WO2019087189A1 - A method for improving ocular blood flow - Google Patents

Abstract

The present invention is directed to a method for improving ocular blood flow in a human subject comprising administering a composition comprising lutein, one or more additional carotenoids and carnosic acid to said subject. The method may be used in the context of treating existing eye diseases in a human subject, wherein said diseases are characterized by impaired ocular blood flow. The method may also be used for preventing reduction in ocular blood flow.

Description

A method for improving ocular blood flow Field of the invention

The present invention is concerned with methods for improving ocular blood flow in human subjects. More specifically, the present invention discloses and claims methods for achieving this aim that involve administering natural product compositions to said subjects.

Background of the invention

Age-Related Eye Disease (ARED) is a group of conditions associated with an increased risk of visual impairment later in life and include: age-related macular degeneration (AMD), cataract, diabetic retinopathy, glaucoma, dry eye, and low vision. AMD and cataract are the leading causes of visual impairment in the United States.

AMD, a degenerative and progressive disease of the macula, is the leading cause of irreversible central vision loss in developed countries and is expected to affect over 288 million people worldwide by 2040. Recently, vascular abnormalities have been postulated to play a contributory role in AMD pathophysiology. The more common and less severe form is the atrophic subtype, in which extracellular deposits called drusen disrupt the flow of blood and nutrients from the choroid to the retinal pigment epithelium, resulting in retinal cell death and atrophy. In approximately 10-20% of cases, atrophic AMD progresses to exudative AMD via choroidal neovascularization (CNV), where new vessels form around drusen deposits that result in fluid and blood leakage into the retina causing functional and anatomical disruption of the overlying structures. Exudative AMD is rapidly progressive and is responsible for the majority of the severe vision loss associated with AMD. While anti-VEGF agents benefit patients with exudative AMD, there is currently no definite preventative or curative treatment for atrophic AMD.

The severity and irreversibility of ARED pathology has created an interest in researching methods to either prevent or slow its progression. Nutritional methods have been studied in both healthy volunteers and those with ARED to determine its role in disease prevention and progression. Although it has not been confirmed to be beneficial in all eye diseases such as glaucoma, the AREDS vitamin formulation study found that high-risk patients with AMD may experience up to a 25% risk reduction when taking certain vitamin combinations.

Several of the ARED conditions are associated with impaired ocular blood flow. In particular, it has been found that a dysfunctional ocular microcirculation plays a role in the development of two of the leading causes of adult blindness in the developed world, diabetic retinopathy and AMD. Furthermore, impairment of ocular blood flow is also known to occur in various types of glaucoma.

Currently, there are no defined vitamin combinations or other natural product compositions in use which were proven to specifically improve ocular blood flow in human subjects. The present invention provides the use of a composition that meets this need.

Summary of the invention

The present invention is primarily directed to a method for improving ocular blood flow in a human subject, wherein said method comprises administering a composition comprising lutein, one or more additional carotenoids and carnosic acid to said subject.

In some embodiments of this method, the subjects are human subjects without any preexisting ocular conditions.

The present invention also provides a method for treating eye diseases and disorders in a human subject comprising administering a composition comprising lutein, one or more additional carotenoids and carnosic acid to said human subject, wherein said eye diseases and disorders are characterized by impaired ocular blood flow. In some embodiments of the methods of the present invention, the subject to whom the composition is administered has been diagnosed with an eye condition selected from the group consisting of AMD, diabetic retinopathy and glaucoma.

In one embodiment, the aforementioned additional carotenoid(s) may preferably be selected from the group consisting of beta-carotene, zeaxanthin, phytoene, phytofluene, lycopene and astaxanthin. In one preferred embodiment, the additional carotenoid is beta-carotene.

In a particularly preferred embodiment, the composition used in the above-defined method comprises lutein, beta-carotene and carnosic acid.

In a further preferred embodiment, the composition used in the above-defined method comprises lutein, zeaxanthin, beta-carotene and carnosic acid.

It should be noted that the term "lutein" as used in the present disclosure should be understood to include all lutein esters within its scope. In addition, the term "lutein" may also be taken to include within its scope a mixture of lutein and zeaxanthin, since the last-mentioned carotenoid is often present together with lutein. Furthermore, in some embodiments of the method of the invention, the compositions administered comprise additional lutein (i.e. above and beyond any lutein that had been supplied in admixture with zeaxanthin).

In another aspect, the present invention is directed to a method for preventing reduction in ocular blood flow in a human subject in need of such preventative intervention.

