Did you know that eating a cousin of lemon can relieve stress and anxiety? Stress and anxiety are inseparable from living in a fast-paced world. Most people have suffered from stress and anxiety for long periods of time, which is why herbal medicines are often preferred to conventional sedative and anxiolytic medications for mild psychological issues due to their relatively well-established safety profiles. Plants like Valerian, common hop, lemon balm, passionflower, and many more are widely used for this occasion. In this article, we will portray the potential benefits of white sapote for stress and anxiety.

Understanding stress and anxiety

Stress and anxiety are very common conditions that are often confused with one another. On one hand, stress is a physiological response to uncomfortable environmental stimuli, for instance, an argument with another person, but usually goes away on its own when the ‘danger’ is dismissed. On the other hand, anxiety is a persistent feeling of unease and discomfort that might not go away even in the absence of a stressful stimulus. Anxiety can cause sweating, trembling, heart palpitations, headaches, feelings of doom, and difficulty sleeping. Both conditions can be frustrating and can interfere with normal day-to-day activities, and some forms of anxiety may even have crippling effects on a person’s social life. Stress and anxiety are most prevalent in school-age children but are not uncommon in working adults.

Medications used for stress and anxiety are known as anxiolytics, and they work by suppressing central nervous system (CNS) activity, which is why they are also called CNS depressants (this doesn’t mean that they cause depression).

What is white sapote?

White sapote, known under the scientific name Casimiroa edulis (C. edulis), is a plant species of evergreen trees belonging to the Rutaceae family, which also includes citrus plants like lemon, lime, and orange. It is native to some regions of Mexico and Central America. White sapote trees are tall and have palmately compound leaves, resembling those of the horse chestnut tree. The fruits are medium to large drupes with an inedible exocarp and an edible pulp.¹ Inside the fruit pits there are up to 6 white oval-shaped seeds.²

White sapote in traditional medicine

Traditional medicine is often a source for guided research on natural substances. Every culture has its own specific set of plants, fungi, animal products, and minerals that they use to treat common ailments. While many of those are not backed up by science and have proven throughout time to be ill-advised treatments, and we should always take such medicines with a grain of salt, traditional medicine has contributed immensely to the discovery of modern drugs. Examples of plant medicines that have entered active drug campaigns and proved to be effective treatments for socially important diseases with unmet medical needs include:

• Dragon’s blood is a resin obtained from different plants of the Calamus genus. The Arabs, Greeks, and Romans have traditionally used dragon’s blood to treat diarrhoea. It is now known that the astringent and antidiarrheal properties of dragon blood are caused by a class of phenols—oligomeric proanthocyanidins. One such purified compound, known as crofelemer, is approved for non-infectious diarrhoea in HIV/AIDS patients on antiretroviral therapy³
• Artemisia annua (A. annua), also known as sweet wormwood, is a plant widely used since ancient times in traditional Chinese medicine to treat various conditions, including fever episodes in malaria. The discovery of the antimalarial drug artemisinin from the A. annua plant is considered one of the greatest accomplishments in human medicine in recent years⁴
• Salix alba (S. alba)—willow bark has traditionally been used by many cultures in the treatment of fever, joint pain, back pain, and headache. Willow bark contains salicin, which in the body converts to a pain reliever and anti-inflammatory salicylic acid. Today, acetylsalicylic acid is one of the most used over-the-counter medicines to relieve pains, treat inflammation, and prevent blood clotting⁵

White sapote has been traditionally grown in Mexico and Central America for culinary use. The medicinal properties of white sapote have probably been discovered by chance whenever served as food by the natives to people with various health conditions. It was widely used by the Aztecs for hypertension, joint pain, and insomnia. The fact that the name of the plant itself means “sleep-producing” in Nahuatl (Aztec) is strong evidence that the natives believed in its sedative and hypnotic properties.

Does white sapote really work?

