Cancer is increasingly a global health burden that has caused an intolerable number of deaths worldwide. It is one of the most horrific diseases of the twenty-first century, with approximately 6 million cases reported annually [5]. The International Agency for Research on Cancer (IARC) reported that there were 18.1 million new cancer cases and 9.5 million cancer-related deaths worldwide in 2018 [6]. The IARC also projected that the number of new cancer cases per year will reach 29.5 million and the number of cancer-related deaths is expected to reach 16.4 million by 2040 [6]. Globally, Australia tops the list of countries with the highest number of cancer rates, followed by New Zealand and Ireland [7]. Recently, studies have found that developing countries, in particular those in Africa, are facing an increasing incidence of cancer [8]. This is attributed to the aging and growth of the population as well as increased occurrence of risk factors linked with economic transition, including physical inactivity, obesity, reproductive behaviors and smoking [8]. In South Africa, there were about 108,168 new cancer cases and 56,802 deaths in 2020 among all ages [9]. Prostate cancer (25.8%) has recently been reported to be the number one cancer diagnosed among South African men, followed by lung cancer (12%), colon/rectum cancer (7.3%) and Kaposi sarcoma (4.9%), while in women, the most prevalent type is breast cancer (27.1%), followed by cervix uteri (18.7%), colorectum (6.3%), lung (4.9%) and corpus uteri (3.9%) cancers [9]. Although the burden of cancer in South Africa has increased, cancer continues to be a relatively low public health priority. This is mainly because of limited resources and other unrelenting public health challenges, including tuberculosis, diabetes, cerebrovascular diseases and communicable diseases.

In recent years, there have been several anticancer agents or drugs used for the management of cancer. These existing anticancer agents are divided into several categories, namely alkylating agents, antibiotics, antimetabolites, mitotic inhibitors, platinum compounds, biological response modifiers and hormone therapeutics. Table 1 shows the cancer types these anticancer agents are typically used for. A detailed description of the different types of these anticancer agents along with their potential side effects is provided below.

Alkylating agents are genotoxic drugs used for the treatment of cancer. They affect the nucleic acids and their function, thereby binding to the DNA, intervening with replication and transcription resulting in mutations [10]. The primary goal of alkylating agents is to trigger DNA damage in cancerous cells, causing them to enter apoptosis. These agents work by three distinctive mechanisms: (1) the attachment of alkyl groups to DNA bases, which in turn causes DNA to be fragmented by repair enzymes in a process to replace the alkylated bases, (2) alkylating agents causing the formation of cross-bridges, bonds between atoms in the DNA, thereby preventing DNA from being separated for synthesis or transcription and (3) they cause the mispairing of nucleotides, thereby leading to mutations [11]. However, due to the genetic damage caused by this class of drugs, the treatment of cancer patients with alkylating agents has been reported to be associated with an increased risk of secondary cancers [11]. Reports have also shown that alkylating agents are linked with gastrointestinal side effects and dose-limiting bone marrow toxicity [12]. Examples of alkylating agents include melphalan, bendamustine, cisplatin and dacarbazine.

Antibiotics used for the treatment of cancer are chemicals produced by microorganisms with anticancer activity [13]. These are mainly peptides and anthraquinones that inhibit uncontrolled proliferation, aggressive growth and metastatic activity of malignant cancers. They work by interacting with DNA in a variety of ways, including squeezing between the base pairs (intercalation), DNA strand breakage and inhibiting enzyme topoisomerase II [14]. They can kill cells throughout the proliferation cycle, even G0 phase cells, thereby fulfilling the antiproliferation capability of cancer cells by affecting the cell cycle [15]. However, a recent report indicated that antibiotics induce apoptosis of cancer cells, thereby targeting apoptotic gene B cell lymphoma-2 (Bcl-2), apoptotic pro-Bcl-2-associated x gene (Bax) and cancer suppressor gene P53, thus promoting cancer cell apoptosis in patients [13]. Antibiotic anticancer drugs are classified into different groups. These include anthracyclines, bleomycin, Adriamycin, dactinomycin and mithramycin. Anthracyclines are among the most important antibiotic anticancer drugs used to treat a variety of cancers. One of the main concerns when administering anthracyclines is that they can cause permanent damage to the heart if administered in high doses [16]. Examples of anthracycline antibiotic drugs include doxorubicin (Adriamycin), epirubicin and mitoxantrone.

