Nontoxic to self but deformer for others

Quinolizidine alkaloids are non-toxic to the legumes which produce them. On the other hand, the quinolizidine alkaloids can be toxic and in some cases very toxic to other organisms7. The biotoxicity of alkaloids has for some time been considered to be connected with their bitter taste470 471. The quinolizidine alkaloids are certainly bitter in taste to humans. However, not all alkaloids are. Literature states that some pyrrolizidine and indolizidine alkaloids are not bitter in their pure forms471. Furthermore, there are many non-alkaloid compounds, such as flavonoids, that are bitter in taste but non-toxic. Therefore, although quinolizidine alkaloids are bitter, the connection between biotoxicity and bitter taste is not absolute.

The most toxic quinolizidine alkaloids are tetracyclic with a pyridone nucleus. One of these is anagyrine. One case mentions in anagyrine being passed to the human body via milk from goats foraging on Lupinus latifolius260. The anagyrine caused severe bilateral deformities of the distal thoracic limbs in a baby boy.

The literature presents terrible cases of the poisoning of humans, adults and children by lupine alkaloids476. According to results, the acute toxicity of a mixture of quinolizidine alkaloids varies. The lethal dose (LD50) for the extract of L. angustifolius L. is 2279 mg kg-1, and for extract with lupanine 1464 mg kg-1. In other studies the oral LD50-value of sparteine was 220mgkg-1 and of lupanine 410mgkg-1. According to the newest results (Figure 88), the LD50-value for sparteine is 60mgkg-1, lupanine 159mgkg-1, 13-hydroxylupanine 189mgkg-1, 17-hydroxylupanine 177mgkg-1 and oxolupanine 190mgkg-1 476. The biological effect of the quinolizidine alkaloids is on the nervous system. Tremors, convulsions and pulmonary arrest have been noted in laboratory animals. Quinolizidine alkaloids cause depression, laboured breathing, trembling, convulsions and respiratory paralysis in sheep236.

Yovo et al.238 stated that these alkaloids act via inhibition of ganglionic impulse transmissions of the sympathetic nervous system. It is evident that each alkaloid has its own effect. Anagyrine caused skeletal deformity in foetuses when pregnant cows consumed toxic lupines236. On the other hand, some quinolizidine alkaloids are used as a drug in folk medicine477. They probably have chronic toxicity7. However, adequate knowledge about the chronic toxicity of these alkaloids and especially of chronic toxication across generations is not available. The premise that quinolizidine alkaloids have not produced hereditary symptoms has not been checked with total reliability.

420 -r 400 -380 -360 -340 320 300 280 260 240 220 -200 -180 -160 -140 -120 -100 -80 60 40 20 0

1 Sparteine

0

2 Lupanine

3 13-Hydroxylupanine

v

4 17-Hydroxylupanine

5 Oxolupanine

6 Cytisine

7 W-Methylcytisine

o

8 Angustifoline

9 W-Methylangustoline

a

10 Anagyrine

t

11 Tinctorine

0

12 Rhombifoline

5 6 7 8 Quinolizidine alkaloids

10 11 12

Figure 88. Acute toxicity (LD50) of some quinolizidine alkaloids in mice (Refs [394, 472,473, 474, 475]).

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