Herbs from Distant Lands: August 2016

PLANT PROFILE

Solanum torvum is a robust bush from solancae family, that produce clusters of berries. These berries are commonly known as Pea Aubergine, Pea Eggplant or Turkey Berry and are used as a vegetable in many tropical countries. It is especially popular nowadays in East Africa and South-East Asia, playing important role in cuisine of Thailand, South India and Ghana and being significant part of local diet as it is a good source of essential minerals and vitamins. The plant is believed to oryginate from Central and South America. But it spread due to vegetable garden cultivation throughout all tropical regions, get naturalized and in many places become even obnoxious weed.
Good nutritious value of Solanum torvum fruits is not it's only value. In many tropical and subtropical countries not only fruits, but also leaves, stems and roots of this plant are used in traditional healing. It become important medicine used by practitioners of Ayurveda, Siddha and Traditional Chinese Medicine systems. It is regarded as very useful herb in treatment of many different infections, liver problems, diabetes, cancer and more. Many scientifical studies had been made in many different countries, to indentify chemical constituents of this plant and it's pharmacological actions. Most of it was conducted in India (mostly in Tamil Nadu), and some in Ghana, Cameroon, Japan, Bangladesh, Taiwan, China, Indonesia, Thailand and Cuba. One of those studies resoulted in isolation from Solanum torvum tissues a chemical structure called solasonine - which become used as a start product in hemisynthesis of cortisone and steroidal sex hormones for oral contraceptives.
In 1998 in Malaysia a post stamp depicting Solanum torvum has been released, as a part o Medicinal Plants of Malaysia series.
In India there is a very similar species called Solanum indicum, it often shares the same common names with Solanum torvum, and it's berries are consumed and used medicinaly (leaves and roots too) in the same way. The main difference between those two species is that S. torvum have white flowers, while S. indicum flowers are violet.
The other popular english common names for this plant and it's berries, beside those that I've mentioned before, are : Devil's Fig, Cherry Eggplant, Wild Eggplant, Thai Eggplant and Gully Bean.
Here are just some of many other vernacular names of Solanum torvum : Susumber (Jamaica), Melongene-diable, Bellangere Batarde, Aubergine Pois (French), Pokastrauch, Teufels-Nachtschatten (German), Belangera Cimarrona, Terongan (Spanish), Jurubeba (Portugese), Morella della Giamaica (Italian), Suzume Nasubi (Japanese), Dian Qie Ze, Ci Quie, Shan Dan Quie (China), Soni, Katai, Kaisurisuri (Fiji), Sundai (India), Bhurat, Bhankatiya (Hindi), Shveta Brihati (Sanskrit), Marang (Marathi), Kaatuchunta, Anachunda, Malamchunda (Malayalam), Chitra, Kottuvastu (Telugu), Sundaikkai, Karimulli, Mulli (Tamil), Bhi-tita (Assamese) Ban Begun, Gotha Begun (Bangladesh), Byako (Arunachal Pradesh), Thibbatu (Sinhala), Tokrakur (Nepal), Terung Rajah Wang, Terung Belanda, Terung Mangas, Terung Belah, Terung Pipit (Malaysia), Top Na Aka (Cameroon), Kantosi, Ama Dweridi, Anona Ntroba, Kwahu Nsusuwa, Abedrow (Ghana), Igba-yinrin-elugun (Nigeria), Yakandroa (Ivory Coast), Brinjal Pea (South Africa), Prendejera (Cuba), Put Nhorng Deum (Cambodia), Ca Dai Hoa Trang, Ca Hoang, Ca Nong (Vietnam), Kazaw-Kha, Hkawhkam- Kaju (Myanmar), Ma Khuea Phuang, Ma Kae, Makhua Phuong (Thailand), Kheengz Faaz (Laos), Shu Qie Zi (Singapore),Takokak, Cepoka, Pokak, Terongan (Indonesia), Guis (Guatemala), Tandang-aso, Talampay, Talongon, Dagutung, Gambol (Philippines).
Solanum torvum have also many botanical synonymes like : Solanum longiflorum, Solanum indicum, Solanum mayanum, Solanum stramonifolium, Solanum daturifolium, Solanum acanthifolium, but none of them or others are used nowadays.

