Written by Nikolina Nikolaou
Mankind has been using herbal medicine for healing purposes from the beginning of human civilization by forming the origin of a much modern therapeutic field. Many conventional drugs derived from plant sources are today used to cure severe aliments that burden our world. Yet, in recent times, use of herbal medicine for healthcare has increased globally. Although, herbal products are considered to be safe, significant adverse effects have been reported with the health walkers reconsidering the effectiveness and the accuracy of some plant species. Retama sphaerocarpa (=yellow broom) is a Spanish herb that naturally grows in the Mediterranean area of North Africa and Iberian Peninsula, however, later was also distributed throughout the regions of Plateaus, Levant, Aragon, Portugal and Navarra. Retama sphaerocarpa is a highly branched shrub mostly leafless that can reach 3m in height and its flowers are grouped in clusters, importantly there are almost 5 different retama species. The retama species are mainly employed as ethnomedicinal remedies in countries like Algeria, Egypt, Italy, Lebanon, Morocco, and Spain. Plants of the Fabeceae genus family are popular as they are used in traditional medicine as emetic, purgative and vermifuge. Certain retama species are also employed to treat a multitude of disorders, including diabetes, hepatitis, sore throat, skin diseases, join pain, fever, and inflammation.
Scientists after achieving a range of experimentations on retama sphaerocarpa they successfully isolated some important bioactive ingredients of the fruit, including isoflavones (daidzein and genistein derivatives), flavanols (apigenin, isorhamnetin, kaempferol and quercetin derivates) and extracts especially methanolic which later was found out to be richer in flavonoids possessing good in vitro antioxidant and antiglycation properties. A recent study showed that seven flavonoids isolated from the methanolic extracts (chloroform, ethyl acetate and butanol) of the aerial parts of the retama sohaerocarpa have been assessed for cytotoxic activity against three human cancer cell lines: TK-10 (renal adenocarcinoma), MCF-7 (breast adenocarcinoma) and UACC-62 (melanoma). All these flavonoids were active in at least three cell lines, after reviewing the results we have concluded that retama possess anti-tumor activities. The flavonoid genistein and the antineoplastic agent, etoposide (chemotherapy medication) were taken as positive controls for comparison with the tested flavonoids and extracts. Interestingly, the three extracts showed cytotoxic activity on the three cell lines based on the recommended NCI doses, except BuOH (butanol) extract on TK-10 cell line. Althhough, this extract was the most cytotoxic on MCF-7 cell line. Finally, all the flavonoids were found to possess cytotoxic activities in at least one of the three cell lines, with the glycosylated flavanol rhamnazin to be the most active on MCF-7 and UACC-62 cell lines. One remarkable outcome was that on the TK-10 the most active flavonoid is the isoflavone genistin. Finally, rhamnazin and genistin were the only two cytotoxic tested compounds against the TK-10 cell line.
Following the years, the use of retama sphaerocarpa has also spread to the industrial world. People support the action of this plant as it can be used in the industry to make baskets, containers, and rappers by using the branches of the broom, yet baskets made from broom are less resistant than those made with wicker. Also, houses, buildings and agricultural facilities use broom to cover the roofs so that the water can drains easily and last longer. Additionally, retama shrub can be used to create wine vats and jars, broom was also helped as a bioindicator to predict the agricultural production of the year, especially for the olive tree and livestock. Specialists support this idea as when the broom makes a lot of grain, it is that the year is going to be bad for the olives and the cattle.
However, the importance of retama sphaerocarpa wasn’t limited only on the industrial word but expanded as a medicine for treating aliments and as food-source recipes. In the modern world, retama is believed to be an essential drug for patients dealing with constipation and diabetes due to its laxative and anti-diabetic properties. Additionally, retama can be described as a therapeutic drug for jaundice, liver diseases, stomach pain and caries. It was the remedy of circulatory problems as the branches of the flower are used as infusion (extract prepared by soaking the leaves of the plant in liquid) for heart conditions. Veterinarians also uses this herb to help in conception, pregnancy and even birth. At least, in Algarinejo and llora the hardest parts of the plant, especially the branches and roots are used to cause an oxytocic effect to assist in animal birth and afterwards to encourage them to expel the placenta. Ancient cultures used the broom in order to delay the food decomposition of meat mainly and also to expel the bugs for approaching the meat and cause contamination. According to the world health organization (WHO), retama sphaerocarpa it is considered to be quite toxic to livestock and the boom grains are poisonous if we drink the water that results after boiling it. A recent study demonstrates the presence of two other compounds found in the bark and branches of the plant, compound 1: retamina and compound 2: d-sparteine an antiarrhythmic agent and sodium channel blocker. However, FDA couldn’t approve the effect of retama as antiarrhythmic, thus its internal use is inadvisable due to its toxicity. Veterinarians have also reported that if the boiling water was given to an animal to two three times, the animals will eventually burst and die, expect goats.
