Anti-inflammatory effect of Heliotropium indicum Linn on lipopolysaccharide-induced uveitis in New Zealand white rabbits

AIM

To investigate the anti-inflammatory effect of an aqueous whole plant extract of Heliotropium indicum (HIE) on endotoxin-induced uveitis in New Zealand white rabbits.

METHODS

Clinical signs of uveitis including flares, iris hyperemia and miosis, were sought for and scored in 1.0 mg/kg lipopolysaccharide (LPS) -induced uveitic rabbits treated orally with HIE (30-300 mg/kg), prednisolone (30 mg/kg), or normal saline (10 mL/kg). The number of polymorphonuclear neutrophils infiltrating, the protein concentration, as well as levels of tumor necrosis factor-α (TNF-α), prostaglandin E2 (PGE2), and monocyte chemmoattrant protein-1 (MCP-1) in the aqueous humor after the various treatments were also determined. A histopathological study of the anterior uveal was performed.

RESULTS

The extract and prednisolone-treatment significantly reduced (P≤0.001) both the clinical scores of inflammation (1.0-1.8 compared to 4.40±0.40 in the normal saline-treated rabbits) and inflammatory cells infiltration. The level of protein, and the concentrations of TNF-α, PGE2 and MCP-1 in the aqueous humor were also significantly reduced (P≤0.001). Histopathological studies showed normal uveal morphology in the HIE and prednisolone-treated rabbits while normal saline-treated rabbits showed marked infiltration of inflammatory cells.

CONCLUSION

The HIE exhibits anti-inflammatory effect on LPS-induced uveitis possibly by reducing the production of pro-inflammatory mediators.

Anti-glaucoma potential of Heliotropium indicum Linn in experimentally-induced glaucoma

Background

Heliotropium indicum is used as a traditional remedy for hypertension in Ghana. The aim of the study was to evaluate the anti-glaucoma potential of an aqueous whole plant extract of H. indicum to manage experimentally-induced glaucoma.

Methods

The percentage change in intraocular pressure (IOP), after inducing acute glaucoma (15 mLkg⁻¹ of 5 % dextrose, i.v.), in New Zealand White rabbits pretreated with Heliotropium indicum aqueous extract (HIE) (30–300 mgkg⁻¹), acetazolamide (5 mgkg⁻¹), and normal saline (10 mLkg⁻¹) per os were measured. IOPs were also monitored in chronic glaucoma in rabbits (induced by 1 % prednisolone acetate drops, 12 hourly for 21 days) after treatments with the same doses of HIE, acetazolamide, and normal saline for 2 weeks. The anti-oxidant property of the extract was assessed by assaying for glutathione levels in the aqueous humour. Glutamate concentration in the vitreous humour was also determined using ELISA technique. Histopathological assessment of the ciliary bodies was made.

Results

The extract significantly reduced intraocular pressure (p ≤ 0.05–0.001) in acute and chronic glaucoma, preserved glutathione levels and glutamate concentration (p ≤ 0.01–0.001). Histological assessment of the ciliary body showed a decrease in inflammatory infiltration in the extract and acetazolamide-treated group compared with the normal saline-treated group.

Conclusion

The aqueous whole plant extract of Heliotropium indicum has ocular hypotensive, anti-oxidant and possible neuro-protective effects, which therefore underscore its plausible utility as an anti-glaucoma drug with further investigation.

The Claim of Anti-Cataract Potential of Heliotropium indicum: A Myth or Reality?

Introduction

Heliotropium indicum has several uses in traditional medicine attributable to its numerous bioactive compounds. It is used as a traditional remedy for cataracts in Ghana without any scientific verification. This study aimed at verifying the anti-cataract properties of an aqueous whole plant extract of H. indicum.

Methods

The effect (cataract score) of 30, 100, and 300 mg kg⁻¹ extract (bid for 21 days, per os) on the development of 30 µmol kg⁻¹ sodium selenite-induced cataract in 10-day-old rat pups was investigated. Soluble lens proteins alpha A and alpha B crystallins, total lens protein, total lens glutathione, and aquaporin 0 in enucleated lens homogenates were determined spectrophotometrically using commercially available kits. Histopathological studies on the lenses were also performed. The 2,2-diphenyl-1-picrylhydrazyl scavenging effect and linoleic acid autoxidation (antioxidant properties) of the extract (0.1–3.0 mg ml⁻¹), compared to n-propyl gallate, were ascertained using standard procedures.

Results

Cataract scores showed that the extract, at all dose levels, significantly alleviated selenite-induced cataracts (P ≤ 0.001). Markers of lens transparency (aquaporin 0, alpha A and B crystallins), as well as total lens proteins and lens glutathione levels, were significantly preserved (P ≤ 0.01–0.001). The extract exhibited activity relevant for scavenging free radicals and inhibition of lipid peroxidation. Epithelial and lens fiber integrity in the histopathological assessment were maintained with HIE treatment.

Conclusion

The aqueous whole plant extract of H. indicum significantly inhibited the development of cataracts in rats via multiple mechanisms.

A comparison of the effect of reduced illumination and tinted lenses on stereospsis at near

Relative depth may be appreciated with the use of one eye using linear perspective, shadows, parallax and texture as monocular cues to depth. Stereopsis, on the other hand, is the directappreciation of relative depth that requires the use of both eyes to construct a three-dimension-al percept from disparate two-dimensional retinal images. The advantage of stereopsis is with respect to complex visual tasks especially that requiring accurate hand-eye coordination. Tinted lenses are prescribed for a variety of reasons, including but not limited to photophobia, asthenopia, improving colour perception in colour deficient individuals, enhancing cosmesis and protection against glare or harmful radiation and enhancing visual performance as in sports. The aim of this study was to investigate the comparative effects of six specific CR39 tinted spectacle lenses (grade B), and a white CR39 lens, against a no lens condition, on stereoacuity over a range of illumination levels. Illumination was varied with the use of neutral density (ND) filters, while the Titmus Fly Stereotest (TFS) wasused to measure stereoacuity. Participants (n =60) between the ages of 17 - 29 years (mean =23.58; sd = 3.14) were purposively sampled from a clinical practice to participate in this research study.  Using repeated measures ANOVA and appropriate post-hoc multivariate analysis, it was evident that there was a significant decline in stereopsis as the level ofillumination decreased,regardless of tint condition; also there was no statistically significant difference in stereopsis between the no lens and white lens conditions at each level of illumination; and stereopsis wassignificantly superior with the no lens conditioncompared to all six other tint conditions (gradeB), at each level of illumination. These results indicate that stereoacuity, as measured by the TFS, is adversely affected by adecline in retinal illuminance and by the use of tinted lenses. This information could be utilised to advise patients on the performance implications of the six tinted lenses tested with respectto their effects on stereoacuity under different illumination levels.