Antimetabolites are also known as cytotoxic agents, have been developed for more than 60 years and are regarded as a pillar of cancer chemotherapy. They work by interfering with nucleic acid synthesis, thus acting as false metabolites, which are incorporated into DNA strands or block essential enzymes, thereby preventing DNA synthesis [17], and if new DNA cannot be made, cells are incapable of division. Antimetabolites are similar in structure to natural metabolites or enzymatic substrates, but they cannot be used productively by the body. They are confounded with the metabolites they resemble and are treated in the cell in a manner similar to normal compounds. However, like most cytotoxic anticancer agents, antimetabolites are toxic to normal cells, particularly to those in the gastrointestinal tract and bone marrow [12]. In addition, another report also indicated that antimetabolites cause side effects of immunosuppression, severe nausea and vomiting [18]. Some of the antimetabolite drugs from this class include gemcitabine, methotrexate and 5-fluorouracil (5-FU).

Mitotic inhibitors are another type of anticancer drugs used to treat several cancer types including lung cancer, breast cancer and lymphomas [19]. They inhibit mitosis (cell division) by disrupting microtubules, which are structures that separate the cell when it divides. They are frequently plant alkaloids and other compounds derived from natural products. Mitotic inhibitors work by discontinuing mitosis in the M phase of the cell cycle, but can damage cells in all phases, thus preventing enzymes from creating the proteins required for cell reproduction [20]. Some of the potential reported side effects of mitotic inhibitors include abdominal pain, weakness, back pain and lack of appetite [21]. Some of the examples of mitotic inhibitor drugs include vinblastine, paclitaxel and docetaxel.

Platinum compounds are another class of drugs used for cancer therapy. About half of the patients on chemotherapy are given platinum drugs [22]. The report also indicated that platinum drugs make up about 32 of 78 treatment regimens (combined with other drugs) [23]. They work by covalently binding to DNA, causing intra- and interstrand DNA adducts, thus resulting in the restriction of DNA replication, transcription, cell cycle arrest and programmed cell death [24]. The platinum drugs currently used with marketing approval in different parts of the world include carboplatin and cisplatin. While these drugs are effective, their use is limited by severe side effects ^[25][26][25,26]. For example, cisplatin is reported to be extremely nephrotoxic (damages the kidney) and also associated with severe nausea and vomiting in almost all patients [27]; carboplatin used in place of cisplatin is sometimes also reported to cause liver damage [26]. Oxaliplatin is reported to cause neurotoxic and pulmonary fibrosis (scar tissue in the lung connective tissue) [26].

Biological response modifiers (BRMs) have been reported to enhance the body’s ability to fight cancer through immune stimulation [28]. Several BRMs are generally accepted for the treatment of some types of cancer [29]. They can be both endogenous (produced naturally in the body) and exogenous (pharmaceutical drugs), and they can either improve or suppress the immune response. The BRMs work by blocking or reversing the processes that change normal cells or precancerous cells into cancer cells [30]. Furthermore, they increase the body’s capacity to repair or replace damaged or destroyed cells by other forms of cancer treatment, such as chemotherapy [30]. Similar to other forms of cancer treatments, BRMs also cause certain side effects depending on the type of treatment, though they slowly disappear once treatment is stopped. Typical side effects of BRMs include fever, fatigue, chills, nausea, back and joint pain [31]. Examples of BRMs are cytokines, interleukins, monoclonal antibodies (MAbs) and interferons.

Hormone therapy is another form of cancer treatment that is mainly used to treat specific types of breast cancer and prostate cancer that depend on sexual hormones to grow. Furthermore, several other cancers have also been reported to be treated with hormone therapy [32]. Hormone therapy works by stopping or slowing down the body from making hormones [32]. Since hormone therapy blocks the body’s capacity to produce hormones or interferes with how hormones behave, it can lead to undesirable side effects. Side effects always depend on the type of hormone therapy and the reaction of the body to it. Some side effects also vary between males and females. Some side effects reported in some men who use hormone therapy for the treatment of prostate cancer include nausea, fatigue, diarrhea, hot flashes and loss of interest in or ability to have sex [33] while the reported side effects in women who use hormone therapy for the treatment of breast cancer include loss of interest in sex, vaginal dryness, mood changes and nausea [34]. Examples of hormone therapy drugs include anastrozole, Zoladex, Trelstar and letrozole.

