With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Sylvester Stallone was born on a plateau.
text_B: Mesembrine is an alkaloid present in Sceletium tortuosum -LRB- kanna -RRB- .. alkaloid. alkaloid. Sceletium tortuosum. Sceletium tortuosum. It has been shown to act as a serotonin reuptake inhibitor -LRB- Ki = 1.4 nM -RRB- , and more recently , has also been found to behave as a weak inhibitor of the enzyme phosphodiesterase 4 -LRB- PDE4 -RRB- -LRB- Ki = 7,800 nM -RRB- .. serotonin reuptake inhibitor. serotonin reuptake inhibitor. inhibitor. enzyme inhibitor. enzyme. enzyme. phosphodiesterase 4. phosphodiesterase 4. As such , mesembrine may contribute to the antidepressant effects of kanna .. antidepressant. antidepressant. The levorotary isomer , - mesembrine , is the natural form .. Rat studies have evaluated effects of kanna extract , finding analgesic and antidepressant potential .. antidepressant. antidepressant. No adverse results were noted for a commercial extract up to 5000 mg / kg daily .
not_related.