Seminar of Physics of the Living State
(The Applied Physics Scientific Section)
2010 Academic Year
Tuesday, 16 November 2010
Time: 15.30
Oppenheimer Meeting Room, Second Floor, Leonardo Building
IS LIPID TRAFFICKING BY TRANSFER OR MEMBRANE FUSION?
A case study of cholesterol (*)
Jonathan O. Babalola (**)
Department of Chemistry, University of Ibadan, Ibadan, Nigeria
(*) Summary.
Sickle Cell Disease (SCD) is one of the most neglected diseases of the
21st century with an important death rate in children living in the
third world especially in Africa. Like malaria, SCD is also a major
public health problem and is the first genetic disease by the number of
affected people in tropical Africa regions. Clinical symptoms of SCD
are associated to the polymerization of unstable haemoglobin S under
anoxic conditions. These symptoms include erythrocytes shape and
membrane modification, as well as anaemia.
Some
agents were developed by rational drug design to inhibit the red blood
cells sickling process. Most of these agents, unfortunately, did not
show promising success in terms of clinical use. Conventional
treatments are expensive and unaffordable by the rural populations.
These
last few years, use of medicinal plants is explored as a therapeutic
approach that can relieve this disease. Indeed, the use of medicinal
plants seems to be simple, inexpensive and appropriate strategy for
disease control in developing countries.
The progress made during these last few years in biochemistry and
cellular biology of SCD has indicated that three main targets are of
particular importance for chemotherapy. These include haemoglobin S
polymerization and stability erythrocyte membrane.
So
same tests such as Emmel test, Itano test and membrane osmotic
fragility test are used to evaluate in vitro the effect medicinal
plants extracts on erythrocyte shape modification, Haemoglobin S
aggregation in low O2 pressure conditions and membrane stability. The
first plant that showed an antisickling activity was Fagara
Zanthoxyloides. Some other plants extracts have showed antisickling
activity.
The
ethnobotanical investigations carried out during the last few years by
our research team have revealed that 53 medicinal plant species
belonging to 30 different families are used by Congolese Traditional
Healers for the treatment of SCD in the DRCONGO. A preliminary
screening for the in vitro antisickling activity using Emmel test has
indicated that the polar extracts of 50 of 53 plants studied possess a
significant sickling suppressive rate in hypoxic conditions. Bio-guided
extraction has indicated that anthocyanins extracts would be among the
secondary metabolites responsible of the antisickling activity.
One
of these plants Vigna unguiculata (known as Cowpea or Black-eye Pea) is
now been experimented as medicinal food in sickle cell disease.
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(**) Biodata:
Dr Jonathan Oyebamiji BABALOLA obtained his B.Sc from Obafemi Awolowo
University, Ile-Ife, Nigeria in 1989. He later proceeded to University
of Ibadan, Nigeria where he obtained his Ph.D. in 1999. He had a stint
of lecturing at Ladoke Akintola University of Technology Ogbomoso
before he was employed in University of Ibadan into the Physical
Chemistry Unit of the Department of Chemistry in 1997.
Dr
Babalola is the present Head of the Physical Chemistry Unit and the
same time the Sub-Dean (Sciences) of the Postgraduate School,
University of Ibadan. His research has been majorly on the
structure-function relationship of hemoglobin and recently on lipid
transfer and biosorption. Dr Babalola has published widely in reputable
national and international journals. He is one of the Pilot Associates
of the Organisation for the Prohibition of Chemical Weapon, The Hague,
The Netherlands; an associate of the Academy of Sciences for the
Developing Countries (TWAS); a Regular Associate of ICTP, a TRIL, DAAD
and Humboldt Fellow.
