih.gov/25214105/.
“Eriobotrya Japonica.” Eriobotrya Japonica (Japanese Medlar, Japanese Plum, Loquat) | North Carolina Extension Gardener Plant Toolbox, https://plants.ces.ncsu.edu/plants/eriobotrya-japonica/.
Ge JF;Wang TY;Zhao B;Lv XW;Jin Y;Peng L;Yu SC;Li J; “Anti-Inflammatory Effect of Triterpenoic Acids of Eriobotrya Japonica (Thunb.) Lindl. Leaf on Rat Model of Chronic Bronchitis.” The American Journal of Chinese Medicine, U.S. National Library of Medicine, https://pubmed.ncbi.nlm.nih.gov/19507274/.
Gumy C;Thurnbichler C;Aubry EM;Balazs Z;Pfisterer P;Baumgartner L;Stuppner H;Odermatt A;Rollinger JM; “Inhibition of 11beta-Hydroxysteroid Dehydrogenase Type 1 by Plant Extracts Used as Traditional Antidiabetic Medicines.” Fitoterapia, U.S. National Library of Medicine, https://pubmed.ncbi.nlm.nih.gov/19535018/.
Kim, Min Sook, et al. “Oral Administration of Loquat Suppresses DMBA-Induced Breast Cancer in Rats - Food Science and Biotechnology.” SpringerLink, The Korean Society of Food Science and Technology, 30 Apr. 2011, https://link.springer.com/article/10.1007/s10068-011-0068-8.
Kubala, Jillian. “7 Surprising Benefits of Loquats.” Healthline, Healthline Media, 18 Oct. 2019, https://www.healthline.com/nutrition/loquats.
Kwon HJ;Kang MJ;Kim HJ;Choi JS;Paik KJ;Chung HY; “Inhibition of NF-kappaB by Methyl Chlorogenate from Eriobotrya Japonica.” Molecules and Cells, U.S. National Library of Medicine, https://pubmed.ncbi.nlm.nih.gov/10901160/.
Laura. “What Is Loquat Honey Good for?” Discover the Benefits of Honey, 12 June 2019, https://healthywithhoney.com/what-is-loquat-honey-good-for/.
Liu, Yilong, et al. “Biological Activities of Extracts from Loquat (Eriobotrya Japonica Lindl.): A Review.” International Journal of Molecular Sciences, MDPI, 6 Dec. 2016, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5187783/.
Low, Kathy. “Carp, Chinese Folklore, Dragons, and Loquats – a Legendary Fruit.” Daily Republic, 5 Feb. 2015, https://www.dailyrepublic.com/all-dr-news/solano-news/local-features/local-lifestyle-columns/carp-chinese-folklore-dragons-and-loquats-a-legendary-fruit/.
Yang Y;Huang Y;Huang C;Lv X;Liu L;Wang Y;Li J; “Antifibrosis Effects of Triterpene Acids of Eriobotrya Japonica (Thunb.) Lindl. Leaf in a Rat Model of Bleomycin-Induced Pulmonary Fibrosis.” The Journal of Pharmacy and Pharmacology, U.S. National Library of Medicine, https://pubmed.ncbi.nlm.nih.gov/23146038/.
Zar PP;Yano S;Sakao K;Hashimoto F;Nakano T;Fujii M;Hou DX; “In Vitro Anticancer Activity of Loquat Tea by Inducing Apoptosis in Human Leukemia Cells.” Bioscience, Biotechnology, and Biochemistry, U.S. National Library of Medicine, https://pubmed.ncbi.nlm.nih.gov/25118018/.
