## 4 Pharmacological Properties of _Elaeedendron_ Species
### Cytotoxic Activity and Antiproliferative Activity  
[PERSON] et al. used 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolzolium bromide (MTT) cell viability assay on Vero cells to assess the cytotoxicity of semi-purified _E. croceum_ stem bark extracts. On cell lines with a treatment response of 250 (therapeutic index), the extract demonstrated only 20% toxicity at a concentration of 25 \(\upmu\)g/mL [57]. Using the MTT assay on Vero cells, [PERSON] et al. assessed the cytotoxic effects of an acetone extract of _E. croceum_ leaves. The extract revealed activity with an LC\({}_{50}\) of 5.2 \(\upmu\)g/mL and SI (selectivity index) values between 0.01 to 0.07, whereas the standard drug, doxorubicin, had an LC\({}_{50}\) of 8.3 \(\upmu\)g/mL [50,58]. The extract was highly cytotoxic, matching the findings of [PERSON] et al., who claimed that the poisonous triterpenoids naringenin, tingenone, 20-hydroxy-20-epi-tingenone, tingenine B, and 11-hydroxy-amyrin obtained from the species' leaves cause cytotoxicity in Vero cells [7]. [PERSON] et al. investigated the cytotoxicity of biologically produced silver nanoparticles from _E. croceum in vitro_ and _in vivo_[59]. The stem of _E. croceum_ was used to make silver nanoparticles, which were then described. The oral acute toxicity experiments were conducted on Wister rats in groups of 500, 1000, and 2000 mg/kg body weight. The WST-1 Cell Growth test was used to assess an _in vitro_ anticancer assay in MDA-MB-231 breast cancer cells. The percent of viable cells after therapy with _E. croceum_ silver nanoparticles (ECAgNPs) and aqueous extracts of _E. croceum_ (ECE) was compared to the percentage of cell viability following treatment with paclitaxel. In vivo investigations demonstrated that the LD\({}_{50}\) was greater than 2000 mg/kg, and that there was no significant change (\(p>0.05\)) in mean organ-to-body weight ratio and all haematological parameters except WBC and haematocrit between both the experimental and comparison groups. For serum electrolytes (Cl, Na+, K+ Mg2+, and Ca2+), aspartate aminotransferase (AST), alanine aminotransferase (ALT), total protein, alkaline phosphatase (ALP), urea, albumin, glutamyl transferase (GGT), and total and conjugated bilirubin, there was no significant difference (\(p>0.05\)) between the treatment and control groups. Cholesterol levels, creatinine, and urea, on the other hand, changed. _In vitro_ studies revealed that ECE and ECAgNPs had IC\({}_{50}\) values of 70.87 \(\upmu\)g/mL and 138.8 \(\upmu\)g/mL against MDA-MB-231 cells, respectively, compared to paclitaxel, which had an IC\({}_{50}\) value of 80 ng/mL. The LD\({}_{50}\) of ECE and ECAgNPs in Wister rats was shown to be larger than 2000 mg/kg body weight, according to the findings. The hazardous chemicals in the aqueous extract were likewise found to be more cytotoxic than the ECAgNPs, suggesting that the toxic compounds in the aqueous extract were involved in the capping of the AgNPs [59]. Although _E. croceum_ has traditionally been used as a medicinal herb in South Africa and Swaziland to cure various human ailments, traditional healers have been accused of using the species roots to induce death [7,18]. According to [PERSON] 2019, _E. croceum_ is classified as harmful to cattle in the KwaZulu Natal region of South Africa and causes mortality. In rabbit experiments, 2.5 g/kg body mass and 10 g/kg body mass of fresh leaves caused mortality 15 min after treatment [18]. These toxicological findings suggest that _E. croceum_ should be used with precaution when used as an herbal medication. [PERSON] et al., investigated the cytotoxic properties of stem bark extract of _E. transwalense_ by testing their effects on hepatocyte and preadipocyte cell lines. At 12.5 g/mL, the extract was cytotoxic to Chang liver cells and 3T3-L1 preadipocytes [60].