Saikosaponins

Bupleurum falcatum L. China Triterpenoid saponins, sapogenins, saikosaponins.21,22,33-510 Relieves tightness, antipyretic, inflammation of inner organs. 

Saikosaponins A, Bl-4, G, D E (triterpene saponin) Bupleurum spp. (Apiaceae) [root] Na+, K+-ATPase... 

From the roots of B. rigidum five new saponins have been isolated and identihed, of which three were saikosaponins, two related to saikogenin F and one to saikogenin D. One of them was also foimd in the aerial parts. Two saponins were related to oleanolic acid. Trivial names of sandrosaponins VII-X wrae given to them. 

From different species of this genus triterpenoid saponins have been isolated, together with other compounds such as lignans, coumarins, flavonoids and polyacetylenes. The saikosaponins from Bupleurum L. are considered as the major bioactive components mainly used for their antiinflammatory and antihepatotoxic actmties. 

The extraction and isolation steps of saikosaponins from aerial parts of B. rigidum are shown in Scheme 1. 

Scheme 1 Extraction and isolation of saikosaponins from B. rigidum... 

The isolated triterpenoid saponins were found to be either of the saikosaponin type or the oleanolic acid type. Ten triterpenoid saponins were monodesmosidic, with a sugar chain at the C-3 position of the aglycone. A bidesmosidic saponin (sandrosaponin IX) showed sugar chains at C-3 (ether linkage) and also at C-28 (ester linkage). 

Sandrosaponin I (1), the major saikosaponin isolated from the aerial parts of B. rigidum, contained a saikogenin F moiety, first described by Kubata... 

With identical sulfated trisaccharide but possessing oxidised derivatives of saikogenin D [26,27], saikosaponins 6 and 8 appeared in minor amounts in the aerial and roots fractions, respectively. 

Some species from Bupleurum genus are often used in combination with other plants as antihepatotoxic, antipyretic, analgesic, sedative and antidepresive agents. Saikosaponins extracted from B. falcatum are reported to have another variety of therapeutic activities such as alleviating hyperlipidemia, hepatic injury and chronic hepatitis as well as cardiac activities. 

Recently, we have reported the in vivo and in vitro anti-inflammatory activity of two saikosaponins isolated from B. rigidum, budlejasaponin IV and sandrosaponin I, in order to establish the possible real value of these kinds of compounds as anti-inflammatory agents [44]. We showed that saikosaponins inhibited the mouse ear edema induced by topical administration of phorbol myristate acetate (PMA). Saikosaponins, at a dose of 1 mg/ear, significantly inhibited swelling and were as potent as the reference drug indomethacin at 3 mg/ear. These findings were supported by vascular permeability analysis [Table 10 and Fig. (4)]. 

Inhibition of PGE,-Release Irom Mouse Peritoneal Macrophages Stimulated with Calcium lonophore A231S7 by Saikosaponins... 

We also investigated the action of saikosaponins on TXBa release induced by calcium ionophore in human platelets. All compounds assayed presented a dose-related response to TXB2 release, with inhibition percentages slightly lower than the reference drug ibuprofen [Table 13 andFig.(7)]. 

Inhlbttlon otTXBrRsloase from Human Pialeleis SlimuMed with Calcium Ionophore A23187 by Saikosaponins... 

Sandrosaponin I was the most active, with an inhibition percentage of around 90% at the highest dose. Without excluding the participation of other possible mechanisms, including non-eicosanoid mediators, our data support the inhibition of arachidonic acid (AA) metabolism as one of the biochemical mechanisms which may contribute to the anti-inflammatory activity of these saikosaponins. 

Additionally, saikosaponin D isolated from the roots of B. falcatum exhibited a potent anti-cell adhesive activity and a strong hemolytic action [53, 54]. It is suggested that the mechanism for anti-cell adhesive activity of this compound may resemble the mechanisms for its hemolytic action [ 55]. Saikosaponin D has been shown to inhibit the cell growth and DNA synthesis of several human cell lines, including human hepatoma cells [56]... 

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