Here is my video about Solanum torvum - https://www.youtube.com/watch?v=d2XSvFRVrA0

CULTIVATION AND HARVESTING

Solanum torvum is a perennial bush that grows naturally in tropical and subtropical climate regions, at elevations from sea level up to around 2000m. It can reach around 4m of height and spread around 3m wide. It usually have prickles on stems and midrib of leaves, but in there are also thornless cultivars. Leaves are 10-20cm long, and their surface is velvety, just like it's young stems too. Fruits have 1-1,5cm in diameter, with structure of a berry, and is yellowish when ripe but quickly turn brown. Solanum torvum like moist, acidic, fertile soils, but can grow also on pore and dry lands. It can withstand well heavy seasonal droughts and also slight frost. It like sunny or slightly shaded areas.
This plant can easily become invasive weed, as it is spreading fast from seeds, esspecialy in disturbed soils, near roads, etc. It can regrow from the root after fire. It's seeds require sunlight for germination. Cuttings are better for propagation of S. torvum, due to preservation of characteristic features and phytochemicals content (which is very important when planted for consumption and medicinal use of Pea Aubergine, as toxic strains and hybrids of this plant with related species are reported to cause poisoning).
It sometimes may suffer from diseases and pests affecting other solancae crops plants, like Early Blight (Alternaria solani ) and Eggplant Anthracnose (Colletotrichum gloeosporioides f. melongenae), the Rust (Aecidium habunguense) and aphids, leucinodes, leaf hoppers and caterpilars. Solanum torvum is used in intercropping cultivation to control bacterial and fungal diseases of S. melongena in Indonesia. It is sometimes also used as a rootstock for tomatoes and aubergines, where it conveys resistance to bacterial wilt and nematodes.
In tropical climate Pea Aubergine flowers and produces fruits all year round. The fruits can be consumed fresh or dried, and are picked when unripe but fully developed (green, not very hard and not smaller than 1cm). It is gathered by cutting off the whole clusters, and sold in the in such a form, which make them keep fresh for longer time. Make sure you have a sharp tool, as fruits cluster stem is tough and will not brake easily from its branch. Leaves, whole stems or roots, can be gathered at any time for medicinal purposes, and used fresh or dried in shade.

CULINARY USES

Pea Aubergine fruits are important ingredient in Thai, South Indian and Ghanian cuisine, appreciaten not only for it's flavour and texture, but also it's for nutritious and medicinal value. It is used unripe, usually fresh, but also in dried form. It have a bitter taste but with a bit of sweet note, some cultivated varieties are less bitter. It is cooked in soups, sauces, stir-fried, braised, grilled, baked, pickled, turned into chutney, or just munched raw as an appetizer.
I get to know this vegetable a few years ago, when I found it in food shop specialized in asian and african food, in Milton Keynes, England. It was the most expensive vegetable aviable there, and never I saw it again neither in Britain nor anywhere else in Europe. The owner of the shop wasn't able to give me any informations about how to use it. But his customer, woman born in Ghana, have told me that Pea Aubergine tastes bitter, and they usually chop it and add to stews in moderate amounts.
The whole fruits are commonly added to spicy Thai curries, and pounded added to sauces to balance the spiciness. In Sri Lanka dried fruits are fried with spices , grounded into powder and added to rice. In Tamil Nadu, India, the fruits soaked in curd are dried and later fried in oil, such a product is called Sundaikkai Vattral and it is avaiable in Tamil supermarkets.
Solanum torvum leaves and fruits decoctions have many health benefits. But when I first made it to use as a rinse to combat tootchache caused by gum infection, I was really suprised how good it tastes. As I had expected it to be just like many other of those healthy but unpalatable bitter drinks. Who knows, maybe it was not strong enough (two leaves and two clusters of berries, fresh and chopped, shortly boiled in two teacups of water, it helped with the pain and inflammation anyway), but thanks to that I've discovered another decoction that matches my taste as a beverage tea, and is truly a good tonic. Leaves and flowers of Solanum torvum are used to made syrup taken as a treatment for colds.
Make sure you have your Solanum torvum fruits from reliable source. If you had gathered it yourself, from wild growing plants that noone particularly recomeded to be fully safe. Than you have to be extremly carefull with trying it. As there are strains of this plant, that bears toxic fruits that looks just like the edible ones.