In line with some limitations linked with the use of current synthetic anticancer agents, the use of medicinal plants for the treatment of cancer has been greatly accepted as part of medical interventions. This is mainly due to their fewer probable side effects, lesser costs and effectiveness, with several chemical compounds for the discovery of novel active substances against cancer ^[40][41][40,41]. Plants have always been an exemplary source of many of the currently available anticancer drugs. Almost two-thirds of the anticancer drugs are extracted from plants. For examples, vinblastine and vincristine (class: antimitotic drugs) used as anticancer drugs are derived from Catharanthus roseus (vinca plants) [42]. In general, plants continue to play a tremendous role in providing newer drugs and as such are a reservoir of natural chemicals which may provide chemoprotective ability against cancer. It is scientifically evident that several medicinal plants possess anticancer properties against a wide-ranging spectrum of cancers (Figure 1), thus overwhelming cancer-stimulating enzymes, inducing antioxidant effects, repairing DNA damage and increasing body immunity ^[43][44][43,44]. These anticancer properties of medicinal plants have been attributed to the active chemical constituents’ presence in these plants [45].

The search for medicinal plants for the treatment of cancer is still currently ongoing worldwide. Several review reports on plants with anticancer activity from different parts of the world have also been described in the literature ^[46][47][48][46,47,48]. In South Africa, many scientific researchers have reported several ethnobotanical surveys of plants used traditionally for the treatment of cancer ^[49][50][49,50]. A review by Chota et al. [51] reported the potential treatment of breast and lung cancer with Dicoma anomala. Another study conducted by Mfengwana [50] reported some traditional plants used for the treatment of cancer by South African communities. Despite the extensive use of these plants in the treatment of this deadly disease, there are still numerous indigenous medicinal plants that need urgent scientific documentation before they are permanently lost to future generations. It is in this context that this study focused on the Eastern Cape province, South Africa.

The Eastern Cape province is one of the poorest South African provinces, with the highest provincial unemployment rate (55%), and the majority of the population are rural dwellers, thereby they tend to rely heavily on medicinal plants for the treatment of diseases, including cancer. This is primarily because of their cultural beliefs, low cost, efficacy and safety claims of medicinal plants ^[52][53][52,53]. The Eastern Cape province is mostly inhabited by the isiXhosa-speaking people of Cape Nguni ancestry, and the use of medicinal plants for the treatment of diseases is an essential part of their cultural life, and this is not likely to change in the years to come.

2. Plants Used in the Eastern Cape Province with the Anticancer Potential

From the ethnobotanical survey, twenty-four plant species belonging to twenty botanical families have been claimed as anticancer plants by the people of Eastern Cape province (Table 2), though some of these plant species have been scientifically explored to justify their traditional usage. Only eight are yet to be scientifically investigated for their anticancer activity (Table 3). However, many of these anticancer plants have also been reported to possess several biological activities (Table 4). A comprehensive description of some plants used in Eastern Cape for the management of cancer with their anticancer activities, and their active phytochemicals (Figure 2) is as follows.

2.1. Aspalathus linearis

Aspalathus linearis is an erect and highly variable shrub up to 2 m in height that belongs to the family Fabaceae [54]. The leaves of the plant are green and needle-like, about 15–60 mm long and 1 mm thick. A. linearis is easily dispersed in the winter rainfall area, predominantly in the Western Cape, Northern Cape and Eastern Cape provinces of South Africa [54]. In traditional medicine, the leaves are boiled and drunk as a tea for the treatment of cancer [55]. In addition, the plant is also used as an ingredient in cosmetics [54]. Literature surveys have shown that extracts from A. linearis have been reported to inhibit cell proliferation, thereby interfere with the growth of cancerous cells in the skin [56]. Furthermore, compounds (aspalathin and nothofagin) isolated from the methanol extract of A. linearis have also been reported to exhibit anticancer activity [57].