The present invention further encompasses a composition comprising lutein, one or more additional carotenoids and carnosic acid (as defined hereinabove) for use in improving ocular blood flow in human subjects.

The present invention is also directed to a composition comprising lutein, one or more additional carotenoids and carnosic acid (as defined hereinabove) for use in the treatment or prevention of eye disorders characterized by impaired ocular blood flow. Examples of such eye disorders are provided hereinabove.

The present invention is further directed to a composition comprising lutein, one or more additional carotenoids and carnosic acid (as defined hereinabove) for use in preventing reduction in ocular blood flow.

Brief description of the drawings

Fig. 1 provides a schematic summary of the design of the study performed in human subjects by the present inventors.

Fig. 2 graphically shows the effect of the lutein-containing composition of the present invention on mean retinal capillary blood flow.

Fig. 3 shows the effect of the lutein-containing composition of the present invention on the size of the avascular areas in the superior and inferior retina.

Fig. 4 graphically demonstrates the effect of the lutein-containing composition of the present invention on systolic and diastolic arterial blood pressure.

Detailed description of preferred embodiments

In the methods of the present invention disclosed hereinabove, the composition comprising the aforementioned active components is preferably administered orally. In other embodiments, the composition may be administered by different routes including, but not limited to, intraocularly, topically, intravenously and intramuscularly.

The compositions of this aspect of the present invention may be formulated in several different dosage forms for administration to human subjects by the routes indicated hereinabove. Suitable dosage forms include (but are not limited to) oral dosage forms, sub-lingual dosage forms, injectable formulations, suppositories, patches for use on skin or mucous membranes, inhalable formulations, topical formulations and so on. Further details of the preparation of such formulations and dosage forms can be obtained from any standard reference on the subject, such as Remington's Pharmaceutical Sciences, Mack Publishing Co, Easton, Pa, USA, 21 ^st edition (2006).

In the methods of the present invention, the composition may be administered once daily or several times (e.g. twice or three times) daily.

The total daily dose of all of the active ingredients (i.e. lutein, other carotenoids and carnosic acid) taken together, for an adult human subject is in the range of 1 -3000 mg, preferably 10-2000 mg, more preferably 15 -100 mg.

In one preferred embodiment, the daily dose of the lutein component of the composition administered in the method of the present invention is in the range of 5-500 mg.

In some embodiments of the method, the composition to be administered is formulated in a unit dosage form suitable for oral administration. A typical dosage unit for oral administration (e.g. capsule, tablet or caplet) containing the composition to be administered in the method of the present invention comprises about 5-500 mg lutein, 0.1 -100 mg of one or more additional carotenoids and 0.5 - 50 mg of carnosic acid.

More preferably, said typical dose unit comprises about 5-20 mg lutein, 1 -10 mg of one ore more additional carotenoids and 1 -10 mg of carnosic acid.

In one preferred embodiment, said typical dosage unit containing the composition to be administered in the method of the present invention comprises 10 mg of lutein.

In another preferred embodiment, the dosage unit comprises 10 mg lutein, 2 mg zeaxanthin, 0.9 mg beta-carotene and 2.3 mg carnosic acid. Various features of the presently-claimed invention will now be exemplified in the following non-limiting Example.

Example 1

Human study showing effect of lutein-containinq composition on ocular blood flow

Materials and Methods

This investigation was conducted at the Glaucoma Research and Diagnostic Center within the Glick Eye Institute in Indianapolis, Indiana in conjunction with the Department of Ophthalmology and the Division of Biostatistics at the Indiana University School of Medicine (IUSM). All study procedures conformed to the tenets of the Declaration of Helsinki and were approved by the Institutional Review Board at IUSM. All subjects signed an informed consent prior to entry into the study.

Subjects

This study was open to all healthy subjects based upon self-reported medical history. All first comers were welcomed to a total enrollment of 16 females, where one randomly selected eye from each subject was examined. Subjects had to meet the following inclusion criteria: healthy males or females of ≥ 18 years of age, no diagnosis of eye disease (other than myopia) or uncontrolled systemic disease, willingness to sign an informed consent statement, and ability to comply with the examination requirements. Participants were excluded for the following self- reported reasons: women who were pregnant, lactating, or planning to become pregnant during the study duration or within one month after study completion; patients receiving medications or dietary supplements with known interaction with the study supplements; smoking during the last ten years; concurrent participation or prior participation in any other clinical trial during the past 30 days involving an investigational drug or device; and concurrent use of any of the components of the study supplement. Study Design

