Rubus idaeus L.
COMMON NAME
In English, this plant is commonly known as
Raspberry. Other languages call it: Gerdera or Gerdonera (Catalan);
Masusta-gorri or Mugurdi (Basque); Framboeseira (Portuguese); Framboisier,
Framboisier Rouge or Framboisier Sauvage (French).
TAXONOMICAL NAME
The scientific name is Rubus idaeus
L. It also can be named under the botanical synonyms of Rubus buschii
and Rubus strigosus. It is part of the Rosaceae taxonomical
family.
Description
Raspberry is a wild plant that is also widely
cultivated in many regions with warm climates, spreading both in North America
and Europe. Its red fruits are highly valued in the food industry. It can be
eaten fresh or cooked as jam, syrup, preserve or liqueur, thanks to excellent
organoleptic qualities. Also, the plant has received a lot of attention in
traditional and integrative medicine, especially thanks to preparations made
with the leaves.
Part used
In phytotherapy, the leaf is most used (Rubi
idaei folium). According to the European Pharmacopoeia, the vegetable drug
consists on the dried leaf (whole or fragmented) and must be harvested in sprig
or at the start of summer; and also keep a minimal content of tannins of 3%. In
addition, the ripe fruits are usually used, together with the seeds, to
extract the valuable seed oil.
Active compounds
Biochemical components vary depending on the
level of maturation and the processing method.
- In
the leaf: It
is rich in tannins (2.6-11.2%), notably hydrolysable
tannins, type ellagitannins (like sanguiin H-6) and gallotannins. Flavonoids
such as quercetin and kaempferol derivatives also stand up
(0.29-0.57%). Other components are: phenolic acids (caffeic,
ferulic, p-coumaric, etc.), methyl gallate, ascorbic acid, glutathione,
vitamin E (alpha-tocopherol) and many minerals like calcium, magnesium and
zinc.
- In
the fruit: Sugars
(5-6%) like glucose and fructose and a wide diversity of organic acids
(0.5-2%) such as citric, malic and oxalic acid. Furthermore, the
fruit contains pectin (0.1-1%), vitamin C, and powerful polyphenols like
catechins and anthocyanosides (which are responsible of the bright red
pigment). That peculiar smell of raspberry is attributed to volatile
compounds, mainly ketone 1-(p-Hydroxyphenyl)-3-butanone.
Pharmacological action
- Leaves: Traditional medicine attributes
them astringent (healing and antidiarrheic), diuretic and
anti-inflammatory effects. Different in vitro and in vivo
studies suggest that modulation of the uterus’ smooth muscle happens.
Apparently, this phenomenon depends on the dosage and state of the tissue
and can manifest a stimulant action (by contracting the tissue),
spasmolytic effect, or relaxing ones. At the same time, strong antiplatelet
effects have been detected. They inhibit the activation of platelets by
directly interacting with ADP receptors.
- Fruits: They traditionally act as
aromatic and vitaminic agents. Recent research attribute them a high antioxidant
activity, thanks to anthocyanidins and ellagitannins. They are
antibacterial and are able to attack the membrane of pathogens like Salmonella
or E. coli. In addition, the fruits present a possible
hypolipidemic effect, heart protecting by means of vasodilation and, also,
they show inhibitory potential of proinflammatory enzymes like
cyclooxygenase-2 (COX-2).
Indications
The European Medicines Agency (EMA)
backs and approves the traditional use of raspberry leaves for the systematic
soothing of menstrual pains (dysmenorrhea), the symptomatic
treatment of mild diarrhoea and the reduction of oral or pharyngeal
inflammation as mouthwashes and gargles. In traditional medicine, leaf
infusions are applied on the skin in cases of skin ulcers, injuries,
conjunctivitis and vulvovaginitis; and also administered orally in case of
cystitis and renal lithiasis. Traditionally, midwifes have indicated the intake
of raspberry leaves in the final stages of pregnancy to facilitate labour;
although the clinical effectiveness is still questioned. The fruit is massively
used as a food and therapeutic syrup. The oil extracted from the seeds are
widely used in skin cosmetics.
Contraindications
The use of raspberry botanical preparations is
contraindicated in cases of hypersensitivity to the plant or individual
active compounds. Since the leaves are high on tannins, this plant is not
recommended in patients suffering from duodenal ulcer or active gastric ulcer,
due to a possible irritation of mucosae. In theory, the leaves have shown in
animal models the possibility of producing mild oestrogenic effects. As a
consequence, people with hormone-sensitive medical conditions like
endometriosis, uterine fibroids, or ovary, uterus and breast cancers must avoid
the intake.
