Schisandra: Benefits, Dosage, Contraindications

Adaptogen

In Traditional Chinese Medicine, schisandra is considered an adaptogen and prescribed with other herbs to increase resistance to physical and emotional stressors and to improve allostasis. In animal research, schisandra reduces the increase in heart rate during exercise, leading to a decrease in fatigue and an improvement in performance, as well as enhanced endurance.The mechanisms of these effects are not yet known. PGC-1b1 appears to be a major regulator of mitochondrial biogenesis and a candidate for interacting with schisandra to promote more efficient physical exertion, but further studies on this subject are needed.

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Anti-inflammatory

In vitro, schisandrin inhibits the production of nitric oxide (NO), the release of prostaglandin E2, cyclooxygenase-2, and nuclear factor kappaB (NF-baB). In vitro and in vivo studies have identified anti-inflammatory activity for gomisin A, gomisin J, wuweizi C, schisandrin B, schisandrin C, gomisin N, and schisandrin derivatives. Several schisandra lignans, including gomisin N and schisandrone A, have shown potent inhibition of the nuclear factor of activated T-cells in vitro.

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Hepatoprotective

In vitro and in vivo studies have shown hepatoprotective effects with schisandra against carbon tetrachloride toxicity and mercuric chloride toxicity. Research on 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, inhibiting carbon tetrachloride-induced lipid peroxidation. However, additional mechanisms seem probable. More recently, the whole schisandra fruit extract has been shown to induce glutathione S-transferases in vitro. Moreover, several lignans have been found to induce phase II detoxification enzyme expression in vitro, a factor considered important in liver cancer prevention.

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Antioxidant

Seven lignans isolated from schisandra showed stronger antioxidant activity than vitamin E at similar concentrations. Schisanhenol appears to have the most significant effects. Schisandra berry essential oil has also demonstrated antioxidant activity.

Anticancer

In vitro, schisandra extracts and several isolated constituents have demonstrated anticancer activity against various cancer cell lines, including leukemia, breast cancer, liver cancer, stomach cancer, colon cancer, and lung cancer. The mechanisms of action are generally linked to apoptosis induction, protection of nucleic acids, and carcinogen excretion.

Antiallergic

Schisandra has shown various antiallergic effects, including inhibition of eosinophil recruitment in human pulmonary epithelial cells in vitro and reduction of atopic dermatitis severity in vivo. In vivo, schisandrin has shown significant antiasthmatic activity via inhibition of eosinophil accumulation in the airways, reduction of IL-4, IL-5, interferon-3b3, and TNF-3b1 levels in bronchoalveolar lavage fluid, reduction of oxidative stress, and inhibition of inflammatory cell infiltration in lung tissue.

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Antihistamine

Schisandra has shown various antiallergic effects, including inhibition of eosinophil recruitment in human pulmonary epithelial cells in vitro and reduction of atopic dermatitis severity in vivo. In vivo, schisandrin has shown significant antiasthmatic activity via inhibition of eosinophil accumulation in the airways, reduction of IL-4, IL-5, interferon-3b3, and TNF-3b1 levels in bronchoalveolar lavage fluid, reduction of oxidative stress, and inhibition of inflammatory cell infiltration in lung tissue.

Neurological

Schisandrin and schisandrin B inhibit lipopolysaccharide-induced microglial activation and significantly improve neuron cell death in vitro and in vivo via inhibition of the microglia-mediated neurotoxic inflammatory response. Microglial activation is involved in the pathophysiology of Alzheimer's and Parkinson's diseases. It has also been demonstrated that schisandrin B has a neuroprotective effect in a transient focal cerebral ischemia model in rats, and improves cerebral antioxidant status. In vivo, pretreatment with schisandrin B prevented scopolamine-induced oxidative stress (a parasympatholytic atropine-type that acts as a competitive antagonist of acetylcholine) and impairment of learning and memory. Schisandrin B appears to decrease acetylcholinesterase activity induced by scopolamine and thus maintain normal acetylcholine levels.

Hypoglycemic

In vitro studies indicate that schisandra possesses antidiabetic activity. Various lignans have been found to improve basal glucose uptake by liver cells, particularly gomisin N. Additionally, in vivo studies show that schisandra extracts reduce blood glucose, improve lipid metabolism, increase liver glycogen content, and reduce polydipsia in diabetic mice. Moreover, aqueous schisandra extracts have reduced postprandial blood glucose in rats via inhibition of alpha-glucosidase and alpha-amylase, enzymes responsible for monosaccharide absorption in the small intestine.