The study was a randomized, double-blinded, placebo-controlled, two-period crossover study with comparisons of administration of supplementation with a lutein- containing composition (Table 1 ) versus placebo (Table 2), which were identical in appearance to the lutein supplement. Testing took place over a period of 6 months. Participants were given detailed medication instructions and were instructed to avoid caffeine intake, smoking, and exercise for 3 hours before each study visit. The first clinic visit obtained pre-supplementation measurements and a questionnaire regarding the participant's medical history and demographic information. Each participant was then randomly assigned to lutein or placebo group (Fig. 1 ). Randomization was accomplished with a randomization table and was maintained in a double-blind manner. Participants were instructed to take their Period 1 supplement dose once daily and return for a follow-up visit three weeks later to repeat testing. After a washout period of three weeks, participants returned for a second pre-supplementation visit and were given the other study supplement to take daily for three weeks during Period 2 before returning for a final evaluation.

Table 1 . Ingredients of lutein-containing supplement

Active ingredient Amount Per capsule (mg)

(Daily dose)

Lutein 10

Zeaxanthin 2

Beta- Carotene 0.9

Carnosic acid 2.3 Table 2. Ingredients of placebo

I Daily dose (mg)

Sunflower oil 325

Objective measures

For consistency and bias limitation, all measurements were taken in the same order at the same time of day and by the same examiner (BS) for each patient. At each visit, any changes in health or medication history were recorded, and subjects were questioned for any adverse effects of the supplementation. The following measurements were obtained at every visit: best corrected visual acuity (VA) using ETDRS eye charts, contrast sensitivity with Vector vision analysis, and intraocular pressure (IOP) via Goldmann applanation tonometry. Brachial artery systolic and diastolic blood pressure (SBP and DBP, respectively) and heart rate were also assessed in the seated/supine position after a 5-minute resting period using a calibrated automated sphygmomanometer at the beginning of each study visit. Ocular perfusion pressure (OPP) was calculated as OPP = ((2/3 MAP) - IOP), where MAP is mean arterial pressure. Mean OPP (MPP) was calculated by subtracting IOP from MAP. Systolic ocular perfusion pressure (SOPP) and diastolic ocular perfusion pressure (DOPP) were determined by subtracting IOP from SBP and DBP, respectively.

Perfusion within peripapillary retinal capillary beds was assessed by Heidelberg confocal scanning laser Doppler, which provides measurements of blood velocity and volume in the retina and allows for the computation of total blood flow and creation of a physical map of flow values. This method allows for quantifying the degree of vascularity of the retina by differentiating avascular tissue (measured as zero flow pixels) from perfused tissue. Peripapillary retinal capillaries were sampled individually using pixel by pixel analysis in a 40x40 pixel area (-1 ,600 individual pixels per scan) for both supero-temporal and infero-temporal areas adjacent to the optic nerve. Data from areas of unsuitable brightness (any DC value <80 or >200) and pixels in poor focus from the rim, large blood vessels, and saccades were excluded.

Velocities and vascular resistance of the retrobulbar vasculature were measured with color Doppler ultrasound within the ophthalmic (OA), central retinal artery (CRA), and nasal (NPCA) and temporal (TPCA) posterior ciliary arteries. In each vessel peak systolic velocity (PSV) and end diastolic velocity (EDV) were determined, and Pourcelot's resistivity index (Rl) was calculated (Rl = (PSV- EDVyPSV).

Statistical analysis was conducted in partnership with the Division of Biostatistics at IUSM. The primary statistical endpoint, accomplished using paired t-tests, was to evaluate the efficacy of lutein supplement in increasing ocular vascular biomarkers compared to placebo. Secondary effects due to supplementation sequence and study period were analyzed with repeated measures analysis of variance (ANOVA). A two-tailed p-value of 0.05 was set as the threshold of statistical significance. Previous studies of populations and test/retest variability of color Doppler measurements of RBF velocities have shown that a sample size of 16 individual provides 90% power to detect a >12% difference in PSV and EDV and a 6% difference in Rl between groups.

Results

Sixteen healthy patients (age 36.8 ± 12.1 years; range 20-56 years; 16 females) were recruited, and there were no patient dropouts throughout the study. The remaining baseline demographic data can be found in Table 3. Patients with hypertension and diabetes were well controlled and complied with the inclusion criteria. No adverse events with either lutein supplement or placebo were reported. Table 3: Patient characteristics at baseline

Table 3 legend: The numbers in parentheses

represent percentage of total study group; N, number.

