Fruits, vegetables, herbs and spices have been used since long to cure various human ailments besides their nutritional importance. This curative potential has been ascribed to various bioactive constituents and antioxidant components present in them and their synergistic effects. The most important activities of blackberry are anti-microbial, antioxidant, anti-inflammatory and anti-cancer. Several factors such as cultivar, agroclimatological conditions, level of ripening and processing method affect the profile and intensity of these pharmacological activities. Most activities performed are on crude extracts without sufficient information on preparation and standardization of extracts so many times results are non-reproducible. Most of pharmacological activities can be linked to various phenolic compounds which help in scavenging free radicals which are root cause of various pathological and metabolic disorders. Although many traditional uses have been verified, however in vitro as well as in vivo pre-clinical and clinical studies are necessary to assess their safety and efficacy.
5.1. Antimicrobial Activity
Riaz and coworkers studied the possible antibacterial activity of the methanol extracts from various parts of the plant against eight bacterial strains (Salmonella typhi
, Escherichia coli
, Streptococcus aureus
, Micrococcus luteus
, Proteus mirabilis
, Bacillus subtilis Citrobacteri sp.
, Pseudomonas aeruginosa
). All extracts were found to inhibit growth of bacteria. The order of potency on minimum inhibitory concentration was stem > root > leaves > fruit. The same authors also screened the methanol extracts for their antifungal potential against nine pathogenic fungal strains (Yersinia aldovae
, Aspergillus parasiticus
, Candida albicans
, Aspergillus niger
, Aspergillus effusus
, Macrophomina phaseolina
, Fusarium solani
, Trichophyton rubrum, Saccharomyces cerevisiae
) without recording any biological activity [88
]. Blackberry juice inhibited the growth of Bacillus cereus
, Bacillus subtilis
, Streptococcus marcescens
and Escherichia coli
from 50% to 75%. A methanol extract of aerial parts of R. fruticosus
inhibited Mycobacterium tuberculosis
with MIC of 1 mg/mL in agar dilution test [89
]. Fruit cordials were reported to be bacteriostatic [90
]. Abachi et al.
, reported that MIC values of aqueous and ethanolic extracts against Helicobacter pylori
were 400 and 450 µg/mL while zone of inhibitions were 8 and 7.3 mm for same extracts respectively [91
]. Radovanović et al.
, reported that blackberry extracts exhibited strong antioxidant potential against Gram (−) bacteria S. enteritidis
ATCC13076and against Gram (−) bacteria S. aureus
ATCC 6538, while weak to moderate activity was observed against Clostridium perfringens
ATCC19404, Bacillus subtilis
ATCC 6633, Listeria innocua
ATCC33090, Sarcina lutea
ATCC9341, Micrococcus flavus
ATCC40240 and against gram negative bacteria like Escerichia coli
ATCC25922, Pseudomonas aeruginosa
ATCC9027, Shigella sonnei
ATCC25931, Klbsiella pneumonia
ATCC 10031 and Proteus vulgaris
ATCC 8427 [37
]. Yang et al.
, reported that juice of fruits of R. fruticosus
had strong antimicrobial potential against food borne pathogens like Listeria monocytogenes
, Salmonella Typhimurium
, Escherichia coli
, Lactobacillus casei
, Lactobacillus plantarum
and Lactobacillus rhamnosus
. The results suggest potential use of juice as a preservative in food processing industries [92
]. Salaheen et al.
