1. “ Survey of potential antimalarial plants”
R.M.Vaid
Engg Chemistry Dept
Model Institute of Engg and Tech(MIET)Jammu

2. What is malaria
Infectious parasitic disease caused by Protozoan plasmodium species
Disease Transmitted by the bite of infected female anopheles mosquito.
Characterized by periodic paroxysm with
shaking chills, high fever, heavy sweating.
Anemia and splenomegaly(Spleen burst) in cases suffering from several attack of paroxysm.

3. Meaning of malaria
The word malaria comes from Italian word mala meaning "bad" and aria meaning "air". Most likely, the term was first used by Dr. Francisco Torti, Italy, when people thought the disease was caused by foul air in marshy areas.  C. Laveran in 1880 was the first to identify the parasites in human blood. In 1889, R. Ross discovered that mosquitoes transmitted malaria Malaria is transmitted from person-to-person through the bite of the female mosquito, which needs blood for her eggs. 

4. Malaria world scenario
Today approximately 40% of the world's population mostly those living in the world's poorest countries is at risk of malaria. The disease was once more widespread but it was successfully eliminated from many countries with temperate climates during the mid 20th century. Today malaria is found throughout the tropical and sub-tropical regions of the world and causes more than 300 million acute illnesses and at least one million deaths annually.

5. History of Malaria
Malaria parasites have been with us since the dawn of time. They probably originated in Africa (along with mankind), and fossils of mosquitoes up to 30 million years old, show that the malaria vector, the malaria mosquito, was present well before the earliest history.Indian scriptures have reference of the disease. Hippocrates, Greece physician regarded as the "Father of Medicine", was the first to describe the manifestations of the disease. Before this, the supernatural was blamed. Recent molecular studies have found evidence that human malaria parasites probably jumped onto humans from the great apes, probably through the bites of vector mosquitoes.

6. Origin of the human malaria
Nature 467,420–425 (23 September 2010)
 These findings indicate that P. falciparum is of gorilla origin and not of chimpanzee, bonobo (pygmy chimpanzee)or ancient human origin.

7. World Distribution of Malaria
Central America,Soth America,Africa and Asia

8. Anopheles Mosquito

9. PlasmodiumMalarial Parasite

10. Primary and Secondary Host
Plasmodium Vector Anopheles Mosquito Secondary Host-Humans Mosquito Human
Plasmodium
Plasmodium

11. Types of Plasmodium Five species of plasmodium cause malaria
in human.
P. vivax, P. ovale.
P. malariae P. falciparum
P.knowlesi
Each species has its own morphologic, biologic,
pathogenic, and clinical characteristics

12. Diagram of the malaria parasite’s life cycle

13. Types of malaria
A)Uncomplicated malaria (can be caused by all strains of Plasmodium)
Malaria is considered uncomplicated when symptoms are present but there are no clinical or laboratory signs to indicate severity or vital organ dysfunction.2 The symptoms of uncomplicated malaria are non-specific and include fever.
Severe malaria (only caused by P. falciparum)
Infection with P. falciparum, if not promptly treated, can quickly progress to severe malaria. The main symptoms of severe malaria include: coma, severe breathing difficulties, low blood sugar, and low blood haemoglobin (severe anaemia). It is diagnosed on the basis of the presence P. falciparum parasites and one of the above symptoms with no other obvious cause. Children are particularly vulnerable since they have little or no immunity to the parasite. If untreated, severe malaria can lead to death.
Cerebral malaria (only caused by P. falciparum), and now increasingly in Southeast Asia, ACTs are taking longer and longer to clear the parasite from patients

14. MalariaSymptoms
What are the symptoms of malaria?  Symptoms vary depending on the specific type of Plasmodium involved, but include high fever, chills, sweats, and headache. In some cases, the illness can progress to lethargy, renal or respiratory failure, coma and death. If not treated, the symptoms can continue for weeks or months with episodes of fever and chills. With some types of malaria, relapses of the disease may occur for years after treatment. Malaria has been misdiagnosed as the flu.
How soon after exposure do symptoms appear?  The symptoms usually appear from 12 to 30 days after the bite of the mosquito, depending on the type of Plasmodium involved. Some strains may not cause symptoms for 10 months or even longer.
How long can an infected person carry this parasite?  Direct person-to-person spread does not occur but the untreated or inadequately treated person can carry the infection for one to three years depending on the type.

