Three stilbenes from pigeon pea with promising anti-methicillin-resistant Staphylococcus aureus biofilm formation activity.

Cajaninstilbene acid (CSA), longistylin A (LLA), and longistylin C (LLC) are three characteristic stilbenes isolated from pigeon pea. The objective of this study was to evaluate the antibacterial activity of these stilbenes against Staphylococcus aureus and even methicillin-resistant Staphylococcus aureus (MRSA) and test the possibility of inhibiting biofilm formation. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of these stilbenes were evaluated. And the results showed that LLA was most effective against tested strains with MIC and MBC values of 1.56 µg/mL followed by LLC with MIC and MBC values of 3.12 µg/mL and 6.25 µg/mL as well as CSA with MIC and MBC values of 6.25 µg/mL and 6.25-12.5 µg/mL. Through growth curve and cytotoxicity analysis, the concentrations of these stilbenes were determined to be set at their respective 1/4 MIC in the follow-up research. In an anti-biofilm formation assay, these stilbenes were found to be effectively inhibited bacterial proliferation, biofilm formation, and key gene expressions related to the adhesion and virulence of MRSA. It is the first time that the anti-S. aureus and MRSA activities of the three stilbenes have been systematically reported. Conclusively, these findings provide insight into the anti-MRSA mechanism of stilbenes from pigeon pea, indicating these compounds may be used as antimicrobial agents or additives for food with health functions, and contribute to the development as well as application of pigeon pea in food science.

Four new eudesmane-type and one new eremophilane-type sesquiterpenes from the whole plant of Carpesium abrotanoides L.

The extract of the whole plant of Carpesium abrotanoides L. yielded five new sesquiterpenes including four eudesmanes (1-4) and one eremophilane (5). The new compounds were characterized by spectroscopic analysis especially 1D and 2D NMR spectroscopy and HRESIMS data. Structurally, both compounds 1 and 2 were sesquiterpene epoxides and 2 owned an epoxy group at C-4/C-15 position to form a spiro skeleton. Compounds 4 and 5 were two sesquiterpenes without lactones and 5 possessed a carboxy group in the molecule. Additionally, all the isolated compounds were preliminarily evaluated for the inhibitory activity against SARS-CoV-2 main protease. As a result, compound 2 showed moderate activity with an IC50 value of 18.79 µM, while other compounds were devoid of noticeable activity (IC50 > 50 µM).

Factors associated with patient delay for older adults with benign prostatic hyperplasia: A descriptive qualitative study.

Based on the theory of planned behavior, the aim of this study was to describe the influencing factors of patient delay intentions and behaviors in benign prostatic hyperplasia (BPH) patients and to provide a reference for the development of a patient delay intention scale. This study was carried out over 4 months in 2021 in Daqing, Heilongjiang, China. The participants were 20 patients with BPH who were aged 60 to 82 years and experienced patient delay; participants were selected through a purposive sampling method. The data were collected via face-to-face semistructured interviews. Five main themes emerged from the interviews, including an insufficient understanding of symptoms, experiences of coping instead of seeking health care, negative attitudes toward care-seeking, the influence of others on decision-making for care-seeking, and obstacles to seeking health care. In conclusion, the patient delay intentions and behaviors of BPH patients are the result of a combination of many factors.

Evaluation of toxicity studies of flavonoid fraction of Lithocarpus polystachyus Rehd in rodents.

The aim of the study was to evaluate the safety of flavonoid fraction of Lithocarpus polystachyus Rehd (Sweet Tea-F, ST-F) in mice and rats through acute and sub-chronic toxicity studies respectively. For acute toxicity study, a single dose of 5000 mg/kg of ST-F was given orally to healthy KM mice. The mice were observed mortality and toxic symptoms for 24 h, then once a day up to 14 days. In the sub-chronic toxicity study, ST-F was administered orally at doses of 0, 70, 140, 560 mg/kg/day to rats for 26 weeks. Body weight and food intake were recorded weekly. Hematological, biochemical, coagulation and organ parameters were analyzed at the end of 26 weeks administration. Vital organs were evaluated by histopathology. In the acute toxicity study, ST-F caused neither significant toxic symptoms, nor mortality in mice. In sub-chronic toxicity study, daily oral administration of ST-F at the dose of 70 mg/kg resulted in a significant increase (P < 0.05) in the relative body weight at the 10-week, and the same situation brought at the dose of 140 mg/kg/day at the 22-week. Hematological and biochemical showed significant changes (P < 0.01 or P < 0.05) in WBC, GLU, ALP, AST and serum electrolytes levels at the dose of 560 mg/kg/day. The amount of RBC decreased significantly (P < 0.05) while the content of PLT slightly increased (P < 0.05) at the dose of 140 mg/kg/day. In additional, no obvious histological changes were observed in vital organs of ST-F treated animals compared to control group. The ST-F may be exit slight side effects at the dose of 560 mg/kg/day in rats. Thus, the overall results show that the no-observed adverse effect level (NOAEL) of ST-F was considered to be 140 mg/kg for male SD rats.

[New processing procedure for Croton tiglium with study on comparison of Croton tiglium and processed product].

OBJECTIVE: To build a new processing procedure for Croton tiglium, providing a more simple, efficient and safe way of processing. METHODS: Used the contents of isoguanosine and toxic protein in Croton tiglium as the indexes to investigate the effect of different temperature, thickness and baked time on processing for Croton tiglium. After established all factors and levels, processed a batch of Croton tiglium under optimum processing conditions and compared it with raw Croton tiglium in the test of acute toxicity and gastrointestinal propulsive motility. RESULTS: The parameters of optimum processing were as follows:the temperature was set at 180 degrees C, the thickness of placement was 3 cm and baked time was 90 min. The LD50 value of raw Croton tiglium and the processed Croton tiglium was 888 mg/kg and 2139 mg/kg respectively. CONCLUSION: The processing procedure is simple, affordable, safe and efficient, deserved to promote for application.

