Medicinal Properties of Eggplant
The flavonoid nasunin isolated from the peel of the eggplant fruit is a potent antioxidant and free radical scavenger and has been demonstrated to guard cell membranes from damage.
EGGPLANT SEASON New Mexico's August heat brings the chiles and the eggplants. A new harvest every day. I pick the eggplants when they're soft and tender, no need to peel or salt, and then grill, roast, or stew. Eggplants stewed in soy sauce with chiles and garlic over noodles - my favorite comfort food from rainy days studying Chinese in Taiwan.
HISTORY The eggplant (Solanum melongena) is a plant species in the nightshade family Solanaceae. Botanically a fruit, large eggplant (brinjal) are indigenous to India and small eggplant (茄子) are indigenous to China. The texture of eggplant brings an earthiness and heft to vegetable-based cuisines and vegetarian diets. Chefs recommend that eggplant not be stored hot or cold. It is highly perishable.
Medieval Europeans were ambivalent toward eggplant, perhaps because of the bitter taste of earlier cultivated varieties. The literature warns about bitterness and pungency and the belief that eggplant creates a melancholic and angry mood. Salting and rinsing counteracted these properties, which are far less pronounced in current eggplant cultivars. Since the development of varieties without the bitter taste, the popularity of eggplants has increased. They are now celebrated worldwide for their health benefits and medicinal properties.
Henry C. Lu notes in the Chinese System of Food Cures: Preventions and Remedies that eggplant nourishes the blood, supplements vegetarian diets, and contains vitamin P (flavonoids). Eggplant possesses anticancer and antioxidant effects and prevents hardening of the blood vessels. Historically, in Traditional Chinese Medicine, eggplant was used to treat abscesses as well as for intestinal bleeding and toothache.
Pakistan Journal of Nutrition (2004). Rabbits fed a normal diet supplemented by eggplant had lower levels of lipids in the blood and increased levels of high-density lipoprotein cholesterol (good cholesterol). There were strong hypolipidemic effects from Solanum melongena and Solanum gilo, as well as an improved HDL/LDL ratio, indicating eggplant's potential for treating ischemic heart disease and arteriosclerosis.
Modern Medical Laboratory Journal (2018). The cytotoxic effects of eggplant peel extract on human gastric cancer cells and normal cells from a cell bank in Iran were investigated. Delphinidin 3-rutinoside-5-galactoside may have antioxidant properties and protective activity against lipid peroxide. A relationship between eggplant’s cytotoxic effects and its antioxidant activity has been demonstrated.
Food Elixir Science (2014). An evaluation of the nutrient and phytochemical constituents of four eggplant cultivars found high concentrations of alkaloids, tannins, and saponins. Tannin compounds have antibacterial, antiviral, and antiparasitic effects, and alkaloids and saponins have antimicrobial properties. Polyphenols may promote the uptake of glucose in tissues and improve insulin sensitivity.
Journal of Carcinogenesis & Mutagenesis (2013). Three steroidal alkaloids and two steroidal glycosides isolated from the peel of Solanum melongena L. exhibited moderate to potent activity against human cancer cell lines – activity was most pronounced against liver cancer cell lines. Subsequent in vivo testing against hepatocellular carcinoma in rats demonstrated reduced tumor marker levels. The compounds also restored levels of AST, ALT, and albumin.
CHEMICAL CONSTITUENTS OF EGGPLANT
Phytonutrients in eggplant include vitamin B1 (thiamine), vitamin B6 (pyridoxine), copper, manganese, potassium, magnesium, vitamin B3 (niacin), and vitamin B9 (folate).
The flavonoid nasunin isolated from the peel of the eggplant fruit is a potent antioxidant and free radical scavenger; it has been demonstrated to guard cell membranes from damage. Flavonoids extracted from the fruits of Solanum melongena showed significant hypolipidemic potential in rats.
The nightshade family is rich is alkaloids. Solanine is the bitter glycoalkaloid found in the vegetation and fruits of most Solanum species. Raw eggplant contains solanine and the fruit should be cooked before eating. Eggplant also has substantial levels of oxalates. If you have a history of oxalate-containing kidney stones, then you should eat eggplant in moderation.
Infants and children Avoid feeding raw eggplant to babies and toddlers. Eggplant contains compounds that may irritate the digestive system. Nitrates in eggplant convert to nitrites when cooked and may present a hazard to infants younger than four months. It is important to know the symptoms of nitrite poisoning.
People with chronic inflammatory conditions might consider limiting consumption of eggplant until the cause of the inflammation is resolved.