15. Incubation period of malaria
When a person becomes infected with one of the Plasmodium parasites that cause malaria, he or she will not feel sick immediately. The period between infection with the parasites that cause the disease and the beginning of malaria symptoms is called the malaria incubation period. The infected person may feel normal from 7 to 21 days when infected withPlasmodium parasites. P. falciparum has a shorter incubation period (7 to 14 days) than P. vivax (12 to 18 days). Plasmodium malariae tends to have a much longer incubation period, as you can see below
  Incubation period of malaria parasites days.
P. falciparum 7‒14days
P. vivax 12‒18 days
P. ovale 12‒18days
P. malariae 18‒40days

16. More than 100 years Alphonse Laveran in 1880
Plasmodium discovery
More than 100 years Alphonse Laveran in 1880
French army doctor in Algeria observedparasites inside RBC of malaria patients and proposed for the first time that a protozoan caused disease
Born: 18 June 1845, Paris, France
Died: 18 May 1922, Paris, France
Affiliation at the time of the award: Institut Pasteur, Paris,
France
The Nobel Prize in Physiology or Medicine 1907 was awarded to Alphonse Laveran "in recognition of his work on the role played by protozoa in causing diseases".
Charles Louis Alphonse Laveran

17. Roland Ross Ronald Ross Born: 13 May 1857, Almora, India
Died: 16 September 1932, Putney Heath, United Kingdom
Affiliation at the time of the award: University College, Liverpool, United Kingdom
Prize motivation: "for his work on malaria, by which he has shown how it enters the organism and thereby has laid the foundation for successful research on this disease and methods of combating it"
Field: disease transmission, epidemiology, parasitology
Ronald Ross
The Nobel Prize in Physiology or Medicine 1902

18. Currently used anti-malarials
A. Aminoquinolines,
eg. Chloroquine, Hydroxychloroquine, Amodiaquine
B. 8- aminoquinolines,
eg. Primaquine, Tafenoquine, Bulaquine
C. Arylamino alcohols,Cinchona alkaloids
eg. Quinine, Quinidine
D. Methanols
i. 4 quinoline methanol
ii. 9- phenanthrene methanol
eg. Mefloquine
eg. Halofantrine, Lumefantrine
E. Biguanides
eg. Proguanil
F. Diaminopyrimidines
eg. Pyrimethamine
G. Antimalarial endoperoxidases
i. First generation endoperoxidases
(Artemisinin derivatives)
ii. Second generation endoperoxidases
a. Trioxanes
b. Tetroxanes
eg. Artesunate, Artemether, Arteether
H. Hydroxynaphthoquinone
eg. Atovaquone
I. Benzonaphthyridine deriative
eg. Pyronaridine
J. Antibiotics
eg. Sulfonamides, Tetracycline, Doxycycline, Clindamycin, Azithromycin

20. Artimisinin
Artimisinin %
"qinghaosu"
Artemisia annua

21. Cinchona plant
Quinine %

22. Malaria Treatment Therapy
Combination therapy CT - The concept of combination therapy is based on the synergistic or additive potential of two or more drugs, to improve therapeutic efficacy and also delay the development of resistance to the individual components of the combination.
Artemisinin combination therapy ACT

23. Non-artemisinin based combinations
Chloroquine(CQ) plus sulfadoxine-pyrimethamine(SP)
Amodiaquine plus sulfadoxine-pyrimethamine
Atovaquone-proguanil (MalaroneTM, GlaxoWellcome)
Mefloquine-sulfadoxine-pyrimethamine (Fansimef TMRoche)
Quinine plus Tetracycline or Doxycycline

