• Forskolin is obtained from the plant coleus.

• It is a member of the mint family.

• Chemically, forskolin is a labdane diterpene

• Coleus is grown in warm or subtropical temperate weather in Burma, India and Thailand.

• The plant is perennial in nature and the root is fleshy fibrous.

• In various states of India, it is used as a condiment.

• Synonym: Plectranthus barbatus

• Biological Source: Crude drug is the root of Coleus forskohlii

• Family: Labiatae.

• The marker constituent of the drug is forskolin (labdone diterpenoids).

• Other important phytoconstituents are deoxy forskolin, 1,9dideoxy forskolin, volatile oil (β elemene, humulene, β bisabolene).

• The drug is used as Ayurvedic medicine to treat heart and lung disease, intestinal spasms, insomnia, and convulsions also used as a hypotensive, cardiotonic and spasmolytic

The industrial production of forskolin involves the following steps:

1. Tubers of C. forskohlii are collected, washed, dried, and pulverised into granules.

2. The whole forskolin is extracted (utilising methanol as a solvent) in crude form by the traditional methods.

3. The obtained methanol extract is concentrated, and the resultant concentrate is added with chloroform.

4. An equal volume of water is added to the separating funnel.

5. The resulting mixture is shaken thoroughly, then allowed to settle, after which the chloroform layer is separated.

6. The mixture is treated with water 2 -3 times and the chloroform layer is separated and concentrated.

7. A precipitate of forskolin is obtained by using ice-cold n-hexane.

8. Forskolin is obtained as a reddish-brown to brown coloured powder.

Isolation of Forskolin

Method 1: •

Collect the tubers → washed and dried → pulverized into granules → extract the crude drug with methanol → concentrate the extract → add chloroform in concentrate and an equal volume of water → shake well → to allow the separate chloroform layer and concentrate the chloroform layer → Precipitate the forskolin by adding n-hexane (ice cold) into concentrate chloroform a reddish brown powder of forskolin will get.

Method 2 :

• Take root or tubers of the plant → dried to reduce the moisture 6% → charged the drug into extractor solvent → ethyl acetate or benzene poured into the extractor.

• Extract 2-3 hrs under 80°C temperature with 8-10 lbs/sq inch pressure and agitate for maximum extraction (60-70% in first extraction).

• Repeat 2-3 more washing with the same solvent.

• Distill off the solvent.

• A uniform consistency paste will be obtained.

• In this paste add pet ether 60-80°C (temperature 6-8o C with 2-3 times quantity of petroleum ether compare to paste) and agitate 200-250 rpm for half an hour.

• Filter the formed precipitate and wash it again with chilled petroleum ether and dry the precipitate.

• Concentrate the residual pet ether and chill at temperature 2-4o C for 10 hrs collect the precipitate and dry it.

• Combine both the precipitate which is forskolin

Estimation:

The drug is estimated with HPLC at a constant temperature 30°C using a photodiode detector 210 nm the retention time may be around 6.9 minutes.

The column was RP18 (150 x 4.6mm particle size 5µm) and methanol was used as a mobile phase.

TLC-Mobile Phase - benzene: methanol (9:1)

Stationary Phase: Silica gel 60F 254

Detection: UV Cabinet (long-range 365 nm)

Forskolin has the following uses:

• In Ayurvedic systems of medicine, C. forskohlii has been used in the treatment of heart diseases, abdominal colic, respiratory disorder s, insomnia, convulsions, asthma, bronchitis, intestinal disorders, burning sensation, constipation, epilepsy, and angina.

• Its roots are used to treat infections caused by worms and to relieve the burning sensation in festering boils.

• The root extract mixed with mustard oil is topically used in eczema and skin infections.

• Forskolin is added in the medicinal preparations used to prevent hair greying and to restore normal hair colour.

• It is also used to treat diseases in which reduced intracellular cAMP level is the main factor responsible for the development of the diseases like eczema, asthma, psoriasis, cardiovascular disorders, and hypertension.

• It is used as an immunomodulator as it activates macrophages and lymphocytes.