2.2. Agapanthus africanus

Agapanthus africanus belongs to the family Agapanthaceae [58]. It is one of the most well-known garden plants in South Africa. A. africanus is an evergreen perennial plant that produces a leaf rosette of about 1 m in height from an underground bulb [58]. The leaves of the plant are green and strap-like, approximately 15-mm-wide, with an average length of 350 mm. A. africanus is found in the Eastern Cape and Western Cape provinces of South Africa [58]. Traditionally, powdered dried root of the plant is infused in water and then taken orally to treat cancer in the Eastern Cape province [59]. In addition, the roots of the plant are also used in the treatment of intestinal pain and heart troubles [60]. The literature survey showed no scientific studies on its anticancer properties.

2.3. Cannabis sativa

Cannabis sativa is an erect annual plant up to 4 m tall with leaves alternate and palmately compound. The plant belongs to the family Cannabaceae and is widely distributed in Southern African countries, including South Africa and Botswana [61]. In South Africa, it is distributed in the Eastern Cape, Western Cape, Mpumalanga and KwaZulu–Natal provinces. In the Eastern Cape province, the crushed leaves of the plant are administered orally to treat cancer patients [61]. However, several scientific researchers have confirmed the anticancer activity of C. sativa and its compounds. Studies conducted by Bala et al. [62] revealed that the dichloromethane extract of C. sativa effectively inhibits growth and progression of breast cancer cells, with the IC₅₀ value of 27.8 ± 5.0 μg/mL. Another study reported by Tariz and Reyaz [63] also showed that the acetone extract of the plant effectively exhibits inhibition against the glioblastoma (SF-268), the colon adenocarcinoma (HT-29) and breast adenocarcinoma (MCF-7) cells. The compound cannabidiol (CBD) isolated from C. sativa has also been reported to exhibit anticancer activity. CBD showed antiproliferative effects against breast cancer cells through various mechanisms, including apoptosis, autophagy and cell cycle arrest [64].

2.4. Catharanthus roseus

Catharanthus roseus is a species of a flowering plant that belongs to the family Apocynaceae. It is an evergreen herbaceous or subshrub plant with a height of approximately 1 m. The leaves of the plant range from oval to oblong, 2.5–9-cm-long and 1–3.5-cm-wide [65]. The plant is native to Madagascar and was brought to South Africa as a garden ornamental plant, but has since escaped cultivation to become invasive in many parts of South African provinces, including Eastern Cape [65]. The alkaloid extracts of the aerial parts of the plant are used to treat various forms of cancer, such as uterine and breast cancer [66]. The infusion of the leaf is also used to treat diabetes [67]. Several researchers have reported the anticancer activity of C. roseus. Harshini et al. [68] revealed that the aqueous leaf extract of C. roseus exhibits significant inhibition against the growth of breast cancer cells (MCF-7 cells) at the concentrations investigated in the study. A study conducted by Pham et al. [69] also found that the C. roseus root and stem extracts possess significant cytotoxic activity towards some cancer cell lines. The compound catharoseumine isolated from C. roseus was found to exhibit an inhibitory effect against the human promyelocytic leukemia HL-60 cell line, with the IC₅₀ value of 6.28 μM [70]. In another study, some other compounds (vinamidine, leurosine and catharine) isolated from C. roseus have also been reported to possess an inhibitory activity against a human breast cancer cell line (MDA-MB-231), with the IC₅₀ value range of 0.73–10.67 μM [71].

2.5. Eucomis autumnalis

Eucomis autumnalis is a garden plant that belongs to the family Hyacinthaceae. It is a deciduous bulb that grows in summer. The bulbs of the plant are large, ovoid in shape, and give rise to a rosette of large broad leaves about 12–35 cm long and 7.5 cm wide [72]

[

110

]

[

111]

[109,110,111*

Inhibits a prostate cancer (PC3) cell line

[100]

]

2

Aspalathus linearis

Whole plant

Aqueous, methanol

Nothofagin (

1

) and aspalathin (

2

)

2

Inhibits cell proliferation; thus, interferes with the growth of cancerous cells in the skin

Aspalathus linearis

Antiviral, antioxidant and anti-inflammatory

[112][113]

[112

[56]

,

113

]

3

Agapanthus africanus

(L.) Hoffmanns

*

*

*

*

*

3

Agapanthus africanus

(L.) Hoffmanns

Antifungal

[114]

4

Cannabis sativa

L.