24. Artemisinin-based combinations(ACT)
Artemisinin (qinghaosu), artesunate, artemether and dihydroartemisinin have all been used in combination with other antimalarial drugs for the treatment of malaria
Artesunate plus chloroquine
Artesunate plus amodiaquine
Artesunate plus sulfadoxine-pyrimethamine
Artesunate plus mefloquine
Artemether-lumefantrine (CoartemTM, RiametTM Novartis)

25. Combinations in the pipeline
Piperaquine-dihydroartemisinin-trimethoprim (ArtecomTM) and ArtecomTM plus primaquine (CV8TM)
Pyronaridine plus artesunate
Naphthoquine plus dihydroartemisinin
Chlorproguanil-dapsone plus artesunate
(CDA TM or Lapdap plusTM )

26. Resistance to antimalarials (Drug resistance)
. The World Health Organization (WHO) defines resistance to antimalarials as the ability of a parasite strain to survive and/or to multiply despite the administration and absorption of a medicine given in doses equal to or higher than those usually recommended but within the tolerance of the subject, provided drug exposure at the site of action is adequate.
Resistance to antimalarials arises because
of the selection of parasites with genetic mutations or gene amplifications that confer reduced susceptibility.

27. Antimalarials and Resistance
Quinine -  introduced in   1st case of resistance: Chloroquine -  introduced in   1st case of resistance: Proguanil -  introduced in   1st case of resistance: Sulfadoxine- Pyrimethamine -  introduced in   1st case of resistance: Mefloquine -  introduced in   1st case of resistance: 1982
Atovaquone -  introduced in   1st case of resistance: 1996
Antimalarials and Resistance

28. World Health Organization
Artemisinin resistance
World Health Organization
12 April, 2018

29. Why plants investigation
Developing countries, where malaria is endemic, depend strongly on traditional medicine as a source for inexpensive treatment of this disease. However, scientific data to validate the antimalarial properties of these herbal remedies are scarce. Consequently, it is important that antimalarial medicinal plants are investigated, in order to establish their efficacy and to determine their potential as sources of new antimalarial drugs. Though a large number of traditionally used plants for the treatment of malaria were identified, scientific validation of the traditional claims of anti-malarial properties is imperative. This would establish their candidature for any possible future research for active principles and the possible development of new cheaper and more effective anti-malarial drugs, as well as in the conservation of this rich diversity of anti-malarial plants.

30. Indian medicinal plants used in Tribal/Folk tradition against Malaria
S.No
Plant Name
Used as 1
Achyranthes aspera
Boiled water decoction of leaves 2
Aerva lanata
Whole plant aq paste 3
Ailenthesexcelsa Roxb
Boiled water decoction of tender leaves 4
Alstonia scholaris
Boiled water decoction of stem bark with honey 5
Alternanthera sessilis
Boiled water decoction of whole plant 6
Andrographis paniculata
Boiled water decoction of leaves or in combination with lv of azadirachta indica& ocimum sanctum,leaf paste with honey,leaf paste with Allium sativum 7
Azadirachta indica
Leaf powder with honey 8
Biophytum sensitivium
Plant juice 9
Caesalpinia bonduc
Seed kernel powder with water,leaves 10
Calotropis gigantea
Boiled water decoction of leaves for 5 days 11
Canscora diffusa
Whole plant paste taken orally 12
Cassia hirsuta
Dried seed powder taken orally 3-5 days 13
Catumaregam spinosa Syn Randia dumetorum
Plant root+root of asparagus racemous&boiledwater ext of elphantopus scaber 14
Cipadessa baccifera
Boiled water leaves ext