Changes in measurements from pre-supplementation to post-supplementation with the lutein-containing supplement demonstrated significant findings (Table 4) including increased mean retinal capillary blood flow in the superior retina (Fig. 2), decreased percentage of avascular area in the superior and inferior retina (Fig. 3) and reduced systolic and diastolic arterial blood pressures (Fig. 4).

Fig. 2 indicates that changes in data from pre-treatment to post-treatment with lutein supplement revealed significantly increased mean retinal capillary blood flow in the superior retina (bar on left); p = 0.0466) compared to nonsignificant changes with the placebo (bar on right).

Fig. 3 shows that changes in data from pre-treatment to post-treatment with lutein supplement (left bar of each pair) revealed significantly decreased area of zero retinal capillary blood flow both in the superior (left pair of bars) and inferior retina (right pair of bars; p = 0.0491 , p = 0.0477, respectively) compared to nonsignificant changes with the placebo (right bar of each pair).

Finally, it may be seen from Fig. 4 that changes from pre-treatment to post-treatment with lutein supplement (left bar of each pair) revealed significantly reduced systolic blood pressure (SBP; left pair of bars) and diastolic blood pressure (DBP; right pair of bars; p = 0.0295, p = 0.0441 , respectively) compared to nonsignificant readings with the placebo.

None of these parameters changed significantly in the placebo group. Lutein administration also increased mean retinal capillary blood flow in the inferior retina but did not reach statistical significance. There were no significant differences in RBF velocities or Rl with either lutein or placebo administration; however, there was a trend increase in the PSV of the OA in the lutein group. There were also no significant differences in IOP reduction, visual acuity, contrast sensitivity detection, or OPPs with either supplement.

Table 4: Comparison of change from pre- to post-treatment in lutein supplement and placebo groups.

Change from pre- to Change from pre- Comparison of post-treatment with P-value to post-treatment P-value change of lutein lutein supplement: with placebo: mean to placebo mean (SE) (SE) group (p-value)

