Towards an Integrated Research Policy in the Area of Drug Discovery in the

Arab Countries

Including mechanisms to better utilization of their terrestrial and marine wealth.

Bassem El-Menshawi

NEPAD Sci & Technol Regional Coordinator for Northern Africa,

National Research Centre, Cairo, Egypt

DRUG DISCOVERY

TYPES OF RESEARCH LABORATORIES NEEDED:

This depends on the therapeutic class

required

DRUGS TO BE DISCOVEREDFOR EXAMPLE: IF PRIORITY GIVEN TO:

-ANTITUMORS,

-ANTICARCINOGENIC,

-IMMUNOMODULATORY,

-ANTIVIRAL AGENTS

A CELL CULTURE LAB IS NEEDED

THE STATE OF THE ART OF DRUG DISCOVERY:

• THE USE OF IN VITRO BIOASSAYS

• THE USE OF CELL LINES

(e.g. HUMAN TUMOR CELL LINES)

ADVANTAGES AND DISADVANTAGES In-Vitro Bioassays-Rapid, less selective, but diagnostic, less expensive, -suitable for minute amounts of materials, -suitable for screening large number of samples in Drug Discovery programs. In-Vivo Bioassays More selective, expensive, mostly Time Consuming,Animal model, require large amounts of material,hardly could guide the fractionation of extracts or mixture of compounds.

TYPES OF RESOURCES TO BE UTILIZED:

Natural Resources Line : - Plants - Microbes (bacteria, fungi) - Marine Organisms

Synthetic Line: - Novel Chemical Entities - Generics

THE BASIC CHEMICAL LABS:

LAB FOR NATURAL PRODUCTS(Isolation of Natural Compounds)

LAB FOR SYNTHESIS

(Rational Pharmacological, &

Computer Aided Drug Design)

IN ADDITION TO

- ANTI-VIRAL TESTING LAB

- PHARMACOLOGICAL PROFILE &

TOXICOLOGY LAB

FOR BIOTECHNOLOGICAL PRODUCTS

A BIOTECH / MOLECULAR BIOLOGY

FOR DISCOVERY OF ANTIBIOTICS:

A MICROBIOLOGY / FERMENTATION LAB

FOR ANTI-SCHISTOSOMIASIS:

PARASITOLOGY LAB

THERAPEUTIC NATURAL PRODUCTS

- ACTIVE COMPOUNDS

- ACTIVE EXTRACTS

- COMBINED ACTIVE EXTRACTS

METHODS OF DRUG DISCOVERY FROM NATURAL PRODUCTS

How the Active Principle be identified ? -Phytochemical Approach -Bio-Activity Approach -High Throughput Screening -Computer Aided HPLC/MS

EXISTING PROJECT MODEL:AT THE NATIONAL RESEARCH CENTRE, EGYPT

A SEARCH FOR

SCHISTOSOOMICIDAL, ANTITUMOR, ANTICARCINOGENIC,

IMMUNOMODULATORY,

AND ANTIVIRAL AGENTS

IN EGYPTIAN PLANTS

• This is a drug discovery program conducted at NRC

• based on Egyptian plants,

• utilizes universally accepted protocols

for bioabioactivitctivity-guided fractionationy-guided fractionation

of plant extracts,

• and in-Vitro Bioassays.

Under this project Egyptian plants

are Bio-assayed for specific

medicinal activities:

1. Schistosomicidal

2. Antitumor

3. Cancer chemopreventive

[anticarcinogenic]

4. Immunomodulating

5. Antiviral

BIOACTIVITY APPROACH:

-Extracts are screened for a specific medicinal activity (an in-vitro bioassay).

-Only BioActive extracts are fractionated.

-Active fractions are further fractionated

to isolate the active compound(s) in pure form.

-Characterization of its structure.

• Only Bio-Active Extracts are subjected to

Bioassay-Guided Fractionation, in 2

steps:

1. Initial Partitioning

2. Comprehensive Fractionation

for the isolation of their active

principles.

EX-VIVO BIOASSAY

• In-Vivo / In-Vitro

• Used for assaying the activity of compounds isolated in limited amounts,

• untill additional materials could be obtained sufficient for in-vivo bioassy.

• It detects the effect of in-vivo absorption and metabolism on compounds that are active in-vitro.

Active compounds isolated are then bioassayed in animal models

to confirm the bioactivity

and determine their therapeutic value and toxicity profiles.

The overall accomplishments After 3 years of the project’s life are as follows:

1. Plant Collection

1625 plant samples collected(Corresponding to 958 species:534 wild, and 424 cultivatedspecies).