31. Indian medicinal plants used in Tribal/Folk tradition against Malaria

32. Effect of methanolic extracts of selected medicinal plants on schizont maturation of Plasmodium falciparum
Name of the plant
Dose (µg/ml)
%Inhibition
Adhatoda zeylanica
10 &25
45.83 ± 9.54 & ± 6.25
Clerodendron phlomidis
8.33 ± 3.60 & ± 3.60
Embelia ribes
41.66 ± 3.60 &54.16 ± 3.60
Enicostemma littorale
18.75 ± 6.25& ± 3.60
Erythrina indica
27.08 ± 3.60& ± 6.25
Ficus religiosa
6.25 ± 0& ± 3.60
Ficus virens
18.75 ± 6.25& ± 3.60
Nardostachys jatamansi
8.33 ± 3.60& ± 7.21

33. Contd. Solanum xanthocarpum 10 &25 33.16 ± 7.07 45.83 ± 3.60
Tinospora cordifolia
12.5 ± 6.25
27.08 ± 3.60
Ventilago calyculata
31.25 ± 6.25
45.66 ± 3.75
Onosma bracteatum
12.5 ± 0& ± 3.60
Picrorrhiza kurroa
14.58 ± 3.60& ± 3.60
Piper nigrum
39.58 ± 3.60& ± 6.25
Plumbago zeylanica
31.25 ± 6.25& ± 3.75

34. Effect of methanolic extract of the selected medicinal plants on Plasmodium falciparum lactate dehydrogenase (PfLDH)
Name of the plant
Methanolic
extract (µg/ml)
% Inhibition∗
IC50
(µg/ml)
Adhatoda zeylanica 10 25 50
100
36.32 ± 0.50
48.9 ± 0.48
63.25 ± 0.24
70.87 ± 0.37
82.24 ± 0.50
5.80
Embelia ribes 1
26.92 ± 0.61
38.03 ± 0.37
51.08 ± 0.42
67.71 ± 0.60
80.93 ± 0.50
13.10
Piper nigrum
26.19 ± 0.50
38.43 ± 0.24
51.00 ± 0.37
59.85 ± 0.24
76.88 ± 0.49
16.25
Quinine dihydrochloride
0.001
0.005
0.01
0.015
0.020
19.86 ± 1.01
31.87 ± 0.49
45.25 ± 0.87
60.82 ± 0.73
72.5 ± 0.64
0.0089
shodhganga.inflibnet.ac.in/jspui/bitstream/10603/1379/.../08_chapter3.p...‎
by YS Biradar - ‎2010

35. Antimalarial activity of Plants and marine extracts
SNo
Plant
Anti Plasmodial activity
Remarks 1
Triclisia patens
good 2
Cissampelos
pareira 3
Cordia polycephala 4
Trichilia hirta 5
Turnera ulmifolia 6
Lippia
alba
(flora of Puerto Rico) 7
Combretum molle 8
Abutilon grandiflorum
Active 9
Bidens pilosa
flavonoid and acetylene compounds 10
Phlomis kurdica 11
, P. leucophracta 12
, Scrophularia cryptophila

36. Antimalarial activity of Plants and marine extracts
SNo
Plant
Anti Plasmodial activity
Remarks 13
, Morina persica 14
Asperula nitida 15
Rhododendron ungernii {leaves}
(IC50 =good 16
R.smirnovi
(IC50 = good 17
Arcangelisia flava 18
Fibraurea tinctoria 19
, Harrisonia perforata
Active 20
Irvingia malayana 21
Elaeocarpus kontumensis 22
Anneslea fragrans 23
Maytenus
putterlickioides
antimalarial activities in low micromolar
Concentrations 24
, Warburgia stuhlmannii

37. Anti Plasmodial activity Remarks
SNo
Plant
Anti Plasmodial activity
Remarks 25
Pentas bussei 26
Ludwigia erecta
IC50 <highly active 27
Fuerstia africana 28
Schkuhria pinnata 29
Microcosmus goanus,
good
different marine species inhibited
parasite growth by 50% 30
Ascidia sydneiensis 31
Phallusia nigra

38. Antimalarial screeningFrom costa rica

39. From Brazil, Caesalpinia pluviosa (stem bark) ethanol extract was effective against the two main strains of the malaria parasite.
It’s important that we continue to find new antimalarials because the parasite becomes resistant. The current main therapy is ACT (artemisinin-based combination treatment), introduced when the parasite became resistant to chloroquine, a quinine derivative. Now artemisinin resistance is becoming increasingly common and no new class of antimalarial has been introduced since The authors warn “the discovery of new potential anti-malarial compounds is urgently needed.”

