Artemisinin(qinghaosu), is a drug used for treatment of malaria. It is extracted from the Chinese herb Artemisia annua.
It has three major derivatives— Artemether, Artesunate and Dihydroartemisinin
2. Artemisinin (qinghaosu), extracted from
the Chinese herb Artemisia annua.
It has three major derivatives—
Artemether, Artesunate and
Dihydroartemisinin
This drug is identified as antimalarial and
found active against all species of the
malaria parasite.
Since the early 1980s, artemisinin and its
derivatives have been found efficacious
against Schistosoma spp., notably larval
parasites, and artemisinin derivatives
have played a critical role in the
prevention and treatment of human
schistosomiasis in China.
Schistosomiasis, caused by the infection
with the blood flukes of the genus
Schistosoma, is a major neglected
parasitic disease in the tropical and
subtropical regions.
3. DERIVATIVES OF ARTEMISININ
1. Artemether:
• Artemether is a methyl
ether derivative of
artemisinin.
• Active against S.
japonicum
• It may interact with
haemin & then cleave the
endoperoxide bridge &
generate free radicals
that may form covalent
bond with schistosome
specific proteins.
4. 2. Artesunate:
• It ha an antischistosomal
action.
• Given in a combination with
Praziquantel.
• It causes ligamental
alterations & inhibition on
energy metabolism of
schistosomes.
• Recently it is found that it
kills schistosome parasites
through reducing the
expression of schiotosome
glutathione reductase &
cytochrome C peroxidase
6. MECHANISM OF ACTION
Artemisinins are prodrugs of the biologically active
metabolite dihydroartemisinin, which is active during the
stage when the parasite is located inside red blood
cells.
Although there is no consensus regarding the
mechanism through which artemisinin derivatives kill
the parasites.
Several lines of evidence indicate that artemisinins
exert their antimalarial action by radical formation that
depends on their endoperoxide bridge.
When the parasite that causes malaria infects a red
blood cell, it consumes hemoglobin within its digestive
vacuole, a process that generates oxidative stress.
7.
8.
9. Haemozoin is parasite pigment
deposited within a food vacuole after
digestion of haemoglobin.
The iron of the heme
directly reduces the peroxide bond in
artemisinin, generating high-valent iron-
oxo species and resulting in a cascade
of reactions that produce reactive
oxygen radicals (disrupts cellular redox
cycle) which damages the parasite and
lead to its death.
10. DOSING
Artemisinin derivatives have half-lives of
the order of an hour, and therefore
require at least daily dosing over several
days.
the WHO-approved adult dose of co-
artemether is 4 tablets at 0, 8, 24, 36, 48
and 60 hours (six doses)
Artemisinin is not soluble in water,
therefore Artemisia annua tea was
postulated not to contain
pharmacologically significant amounts of
artemesinin.
11. ADVERSE EFFECTS
Side effects:
1. Vomiting
2. Nausea
3. Anorexia
4. dizziness
5. Mild blood abnormalities
Adverse effects:
i. allergic reaction
ii. significant liver inflammation
12. REFERENCES
www.wikipedia.com
Zhang J.-F. Yang Cheng Evening News
Publishing Company; 2005. A Detailed
Chronological Record of Project 523 and
the Discovery and Development of
Qinghaosu (Artemisinin)
Kremsner P.G., Krishna S. Antimalarial
combinations. Lancet. 2004;364:285–
294. [PubMed]