Preincubation of Stigmasterol with IL-1beta-treated cells demonstrated significant reductions in PGE2 protein in both humans and animals, as well as MMP-3 mRNA, MMP-3 protein, and MMP-13 mRNA in both humans and mice. Additionally, stigmasterol can inhibit the NF-κB pathway that IL-1beta causes [1].

Absorption, Distribution and Excretion
This study investigated the metabolism of phytosterols and squalene via intravenous administration of a chylomicron (CM)-like lipid emulsion. The CM-like lipid emulsion was prepared by dissolving squalene in commercially available Intralipid. Six healthy volunteers received a 30 mL intravenous bolus containing 6.3 mg cholesterol, 1.9 mg campesterol, 5.7 mg β-sitosterol, 1.6 mg stigmasterol, 18.1 mg squalene, and 6 g triglycerides. Blood samples were drawn from the contralateral arm before and 2.5 to 180 minutes after injection. The decay of squalene, phytosterols, and triglycerides in the CM exhibited a single exponential decay. The half-life of squalene in CM was 74±8 minutes, and that of campesterol was 37±5 minutes (P<0.01 compared to squalene). The half-lives of β-sitosterol, stigmasterol, and triglycerides were 17±2 minutes, 15±1 minutes, and 17±2 minutes, respectively (P<0.01 compared to squalene and campesterol). At 180 minutes post-injection, the concentration of squalene in CM remained higher than baseline (P=0.02), while the concentrations of campesterol and triglycerides returned to baseline levels between 45 and 120 minutes post-injection. The half-lives of squalene and campesterol were positively correlated with their fasting CM concentrations. In addition, the concentrations of VLDL squalene, campesterol, and triglycerides, VLDL, LDL, and HDL sitosterol, and VLDL and LDL stigmasterol were all significantly increased…
Rats were administered via oral gavage samples of 14C-labeled cholesterol, β-sitosterol, or β-sitosterol dissolved in sunflower seed oil, or 3H-labeled β-sitosterol, campesterol, campesterol, or stigmasterol. Urine and feces were collected after administration for 96 hours. …Animal sacrifice was performed, and whole-body autoradiography or determination of 14C or 3H content in tissues and cadaveric residues was conducted. Based on the radioactivity levels in tissues and cadavers, the overall absorption rate of phytosterols was low. The drug was mainly excreted in feces, initially at a very rapid rate, but trace amounts were still excreted up to 4 days after administration. Due to a lack of bile excretion data, the total absorption rate of phytosterols could not be fully quantified, but it was clear that cholesterol had the highest absorption rate (27% of the dose in women within 24 hours). Campesterol (13%) had a higher absorption rate than β-sitosterol and stigmasterol (both 4%), while β-sitosterol and stigmasterol had higher absorption rates than β-sitosterol and campesterol (1-2%). Women absorbed phytosterols slightly more readily than men. For each test material, the overall distribution pattern of radioactivity in tissues was similar, with the highest levels and longest residence times observed in the adrenal glands, ovaries, and intestinal epithelium.
Using intestinal perfusion technology, with β-sitosterol as a non-absorbable marker, the intestinal absorption rates of cholesterol, campesterol, campesterol, stigmasterol, and β-sitosterol were determined in a 50 cm segment of the upper jejunum from 10 healthy subjects. Cholesterol had the highest absorption rate, averaging 33%; β-sitosterol had an average absorption rate of 4.2%, and stigmasterol had an average absorption rate of 4.8%. ...
To investigate the effects of dietary stigmasterol on sterol and bile acid metabolism, researchers fed Wistar rats diets containing different doses of stigmasterol. Feeding high doses of stigmasterol (11, 26, or 52 mg/day) led to increased excretion of cholesterol, fecal sterol, and bile acids. These effects were dose-dependent and may be related to the inhibitory effect of phytosterols on cholesterol absorption. Furthermore, this also explains the beneficial cholesterol-lowering effect of stigmasterol.
Tobacco sterols (cholesterol, β-sitosterol, campesterol, and stigmasterol) are present in tobacco smoke and appear in the plasma of mammals exposed to cigarette smoke. Since tobacco sterols may play an important role in the pathogenesis of smoking-induced lung and vascular diseases, we investigated the deposition patterns of tobacco sterols in the rat lungs and their presence in plasma and other organs. Rats were exposed to 5 mL of [4-14C]cholesterol or β-[4-14C]sitosterol-labeled tobacco smoke 20 times. They were sacrificed immediately after exposure (day 0) and on days 2, 5, 8, 11, 15, and 30, and the activity of their lungs and selected organs was analyzed. … Cigarette sterols bind to particulate matter in cigarette smoke and are deposited primarily in the distal air spaces and lung parenchyma of the lungs, persisting in plasma and multiple organs for more than 30 days after a single exposure to cigarette smoke. The levels of radiolabeled sterols in bronchoalveolar lavage fluid were relatively low only in the first few days, indicating that most of the sterols were rapidly absorbed by the lung parenchyma…

