Descriptive Study of Medicinal Plants Native to Saudi Arabia

Overview of Saudi Arabia's Geographical and Climatic Context

• Saudi Arabia (KSA) is characterized by a hot desert climate where rainfall is remarkably scarce across most regions.

• The Kingdom possesses high ecological and economic significance, covering approximately $1,969,000\,km^2$. This landmass accounts for two-thirds ($2/3$) of the Arabian subcontinent.

• Saudi Arabia is recognized for hosting diverse natural sites that exhibit significant biological productivity and diversity.

• The distributional behavior of medicinal plants within different countries, including KSA, shows variations attributed to several factors:

  • Changes in available water resources.

  • Climatic factors.

  • Edaphic variables (topographic changes).

  • Anthropogenic pressures (human-influenced impacts).

• The composition of vegetation in KSA is a reflection of its strategic geographical position situated between Africa, Asia, and Europe.

• The climate is broadly defined as arid. Ecologically, arid zones are characterized as:

  • Fragile.

  • Difficult to develop.

  • Difficult to use except in specifically limited areas.

• Vegetation in these arid areas is typically:

  • Sparse.

  • Highly specialized, utilizing both morphological and physiological adaptations.

• Consequently, the region serves as a natural reservoir for a wide variety of wild medicinal and aromatic plants.

Conservation and Floristic Statistics of Saudi Arabia

• Conservation Concerns: Many plant species are collected by local communities without regard for conservation needs. Plants are collected and sold in both local and international markets to support livelihoods in mountainous and arid environments.

• Total Recorded Species: There are $2172$ recorded species of flowering plants in the country.

• Regional Density: A significant number of these species are concentrated in the wetter areas of the south-western part of the country.

• Botanical Classification: These species represent $840$ genera and $149$ families.

• Potential Diversity: The count could potentially increase to $2250$ species when accounting for subspecies, extinct species, and species that remain unidentified.

• Distribution of Utility among Flowering Plants:

  • Approximately $450$ species ($18\%\text{}$) have a direct benefit to humans.

  • $45$ species ($1.8\%\text{}$) are classified as poisonous.

  • Approximately $334$ species ($13.4\%\text{}$) are utilized in folk medicine or possess known medicinal value.

  • $38$ species are recognized as important palatable fodder plants.

  • $6$ species are vital as fuel-wood.

  • $25$ species are used as human food plants.

  • $47$ species serve as ornamentals or for other miscellaneous purposes.

Selected Native Medicinal Plants and Their Traditional Uses

• Haloxylon salicornicum (Armas/Ar-ramth):

  • Description: A stout herb featuring green succulent branches found across all regions of Saudi Arabia.

  • Uses: Treatment of jaundice (yellowing of the skin), gall bladder stones, liver diseases, digestive problems, inflammatory disorders, and joint diseases.

• Juniperus procera (Arar):

  • Description: A long tree with needle-like leaves, primarily located in the Hejaz and southern regions of Saudi Arabia.

  • Uses: Historically used in Saudi traditional medicine for liver disease, jaundice, digestive problems, and inflammatory diseases.

• Peganum harmala (Harmal/Naqt):

  • Description: A glabrous shrub found mostly in the northern Hejaz and eastern Najd regions.

  • Uses: Traditional treatment for jaundice, digestive disorders, liver diseases, and arthritis.

• Pergularia daemia (Ghalqa):

  • Description: A climbing plant with thin glabrous leaves found in the Najd region.

  • Uses: The entire aerial part of the plant is used extensively to treat jaundice, liver diseases, and inflammatory disorders.

• Cassia italica (Senna/Senna Mecca):

  • Distribution: Grows on the Tihama (the southwestern coastal plain).

  • Uses: Known specifically for the laxative properties yielded by its leaves and pods.

• Heliotropium ramosissimum (Ram-ram):

  • Distribution: Found in eastern and central Saudi Arabia.

  • Uses: In the Eastern Province, it is a remedy for snake bites. In central Saudi Arabia, the plant is boiled in water to create a mouthwash for curing sore gums and mouth blisters.

