Analysis Of The Main Chemical Components Of Peony Pollen And Evaluation Of Its Efficacy On Benign Prostatic Hyperplasia

Benign prostatic hyperplasia（BPH）is a common urological disorder in middle-aged and older men.Men tend to start developing BPH at the age of 40,and the incidence gradually increases with age,especially during the accelerated aging of the population,and the number of BPH is predicted to continue to grow in the future.At present,the clinical drugs used for the treatment of BPH are characterized by clear target and single efficacy;however,they are also accompanied by serious side effects,such as impotence,decreased libido and retrograde ejaculation.Therefore,it is especially important to find drugs with high efficiency and low toxicity for BPH from traditional Chinese medicine.As the national flower of China,peony not only has ornamental value,but also has high medicinal value.The root bark of peony,"Danpi",is a common Chinese medicine in Chinese medicine.In recent years,peony seeds and petals have also been developed and applied to food and medicine,while peony pollen has rarely been studied.China has planted more than 15,000 mu of peony,and there are many resources of peony pollen,but few of them are actually exploited,and a large amount of resources are abandoned.In this paper,the compounds in peony pollen were initially extracted,separated,purified and analyzed,and the inhibitory effect of peony pollen on BPH was evaluated using a testosterone-induced prostate hyperplasia rat model,aiming to provide theoretical and data support for the development and utilization of peony pollen.1.The three compounds with high content in peony pollen were extracted and isolated,and structurally characterized.The separation,purification and structural characterization of the three compounds with high contents in peony pollen were carried out by preparative high performance liquid chromatography,LC-MS and NMR.The results showed that the molecular weight of compound 1 was 670 and the UV maximum absorption wavelength was 357 nm.Based on the comparative analysis of ¹H-NMR and ¹³C-NMR data,compound 1 was identified as limocitrin-3-O-sophoroside.The molecular weight of compound 2 was 599,the UV maximum absorption wavelength was 297 nm,and the¹³C-NMR analysis showed that its NMR C signal appeared in groups,which was presumed to be an enantiomeric isomer with unknown structure,and was tentatively named as MTP-1.The molecular weight of compound 3 was 583,the UV maximum absorption wavelength was 295 nm,and the NMR analysis showed that its NMR C signal also appeared in groups.It is assumed that this compound may also be an enantiomer with unknown structure,and is tentatively named as MTP-2.2.Peony pollen contained 11 major chemical components.The main chemical components contained in peony pollen were detected and quantitatively analyzed by high performance liquid chromatography.The results showed that the 11 compounds and their contents in peony pollen were:namely,apigenin-7-O-β-D-glucoside（0.366mg/g）,gallic acid（0.656mg/g）,oxypaeoniflorin（4.051mg/g）,paeoniflorin（5.962mg/g）,Rhoifolin（0.28mg/g）,1,2,3,4,6-pentagalloylglucose（0.795mg/g）,Cynaroside（0.369mg/g）,rutin（0.53mg/g）,limocitrin-3-O-sophoroside（18.987mg/g）,MTP-1（9.347mg/g）,MTP-2（35.588mg/g）.3.Peony pollen was found to have a significant inhibitory effect on testosterone-induced prostatic hyperplasia rats.Testosterone-induced prostatic hyperplasia model caused by castrated rats was induced with low（0.5g/kg）,medium（1g/kg）and high（2g/kg）doses of peony pollen,with qianliekang（QLK）and baoliezhi（BLZ）as positive drugs,and each group was administered continuously by gavage for 4 weeks.The results showed that the prostate index and prostate volume of the rats in the model group were significantly higher than those of the normal control group;as seen from the pathological sections of the prostate,there was a significant thickening of the prostate epithelium in the model group,and the epithelial cells were arranged in multiple layers with a rough surface.The prostate volume,prostate index and prostate epithelial thickness were significantly reduced in the high,medium and low dose groups of peony pollen compared with the model group;among them,the pathological improvement was most obvious in the high dose group of peony pollen,and the prostate epithelium almost returned to the normal state;both high and medium doses of peony pollen significantly reduced the serum levels of sex hormones in rats.4.The mechanism of action of peony pollen to inhibit prostate hyperplasia may be related to its inhibition of PI3K/AKT signaling pathway.The protein expressions of AR,PCNA,p-PI3K,PI3K,p-AKT and AKT in rat prostate were determined using Western blotting.The results showed that the protein expression of AR and PCNA in the prostate of rats with BPH induced with androgens was significantly higher than that of rats in the normal group;the protein expression levels of AR and PCNA in the prostate were reduced in the high,medium and low dose peony pollen groups,and after treatment with QLK and BLZ.In addition,the p-PI3K/PI3K and p-AKT/AKT ratios were significantly reduced in both the medium and high dose groups of peony pollen.It indicates that peony pollen can significantly inhibit the activated PI3K/AKT signaling pathway.5.MTP-2 and pentagalloylglucose in peony pollen may be the main active components for BPH inhibition.Two cell lines,WPMY-1 and RWPE-1,were used to evaluate the activity of 11 compounds in pollen.The MTP-2 compound was confirmed to have the strongest inhibitory activity on the viability of WPMY-1 cells;while the pentagalloylglucose compound inhibited the viability of RWPE-1 cells most strongly;their IC₅₀values were1.955μg/m L and 3.554μg/m L,respectively.2μg/m L of MTP-2 significantly inhibited the proliferation of WPMY-1 cells induced by testosterone propionate MTP-2 at 2μg/m L significantly inhibited the proliferation of WPMY-1 cells induced by testosterone propionate;the viability of WPMY-1 cells induced by testosterone propionate was largely restored to normal using a low dose of 0.5μg/m L MTP-2.Conclusion:The chemical composition of peony pollen is complex,and only 11 of them have been clarified so far;peony pollen has a significant inhibitory effect on testosterone-induced prostate hyperplasia in rats,and the mechanism may be related to the reduction of hormone levels and inhibition of PI3K/AKT signaling pathway in vivo.