Stem, fruit and leaf

Dichloromethane, methanol and acetone

Delta-9-tetrahydrocannabinol (THC) (

3

) and cannabidiol (CBD) (

4

)

Inhibits the growth of breast adenocarcinoma (MCF-7), glioblastoma (SF-268) and colon adenocarcinoma (HT-29) cells

[62

4

Cannabis sativa

L.

Antimicrobial and antioxidant

[115]

]

[63]

[62,63]

5

Catharanthus roseus

(L.)

*

Apocynaceae

Leaves, whole plant

NT, NE

The extract from the aerial part is administered orally

Breast, lung and uterine cancers

5

Celtis africana

Burm.f.

*

*

[92]

*

*

*

5

Catharanthus roseus

(L.)

Antimicrobial, antioxidant, anthelmintic, antifeedant, anti-sterility, antidiarrheal, antidiabetic

[116][117][118]

[116,117,118]

6

Celtis africana

Burm.f.

UmVumvu

Cannabaceae

Bark and leaves

NT, NE

Dried bark and roots of the plant are pulverized and infused in milk and then taken orally

6

Cissampelos capensis

Unspecified

L.

[59]

Rhizomes

6

Celtis africana

Burm.f.

Antioxidant and anti-inflammatoryAlkaloid

[119][120]

[119,Bisbenzyltetrahydroisoquinoline (

5

), 12-O-methylcurine (

6

), and cycleanine (

7

)

Inhibits the growth of breast adenocarcinoma (MCF7), melanoma (UACC62) and renal (TK10) cells

120]

[93][101]

[93,101]

7

Cissampelos

7

capensis

L.

Catharanthus roseus

Umayisake

(L.)

Leaves, stem

Menispermaceae

Alkaloid, aqueous

Vinamidine (

8

), leurosine (

7

9

) and catharine (

Cissampelos capensis

Root

NT, NE

The root is used as a paste and applied directly

10

Skin and stomach cancers

)

[

Cytotoxicity against ovarian (A2780), lung (H460), skin (A431), prostrate (Du145), colon (HT29 and) breast (MCF-7 and MDA-MB-231) cell lines

93]

[

69

]

L.

Antimicrobial

[

121]

8

Curcuma longa

Tumeric

Zingiberaceae

Root

NT, NE

The infusion of the root is taken orally

Unspecified

[55]

8

Curcuma longa

Leaves, rhizomes

Aqueous

Curcumin (

11

) and desmethoxycurcumin (

12

)

Inhibits the proliferation/viability of human lung cancer (A549), colon cancer (HT29), glioblastoma (T98G) and Chinese hamster ovary (CHO) cell lines

8

Curcuma longa

Antioxidant, anti-inflammatory, antimicrobial, hepatoprotective effect, exhibits protective effects against gastrointestinal tract cancer

[122][123][124]

[122,123,

[

102][103]

[102,103]

124

]

9

Curtisia dentata

(Burm.f.) C.A.Sm.

UmLahleni, UmGxina

Cornaceae

Bark and leaves

NT, NE

A decoction is prepared from boiled bark and roots and administered orally

9

Curtisia dentata

Esophageal cancer

(Burm.f.) C.A.Sm.

[94]

Leaves

9

Acetone

Curtisia dentata

(Burm.f.) C.A.Sm.

