Antioxidant, Anti-Inflammatory, and Anti-Cancer Properties of Amygdalin Extracted from Three Cassava Varieties Cultivated in Benin

Abstract

Given that cancer is a disease that is rampant in the world and especially in Africa, where the population has enormous difficulty treating it, plants are a safer and less expensive alternative. Cassava is a plant species valued in Benin because of its numerous medicinal and nutritional virtues. This study evaluated the biological activities of amygdalin from the organs of three cassava varieties most commonly produced in Benin (BEN, RB, and MJ). HPLC analysis was used to quantify amygdalin in cassava organs and derivatives. Phytochemical screening was performed to determine secondary metabolite groups. DPPH and FRAP methods were used to assess antioxidant activity. Cytotoxicity of the extracts was tested on Artemia salina larvae. The anti-inflammatory activity was evaluated in vivo in an albino mouse paw edema model induced by 5% formalin. The anticancer activity was evaluated in vivo on Wistar rats rendered cancerous by 1,2-dimethylhydrazine (DMH) using 5-fluorouracil as a reference molecule. The results showed that the organs of all three-cassava varieties contained glycosides, flavonoids, saponosides, steroids, tannins, coumarins, and cyanogenic derivatives. Young stems and fresh cassava leaves had the highest amygdalin concentrations, with 11,142.99 µg 10 g^-1 and 9251.14 µg 10 g^-1, respectively. The Agbeli derivative was more concentrated in amygdalin, with a content of 401.56 µg 10 g^-1 than the other derivatives. The antioxidant activity results showed that the amygdalin extracts were DPPH radical scavengers with IC₅₀ values ranging from 0.18 mg mL^-1 to 2.35 mg mL^-1. The cytotoxicity test showed no toxicity of the extracts toward shrimp larvae. Administration of amygdalin extracts from the leaves of BEN and MJ varieties prevents inflammatory edema. The percentages of edema inhibition varied between 21.77% and 27.89%. These values are similar (p > 0.05) to those of acetylsalicylic acid (25.20%). Amygdalin extract of the BEN variety significantly (p < 0.0001) reduces edema. Both BEN extracts inhibited cancer induction with DMH. In preventive and curative treatments, rats fed with amygdalin extracts showed low anti-cancer activity under the effect of DMH and a significant difference in biochemical results. Thus, the organs of all three cassava varieties studied have secondary metabolites and good antioxidant activity. The leaves contain high levels of amygdalin and can be used as anti-inflammatory and anticancer agents.

Keywords: Benin; amygdalin; biological activities; cassava; phytochemistry.

Figure 1

Chromatogram of amygdalin standard (a); standard sample (b) and standard derived (c).

Figure 2

Amygdalin content (µg/10 g of cassava stem powder). Legend: BJT_F = BEN Young Fresh Stem; RBJT_F = RB Young Fresh Stem; MJT_F = MJ Young Fresh Stem; BGT_F = BEN Large Fresh Stem; MJGT_F = MJ Large Fresh Stem; RBGT_F = RB Large Fresh Stem.

Figure 3

Amygdalin content (µg/10 g of cassava leaf powder). Legend: BF_F = BEN Fresh leaf; RBF_F = RB Fresh leaf; MJF_F = MJ Fresh leaf; BF_OM = BEN Shade dried leaf; RBF_OM = RB Shade dried leaf; MJF_OM = MJ Shade dried leaf.

Figure 4

Amygdalin content (µg/10 g of cassava derivatives powder). Legend: RBCBO = RB Boiled Flesh; BCBO = BEN Boiled Flesh; MJCBO = MJ Boiled Flesh.

Figure 5

Larval cytotoxicity of extracts.

Figure 6

Percentage increase in hind paw edema in mice as a function of time. Legend: E/MJ (amygdalin extract of MJ variety); E/BEN (amygdalin extract of BEN variety); AAS (acetyl salicylic acid).

Figure 7

Percentage inhibition of hind paw edema in mice as a function of time. Legend: E/MJ (amygdalin extract of MJ variety); E/BEN (amygdalin extract of BEN variety); AAS (acetyl salicylic acid).

Figure 8

Histology of experienced Wistar rat colon (original magnification 400×). Legend: Lieberkühn gland (G); cell infiltrates (IC; caliciform cells (arrows). Magnification: 4000×. (a) group 1: DMH and amygdalin; (b) group 2: DMH only; (c) group 3: DMH, then amygdalin next week; (d) group 4: amygdalin, then DMH next week; (e) group 5: DMH and 5-fluorouracil combined; (f) control group: no treatment.

Figure 9

Histology of the liver of tested Wistar rats (original magnification 400×). Legend: venous sinusoids (S); centrilobular veins (VC); (a) group 1: DMH and amygdalin; (b) group 2: DMH only; (c) group 3: DMH, then amygdalin next week; (d) group 4: amygdalin, then DMH next week; (e) group 5: DMH and 5-fluorouracil combined; (f) control group: no treatment. Black arrow show venous sinusoids.

Figure 10

Histology of the kidneys of tested Wistar rats (original magnification 400×). Legend: glomeruli (G); renal tubules (RT); (a) group 1: DMH and amygdalin; (b) group 2: DMH only; (c) group 3: DMH, then amygdalin next week; (d) group 4: amygdalin, then DMH next week; (e) group 5: DMH and 5-fluorouracil combined; (f) control group: no treatment.