Precautions
Individuals with sensitive or pre-disposed
stomachs, the intake may cause temporary gastric discomfort, due to the
quantity of tannins.
- Pregnancy
and breastfeeding: It is possibly safe under strict medical supervision during
the last stages of pregnancy, but self-madication through all pregnancy
is considered unsafe, due to the effects on myometrium and the
oestrogenic action. As a common food, it does not represent any risk
during pregnancy end breastfeeding.
- Drug
interaction:
According to big-scale studies, leaves do not present severe interaction,
but do ask for precaution when combining it with insulin, since they can
unchain a hypoglycaemic event. Extreme caution must be taken into account
when combining raspberry with anticoagulant or platelet anticoagulant
drugs or food supplements, since the risk of bleedings increases
moderately, as it derivates from the in vitro demonstrated activity
as an inhibitor of platelet antiaggregation.
Side effects and toxicity:
At normal, dietetical quantities, raspberry
fruit presents a high margin of safety and is not related to toxicity or risk
of overdose. Occasionally, high medicinal doses can induce stomach troubles
such as epigastric pain and diarrhoea. A series of studies centred
around pregnant women who drank raspberry leaf infusions, a little but higher
rate of constipation was reported, as well as the occasional increase of normal
contractions, which are known as Braxton Hicks contractions. In addition, there
was an isolated case of hypoglycaemia in a diabetic pregnant woman. Regarding
the industrial processing, lyophilised powder of raspberry, when inhaled, was
capable of producing severe cases of occupational asthma, dyspnoea and
respiratory wheeziness.
Studies
Many trials evaluate the clinical therapeutic
limits of the species:
- Metabolic
and cardiosymptomatic health: Although there was some hope of antioxidant protective effects,
clinical studies made on obese and overweight humans demonstrated that
taking up to 280 g of raspberry daily for 8 weeks does not contribute
to reduce body mass index (BMI), glycosylated haemoglobin, triglycerides,
glucose or abdominal circumference, when compared to the control
groups. As a counterpart, many review articles point out that other
extracts reduce postprandial glycaemia and benefit the metabolic syndrome.
- Labour
development:
Research centred on evaluating obstetric effectiveness, the continued
intake of 2.4 g of raspberry leaves from week 32 did not reduce labour
nor minimised the volume of analgesic drugs used, contradicting the
majority of the folkloric dogma.
- Joint
disorders and dermatology: A randomised study demonstrated that high doses of Rubus idaeus
leaf extract (400 mg) can improve basal pain caused by knee
osteoarthritis, even though the objective improvement in mobility and
rigidity were non-existent. At skin and dermatological level, a serum
formulated with botanical cellular extract of raspberry leaves, together
with vitamin C and E, mitigates wrinkles and provides radiometry and
elasticity to a photo-aged skin after 8 weeks.
- Colorectal
cancer: Fruit
powder used in a clinical trial under the form of a suppository showed
antineoplastic potential by notably reducing the surface of rectal polyps
in a group of 14 patients suffering from adenomatous polyposis.
Bibliography
- Cheang KI, Nguyen TT, Karjane NW, Salley KE.
Raspberry leaf and hypoglycemia in gestational diabetes mellitus. Obstet Gynecol. 2016; 128 (6):
1421-1424.
- Franck M, de Toro-Martín J, Garneau V, Guay V,
Kearney M, Pilon G, et al. Effects
of daily raspberry consumption on immune-metabolic health in subjects at
risk of metabolic syndrome: a randomized controlled trial. Nutrients.
2020; 12 (12): 3858.
- Bowman
R, Taylor J, Muggleton S, Davis D. Biophysical effects, safety and
efficacy of raspberry leaf use in pregnancy: a systematic integrative
review. BMC Complement Med Ther. 2021; 21 (1): 56.
- Henrotin Y, Cozannet RL, Fança-Berthon P, et al. Rubus idaeus extract improves
symptoms in knee osteoarthritis patients: results from a phase II
double-blind randomized controlled trial. BMC Musculoskelet Disord. 2022;
23 (1): 650.
- EMA-HMPC.
Community herbal monograph on Rubus idaeus L., folium. London: EMA. Doc.
Ref.: EMA/HMPC/44211/2012; 2014.