Lupeol (

13

), betulinic acid (

14

), ursolic acid (

15

) and β-sitosterol (

16

)

Inhibits the growth of human breast adenocarcinoma (MCF7), human cervical cancer cells (Hela), human colorectal carcinoma cells (caco-2) and human hepatocellular carcinoma cells (HepG2)

Antimicrobial and antioxidant

[

[125]

104][105]

[104,105]

10

Elytropappus rhinecerotis

*

Asteraceae

Whole plants

NT, E

Infusions of young branches in brandy or wine

10

Elytropappus rhinecerotis

Stomach cancer

*

*

*

*

[95]

*

11

10

Elytropappus rhinecerotis

Antimicrobial

[126]

Eucomis autumnalis

(Mill.) Chitt

11

Umathunga

Hyacinthaceae

Bulbs

V, NT

Eucomis autumnalis

Decoctions are prepared from warmed bulbs and taken orally

(Mill.) Chitt

Root

Unspecified

Methanol

[59]

*

Inhibits the growth of a human hepatoma cell line (Huh-7)

[

73

]

11

Eucomis autumnalis

(Mill.) Chitt

Antibacterial and antioxidant

[73]

12

Euphorbia ingens

E.Mey. ex Boiss

Nkondze

Euphorbiaceae

Latex

NT, NE

Latex is applied topically on external cancers every day

Skin cancer

[59]

12

Euphorbia ingens

12

E.Mey. ex Boiss

*

*

*

Euphorbia ingens

*

E.Mey. ex Boiss

Antimicrobial*

[

127

]

13

Gunnera perpensa

L.

Ighobo

13

Gunneraceae

Rhizomes

NE

A decoction or infusion is prepared from the rhizome and taken orally

Gunnera perpensa

L.

Root

Dichloromethane

Z-venusol 5 (

17

) and pyrogallol (

18

)

Cytotoxicity against prostate (PC3) and breast cancer (MCF-7) cell lines

13

Gunnera perpensa

L.

Unspecified

Antibacterial, antifungal, anti-inflammatory, antinociceptive and antioxidant

[128][129][130]

[128,129,130

[

92]

[

50

]

14

]

Hermannia depressa

Seletjana

Malvaceae

Leaves, roots

NT, NE

Crushed leaves are used to treat cancer

Unspecified

[96]

14

Hermannia depressa

Shoot

Acetone and aqueous

*

Inhibition of breast cancer (MCF-7) and cervical cancer HeLa cell lines

14

Hermannia depressa

[

96

]

Anti-inflammatory and antibacterial

[

131

]

15

Hypoxis argentea

Harv. ex Baker

Inongwe

Hypoxidaceae

Corms

NT, NE

15

Fresh corms are boiled in water and then administered orally

Hypoxis argentea

Harv. ex Baker

*

*

Unspecified

*

[59]

15

Hypoxis argentea

*

Harv. ex Baker

Antioxidant and antidiabetic

[132]

*

[

133

]

[132,133]

16

Hypoxis hemerocallidea

Fisch., C.A.Mey. and Avé-Lall

Ilabatheka, Ilabatheka

16

Hypoxis hemerocallidea

Fisch., C.A.Mey. and Avé-Lall

Hypoxidaceae

Corms

Corms

NT, NE

Chloroform

Hypoxoside (

19

)

Inhibits the growth of colon adenocarcinoma (HT-29), human cervical cancer cells (Hela) and breast adenocarcinoma (MCF7) cells causing DNA cell cycle arrest at the late G1 and/or early S phase

[106]

16

Hypoxis hemerocallidea

Fisch., C.A.Mey. and Avé-Lall

Anticonvulsant, antiuropathogenic, antioxidant, antidiabetic and antibacterial

[134]

[134

[135]

,

Pulverized corms are boiled in water and taken orally

135

Prostate cancer

[59][75]

[59,75]

17

Ranunculaceae

Leaves

V, E

Crushed leaves are prepared as poultices and applied directly on external tumors

Skin cancer

[

59

]

17

Knowltonia capensis

(L.) Huth

*

*

*

*

*

18

Merwilla plumbea

(Lindl.) Speta

Umasixabane, Ugontsana

Hyacinthaceae

Bulbs

NT, NE

Decoctions are prepared from warmed bulbs and taken orally

Unspecified

[59]

18

Merwilla plumbea

(Lindl.) Speta

*

*

*

*

*

19

Melianthus major

L.

