Schisandra: Background. Actions

Common Name

Schisandra

Other Names

Chinese magnolia vine, gomishi, sheng-mai-san, wuweizi

Botanical Name / Family

Schisandra chinensis (family Schisandraceae)

Plant Part Used

Fruit

Chemical Components

Dibenzocyclooctene lignans (schisandrin, schisandrins A-C, schizabdrols, schisantherins and gomisin A), essential oil, malic, tartaric, nigranoic and citric acids, resins, pectin, vitamins A, C and E, niacin, beta-carotene, sterols, tannins and several minerals.

Historical Note

Schisandra has an extensive history of use in TCM. It has sour and warm qualities and is used to treat spleen and kidney ‘deficiency’, restore Qi and also as a treatment for chronic cough, wheezing, diabetes, insomnia and palpitations.

Schisandra: Main Actions

Studies have been conducted with schisandra and a number of its constituents in isolation, such as schisandrin B and gomisin A. Currently, most evidence is derived from in vitro and animal studies, as it has not been significantly investigated in clinical studies.

ANTIOXIDANT

In vitro tests have identified antioxidant activity. More specifically, seven lignans isolated from schisandra have demonstrated stronger antioxidant activity than vitamin E at the same concentrations, with schisanhenol exhibiting the strongest effects. An extract of schisandra and the isolated constituent schisandrin B have both demonstrated the ability to significantly decrease ALT and increase glutathione levels in CCL4 damaged liver in vivo. It appears that several constituents also have indirect antioxidant activity and can increase hepatic and myocardial glutathione levels.

HEPATOPROTECTIVE ACTIVITY

Decreases hepatotoxic damage

Several in vitro and in vivo studies have identified hepatoprotective effects with schisandra against carbon tetrachloride toxicity. Research with schisandrin B suggests it is the main constituent responsible for these beneficial effects. Further investigation reveals that schisandrin B increases the efficiency of the hepatic glutathione antioxidant system, thereby inhibiting carbon tetrachloride induced lipid peroxidation; however, additional mechanisms appear likely.

Protection against paracetamol-induced liver damage has been demonstrated in animal models using gomisin A. Gomisin A inhibited not only the elevation of serum aminotransferase activity and hepatic lipoperoxide content, but also the appearance of histological changes such as degeneration and necrosis of hepatocytes.

In 2003, protection against paracetamol-induced liver damage and d-galactosamine-induced liver damage was confirmed for a fractionated extract of 5. chinensis in an experimental model.

Liver regeneration

Two animal studies have demonstrated that oral administration of gomisin A, a lignan isolated from S. chinensis, accelerates liver regeneration after partial hepatectomy and hastens recovery of liver function. The mechanism for these effects is not fully elucidated; however, gomisin A increases ornithine decarboxylase activity, which is important during the early stages of regeneration and suppresses fibrosis proliferation.

Schisandra:  Other Actions

INHIBITS LEUKOTRIENE FORMATION

Gomisin A has been found to inhibit the biosynthesis of leukotrienes by preventing the release of arachidonic acid in vitro.

PLATELET-ACTIVATING-FACTOR ANTAGONIST

Several lignans inhibit platelet-activating-factor in vitro.

ANTI-INFLAMMATORY

Animal studies have identified anti-inflammatory activity for gomisin A, gomisin J, and wuweizi C isolated from S. chinensis. Several lignans from schisandra, including gomisin N and schisandrol A, have shown potent inhibition of nuclear factor of activated T cells (NFAT) in vitro. Excessive activation of NFAT has a significant role to play in autoimmune disease, but further study is needed to assess schisandra’s usefulness in immunopathological disease states.

CARDIOPROTECTIVE EFFECTS

Schisandrin B demonstrated protective effects against ischaemia-reperfusion-induced myocardial damage in a dose-dependent manner in an animal model. The myocardial protection was associated with an enhancement in myocardial glutathioneantioxidant status.

NEUROPROTECTIVE

Preliminary in vitro data suggests that certain lignans from schisandra are protective against l-glutamate induced neurotoxicity in rat cortical cells. Schisandrin B appears to also improve cognition and hepatic function in mice treated with tacrine, the common Alzheimer’s dementia medication.

CYTOCHROMES AND P-GLYCOPROTEIN

Conflicting in vivo data suggests that certain constituents from schisandra, in particular gomisin C, may inhibit CYP450 3A4 activity. Schisandrin B has demonstrated an inhibitory effect on P-glycoprotein in vitro. The clinical importance of this is as yet unknown.