By the years, the therapeutical effects of retama sphaerocarpa on human health were visible. Some varieties of the retama family have traditionally been used the as medicinal herbs as infusions to combat infection that harm the respiratory system, rheumatism, gout and sciatica, also to ward off skin infections and herpes. Pilgrims on the Camino de Santiago had initially collected this plant and use it to treat acute respiratory conditions and eruptive fevers (anti-viral properties). Sometimes, curative properties are attributed to the broom or its seeds that have not been verified and most probably do not exist. Therefore, broom is not useful, and its use is not recommended in treating problems with the kidneys, sinusitis, hemorrhoids, hair loss and weight loss. In Huelva, retama leaves have been used as diuretic and emollient (for constipation) medicines. However, in order to take advantage on both diuretic and laxative properties of the herb, infusions are prepared with flowers rich in flavonoids. Currently, the broom branches are harvested to isolate the alkaloid ‘sparteine’, which is primary used by pharmaceutical industries. After reviewing the effects of retama, pharmacists advise anyone who is considering of using this plant to avoid any homemade preparation of the broom or other broom derivative as some of them might contain higher amounts of sparteine alkaloids and can be fatal when consume. Especially, Chinese broom for centuries is used to treat fevers and severe joint, muscle or fibrous tissue inflammations giving a safe dosage guidance for future uses. An infusion was made with about 25 grams of flowers per water liter, which was then placed on the fire until reaches its boiling point, then allowed to cool, to be sweetened to taste and not as bitter as its original taste Chinese people combined it with homemade honey.
In addition, R. sphaerocarpa is providing multiple uses to the inhabitants of the Murcian countryside of other times for healing or medical properties like:
- Stomach achnes
- Soothing cold symptoms
- Dermal issues
Today retama is awarded as one of the best-known dermatological plant sources for the treatment of warts (viral infection-HPV). In Granada, the hardest parts of the plant, especially the roots are used as decoction (beverage) to cause oxytocic effects and induce labor in animals. It is often mixed with other plant species such as matagallos (phlomis purpurea L) or oak bark. Retama sphaercarpa also exhibited relevant inhibition against pathogenic agents like staphylococcus auereus and pseudomonas aeruginosa as lately two new flavonoids were isolated and identified: 6′methoxypseudobaptegenin and Genistein 8-C-glucoside. These results point out the evaluation of retama as a valuable source of natural bioactive compounds, with recognized nutraceutical applications.
A recent study has dealt with the analysis of phenolic fractions of R. sphaerocarpa, although limited amount of phenolic compounds were identified in both stem and grain parts of the plant. Some extracted compounds like: rhamnazin-3-O-β-glupyranosyl-(1–5)-α-arabinofuranoside, apigenin-8-C-glucoside, quercetin-3,7-di-O-β-glucoside and apigenin-6-8-di-C-glucoside were found to exhibit pharmacological properties and cytotoxic activities against different cancer cell lines as mentioned before. Piscidic acid was identified as the major component with the higher amount to be concentrated in the stems of the plant, followed by quinic acid and morin/quercetin-di-O-rhamnoside.
The chemical composition of the lipophilic extracts of the stems and grains of the Retama shrub was identified by gas chromatography-mass spectrometry. This analysis showed that fatty acids is the major compound family in both stem and grain plant parts, representing a total of 86% compounds detected, followed by sterols in stems and monoglycerides in grains. Considerable amounts of the alkaloids retamine and cytisine were also found in stems and grains, respectively. Currently, quinolizidine alkaloids, characteristic of the febaceae family and retama genus, are known to show a wide spectrum of pharmacological and toxicological activities, such as uterotonic, respiratory stimulant, heart tonic, anti-depressant and hallucinogenic. In this vein, stems are found to mainly contain sparteine and retamine, while flowers and pods are full in lupanine, retamine and cytisine.
Given the importance of R. sphaerocarpa in many medicinal and industrial fields, as well as the plant-derived bioactive compounds that indicate to play an immense role in the human health, it is fundamental to extend the knowledge about the uses and the chemical composition of this shrub.
 Retama sphaerocarpa: An unxeploid and rich source of alklaoids, unsaturated fatty acids and other valuable phytochemicals. Available from [online] < https://www.sciencedirect.com/science/article/abs/pii/S0926669015001119> [16/09/22]
 Flavonoid profile, antioxidant and antiglycation properties of retama sphaerxarpa fruit extracts. Available from [online] < https://www.tandfonline.com/doi/full/10.1080/14786419.2017.1356835?scroll=top&needAccess=true> [16/09/22]
 Genus retama: a review on traditional uses, phytochemistry, and pharmacological activities. Available from [online] < https://www.researchgate.net/publication/325766080_Genus_Retama_a_review_on_traditional_uses_phytochemistry_and_pharmacological_activities> [17/09/22]
 Cytotoxic activity of flavonoids and extracts from Ratama Sphaerocarpa Boissier. Available from [online] < https://www.degruyter.com/document/doi/10.1515/znc-2000-1-209/html> [18/09/22]
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