, investigated the effect of extracts of blackberry pomace on growth and pathogenicity of Campylobacter jejuni
. The extracts decreased the growth, swimming and swarming motility of C
and changed cell-surface hydrophobicity and auto-aggregation of these bacteria. The results indicate potential use of pomace extracts to reduce colonization level of C
in poultry and in controlling growth of pathogens in meat and meat products [93
5.2. Antioxidant and Anticancer Activity
There is no standard method of preparation of extract of a plant part and its antioxidant analysis and it has led to diverse rather confusing reports when comparing the antioxidant potential of extracts of the same parts of the same plant, even from same regions with similar agro-geo-climatoligical conditions. Since different protocols for assessment of antioxidant capacity are based on different mechanisms, scientists therefore use a battery of assays when analyzing the antioxidant potential of any plant extract. Blackberries are a rich source of natural antioxidants as they contain high levels of phenols, flavonols and anthocyanins and are therefore well-reputed scavengers and inhibitors of free radicals [68
]. Anthocyanins of blackberry are predominantly cyanidin based in non-acylated form. An ethanol extract of leaves was reported for its strong antioxidant potential [94
]. Due to its antioxidant activity, blackberry exhibited chemopreventive effects in rats [38
]. The antioxidant activity of fruit was also evaluated using ORAC method [68
]. Blackberry extracts effectively suppressed the production of intracellular peroxyl free radicals induced by AAPH in human intestinal cell line (INT-407 cells) and this effect was concentration dependent. The suppression of intracellular oxidation by blackberry extract occurred at concentrations that were not toxic to the INT-407 cell line [95
]. Blackberry powders were mixed with a synthetic diet (AIN-76), at 5% to 10% concentrations and fed to rats (Fischer 344) before, during and after treatment with the esophageal carcinogen N-nitrosomethylbenzylamine. At 25 week of experiment, all berry types inhibited the number of esophageal tumors (papillomas) in NMBA-treated animals by 24%–56% as compared to controls. This inhibition was associated with decrease in the formation of the NMBA-induced O-6-methylguanine adduct in esophageal DNA, indicating that the berries influenced the metabolism of NMBA leading to reduced DNA damage and thus preventing esophageal cancer in rats [38
Cyanidin-3-O-glucoside isolated from blackberry possesses strong antioxidant activity and inhibited neoplastic transformation, metastasis, neoplastic cell migration and invasion, activation of tumor cell markers (NF-αB, AP-I, COX-2, TNF-α and MAPK), activation of cell migration markers (JNK, p38, and ERK), and induces apoptosis in neoplastic cell (HL-60 cells) [96
Halvorsen and coworkers investigated the total antioxidant capacity of cultivated R. fruticosus
collected at three different locations. The wild blueberry, wild blackberry, crowberry, sour cherry, black currant, wild strawberry, cultivated blackberry and cowberry/cranberry contained very high amount of total antioxidant concentration (5.03 to 9.17 mmol/100 g) [97
]. Presence of anthocyanin in general and cyanidin-3-glucoside in particular in blackberry is the source of antioxidant capacity to repress both peroxyl-radical induced chemically and intracellular oxidation [95
]. All conventional anticancer treatments like chemotherapy, surgery and radiotherapy have some side-effects. So scientists are looking for alternative anti-cancer remedies. Apoptosis of cancer cell is a unique target for chemoprevention study. A blackberry extract induced apoptosis in human leukemia HL-60 cells [98
]. Some blackberry extracts (Hull Thornless, Chester Thornless, Triple Crown) induced apoptosis in human leukemia cells (HL-60) in a dose-dependent manner. Induction of apoptosis may be due to presence of various components in the extract; however the possible role of antioxidant potential of the extract may not be neglected in enhancement of cancer cells apoptosis. This indicates that there is a significant relationship between antioxidant activity, antioxidant content and anticancer activity in blackberries [99
Wang and coworkers found that the pre-harvest application of methyl jasmonate (MJ) increased blackberry fruit quality significantly. MJ treated blackberries had low titratable acid content and high soluble solids as compared to untreated fruits. MJ treatment also significantly increased flavonoid contents, the antioxidant capacity and the inhibition of proliferation of cell lines (A549, HL-60) and also induced apoptosis in cell lines (HL-60) [100
]. Tate and coworkers studied eight varieties of R. fruticosus
(Arapaho, Chickasaw, Hull, Chester, Choctaw, Navajo, Kiowa, Triple Crown) to determine the inhibitory effect on UV-C–induced mutagenesis in Salmonella typhimurium
TA100. Chester and Navajo varieties showed significant suppression of mutagenesis [101
Intake of blackberry juice (BJs) prepared in water (BJW) and defatted milk (BJM) affects the plasma antioxidant power and non-enzymatic and enzymatic antioxidants. Ascorbic acid content increased significantly in plasma after intake of both BJs. However α-tocopherol and plasma urate were not affected. The plasma antioxidant capacity increased only after consumption of BJW. Plasma antioxidant capacity showed a positive correlation with ascorbic acid and a negative correlation with urate level. However no correlation was found among antioxidant capacity and total cyanidin or total ellagic acid contents. Intake of blackberry juice also increased plasma catalase level. A significant decrease in the urinary antioxidant capacity was observed [67
]. Antioxidant profile of various cultivars is given in Table 12
]. Since synergetic effects exist between various bioactive compounds, so antioxidant capacity may be higher than measured for individual bioactive constituent, and therefore aggregate antioxidant potential of fruits should be measured instead of individual bioactive compounds.
