Leaves, seeds and exocarp of Ginkgo biloba L. (Ginkgoaceae): A Comprehensive Review of Traditional Uses, phytochemistry, pharmacology, resource utilization and toxicity

Abstract

Ethnopharmacological relevance: Ginkgo biloba L. (Ginkgoaceae) is a treasure species with high medicinal value. The Ming Dynasty "Compendium of Materia Medica" and Qing Dynasty "Bencao Fengyuan" in China recorded this herbal medicine can reduce phlegm, clear poison, treat diarrhea and frequent urination, etc. AIM OF THE STUDY: Until now, there is no painstakingly summarized review on leaves, seeds and exocarp of G. biloba simultaneously. This review will systematically summarize and compare current knowledge of G. biloba.

Materials and methods: Ample original publications related to traditional uses, phytochemistry, pharmacology, resource utilization and toxicity of G. biloba leaves, seeds and exocarp till the end of 2021 were searched and collected by using various literature databases, including China National Knowledge Infrastructure, PubMed, Elsevier, Springer, Google Scholar and Web of Science database.

Results: According to classical Chinese herbal books and Chinese Pharmacopoeia, relieving cough, reducing phlegm, clearing poison and relieving diarrhea are the main pharmacological effects of G. biloba. The common chemical ingredients in different parts of G. biloba are flavonoids, terpenoids, phenolic acids, polysaccharides and endotoxin, etc. Among them, flavonoids and terpenoids are the main bioactive compounds in G. biloba leaves. Phenolic acids are the main bioactive compounds in G. biloba exocarp. G. biloba seeds are rich in nutritional ingredients, such as starch, adipose, protein, etc. Modern pharmacological studies showed that the crude extracts or compounds of G. biloba leaves, seeds and exocarp can be used for treating cardiovascular and cerebrovascular diseases, Alzheimer's disease, atherosclerosis, cancer, asthma, non-alcoholic fatty liver, diabetic complications and other diseases. In daily life, G. biloba seeds were usually used as raw material or additives for commodities, healthy food, drinks, even insecticides and antibacterial agents, etc. G. biloba leaves and seeds have been mainly applied for treating cardiovascular and cerebrovascular diseases, cough and asthma in clinical. However, endotoxins and ginkgolic acids have been identified as the dominating toxic ingredients in different parts of G. biloba. Besides, flavonoids and ginkgolides also have been proved to have toxicity recently.

Conclusions: This review systematically sums up and compares the traditional uses, phytochemistry, pharmacology, resource utilization and toxicity research progress of G. biloba leaves, seeds and exocarp for the first time. It will provide some comprehensive reference data and suggestions for future research on this herbal medicine.

Keywords: Ginkgo biloba; Pharmacology; Phytochemistry; Resource utilization; Toxicity; Traditional uses.