COSMETIC USES

In one blog I have read an information, that fruits and leaves of Solanum torvum are eaten as a salad or cooked in curry, to enlarge breasts. The author Nancy Chan, have claimed to read this on the plant information display at Malaysian Herbal Garden - Taman Herba Negeri Perak. I haven't found any other source to mention this particular use, but in Ghana and Nigeria, women eat Pea Abergine fruits to induce and improve lactation.

MEDICINAL USES

Solanum torvum fruits, and also leaves and roots have been used as a medicine for a long time, by many different cultures that it was brought to threw cultivation, from Central or South America. It is used in Ayurveda, Siddha (traditionan system of medicine in Sri Lanka) and Traditional Chinese Medicine, in the same way as very similar species - Solanum indicum, which is native to India and have been used in the region as a cure since ancient times. In many tropical countries, Solanum torvum is becoming nowadays less of a folk medicine, and more of an official herbal drug. Many modern scientifical tests, have proved it's effectivnes in treatment of particular diseases. And fitochemical studies resoulted in recognition of it's many chemical constituents. One the chemicals isolated from S. torvum tissues is solasonine - which is used as a start product in hemisynthesis of cortisone and steroida sex hormones for oral contraceptives. Fruits, leaves, stems or whole aerial parts and roots, are often mentioned to share the same medicinal uses, used both fresh or dried. Nonetheless I've decided to keep seperate the informations about medicinal aplications of particular parts of the plant.

FRUITS

Fruits of Solanum torvum are very nutritious, containing important vitamins and minerals that improve body functions. 100g of fruits provide 47cal. Pea Aubergine possess a very high moisture content (80-86%), it contain carbohydrates 7.03%, proteins 2.32%, fats 0.27%, ash 0.14% and crude fiber 3.99%. It is rich in essential metals like iron 76mg/kg, manganese 19mg/kg, copper 2.6mg/kg and zinc 21mg/kg. It also have a lots of vitamin C (2.686 mg/100g), B-complex (Thiamin, Riboflavin, Niacin), vitamin A (0.078mg/100g), vitamin E and calcium 221mg/kg.
The fruits contains bioactive organic compounds : sitosterol D-glucoside, carpesterol, glycoalcaloids (solamargine, up to 1% solasonine), phenols (phenol 2,3,5 trimethyl), flavonoids, isoflavonoids (torvanol A), isoflavonoid sulfate, steroidal glycosides (torvosides), jurubine, saponins, terpenoids, tannins, methyl caffeate, chlorogenone and stigmasterol (in seeds).
Just like with many other of edible and medicinal Solanaceae species, it is important to be very carefull with Solanum torvum, if you are not 100% sure if its safe. There are hundreds of Solanum species, many of which looks very similar and easily crosspolinate creating hybrids, also mutations happens that may create a toxic strain. Chemical composition of those plants also vary due to environment, soil, weather, polutions etc. There had been recorded cases of poisoning with fruits that looked just like regular Solanum torvum berries, but later tests showed unusual toxic elements in it. Some of reported cases patients had substantial neurological disfunctions like : dizziness, slurred speach, facial paralysis, ataxia, weakness, also hypertension, confusion, gastrointestinal distress. Couple of cases was severe and required intensive care admission, with respiratory failure, requiring emergency ventilation. Therefore it is best to use only S. torvum from reliable supply and grow plants only propagated threw cuttings (for its oryginal genes preservation). But if you want to check yourself unknown Pea Aubergine-lookalike wild plant, be extremly cautious.