Phenolic, anthocyanin and ascorbic acid contents and DPPH radical scavenging activity of blackberry fruits [49
Phenolic, anthocyanin and ascorbic acid contents and DPPH radical scavenging activity of blackberry fruits .
|Cultivar||Total Polyphenols (mg/100 g)||Total Anthocyanins (mg/100 g)||Ascorbic Acid (mg/100 g)||EC50 (mg)|
|Thornless Boy Sembes||329.1||126.9||12.5||5.2|
Huang et al.
, reported that blackberry extracts exhibited a strong DPPH scavenging activity (95.37%) at 2 mg/mL. Antioxidant activity observed was TEAC was 11.48 mmol Trolox/100 g DW, EC50 of DPPH was 0.44 mg/mL, TAC was 3.99 mg catechin/g DW,TFC was 11.83 mg rutin/g DW, TPC were v5.58 mg gallic acid/g DW. Phenolic acids, flavonoids and tannins detected were gallic acid; gallocatechin; protocatechuic acid; epigallocatechin; catechin;7, p
-hydroxybenzoic acid; caffeic acid; malvidin-3-glucoside; p
-coumaric acid; catechin gallate; cyanidin; ellagic acid; quercetrin (quercetin-3-rhamnoside); cinnamic acid and luteolin [102
Samec et al.
, investigated effect of temperature and time on blackberry fruits (Table 13
). Storage of blackberry fruits at refrigerator temperature helped in preservation of fruit qualities by 1.6 to 5.5 fold as compared to at room temperature. Storage at 25 °C led to spoilage of analyzed fruits while storage at 4 °C did not adversely affect phytochemicals in analyzed fruits [103
Antioxidant components of blackberry fruits stored at 25 °C and 4 °C [103
Antioxidant components of blackberry fruits stored at 25 °C and 4 °C .
|Days||Total Phenol Content (mg GAE/100 g FW)||Total Flavonoid Content (mg CE/100 g FW)||Total Anthocyanin Content (mg CGE/100 g FW)|
| ||25 °C||4 °C||25 °C||4 °C||25 °C||4 °C|
|9|| ||391.27|| ||65.20|| ||163.90|
|14|| ||379.88|| ||73.77|| ||144.22|
Stajčić et al.
, reported chemical composition, total phenolic, flavonoid and monomeric anthocyanin contents as well as antioxidant activity two blackberry cultivars, i.e.
, Čačanska bestrna and Thornfree (Table 14
Total phenolic, flavonoid and monomeric anthocyanin contents and antioxidant activity two blackberry cultivars [31
Total phenolic, flavonoid and monomeric anthocyanin contents and antioxidant activity two blackberry cultivars .
|Total Phenolic Contents (mg GAE/100 g FW)||235.09||270.22|
|Total Flavonoind contents (mg RE/100 g FW)||143.33||172.95|
|Total Monomeric Anthocyanin Contents (mg CGE/100 g FW)||50.95||102.31|
|DPPH radical Scavenging Activity|
|EC50 (mg FW/mL)||0.8188||0.6691|
|EC50 (mg extract/mL)||0.0616||0.0646|
Radovanović et al.