White tea displays a range of CNS-depressant effects, including anxiolytic, anticonvulsant, and sedative effects. The effects of various white sapote extracts have been demonstrated in animal models:

• Anxiolytic effects of aqueous C. edulis leaf extracts were displayed in male Wistar rats via the elevated plus-maze test. This method uses a plus-shaped maze consisting of two open and two enclosed arms. By measuring the relative time that rats spend in open versus enclosed spaces and the number of times rats move from one arm to another, scientists can compare the anxiolytic effects of the tested extracts to drugs with known activity, i.e. increased time spent in open spaces correlates with a greater anxiolytic effect⁶
• Aqueous C. edulis leaf extracts have been tested on male Wistar rats in electrically and chemically-induced seizures and have exhibited anticonvulsant activity⁷
• The same group of scientists later performed additional experiments with C. edulis, this time using aqueous extracts made from the plant seeds. Like the leaf extracts, the seed extracts showed anticonvulsant activity in male Wistar rats with both electrically and chemically induced seizures. The outcomes of the tests performed with the aqueous extracts were compared to and surpassed those of ethanolic seed extracts⁸
• In another study, a hydroalcoholic leaf extract was tested for hypnotic, anxiolytic, and motor activity in mice and rats. When administered orally in mice before a barbiturate injection (a sedative and hypnotic drug), the extract did not shorten the time needed for the drug to take effect; however, it did prolong the duration of hypnosis. When administered intraperitoneally in rats, the extract was able to reduce motor activity. In the elevated plus-maze test, the extract increased the time spent in the open arms and increased the number of entries in the open arms, thus also exhibiting an anxiolytic effect⁹

How does white sapote treat stress and anxiety?

Through phytochemical assays, different bioactive compounds in white sapote have been discovered, including alkaloids, flavonoids, and essential oils, to which the psychoactive activity is attributed.

Alkaloids

Alkaloids are a class of natural compounds that contain at least one nitrogen atom that gives them their signature alkaline properties (“alkaloids” comes from the word “alkaline” itself). Alkaloids very often have potent pharmacological effects, and many of the plant-derived medicines used in modern medicine contain different alkaloids.

C. edulis produces several alkaloids, two of which are associated with its CNS activity: casimiroin and casimiroedine, both named after the Casimiroa genus. Casimiroin is a quinoline alkaloid, while casimiroedine has a more complex structure featuring an imidazole-glycoalkaloid core attached to a cinnamamide moiety. The sugar residue in casimiroedine makes it well soluble in water and might be the reason for the stronger CNS effects of aqueous C. edulis extracts compared to non-aqueous ones.^10,11 Casimiroedine has been shown to persistently lower blood pressure in anaesthetized guinea pigs.¹² 

Flavonoids 

Flavonoids (also known as bioflavonoids) belong to a larger class of bioactive plant compounds known as phenols. The name “flavonoid” comes from the Latin flavus, meaning yellow, due to its naturally yellow colour. Flavonoids in general have prominent antioxidant activity due to their free radical-scavenging abilities. C. edulis contains two notable flavonoids: quercetin and kaempferol.¹³ Both of them are flavonol derivatives that are attributed to the sedative effects of different plant species like basswood and therefore might work in conjunction with casimiroedine and casimiroin to potentiate their CNS effects.¹⁴

Essential oil 

Essential oils are plant-derived concentrated liquid mixtures of volatile compounds, primarily hydrocarbons known as terpenes. Essential oils are not just responsible for the fragrance of plants but often have distinctive pharmacological activity. The chemical composition of C. edulis leaf essential oil is dominated primarily by two terpenes - germacrene D and (E)-caryophyllene - determined by gas chromatography coupled with mass spectrometry. Both of these terpenes belong to the sesquiterpene subclass and are known to have sedative and hypnotic activity.¹⁵ Thus, the bioactive compounds in C. edulis might work in unison to induce CNS-depressant effects and cause stress and anxiety relief.

Conclusion

Not only does white sapote have a high nutritional value¹⁶ and delicious taste, but it also can be useful to treat stress and anxiety, backed up by traditional medicine and research in animal models. White sapote fruit can be incorporated into diets both in a fresh and dried state or in the form of food supplements. As mentioned above, aqueous extracts from C. edulis have potent effects on the nervous system. Thus, white tea might be an attractive drink for people trying to cope with stress and anxiety. Although herbal medicines can be useful, people should always handle stress and anxiety in a complex manner by practising fitness, self-care, proper rest, and minimising stress-inducing factors. People should always be wary of potential interactions between herbal products and medications. Even though white sapote is considered safe for consumption, it can potentially increase the effects of sleep-inducing drugs, precipitating the manifestation of side effects.