Heart rate -3.31 (1.59) 0.0552 0.00 (3.39) 1.000 0.4334

Systolic BP -4.06 (1.69) 0.0295 0.06 (2.29) 0.9786 0.0506

Diastolic BP -3.69 (1.68) 0.0441 0.31 (2.57) 0.9048 0.0357

MAP -1.52 (1.50) 0.3265 -1.02 (2.55) 0.6947 0.6447

IOP 0.50 (0.41) 0.2396 -0.38 (0.34) 0.2875 0.0546

OPP -1.01 (1.00) 0.3265 -0.68 (1.70) 0.6947 0.6447

Systolic OPP -0.19 (2.73) 0.9461 0.44 (2.23) 0.8469 0.7419

Diastolic OPP -2.94 (1.67) 0.0989 -1.19 (3.13) 0.7094 0.4331

Mean OPP -2.02 (1.49) 0.1955 -0.65 (2.61) 0.8078 0.3984

Visual Acuity -0.029 (0.020) 0.1777 -0.006 (0.018) 0.7326 0.3022

Row A -0.018 (0.034) 0.6128 -0.009 (0.038) 0.8084 0.7162

Row B 0.064 (0.039) 0.1252 0.010 (0.042) 0.8165 0.3074

Row C -0.006 (0.058) 0.9158 -0.019 (0.061) 0.7635 0.9598

Row D -0.003 (0.061) 0.9597 -0.107 (0.052) 0.0559 0.0908

OA PSV 1.46 (0.70) 0.0545 0.89 (0.57) 0.1360 0.2813

OA EDV -0.02 (0.18) 0.9183 0.36 (0.21) 0.1002 0.2931

OA RI 0.012 (0.008) 0.1459 -0.009 (0.011) 0.4233 0.1870

CRA PSV 0.36 (0.19) 0.0714 -0.33 (0.21) 0.1444 0.0384

CRA EDV -0.11 (0.16) 0.5254 -0.24 (0.15) 0.1145 0.6906

CRA RI 0.022 (0.014) 0.1494 0.016 (0.014) 0.2859 0.5786

NPCA PSV -0.11 (0.15) 0.4977 0.29 (0.21) 0.1729 0.0990

NPCA EDV -0.01 (0.13) 0.9637 0.16 (0.12) 0.2177 0.3771

NPCA RI -0.010 (0.016) 0.5501 -0.008 (0.015) 0.5982 0.8144

TPCA PSV 0.06 (0.12) 0.6587 -0.09 (0.27) 0.7375 0.7280

TPCA EDV -0.03 (0.17) 0.8860 -0.07 (0.22) 0.7465 0.9241

TPCA RI -0.001 (0.020) 0.9622 -0.004 (0.023) 0.8635 0.8518

SUP zero flow -0.029 (0.014) 0.0491 -0.007 (0.008) 0.3710 0.1994

SUP mean FV 60 (28) 0.0466 -56 (72) 0.4498 0.1639

INF zero flow -0.023 (0.011) 0.0477 -0.003 (0.016) 0.8658 0.3894

INF mean FV 47 (24) 0.0747 -52 (57) 0.3792 0.1672

P-values of statistical significance (p<0.05) are in bold. (The numbers in parentheses represent mean or standard error. Statistically significant P values (<0.05) are shown in bold.)

Table legend: BP, blood pressure; The numbers in parentheses represent mean or standard error. Statistically significant P values (<0.05) are shown in bold. Table legend: BP, blood pressure; CRA, central retinal artery; EDV, end diastolic velocity; FV, flow volume; INF, inferior; lOP, intraocular pressure; MAP, mean arterial pressure; NPCA, nasal posterior ciliary artery; OA, ophthalmic artery; OPP, ocular perfusion pressure; PSV, peak systolic velocity; Rl, resistivity index; SUP, superior; TPCA, temporal posterior ciliary artery; Row A/B/C/D refers to contrast sensitivity.

Minor differences were detected between groups within the pre-lutein- supplementation data such as lower lOP (p=0.0058), higher VA (p=0.0321 ), lower Row D contrast sensitivity (p=0.0465), lower CRA EDV (p=0.0101 ), and higher CRA Rl (p=0.001 1 ). Additional differences between supplement periods were lower Row C and Row D contrast sensitivity in period 1 (p=0.0037 and p=0.0386, respectively), and higher CRA EDV in period 1 (p=0.0405). Pre-supplementation sequence effects were seen with MAP and OPP. However, as the lutein supplement had less of an effect on these values than placebo, it is unlikely to adversely affect conclusions.

Data comparison between the two supplement groups revealed a significant decrease in systemic DBP (p=0.0357) and an increase in CRA PSV (p=0.0384) with lutein supplement. Data analyses from the placebo group were all non-significant (Table 2). Within the study periods a decrease in MPP during period 1 (p=0.0428), an increase in CRA PSV during period 2 (p=0.0282), and a decrease in CRA EDV in period 1 (p=0.0159) were observed. An increase in lOP (p=0.0412) was demonstrated in the lutein-placebo arm while the placebo-lutein arm showed a nonsignificant lOP decrease. This finding was determined to not have adversely affected data interpretation upon further examination of the lOP trends. Discussion

The results of the present study indicate that daily supplementation with a lutein- containing composition produces increased blood flow in the retina and optic nerve supplying vessels in healthy subjects.

Claims

1 . A method for improving ocular blood flow in a human subject comprising administering a composition comprising lutein, one or more additional carotenoids and carnosic acid to said subject.

2. A method for treating eye diseases and disorders in a human subject comprising administering a composition comprising lutein, one or more additional carotenoids and carnosic acid to said human subject, wherein said eye diseases and disorders are characterized by impaired ocular blood flow.

3. The method according to either claim 1 or claim 2, wherein the additional carotenoid is beta-carotene.

4. The method according to either claim 1 or claim 2, wherein the composition comprises lutein, zeaxanthin, beta-carotene and carnosic acid.

5. The method according to either claim 1 or claim 2, wherein the total daily dose of. lutein, the additional carotenoid(s) and carnosic acid taken together is in the range of 1 -3000 mg.

6. The method according to either claim 1 or claim 2, wherein the composition is contained in a unit dosage form for oral administration, and wherein said unit dosage form comprises about 5-500 mg lutein, 0.1 -100 mg of one or more additional carotenoids and 0.5 - 50 mg of carnosic acid.

7. The method according to claim 6, wherein the dose unit comprises about 5-20 mg lutein, 1 -10 mg of one or more additional carotenoids and 1 -10 mg of carnosic acid.

8. The method according to claim 7, wherein the dose unit comprises 10 mg lutein, 2 mg zeaxanthin, 0.9 mg beta-carotene and 2.3 mg carnosic acid.