Ubutyayi

Melianthaceae

Leaves

NT, E

Decoctions are prepared from leaves and then administered orally

Unspecified

[97]

]

Knowltonia capensis

17

(L.) Huth

Knowltonia capensis

(L.) Huth

*

Antibacterial

[136]

18

Merwilla plumbea

(Lindl.) Speta

Antimicrobial, antioxidant, antifungal

[137][138]

[137,138]

19

Melianthus major

L

Leaves

19

Melianthus major

L

Antimicrobial and antioxidantPetroleum ether, chloroform, ethyl acetate and methanol

[108][139]

[108,139

21

)

Cytotoxicity towards human epithelial larynx carcinoma (Hep 2) and breast cancer (MCF-7) cell lines

]

[107][108]

[107,108]

20

Pittosporum viridiflorum

Sims

Umgqwengqwe

20

Pittosporum viridiflorum

Sims

Leaves and bark

Pittosporaceae

Bark and root

Acetone, methanol

Pittoviridoside (

22

)

NT, NE

Infusions are prepared from stamped bark and roots and then administered orally

Inhibits the growth of breast MCF-7, colorectal Caco-2, lung A549, cervical Hela and ovarian cancer A2780 cells

[78]

Unspecified

[59]

Bufadienolide (

20

) and 2β-acetoxy-3,5-di-O-acetylhellebrigenin (

[

78

[

80]

,80]

20

Pittosporum viridiflorum

Sims

Antidiarrheal, antimalarial, anti-inflammatory, antioxidant and antimicrobial

[78]

21

Sarcophyte sanguinea

Sparrm. subsp.

sanguinea

*

Balanophoraceae

Whole plants

NT, NE

A decoction from the whole plant is administered orally

21

Sarcophyte sanguinea

Sparrm. subsp.

sanguinea

*

*

*

*

*

21

Sarcophyte

Unspecified

sanguinea

Sparrm. subsp.

[

97

]

sanguinea

Antimicrobial

[140]

22

Solanum aculeastrum

Dunal subsp.

aculeastrum

Itunga, Umthuma

Solanaceae

Fruits and leaves

NT, NE

A decoction is prepared from boiled fruit is filtered and then administered orally

Breast cancer

[98]

22

Solanum aculeastrum

Dunal subsp.

aculeastrum

Fruit

Methanol and aqueous

Tomatidine (

23

) and solasodine (

24

)

Antiproliferative activity against cervical HeLa, breast adenocarcinoma (MCF7) and colon adenocarcinoma (HT29) cells by blocking the cell cycle in the G0/G1phase; cytotoxic effect against A2780 ovarian carcinoma, DU145 prostate carcinoma and Sk-Br3 breast adenocarcinoma cells

[83][

22

Solanum aculeastrum

Dunal subsp.

aculeastrum

84

Antimicrobial and antioxidant

[82][98]

[82,

]

[83,84]

23

Sutherlandia frutescens

L. R.Br.

98

]

Umnwele

Fabaceae

23

Sutherlandia frutescens

L. R.Br.

Whole plant

23

leaves, flower and seed

Sutherlandia frutescens

V, NE

L. R.Br.

Antibacterial, antioxidant, anti-inflammatory and antidiabetic

Decoctions are prepared from all the plant parts and administered orally

Methanol and aqueous

Colorectal cancer

[141][142][143

L-canavanine (

25

[59][

[59

86]

,86]

)

Induces apoptosis and cytotoxicity in neoplastic cells (cervical carcinoma) and CHO (Chinese hamster ovary cells) cell lines; induces growth inhibition of human squamous carcinoma (SiHa cell line) thereby causing cell cycle arrest at the S phase

]

[141

[

87

][88]

[87,88]

24

Tulbaghia violacea

Harv

Utswelane

Alliaceae

Leave, bulb

NT, E

The fresh bulbs are boiled in water and the decoctions are taken orally

Esophageal cancer

[92][99

24

Tulbaghia violacea

Harv

Leaves

Methanol, hexane, acetone, butanol

*

Induces apoptosis in breast cancer (MCF7 and MB MDA231), cervical cancer (HeLa and ME-180) and oral cancer (KB) cell lines causing cell cycle arrest at the G2/M phase

[88]

*: not available.

Table 4. Pharmacological activities of anticancer plant species used in Eastern Cape.

,
142
,
143
]
24
Tulbaghia violacea
Harv
Antibacterial, antifungal, antioxidant and antidiabetic
[
144
]
[
145
]
[
144
,
145
]	]	[	92	,	99	]