40. Recent advances in antimalarial drug discovery from natural sources
Plants and marine extracts,alkaloids (naphthylisoquinolines, bisbenzylisoquinolines, protoberberines and aporphines, indoles, manzamines, and miscellaneous
alkaloids) terpenes (sesquiterpenes, triterpenes, diterpenes, and miscellaneous terpenes) quassinoids,
flavonoids, limonoids, chalcones, peptides, xanthones, quinones and coumarines, and miscellaneous antimalarials from nature

41. Triterpenes and diterpenes

43. Isolated compounds Having antimalarial activity

44. Manzaminealkaloids and Antimalarial terpenes

45. Indole alkaloids

46. Isolated alkaloids contd.

47. No of compd having moderate or high activity

48. Seaweed a Source of Potential Antimalarial Drug
In the war against malaria, researchers have recruited an unlikely ally: a seaweed found in Fiji. The seaweed, a red alga, produces an antifungal compound, which tests show kills the malarial parasite. If the compound proves effective in animal and human studies, it could become the newest weapon against a disease that kills more than a million people a year.  Already, resistance has appeared in Cambodia against the latest compound in the anti-malaria arsenal: artemisinin. In 2005, Kubanek's group discovered that the red alga, Callophycus serratus, had a family of unusual ring-shaped compounds called bromophycolides that were particularly effective against certain fungi. In 2009, the biomedical screening revealed that one had strong antimalarial properties.

49. Bromophycolides from Seaweed

50. Antimalarial activities of bromophycolides
compound
antimalarial IC50 (μM) 1
2.7 2 44 3
9.8 4
0.5 5
1.4 6 7
2.9 8 9
0.9 10
4.8 11 56 12
0.3

51. Antimalarial activities of bromophycolides
compound
antimalarial IC50 (μM) 13
0.8 14 18 15 16
0.9 17
2.5
>100
Artemisinines 
 (IC50 values <7 nM)

52. New antimalarial drug class resists resistance-(MMV)
Drawing on past toxicity problems scientists used an enlarged quinolone to improve selectivity for the malaria parasite
A Quinolone-3-DiarylethersELQ300: A New Class of Antimalarial Drug
 new class of antimalarial drugs that is effective across various stages of the malaria parasite’s lifecycle has been developed by an international research team. Early indications also show that it may take longer for the parasite to develop resistance to the new molecules than it has for existing drugs targeting the same pathway.
Malaria is a devastating disease worldwide, and the ability of the Plasmodium family of parasites that cause the disease to develop resistance to drugs leads to a constant arms race for new medicines

53. New antimalarial
Ranbaxy developed Synriam as a fixed-dose combination of arterolane maleate and piperaquine phosphate, where arterolane is the new chemical entity (NCE) that was developed as an alternative to artemisinin. 
Arterolane maleate and piperaquine are not the find of Ranbaxy litrature available

54. Researchers used plant to produce effective anti-malaria drug;
Although tobacco in the form of cigarettes is generally recognized as being a killer of millions, the plant has been used by Hebrew University researchers to produce an effective anti-malaria drug. The researcher developed genetically engineered tobacco plants carrying genes encoding the entire biochemical pathway needed for producing artemisinin. In light of tobacco’s high biomass and rapid growth, this invention will enable a cheap production of large quantities of the drug, 

55. Scientists Identify New Class of Antimalarial Compounds
Imidazolopiperazine,The imidazolopiperazine family of compounds was especially attractive because it was chemically unrelated to existing antimalarial drugs, and therefore less likely to run into problems with existing resistance.It is effective against liver and blood stage of malarial parasite