---

Metabolism/Metabolites
This study investigated the metabolism of phytosterols using rat feces and liver microsomes. Feces were collected after rats were orally administered phytosterols (a well-defined mixture containing 40% β-sitosterol, 30% campesterol, and dihydrobrassinosteroidol). Metabolites of phytosterols were identified using gas chromatography-mass spectrometry (GC/MS). Three peaks were observed at 12.47, 12.65, and 12.87 min, with characteristic molecular ions at m/z of 428, 430, and 432, respectively. Three metabolites, androstenedione, and androstenedione, were identified in feces. No metabolites were detected in the rat liver microsomal reaction mixture. The results indicate that phytosterol metabolites in rat feces are formed in the rat large intestine via oxidation at position 3, saturation at positions 5 and 6, and side-chain cleavage at position 17. Phytosterols are essential components of cell membranes in all eukaryotic organisms. They can be synthesized de novo or absorbed from the environment. Their function appears to be controlling membrane fluidity and permeability, although some phytosterols have specific functions in signal transduction. Phytosterols are products of the isoprene pathway. The dedicated pathway for sterol synthesis in photosynthetic plants occurs at the squalene stage, catalyzed by squalene synthase. While the activity of 3-hydroxymethyl-3-glutaryl-CoA (HGMR) is the rate-limiting step in cholesterol synthesis, this does not appear to be the case for phytosterol synthesis. Upregulation of HGMR appears to increase cycloartenol biosynthesis but not Δ5-sterol biosynthesis. The decrease in sterol synthesis is associated with inhibition of squalene synthase activity, which may be a key step controlling carbon flux and final product formation. Major post-squalene biosynthetic pathways are regulated by key rate-limiting steps, such as the methylation of cycloartenol to cycloeusenoic acid. Little is known about the factors controlling the biosynthesis of final sterol esters or steranols.

[1]. Gabay O, et al. Stigmasterol: a phytosterol with potential anti-osteoarthritic properties. Osteoarthritis Cartilage. 2010 Jan;18(1):106-16

Stigmasterol is a 3β-sterol composed of 3β-hydroxystigmasterane, with double bonds at positions 5, 6 and 22, 23. It is a plant metabolite. Stigmasterol is a 3β-sterol, stigmasterane sterol, 3β-hydroxy-Δ(5)-steroid, belonging to the class of phytosterols. It is derived from the hydride of stigmasterane. Stigmasterol has been reported in tanshinone, rhodiola rosea, and other organisms with relevant data. Stigmasterol is a steroid derivative characterized by a hydroxyl group at the C-3 position of the steroid skeleton, and unsaturated bonds at positions 5-6 of the B ring and at positions 22-23 of the alkyl substituent. Stigmasterol is found in the fats and oils of soybeans, calabash beans, and rapeseed, as well as in some other vegetables, legumes, nuts, seeds, and unpasteurized milk. See also: Lithospermum erythrorhizon root (partial); Saw palmetto (partial); Plantain seed (partial).