2. Preparation of Plant Extracts

1787 13501149

plant organs dried andpowderedalcoholic extracts preparedwater extracts prepared

3. In-Vitro Bioassays

3.A. Schistosomicidal bioassay

17961196 600

extracts bioassayedalcoholicaqueous

3.B. Antitumor bioassay:

(i) Brine Shrimp Bioassay

21181268 850

extracts bioassayedalcoholicaqueous

(ii) Ehrlich Ascites Carcinoma

1447 951 496

extracts bioassayedalcoholicaqueous

3.C. Anti-carcinogenic activity

Micronucleus bioassay Antioxidant prescreen

10

200

Extracts bioassayed Extracts bioassayed

3.D. Immunomodulatory activity Murine Lymphoprol- Iferative

153

Extracts bioassayed

3.E. Antiviral Activity

Foot & Mouth Disease virus

259 Extracts bioassayed

Hepatitis-A virus 80 Extracts bioassayed

Herpes Simplex 372 Extracts bioassayed

342

176

24 44

14

3 1

55

25

Extracts have been classified as “Promising Bioactive” in all the bioassayys. Are as follows:

lcoholic extracts possessed 100% activity at 100ppm as Schistosomicidals. alcoholic extract possessed 100% at 50ppm (Brine Shrimp). extracts gave 75% at 100 ppm as Antitumor (Ehrlich). Anticarcinogenic. Micronucleus: Activity is under investigation extracts with 90% activity (% of inhibitory activity of radicle production) at 25 μg / ml as Antioxidant. extracts showed activity as Immunosuppressant. extract showed acivity as immunostimulant

alcoholic extracts with activity higher than 80% at 30 and 40μg /ml (43 contain tannins, and 12 without tannins) as

water extracts with activity higher than 80% at 40 μg /ml as Antivirals.

4. Initial Fractionation

157

30 27 20

80

50

22 14

5

9

“Most Active” plant extracts in the bioassays were selected for fractionation and

confirmatory testing. active in schistosomicidal bioassay active in the Brine Shrimp lethality bioassay active in the Ehrlich ascites carcinoma bioassay active in the antiviral bioassay (44 of them are of 2nd priority due to their tannin contents) Results: Out of the above 157 extracts were fractionated and bioassayed: active in the Schistosomicidal bioassay active in the Brine Shrimp Lethality bioassay active in the Ehrlich ascites carcinoma bioassay active in the antiviral activity against HSV type I

5. Bioactivity–Guided Fractionation

5 Extracts of the above weresubjected to comprehensivefractionation (completed)

6. Structuredetermination

533

Compounds were isolatedof them were identifiedother compounds are inisolation steps.

7. Bioassay In-Vivo 7 4

Extracts Fractions were tested in ex-vivo bioassay, prior to testing them in-vivo

8. Toxicity in Animals

25 Extracts were studied for their toxicity in animals.

Patenting and Discoveries : Bioactive Compounds Under Patenting

Bioactive Extracts/Fractions under Patenting

4 Antitimors, and 1 schistosomicidal

157 In three bioactivities (Schistosomicides,

Antitumors, and antivirals.

Conclusions

-Screening Large Number of Natural Species

-Using In Vitro Bioassays

-For 5-10 Medicinal Activities

•Conclusions:

-Integrates Arab Natural wealth

-Optimizes Arab IPR

-Enhance the Invention in a

Strategic Area

Conclusions

- 1-3 Central Joint Research Lab (under one strategy, one mechanism, one protocol, and one leader).- Nodes in each country- Joint Surveying of Biodiversity-Joint Ownership of Products- Networking

Conclusions

- Arab Meeting for Strategic Planning of Drug Discovery

- Role of Bibliotheca Alexandrina

ALL THE PRAISES AND

THANKS BE TO

ALLAH

RESEARC TEAM

Prof. Dr. Bassem El-Menshawi NRC Principal Investigator

Prof. Dr. Fouad Youssif TBRI

Prof. Dr. Abdel-Monem Osman NCI/Cairo Univ.

Prof. Dr. Laila Emara NRC

Assoc. Prof. Dr. Mohamed Aly NRC

Prof. Dr. Karima Mahrous NRC

•

• THIS PROJECT IS FUNDED BY THE ACADEMY OF SCIENTIFIC RESEARCH AND TECHNOLOGY, CAIRO, EGYPT, UNDER THE

PROGRAM OF BIOTECHNOLOGY 1998.