56. Antimalarial lead
Cajanus cajan L, a member of the family Fabaceae, was identified from the Nigerian antimalarial ethnobotany as possessing antimalarial properties. The bioassay-guided fractionation of the crude methanol extract of C. cajan leaves was done in vitro using the multiresistant strain of Plasmodium falciparum (K1) in the parasite lactate dehydrogenase assay. Isolation of compound was achieved by a combination of chromatographic techniques, while the structure of the compound was elucidated by spectroscopy. This led to the identification of a cajachalcone, 2′,6′-dihydroxy-4-methoxy chalcone, as the biologically active constituent from the ethyl acetate fraction. Cajachalcone had an IC50 value of 2.0 μg/mL (7.4 μM) and could be a lead for anti-malarial drug discovery.
Journal of Parasitology Research Volume 2013 (2013), Article ID 703781, 5 pages

57. cajachalcone from Cajanus cajan L
IC 50 value of 2.0 μg/mL (7.4 μM)
cajachalcone

58. New potential Antimalarial
From Brazil, Caesalpinia pluviosa (stem bark) ethanol extract was effective against the two main strains of the malaria parasite.
It’s important that we continue to find new antimalarials because the parasite becomes resistant. The current main therapy is ACT (artemisinin-based combination treatment), introduced when the parasite became resistant to chloroquine, a quinine derivative. Now artemisinin resistance is becoming increasingly common and no new class of antimalarial has been introduced since The authors warn “the discovery of new potential anti-malarial compounds is urgently needed.”

59. New potential Antimalarial
From Brazil, Caesalpinia pluviosa (stem bark) ethanol extract was effective against the two main strains of the malaria parasite.
Icacina senegalensis a native plant long used in Senegal to treat malaria. Crude extract and various fractions proved anti-plasmodial (Plasmodium is the malaria parasite) with no toxicity

60. Curcumin potential candidate for cerebral malaria
 in vitro and in vivo indicated that curcumin possesses a moderate anti-malarial activity with an IC50 ranging from 5-10µM in vitro

61. ANTIMALARIAL AERIAL PARTS OF POLYGONATUM VERTICILLATUM (L.)
The crude extract demonstrated potent activity (IC50: μg/ml) which further increased upon
fractionation. The maximum antiparasitic potency was noted for n-hexane fraction (IC50: 4.86 μg/ml) followed by
chloroform (IC50: 5.71 μg/ml)

62. In vitro Anti Plasmodial Activity of Enicostemma littorale
Methanolic extract of plant and swertiamarin isolated from it showed promising results in vitro in schizont maturation inhibition assay having IC50 of and 12 μg mL-1 respectively
The IC50 value of Chloroquine and Quinine is around 10 and 29 μg mL-1 respectively which indicate that swertiamarin lies between the scales.

63. Structure of swertiamarin

64. Untapped potential medicinal plant of Northeast India
Brucea mollis Wall. ex Kurz. is used as traditional medicinal herb for the treatmentof malaria in North-East India. The plant exhibited anticancer and diuretic activity and cardiovascular effect.

65. Natural leads nature provides novel leads, which can be
developed into safe drugs by synthetic strategies as exemplified
by artemether, and quinoline class of antimalarial
provide useful bioactive synthons
, nature has been generous in providing several remedies for the treatment of disease like malaria. However, still thereis vast unexplored flora and fauna, which when systematically explored will provide additional new leads and drugs for malaria
Chemotherapy
Bioorg. Med. Chem. (2009), doi: /j.bmc

66. New semi synthetic artimisinin
 the production of a newsemi-synthetic artemisinin, a key ingredient in today's front-line antimalarial drugs. ...we can advance science to make a real impact in global health.
Genes introduced in microbes which produce precursor of artimisinin- converted to artimisinin yield more.Amyris gave Artemisinic Acid-producing yeast strains to Sanofi, via OneWorld Health

