The antioxidant activity of the curcuminoids ofCurcuma domesticaL. andC. xanthorrhizaRoxb. and eight compounds which are prevalent constituents of their rhizome oils were investigated in an effort to correlate human low-density lipoprotein (LDL) antioxidant activity with the effect of the herbs and their components. The antioxidant activity was examined using thiobarbituric acid reactive substances (TBARSs) assay with human LDL as the oxidation substrate. The methanol extracts and rhizome oils ofC. xanthorrhizaandC. domesticashowed strong inhibitory activity on copper-mediated oxidation of LDL. Curcumin, demethoxycurcumin, and bisdemethoxycurcumin, isolated from the methanol extracts of both plants, exhibited stronger activity than probucol (IC₅₀value 0.57 μmol/L) as reference, with IC₅₀values ranging from 0.15 to 0.33 μmol/L. Xanthorrhizol, the most abundant component (31.9%) of the oil ofC. xanthorrhiza, showed relatively strong activity with an IC₅₀value of 1.93 μmol/L. The major components ofC. domestica, ar-turmerone (45.8%) and zerumbone (3.5%), exhibited IC₅₀values of 10.18 and 24.90 μmol/L, respectively. The high levels of curcuminoids in the methanol extracts and xanthorrhizol, ar-turmerone and zerumbone in the oils, and in combination with the minor components were responsible for the high LDL antioxidant activity of the herbs.

Cardiovascular diseases are the leading cause of death worldwide, with the majority of the cases being heart failure due to myocardial infarction. Research on cardiovascular diseases is currently underway, particularly on atherosclerosis prevention, to reduce the risk of myocardial infarction. Proprotein convertase subtilisin/kexin type 9 (PCSK9) has been reported to play a role in lipid metabolism, by enhancing low-density lipoprotein (LDL) receptor degradation. Therefore, PCSK9 inhibitors have been developed and found to successfully decrease LDL plasma levels. Recent experimental studies have also implicated PCSK9 in platelet activation, having a key role during atherosclerosis progression. Although numerous studies have addressed the role of PCSK9 role in controlling hypercholesterolemia, studies and discussions exploring its involvement in platelet activation are still limited. Hence, here, we address our current understanding of the pathophysiological process involved in atherosclerosis-induced myocardial infarction (MI) through platelet activation and highlight the molecular mechanisms used by PCSK9 in regulating platelet activation. Undoubtedly, a deeper understanding of the relationship between platelet activation and the underlying molecular mechanisms of PCSK9 in the context of MI progression will provide a new strategy for developing drugs that selectively inhibit the most relevant pathways in cardiovascular disease progression.

Hibiscus sabdariffa aqueous extract (HS) is often used as complementary therapy for hypertension. However, some studies have shown that coadministration with a conventional antihypertensive drug can affect drug potency. We compared the effects of HS plus captopril (CAP) coadministration to HS and CAP administration alone on blood pressure and renin-angiotensin-aldosterone system (RAAS) biomarkers in the rat two-kidney-one-clip (2K1C) model of hypertension. Male Sprague Dawley rats were randomly divided into seven groups (n=6/group), a normal control (SHAM) group, and six 2K1C groups. In 2K1C animals, hypertension was induced using a stainless microclip (inner diameter of 0.20 mm). Four weeks after 2K1C surgery, blood pressure was significantly higher than in the SHAM group. Then, model rats were randomly divided into negative control (2K1C, no treatment), positive control (4.5 mg captopril/200 g body weight [BW] orally [p.o.]), HS alone (30 mg/200 g BW; p.o.), and 3 co-treatment groups receiving HS (15, 30, or 60 mg/200 g BW; p.o.) plus 4.5 mg/200 g BW captopril. The treatments were performed for two weeks. Blood pressure was significantly reduced by all the drug treatments to near the level of SHAM controls. Plasma renin level, serum angiotensin converting enzyme (ACE) activity, and plasma angiotensin II level were also significantly elevated in the 2K1C group compared to the SHAM group. Both serum ACE activity and plasma angiotensin II level were significantly reduced to near SHAM group levels by all the drug treatments. Hibiscus sabdariffa aqueous extract alone can reduce blood pressure. This extract appears could be used as a supplement with captopril but may not provide any additional benefit.

Cinnamon bark (Cinnamomum burmannii) and sappan wood (Caesalpinia sappan) have been reported to be beneficial for Type-2 Diabetes Mellitus (T2DM) and the combination is commonly used by Indonesian herbal industries. In the present study, the simultaneous extraction of bioactive compounds from both plants was conducted using natural deep eutectic solvent (NADES), their content analyzed using high-performance liquid chromatography (HPLC), and their dipeptidyl peptidase IV (DPP IV) inhibitory activity evaluated. An additional in silico molecular docking analysis was conducted to ensure their activity. The results showed that NADES (with a composition of choline chloride–glycerol) extraction from cinnamon and sappan wood had DPP IV inhibitory activity of 205.0 and 1254.0 µg/mL, respectively. Brazilin as a marker substance from sappan wood was responsible for the DPP IV inhibitory activity, while none of the marker substances chosen for cinnamon bark (trans-cinnamaldehyde, coumarin, and trans-cinnamic acid) were found to have significant DPP IV inhibitory activity. These results were confirmed by molecular docking conducted in brazilin, trans-cinnamaldehyde, coumarin, and trans-cinnamic acid.

The presence of gamma-oryzanol in rice bran oil can be 10–20-fold higher than tocopherol and tocotrienol. Gamma-oryzanol has various pharmacological properties. The objective of this study was to evaluate the effectiveness of rice bran extract as a gastroprotective in reducing lesions in ethanol-induced acute gastric ulcer models in rat, using the ionic liquid-microwave-assisted extraction (IL-MAE) method. Rice bran extract was obtained using the IL-MAE method with ionic liquid (IL), 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM]BF₄ (concentration 0.7 M), and a ratio of solid/liquid of 15 g/mL, 15 min extraction time, and 10% microwave power. The rats were pretreated with rice bran extract at different doses (100, 200, and 400 mg/kg body weight; BW) for seven days and subsequently exposed to acute gastric lesions induced by 80% ethanol. Omeprazole (36 mg/kg BW) was used as a standard anti-ulcer drug. The ulcer index, gastric juice acidity, and mucus levels were measured to assess the degree of gastroprotection. The results showed that the oral administration of rice bran extract at a dose of 400 mg/kg BW significantly inhibited the development of ulcer formation by 66.75% and reduced gastric acid levels. Moreover, gamma oryzanol and omeprazole protected the gastric mucosa from ethanol-induced gastric lesions by increasing the level of gastric mucus. Rice bran extract is effective as a gastroprotective therapy sourced from natural ingredients in treating the incidence of gastric ulcers. Most likely, this is related to gamma oryzanol as a bioactive compound contained in rice bran (Oryza sativa L.).