, also investigated antioxidant potential of blackberry fruits (Table 15
). Phenolic acids identified were galic acid, caftaric acid, siringic acid, ferulic acid, while flavonoids detected were catechin, epicatechin, quercetin and quercitin-3-glycoside and rutin. All extracts showed high scavenging effect on DPPH radical with IC50
values ranging from 22.19 to 31.18 mL/g [40
Antioxidant potential of blackberry fruits [40
Antioxidant potential of blackberry fruits .
|Total phenols(mg GAE/kg)||7838.26|
|Total tartaric esters(mg CAEb/kg)||291.91|
|Total flavonols (mg QEc/ kg)||647.68|
|Radical scavenging activity(ml/g)||31.18|
Ştefănuţ et al.
, reported the anthocyanins, phenolics and antioxidant activity of fresh fruit of blackberry as 1,343 mg/L, 3,284 mg GAE/L and 17.3 (μM TE/gFM) respectively [39
]. Percentage compositions of anthocyanins detected are reported in Table 16
Anthocyanin contents of acidified ethanol extract of blackberry [39
Anthocyanin contents of acidified ethanol extract of blackberry .
|Anthocyanin Type||% of Total Anthocyanins|
Najda and Labuda reported total phenolic contents, anthocyanin contents and flavonoid contents of fresh fruits which were 101,947, 38,021 and 4,291 per 100 gram of fruits. Values for antioxidant activity (µMTE/g of fresh fruits) were 1,293, 971 and 517 respectively for DPPH, FRAP and ABTS [104
]. Salehi et al.
, determined effect of solvent on phenolic contents and antiradical activity of blackberry extracts (Table 17
). Methanolic and n
-hexane extracts contained highest and lowest amounts of phenolic contents respectively. Same trend was observed for DPPH radical scavenging assay [105
Total phenolic content and antiradical activity of blackberry extracts [104
Total phenolic content and antiradical activity of blackberry extracts .
|Extracts||Total Phenolic Content (mg GAE/g of Extract)||DPPH Radical Scavenging Activity (IC50 μg/mL)|
Ivanovic et al.
, studied effect of sonication time and temperature on yield, anthocyanin (cyanidin) contents and antioxidant potential of ultrasound-assisted extracts of blackberry. It was observed that increase of sonication time as well as temperature increased yield, anthocyanin contents as well as antioxidant potential of extracts. The results suggest use of ultrasound-assisted extraction technique for better isolation of anthocyanins from blackberry extracts [100
]. Total phenolic contents and antioxidant activity of liqueurs made from different fruits was comparatively measured with regard to storage temperature and time (Table 18
). In blackberry liqueur, the phenolic compounds, flavonols and anthocyanins decreased during storage. It is well-known that food commodities and plant parts like fruits and seeds undergo transformations during storage. Contents and composition of phenolic compounds present in them also change with the passage of time depending upon storage conditions. Anthocyanins are degraded because they are prone to oxidation and this process is sped up in the presence of vitamin C or its products. Similarly degradation process of phenolic compounds is initiated by various enzymes present in liqueur [106
Phenolic compound contents in liqueurs made from blackberry fruit at various time and storage intervals [106
Phenolic compound contents in liqueurs made from blackberry fruit at various time and storage intervals .
|Month||Anthocyanin (mg cy-3-glu/100 mL)||Flavonols (mg Quercetin/100 mL)||Sum of Phenolic compounds (mg/100 mL)|
|15 ns||15 s||30 ns||30 s||15 ns||15 s||30 ns||30 s||15 ns||15 s||30 ns||30 s|
Saponjac et al.
