Ce Bai Ye

Pinusolide, a labdane diterpene isolated from the leaves of Biota orientalis (Platycladus orientalis), inhibited platelet-activating-factor-induced aggregation of rabbit platelets with an IC50 of about 5 micromolar, while having no inhibitory effect on aggregation induced by ADP, thrombin or collagen. It also dose-dependently inhibited PAF-induced hypotension in rats, without affecting hypotension induced by acetylcholine, histamine or serotonin. This establishes both that the leaf contains a genuinely potent PAF antagonist and that its antiplatelet action is confined to that one pathway. Note the study is on LEAF, not on the seed.

Pinusolidic acid, obtained from the chloroform extract of Platycladus orientalis, inhibited PAF-induced aggregation of rabbit platelets with an IC50 of about 2.3 x 10-5 M, roughly five-fold weaker than pinusolide from the same source. Confirms that the PAF-antagonist activity of the leaf rests on a series of related labdane diterpenes rather than a single compound.

Nine traditional Chinese medicines extracted with 75% ethanol or water were screened against 5-alpha-reductase from rat epididymis, and Platycladus orientalis leaves were then taken forward for in vivo evaluation in testosterone-treated mice. Hair regrowth was scored daily and hair follicle morphogenesis assessed on longitudinal and transverse sections, alongside effects on androgen metabolism and 5-alpha-reductase type II expression in follicles. Supports the classical use of the leaf for hair, with an antiandrogenic mechanism. Animal model of androgen-driven hair loss; no human outcome data in this paper.

A gradient extract of Cacumen Platycladi made with 1,3-butanediol, ethanol and water and enriched in quercitrin, myricetin and myricitrin was characterised by LC-MS, then tested mechanistically and clinically. In vitro the extract inhibited 5-alpha-reductase, raised antioxidant capacity in human dermal papilla cells, and upregulated PI3K/Akt/mTOR signalling with increased VEGF and collagen type XVII expression. A 12-week clinical trial found the extract significantly reduced hair loss and increased local hair density compared with placebo, with no adverse effects reported. This is the only human controlled evidence for the leaf; it is a topical cosmetic extract, not the oral decoction, and the trial is small and industry-adjacent.

A water extract of Cacumen Platycladi, closest of the tested preparations to a traditional decoction, promoted hair growth through Akt/GSK3-beta/beta-catenin signalling. Complements the 5-alpha-reductase and PI3K/Akt/mTOR mechanisms reported elsewhere and shows that the aqueous fraction, not only alcoholic or butanediol extracts, carries activity. A corrigendum was published in 2023; the paper is not retracted.

The chloroform fraction of Platycladus orientalis leaves and pure compounds from it were tested against pro-inflammatory enzymes and against TNF-alpha and nitric oxide production in LPS-stimulated RAW 264.7 macrophages, with arachidonic acid metabolites measured by HPLC after calcium ionophore A23187 stimulation. For the first time in intact cells, the chloroform fraction, hinokiol and acacetin significantly inhibited formation of 5-HETE and leukotriene B4, with supporting cell-free assays on 5-lipoxygenase, leukotriene A4 hydrolase and cyclooxygenase. Gives a lipoxygenase-pathway basis for the traditional use of the leaf in cough, excess mucus, chronic bronchitis, bronchiectasis and asthma.

Platycladus orientalis leaf extract stimulated proliferation of cultured human dermal papilla cells, with the highest viability from extract batches richer in quercitrin. It reduced the senescence markers p16 (CDKN2A) and p21 (CDKN1A), activated FGFR1, VEGFR2/3 and the non-receptor tyrosine kinases ACK1 and HCK, raised the Wnt/beta-catenin transcription factor LEF1 while downregulating the inhibitor DKK1, and increased bFGF, KGF and VEGF expression. Cell-based work that identifies quercitrin content as a practical potency determinant for the leaf.

Twenty-seven batches of Platycladi Cacumen from different regions were fingerprinted by UPLC with diode array detection, yielding 20 common peaks, of which seven flavonoids (myricitrin, isoquercitrin, quercitrin, afzelin, cupressuflavone, amentoflavone and hinokiflavone) were identified and quantified simultaneously. Regressions were good (R at least 0.9995) with recoveries of 96.4-103.3%. Hierarchical clustering split the batches into five groups that corresponded closely to geographic position and climate, which is the practical basis for expecting real potency differences between sourcing regions.

UPLC-Q-TOF-MS/MS with diagnostic ion filtering identified 43 compounds in Platycladi Cacumen, including organic acids and derivatives, flavonoids and phenylpropanoids, with coumarin and lignan reported in the drug for the first time. Nine major flavonoids were then quantified across 39 raw batches from different origins and 10 batches of the PROCESSED product, showing that flavonoid content differs greatly between samples. This is the evidence base for treating raw and charred Ce Bai Ye as chemically distinct articles.