ANTIHYPERTENSIVES | Rauwolfia

                 ANTIHYPERTENSIVES

                       RAUWOLFIA 

Regional names -: Sarpagandah, Chootchand,

Source -: Rauwolfia consist of the dried roots and rhizomes of Rauwolfia serpentia

Family-:  Apocynaceae

Geographical occurrence-: The plant is a small shrub which grows in India, Pakistan, Burma, Thailand and Jawa.

Collection -: The plants are correctly identified before collection. The roots and rhizomes are dug from plants which are 2 to 4 years old. Some of the root is left in each plant for future growth. The roots are washed and dried in air.

Characters-:

Macroscopic

i)                   The external characters of roots and rhizomes are almost similar. But rhizomes contain small central pith and small pieces of aerial stem.

ii)                Rauwolfia occurs in small pieces (2 to I5 cm long and 0.3 to 2 cm thick). The pieces are cylindrical, tortuous, tapering and rarely branched.

iii)              The outer surface is greyish yellow to light brown and may contain scars of rootlets. The fracture is short. The fractured surface has a yellowish

iv)               Brown dark and a pale yellow wood. The wood occupies three fourths of the area.

v)                 Rauwolfia has no odour but the taste is bitter.

Microscopic--:

 A transverse section of rauwolfia root shows the following structures.

i)                   Cork -: The cork is stratified and contains 2 to 8 zones. Each zone contains layers of smaller, radially narrow lignified cells. They altemate with radially broad non lignified cells.

ii)                Phalloderm -: It is made of parenchymatous cells.

iii)              Phloem --: It is narrow and consists mainly parenchyma. It also contains

1.                 Sieve tubes

2.                 Companion cells

3.                 Starch grains

4.                 Prisms of calcium oxalate

5.                 Sclerenchyma is absent

Xylem --: It is wide and lignified. It contains-:

1.     Fibres

2.     Xylem parenchyma

3.     Many small vessels

4.     Medullary rays.

Medullary rays --: They radiate from the center to cortex. They are lignified in the xylem region and non-lignified in the phloem region Starch and oxalate prisms are also present in the medullary ray cells.

Constituents--:

    Mainly alkaloids. The rauwolfia alkaloids can be classified as-:

i)       Indole alkaloids (strongly basic)-: Reserpine, Rescinnamine and Deserpedine.

ii)    Indoline alkaloids (intermediately basic)-: Ajamaline, Ajamalicine.

iii)  Anhydronium alkaloids (strongly basic)-: Serpentia, Serpentinine and Alstonine.

Uses-:

                                                             i.      Reserpine is used as an antihypertensive and tranquilising agent.

                                                           ii.      Ajamaline is used in angina pectoris and cardiac arrhythmias.