Solanum torvum fruits acts as : anti-inflammatory (properties comparable to hydrocortisone), antioxidant, antibacterial, antiviral, antifungal, anti-diarrhoeal, antidiabetic, hepatoprotective, nefroprotective, cardioprotective, diuretic (as compared to standard drug Furosemide), sedative, analgesic, tonic, haematopoietic and erythropoietic (support new blood cells formation), anticancer, immunomodulatory (regulate immune system activity), carminative and vermifuge. Water fruit-coat extracts shower antibacterial activity comparable to commercial antibiotics - Chloramphenicol and Streptomycin. Seed extracts of S. torvum have showned interesting antidepresant potential. The fruit is also said to strenght nervous system and improve memory.
Pea Aubergine fruits are used, eaten fresh, dried or cooked, and also it's decoctions are drunk for treatment of diseases like : liver and spleen enlargment, cold, cough, bronchial asthma, fever (it is said to increase white blood cells number during fever), malaria, stomachache, diarrhoea, microbial infections (like Candida albians, Streptococcus faecalis and herpes simplex virus type 1), intestinal worms, leucorrhoea, arterial hypertension, for headache and other pains relief, insomnia, rheumatism, leucoderma, and also used as poison antidote.

Solanum torvum fruit is widely used in Indonesia as cure for prostate disorders (fresh unripe fruits are eaten every day). Water extracts of fruits and roots of Solanum torvum have proved to be very effective against breast cancer. In Sierra Leone fruit decoction is given as a cough medicine for children. Fried fruit is also taken for cough. In India Pea Aubergine fruit is used to improve eyesight and consuming fruits is belived to cure paralysis. In Indonesia the berries are mashed together with the leaves of Curcuma domestica (Turmeric) and applied to the eyes to treat trachoma. Nepalese use S. torvum flower juice with salt water as an eye drops. In Cameroon, fruit juice is used to treat skin infections like abscesses, jigger (parasite) wounds, ringworm, athlete's foot, and also skin problems in animals. The fruit juice is also applied locally to ease the irritation of ant bites. Fruit juice or decoction is used as gargle fo mouth ulcers. In Arunachal Pradesh in India crushed fruits are aplied to gums to get relief from gum infection and toothache. In Ghana unripe fruits and leaves of Solanum torvum are used against tuberculosis, fruits are also eaten to stop palpitations. In Sri Lanka powdered fruits are drunk in water daily as a treatment for groins infection, for controling blood sugar fruits are eaten for 4 days in a week, fruits are also eaten raw for strenghtening bones. The fruit ripe or unripe is said to have strenghtening, tonic effect and help increase the amount of blood in the human body, that is particulary uesful in post-partum and anemia. Solanum torvum fruits increase milk secretion, and are part of the diet of women after childbirth.

LEAVES

Solanum torvum leaves are rich in essential minerals, iron, magnesium, zinc, sodium, potassium, vitamins B6, B12 and C. It contain glycoalkaloids (0.0039%), derived from solasodine, solasonine (0.0043%) and solamargine (0.0028%), alkaloids, sterols (sitosterol, stigmasterol, campesterol and steroids, glycosides, flavonoids (quercetin, rutin, kaempferol), isoflavonoids (isoquercetin, torvanol A), tannins, saponins, aminoacids, 2- Hexadecen-OL,3,7,11,15-Tetramethyl, 9,12,15 octadecatrieonic acid, tetratriacontanic acid, triacontanol, elemene, steroidal lactone saponins, spirostanol glycosides, henriacontane, neochlorogenin, neosolaspigein and solaspigenine.