,investigared anthocyanin contents and biological activities of two blackberry cultivars Thornfree (BT) and Cacanska bsetrna (BC). Cyanidin-3-O-glucoside was present in highest concentration being 1397.7 mg/Kg and 1360.6 mg/Kg in BT and BC respectively. Antioxidant activity determined via ABTS assay indicated EC50 of 0.007 and 0.06 g/L respectively for BC and BT respectively [107
5.4. Antidiabetic Activity
Diabetes mellitus (DM) is an endocrine and metabolic disorder characterized by dyslipidemia, hyperglycemia and protein metabolism that result from malfunction in regulating either insulin secretion or insulin action. Persons suffering from DM are more prone to risk of coronary heart diseases and therosclerosis. Despite the availability of modern hypoglycemic agents, ideal treatment of diabetes is still to be achieved, so scientists are searching for treatments from natural sources for diabetes mellitus. An aqueous tea prepared from balckberry fruit was evaluated by an in vitro
glucose diffusion model but no anti-diabetic effect was recorded [115
]. The water and butanol fractions of a R. fruticosus
leaves 70% alcoholic extract were active in the treatment and prevention of noninsulin dependent diabetes. Water and butanol extracts from leaves of R. fruticosus
were reported to be active in non-insulin dependent diabetes [116
]. An aqueous extract of leaves was investigated for its possible anti-diabetic activity in rats. The hypoglycaemic effect demonstrated in normal rats indicates that it is active because counter-regulatory mechanisms cannot normalize rapidly blood glucose levels [117
]. Chromium (Cr3+
) and zinc (Zn2+
) supplementation alleviates hyperglycemia and tea made from R. fruticosus
leaves decreased diabetic symptoms associated with these metals dependent diabetes [118
]. The leaves of R. fruticosus
are advised practically to manage diabetes mellitus. Studies in streptozotocin (STZ)-diabetic mice have evaluated the anti-hyperglycaemic efficacy of RF previously as a dietary supplement. Blackberry fruit was found to exhibit no effect on glucose homeostasis in mice [9
]. Leaves at daily administration of 5 g/kg of the infusion decreased 50% glucose-induced hyperglycemia in alloxan-diabetic rabbits [119
]. Ştefănuţ reported that administration of blackberry extracts to diabetic rats in drinking water for 5 weeks significantly decreased glucose level from 360 to 270 mg/dL [39
The general accepted therapeutic strategy for control of postprandial hyperglycemia is by inhibition of α-glucosidase and α-amylase enzymes. This leads to significant delay of carbohydrate breakdown to monosccharides. Salehi et al.
, reported that n
-hexane and chloroform extract of blackberry exhibited IC50
value of 0.5 and 6.2 in α-glucosidase inhibition activity while α-amylase inhibition potential of n
-hexane and methanol extract was 53.7 thus indicating that extract may be used as potential anti-diabetic remedy [104
]. Pressed residue of two blackberry cultivars Thornfree and Cacanska bsetrna exhibited stronger α-glucosidase inhibitory activity even at the lowest concentration, i.e.
, 0.02 mg/mL, while complete inhibition was achieved at 0.63–2.50 mg/mL [107
]. Collectively, the inhibition of intestinal α-glucosidase and pancreatic α-amylase activities as well as rich profile of antioxidant bioactive constituents indicate berry fruit as a promising dietic therapy for DM. Controlled clinical trials, however, are desirable for well-characterized and standardized blackberry extracts to corroborate its beneficial effects in diabetic patients. Similarly, traditional claimed use of its fruit to control hypertension and obesity should also be investigated in future studies.
5.9. Miscellaneous Actions and Patents
Blackberry extract exhibited strong inhibitory action against monoamine oxidase B (MAO-B) and the inhibitory concentration, IC50
, was found to be between 4 and 7 mg/mL [127
]. Blackberry and its antioxidant components especially phenolics contribute positively to skin health by inhibiting the oxidative damage linked with the formation of wrinkles and other skin-disorders like hyperproliferation and skin dryness. It is used in cosmetic industry due to its specific scent and its antioxidant potential. It is frequently used in the formulation of skin care products, for facial cleansing, hair care products, to treat oily skin, acne as well as boils, skin eruptions and burns. Extracts of leaves are used for skin aging and deodorant composition [128
A water extract of leaves is reported for its angiogenic properties [133
]. Extracts of whole plant are used to prevent and cure inflammatory, immune and metabolic diseases and also as anti-influenza remedy [113
]. The whole plant extract possesses diuretic and hypoazotemic activities [134
An oral pharmaceutical formulation is prepared from Gleditshcia triacanthos
powder, powdered leaves of R. fructicosus
, pectin and corn starch and is used for the treatment of digestive disorders in calves and piglets [135
]. A toothpaste containing R. fruticosus
as active principle is used for dental caries, treating gums and cleaning teeth [136
]. Leaves and fruits of R. fruticosus
are consumed as traditional foodstuff in normal diet to maintain immune health [80
]. Powdered fruit is also used as nutritional supplement [125