Please note: The medicinal properties of eggplant are described above for educational and historical purposes only. This information is not intended to replace the advice of a healthcare provider.
GERMANY In contrast to other countries (Turkey, Kuwait, Malaysia, and Australia), herbal medicine use is very high in Germany with rates soaring from 50% in 1970 to 70% in 2010.
A 2019 online survey examining the role of herbal medicine in the German healthcare system reveals that herbal medicine use in the general German population is very high, and over 90% of regular herbal medicine users self-administer herbal remedies. Yet patients lack awareness of the potential side effects and potential interactions of herbal medicine.
SURVEY DESIGN Based in part on a survey instrument from the U.S. National Health Interview Survey, the questionnaire used quota sampling to provide a representative picture of the German population. A total of 2906 people participated in the survey.
HERBS In the survey, herbal medicine was defined as all plant-derived products in natural form and as pills. Here are the properties and general indications of the herbs used most frequently in Germany.
Peppermint (Mentha piperita) is used primarily to address digestive colic, cramps, and nausea. Of unknown origin, peppermint has been used by the Egyptians, Greeks, and Romans. Its potency is categorized as strong and it has slight emmenagogue effects.
Chamomile (Chamomile recutita) is another traditional remedy used for digestive problems from gastritis to irritable bowel syndrome, to treat tension and irritability, and to promote sleep. Chamomile inhibits the growth of Helicobacter pylori, one of the causes of peptic ulcers. Cautions include allergic hypersensitivity (chamomile is considered a ragweed) and reduced absorption of non-heme iron. Potency is medium and German chamomile contains a strong anti-inflammatory constituent.
Sage (Salvia officinalis) regulates menstruation and reduces sweating. It is indicated for hot flashes. Sage is also considered a digestive tonic. Native to Europe, sage possesses strong potency and is toxic in excess.
Ginger (Zingiber officinalis) is native to Asia and has anti-emetic, appetite-stimulant, and analgesic properties (eases generalized body ache). Its antiseptic properties are beneficial for intestinal infections. Ginger is contraindicated in combination with NSAIDs and should not be administered to patients with ulcers or bleeding disorders. Potency is strong.
Valerian (Valeriana officinalis) is native to Europe and northern Asia. It is a sedative, nerve tonic, and cardiac depressant. Valerian induces relaxation in the smooth muscles of the uterus, colon, and bronchial passages. Overdose causes fainting and vomiting. Valerian may cause diuresis, thus it is not suitable as a sleep aid. Excess use causes depression of the central nervous system. Potency is strong.
Stinging nettle (Urtica dioica) grows in temperate regions of the northern hemisphere. It is diuretic, tonic, and anti-allergenic, and it cleanses the blood. Stinging nettle is contraindicated in pregnancy and possesses medium to strong potency.
St. John’s wort (Hypericum perforatum), native to Britain and Europe, is used to treat depression and anxiety and as a liver tonic. Do not take St. John’s wort during pregnancy and do not combine with birth control pills, statins, antidiabetics, and anticoagulants. Life-threatening serotonin toxicity is possible when used in combination with other antidepressants. Potency is strong.
Arnica (Arnica montana) is found in the mountains of Europe, the United States, and Canada. It is used externally for bruises, sprains, muscle aches, and pains. Arnica is poisonous and should not be taken internally.
In conclusion, herbs were used most commonly to treat cold and flu, respiratory problems, and gastrointestinal disease. Perceived helpfulness of herbal medicine was greatest for insect bites, gastrointestinal issues, and respiratory problems. Herbal medicine was perceived as not very helpful for tinnitus and depression.
SOURCES OF INFORMATION As expected, the internet was the most popular source of information but, paradoxically, participants expressed low trust in internet information. Pharmacists and physicians were viewed as the most trustworthy sources. Does this reflect the lack of a centralized, trusted source of public information on herbal medicines?
POTENTIAL FOR HARM
The survey demonstrates that use of herbal medicine plays an essential role in the German healthcare system. Healthcare providers need to be aware of patient behavior, and the general public needs a trusted source of information.
Caution: Use of herbal preparations is not recommended without the advice of a healthcare provider. Substances in herbal preparations may interact with prescription drugs to eliminate therapeutic efficacy or induce toxicity.
Citation: The importance of herbal medicine use in the German health-care system: prevalence,
usage pattern, and influencing factors (Welz et al., BMC Health Services Research, 2019 19:952)
Kerilyn Sappington is the founder of Integrative Translations, which specializes in the Chinese to English translation of topics in conventional and complementary medicine.