Leaves of S. torvum have following actions : antihypertensive, haemostatic, anti-platelet aggregation, cardiovascular, sedative, digestive, antioxidant, diuretic, anti-inflammatory, analgesic, larvicidal, hepatoprotective, anti-ulcer, antibacterial, anti-fungal, antiviral, anticancer, anticonvulsant and antispasmodic.
The leaves are usually consumed in form of decoction or infusion, but alcoholic tinctures are also made, to treat conditions like : colds, coughs, asthma, fever, malaria, rheumatism, epileptic seizure, liver and spleen enlargment, gonorrhoea, thrush, gastralgia, gastric ulceration, dropsy, prostate disorders, wound infection, arterial hypertension, blood stasis, leukoderma, to improve lactation and convalescence, and are also used as a mouthwash for mouth ulcers or tooth decay,
Externaly leaf decoctions are used as a wash and for compress, on sores, pimples, scabies, bleedings, wounds, burns and rashes. Cubans apply the leaf juice on pimples. Pounded fresh leaves of S. torvum are also used as a poultice, aplied on cuts, wounds and injuries, and dried, powdered leaves are used as a styptic to stoop bleeding. Decoctions of leaves can be also used to bathe the body to cool the sore and itching. In Santa Lucia fresh leaves are rubbed on the foot to treat athlete's foot. Haitians massage crushed leaves and seeds to correct fever.

In Papua New Guinea, juice is extracted from fire-heated leaves, then diluted with water and drunk for headaches and malaria. In Ghana a cupful of decoction from roots and leaves of Solanum torvum is drunk before meals for treatment of malaria. In India the leaf juice is used to reduce body heat, dried leaf powder is taken as a medicine for diabetes, leaf paste is used to bath a newborn baby in order to protect it from infections. Leaves and flowers of Solanum torvum are used to made syrup taken as a treatment for colds.
In Ivory Coast, Anyi-Ndenye women use Solanum torvum leaves during 2-3 trimester (4-9 month) of pregnancy, in form of '' therapeutic meal ''. Although it is also noted to be used traditionaly as a abortifacient in South India - '' 3-5ml leaf extract is given orally for 5 days ''. Other scientific document, from Medical College in Tamil Nadu, states that S. torvum leaves are traditionally known to be useful for '' recuperation and rejuvenation during pregnancy ''. In India roots of closely related Solanum indicum are used to treat infertility in women. As these are the only informations aviable, about safety of use of this herb during pregnancy. You might assume that Solanum torvum leaves are only harmful at early stage of pregnancy (first trimester), but it is better to be cautious with it.

ROOTS

There is not much research on chemical composition of Solanum torvum roots, but steroidal glycosides (astorvosides A-G) and jurubine have been isolated.
The roots are reported to act as anti-bacterial, anti-viral, antifungal, anti-inflammatory and anti-tumor. And it is used usually in for of decoction for stomachache, indigestion, amenorrhea, rheumatism, cystitis, veneral diseases (gonorrhea, urethritis), tuberculosis and malaria. And externally applied on sores, wounds, bleeding, burns and rashes.
In the Philippines Solanum torvum roots decoctions are drunk as an antidote for poisoning, and are given to women after childbirth to prevent blood loss. In Malaysia pounded roots are aplied to heal cracks in the feet. In Indonesia, a tincture made from chopped root steeped in rice alcohol for two weeks, is taken nightly (mostly by slender young women) to promote weight gain. In Bangladesh, combination of S. torvum root and leaf juice is used for treatment of asthma, diabetes and hypertension. In Brasil root juice is used for treatment of liver diseases, tuberculosis and as a anti-anemic. Nepalese use root juice to stop vomiting due to weakness. The pounded root is inserted into the cavity of a decayed tooth to relieve toothache. In Tripura region in India, ashes of dried roots are applied locally for curing condyloma. Solanum torvum root (300 ug/ml) strongly inhibited the melanin production of B16 melanoma cells without significant cytotoxity.