67. How is malaria diagnosed?
The classic and most used diagnostic test for malaria is the blood smear on a microscope slide that is stained (Giemsa stain) to show the parasites inside red blood cells
Rapid diagnositc Test

69. Interfering with malaria's genetic cloaking device
researchers from The Hebrew University-Hadassah Medical School, Jerusalem, Israel, believe they have come very close to finding a cure for malaria. They have discovered a genetic cloaking device used by the parasite to evade the human immune system so that it can establish infection. If a treatment can be devised which interferes with the cloaking device's DNA, the immune system would then have a chance to eliminate the infection early on

70. GSK aims to market world's first malaria vaccine after successful trials
British drugmaker GlaxoSmithKline will seek marketing approval for the world's first malaria vaccine next year after trial data showed the shot significantly cut cases of the disease in AfricaThe vaccine known as RTS,S was found, after 18 months of follow-up, to have almost halved the number of malaria cases in young children in the trial, and to have reduced by around a quarter the number of malaria cases in infants.n children.

73. Primary screen
The K1 strain is used. The compounds are tested at seven concentrations (5000 to 78 ng/ml).
Artemisinin and chloroquine are included as reference drugs.
• If the IC50 is > 5 µg/ml, the compound is classified as inactive.
• If the IC50 is between 0.5 and 5 µg/ml, the compound is classified as moderately active.
• If the IC50 is < 0.5 µg/ml, the compound is classified as active and further evaluated
using two strains, K1 and NF54. A new range of concentrations is chosen depending on
the IC50 determined (e.g. 100 to 1.56 ng/ml)

74. Malaria: in vitro screening model
Parasite cultures
Two strains of P. falciparum are used in this study: the drug-sensitive NF54 (an airport strain of
unknown origin) and K1 (a clone originating from Thailand) which is resistant to chloroquine and
pyrimethamine. The strains are maintained in RPMI 1640 medium with 0.36 mM hypoxanthine,
supplemented with 25 mM N-2-hydroxyethylpiperazine-N’-2-ethane-sulphonic acid (HEPES), 25
mM NaHCO3, neomycin (100 U/ml) and 5 g/l of AlbumaxR II (lipid-rich bovine serum albumin,
GIBCO, Grand Island, NY, USA), together with 5% washed human A+ erythrocytes. All cultures
and assays are conducted at 37°C under an atmosphere of 4% CO2, 3% O2 and 93% N2.
Cultures are kept in incubation chambers filled with the gas mixture. Subcultures are diluted to
a parasitemia of between 0.1 and 0.5% and the medium is changed daily.

75. Screening contd Primary screen
The K1 strain is used. The compounds are tested at seven concentrations (5000 to 78 ng/ml).
Artemisinin and chloroquine are included as reference drugs.
• If the IC50 is > 5 µg/ml, the compound is classified as inactive.
• If the IC50 is between 0.5 and 5 µg/ml, the compound is classified as moderately active.
• If the IC50 is < 0.5 µg/ml, the compound is classified as active and further evaluated
using two strains, K1 and NF54. A new range of concentrations is chosen depending on
the IC50 determined (e.g. 100 to 1.56 ng/ml).
Each drug is tested in duplicate. Active compounds are tested twice for confirmation.
The standard drugs are chloroquine and artemisinin which are run in the same assay. The IC50
values for chloroquine are 2.9 ng/ml for NF54 (range 1.6 – 4.5 ng/ml) and 48 ng/ml (range 19 –
66 ng/ml) for K1; for artemisinin the IC50 values are 1.9 ng/ml ( range 0.8 – 2.4 ng/ml) for NF54
and 0.8 ng/ml (range 0.4 – 1.5 ng/ml) for K1.

76. Plasmodium falciparum stages in Human body
Diagnostic Points

77. Literature referred Malaria web sites WHO websites MMV websites
Open access research articles

78. Speaker
Raj M Vaid Engg Chemistry Dept MIET KotBhalwal Jammu