• Acacia species:

  • A. raddiana (Talh): An important constituent of woody vegetation along Wadis in central Arabia. It produces large amounts of Arabic gum (Al-Samgh Al-'Arabi) and is used in cough and eye medications.

  • A. nilotica (Garat): The seeds are ground into a powder to dry out second-degree burns.

• Portulaca oleracea (Rizlah/Farfahena):

  • Description: An annual herb with branched stems found in the Hejaz and eastern parts of Saudi Arabia.

  • History/Uses: Use traces back to the era of the Pharaohs. It is used for liver disorders, gastrointestinal problems, and inflammatory conditions.

Principles of Medicinal Plant Taxonomy

• Classification criteria for medicinal plants vary based on the specific objectives, including:

  1. Usage.

  2. Active constituents.

  3. Period of life (longevity/cycle).

  4. Taxonomy.

• Arrangement by Active Ingredients: Plants are often arranged based on ingredients stored in specific organs: roots, leaves, flowers, seeds, and other parts.

Detailed Botanical Families and Phytopharmaceuticals

Apocynaceae (Dafliyah Family)

• Characteristics: Species are mostly lianas and herbs; fewer are shrubs, trees, or succulents.

• Examples: Calotropis procera, Pergularia tomentosa.

• Chemical Constituents:

  • Latex (rich in terpenes).

  • Alkaloids.

  • Cardenolides.

  • Cyanogenetic glycosides.

  • Saponins.

  • Tannins.

• Calotropis procera Uses:

  • Treating wounds.

  • Pain relief.

  • Scorpion stings.

  • Strengthening muscles.

Boraginaceae (Al-Hammahiyah Family)

• Characteristics: Includes trees, shrubs, and herbs.

• Examples: Echium angustifolium.

• Chemical Constituents:

  • Naphthaquinones.

  • Red alkanins (found in the roots).

  • Pyrrolizidine alkaloids.

  • Phenolic acids.

  • Tannins.

• Echium angustifolium Uses:

  • Hepatitis (liver inflammation).

  • Kidney issues.

  • Skin problems.

  • Healing wounds.

Brassicaceae/Cruciferae (Mustard or Cabbage Family)

• Characteristics: Known as the mustards or crucifers; most species are herbs, while shrubs and subshrubs are rare.

• Examples: Anastatica hierochuntica (Kaff Maryam).

• Chemical Constituents:

  • Mustard oil glycosides (along with enzymes for hydrolysis).

  • Cardiac glycosides.

  • Mucilage and fixed oils (usually found in seeds).

  • Important minerals.

  • Phenolics.

• Anastatica hierochuntica Uses:

  • Menstrual cramps.

  • Asthma.

  • Depression.

  • Headache.

  • Fatigue.

  • High blood pressure.

  • Infertility problems.

  • Easing childbirth.

Cucurbitaceae (Al-Qura'iyah Family)

• Characteristics: Most species are climbers or trailing herbs with tendrils; shrubs and trees are rare.

• Examples: Citrullus colocynthis (Al-Hanzal).

• Chemical Constituents:

  • Bitter glycosides.

  • High protein and oil content.

  • Secondary metabolite: cucurbitacin.

• Citrullus colocynthis Uses:

  • Leaves, seeds, roots, and dried leaves treat dog, insect, and snake bites.

  • Laxative.

  • Joint pain relief.

  • Hair color.

Euphorbiaceae (Al-Labniyah Family)

• Characteristics: Includes trees, shrubs, herbs, and succulents.

• Examples: Ricinus communis (Castor/Al-Khuru').

• Chemical Constituents:

  • Milky or colored latex.

  • Anthroquinones.

  • Triterpenoids.

  • Unsaturated fattyloid acids.

  • Anti-tumor agents.

  • Alkaloids.

• Ricinus communis Uses:

  • Bad breath (smoke from burnt dried leaves is inhaled).

  • Ulcers.

  • Toothache.

  • Inflamed eyes.

  • Relieving rheumatic pain.