---

Therapeutic Use
/EXPL/ ... The primary objective of this study was to determine the efficacy of a phytosterol-enriched, low-fat spread in reducing total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels in patients with primary hypercholesterolemia. A secondary objective was to assess whether patients taking lipid-lowering medications (fibrates) showed different responses to phytosterols. This study was a randomized, double-blind, placebo-controlled, two-cycle crossover trial involving two treatment regimens and three cycles. Both treatment cycles lasted two months, with a two-month washout period in between. The phytosterol-enriched spread was compared to a control spread without added phytosterols. The fortified fat spread provides 1.6 grams of phytosterols derived from edible vegetable oils and fatty acids derived from sunflower seed oil daily. The phytosterol components include: β-sitosterol ester (50%), campesterol ester (25%), stigmasterol ester (20%), and 10% of other esters. Data from the 53 patients with hypercholesterolemia (31 women and 22 men) who completed the study are as follows: the mean age was 58 ± 12 years, and the mean body mass index was 23.5 ± 2.8 kg/m² (mean ± standard deviation). No diet-related adverse effects were reported. Compared with the control group (0.0% and 1.3%, respectively), consuming phytosterol-rich spreads significantly reduced plasma total cholesterol and low-density lipoprotein cholesterol (LDL-C) concentrations by 6.4% and 8.8%, respectively. No effect was detected on high-density lipoprotein cholesterol (HDL-C) and lipoprotein(a) concentrations. After dividing the subjects into two subgroups according to whether they received fibrates, in the subgroup of patients receiving fibrates, phytosterol supplementation reduced plasma cholesterol and LDL-C by 8.5% and 11.1%, respectively… The conclusion is that phytosterol-rich spreads can be used as an adjunct therapy for patients with hypercholesterolemia. Commonly used plant sterols include β-sitosterol, stigmasterol, and campesterol, which are mainly derived from vegetable oils. Their nutritional value stems from the structural similarity of sterols to cholesterol and their ability to lower plasma cholesterol and low-density lipoprotein cholesterol (LDL-C). Since cholesterol-lowering drugs (statins) have significantly reduced the incidence and mortality of cardiovascular disease, interest in plant sterols lies in their potential as natural preventative dietary products. A study involving 12 healthy men and 12 healthy women (mean age 36 years, mean body mass index 24 kg/m²) aimed to determine the effects of margarine rich in plant sterol esters on fecal short-chain fatty acids (SCFA), fecal bacterial enzyme activity, fecal viable bacteria count, female sex hormones, and serum cholesterol concentration. The study employed a two-period, parallel-dose, randomized, placebo-controlled dietary study design. Under controlled dietary conditions, subjects consumed 40 grams of control margarine for 21 consecutive days (men) and 28 consecutive days (women), respectively. The study then proceeded immediately to its second part, where participants were randomly and equally assigned to either the control or experimental group. Each participant consumed 40 grams of test margarine containing 8.6 grams of plant sterols (a mixture of β-sitosterol, campesterol, and stigmasterol) daily for either 21 or 28 days. All female participants had regular menstrual cycles and used established methods of contraception, excluding oral contraceptives. Compared to the control group, the experimental group showed significantly lower serum total cholesterol and LDL cholesterol concentrations (18% and 23%, respectively) (P < 0.001; P < 0.001), as well as significantly lower fecal lactate concentrations (P = 0.039) and serum progesterone levels (P = 0.021). No other significant therapeutic effects were observed. Several significant changes from baseline were observed within each group. The experimental group showed significantly lower fecal lactate concentrations and the acetic acid/total short-chain fatty acid (SCFA) ratio and butyrate/total SCFA ratio (P = 0.016), while the corresponding ratios were significantly lower in the control group. Compared to baseline, azoreductase activity was significantly decreased in the control group (P = 0.047). The levels of total aerobic bacteria (P = 0.028), lactobacilli (P = 0.003), and staphylococci (P = 0.025) in feces were also significantly decreased in the control group, while only the lactobacilli level decreased in the experimental group (P = 0.019). Of the significant results reported in this study, apart from the beneficial decrease in serum total cholesterol and low-density lipoprotein cholesterol (LDL-C) concentrations, the other results were not biologically significant…

C29H48O

412.7

412.37

83-48-7

5280794

White to off-white solid powder

1.0±0.1 g/cm3

501.1±19.0 °C at 760 mmHg

165-167 °C(lit.)

219.4±13.7 °C

0.0±2.9 mmHg at 25°C

1.531

10.21

1

1

5

30

674

9

C[C@@]12[C@@H]([C@H](C)/C=C/[C@@H](CC)C(C)C)CC[C@H]1[C@@H]1CC=C3C[C@H](CC[C@]3(C)[C@H]1CC2)O

HCXVJBMSMIARIN-PHZDYDNGSA-N

InChI=1S/C29H48O/c1-7-21(19(2)3)9-8-20(4)25-12-13-26-24-11-10-22-18-23(30)14-16-28(22,5)27(24)15-17-29(25,26)6/h8-10,19-21,23-27,30H,7,11-18H2,1-6H3/b9-8+/t20-,21-,23+,24+,25-,26+,27+,28+,29-/m1/s1

(3S,8S,9S,10R,13R,14S,17R)-17-[(E,2R,5S)-5-ethyl-6-methylhept-3-en-2-yl]-10,13-dimethyl-2,3,4,7,8,9,11,12,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-3-ol

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Acetone : 6.67 mg/mL (~16.16 mM)
DMF : 1 mg/mL (~2.42 mM)
H2O : < 0.1 mg/mL
1M NaOH :< 1 mg/mL
Ethanol :< 1 mg/mL
DMSO :< 1 mg/mL
MEOH :< 1 mg/mL

Solubility in Formulation 1: 3.12 mg/mL (7.56 mM) in Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication (<50°C).

---

 (Please use freshly prepared in vivo formulations for optimal results.)