Effect of the flavonoid fraction of Lithocarpus polystachyus Rehd. on spontaneously hypertensive and normotensive rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Lilhocarpus polystachys Rehd. (Sweet Tea, ST) is a folk herbal medicine that has been traditionally used as a natural remedy for hypertension in China, whose mechanism remains unveiled. Flavonoid fraction is considered as the major active components in ST. This study aimed to provide experimental evidence for the anti-hypertension activity of flavonoid fraction of ST (ST-F) and investigate the underlying mechanism. The effect of ST-F on the blood pressure of normotensive rats was also to be determined. MATERIALS AND METHODS: Spontaneously hypertensive rats (SHRs) were treated with ST-F daily for 10 weeks. Blood pressure of SHRs was measured before and biweekly during ST-F treatment. Subsequently, animals were sacrificed either immediately at the end of treatment or 2 weeks after ST-F treatment discontinuance. The activities of plasma rennin (PRA), angiotensin II (Ang-I), endothelin (ET), nitric oxide (NO), superoxide dismutase (SOD) and malondialdehyde (MDA) were measured as well as skin microcirculatory flux. In normotensive rats, blood pressure was determined after six months' treatment of ST-F. RESULTS: ST-F treatment significantly reduced the blood pressure of SHRs along with decreasing plasma levels of PRA and Ang II. ST-F did not show obvious effects on plasma levels of ET, NO or SOD, but it significantly decreased the plasma level of MDA and improved skin microcirculatory flux. Compared to the anti-hypertensive drug enalapril, ST-F showed a modest effect on lowering blood pressure of SHRs without obvious withdrawal reactions. But long-term intake of ST-F did not change the blood pressure in normotensive rats. CONCLUSION: ST-F had an antihypertensive effect on SHRs. The underlying mechanism could be related to modulation on the rennin-angiotensin-aldosterone system (RAAS) and antioxidation system, as well as regulation of skin microcirculation. Compared to its anti-hypertensive effect on SHRs, ST-F did not cause hypotension in normotensive rats. The results indicated that ST-F could potentially be used as natural drugs or functional foods for preventing hypertension.

The hypoglycemic activity of Lithocarpus polystachyus Rehd. leaves in the experimental hyperglycemic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Leaves of Lithocarpus polystachyus Rehd. are used for the treatment of disorders such as diabetes, hypertension, and epilepsy in folk medicine of South China. The possible antidiabetic effects of the leaves were investigated in experimental type 2 and type 1 diabetic rats. MATERIALS AND METHODS: Type 2 diabetic rats received orally three different extracts of Lithocarpus polystachyus Rehd. leaves for 4 weeks (aqueous extract [ST-1], ethanol extract [ST-2], flavonoid-rich fraction [ST-3]). At the end of the experiment biochemical parameters were tested and livers and pancreases were excised for histological study. After the comparison of the pharmacological test results of the three extracts, the one which showed the best bioactivity was further studied to confirm its antidiabetes effect on both type 2 and type 1 diabetic rats. RESULTS: Compared to ST-1 and ST-2, ST-3 had better effects on regulation of blood glucose, glycosylated serum protein, cholesterol, triglyceride, malondialdehyde, superoxide dismutase and attenuation of liver injury in type 2 diabetic rats (p<0.01 or p<0.05). ST-3 administration for four weeks also significantly reduced the fasting serum insulin and C-peptide level and improved the insulin tolerance (p<0.05). In type 1 diabetic rats, ST-3 supplement for three weeks caused significant reduction in fasting blood glucose, total cholesterol, triglyceride, urea nitrogen, creatinine and liver mass, along with significantly inhibiting the decline of insulin level compared to diabetic control (p<0.05 or p<0.01). CONCLUSION: The flavonoid-rich fraction of Lithocarpus polystachyus Rehd. leaves (ST-3) had better beneficial effect than that of the ethanol or aqueous extract in experimental diabetic rats, which means that the bioactivity of the herbal leaves is probably due to the presence of flavonoids. The results also strongly suggest that the antidiabetic effect of ST-3 was possibly through multiple mechanisms of action including blood lipid and antioxidant mediation. The results indicated that the aqueous flavonoid-rich fraction of Lithocarpus polystachyus Rehd. leaves possessed significant protective activity in type 2 and type 1 diabetes.

[Study on the enrichment and purification of total flavonoids in Schizonepeta tenuifolia by macroporous adsorption resin].

OBJECTIVE: To establish an optimum enrichment and purification process of total flavonoids in Schizonepeta tenuifolia by macroporous resins. METHODS: 9 kinds of resins were compared and the best one was chosen. Then the technique condition for separating and purifying total flavonoids from Schizonepeta tenuifolia was studied. RESULTS: HP-20 was selected for its excellent adsorption and desorption properties, 80% ethanol was found to be the best elution solution. The best result was based on the follows: pH value-6.0, feeding rate-2 BV/h,sample concentration-0.4 g/mL, the ratio of total flavonoids to HP-20 macroporous resin-133. 76 mg/g, elution flowing rate-4 BV/h, eluting agent amount-3 BV. Then the purity reached 74. 31% and the yield was 97.13%. CONCLUSION: The total flavonoids of Schizonepeta tenuifolia can be effectively purificated and separated by HP-20 macroporous resin.